Science.gov

Sample records for air vehicle inlets

  1. The Role of Design-of-Experiments in Managing Flow in Compact Air Vehicle Inlets

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Miller, Daniel N.; Gridley, Marvin C.; Agrell, Johan

    2003-01-01

    It is the purpose of this study to demonstrate the viability and economy of Design-of-Experiments methodologies to arrive at microscale secondary flow control array designs that maintain optimal inlet performance over a wide range of the mission variables and to explore how these statistical methods provide a better understanding of the management of flow in compact air vehicle inlets. These statistical design concepts were used to investigate the robustness properties of low unit strength micro-effector arrays. Low unit strength micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. The term robustness is used in this paper in the same sense as it is used in the industrial problem solving community. It refers to minimizing the effects of the hard-to-control factors that influence the development of a product or process. In Robustness Engineering, the effects of the hard-to-control factors are often called noise , and the hard-to-control factors themselves are referred to as the environmental variables or sometimes as the Taguchi noise variables. Hence Robust Optimization refers to minimizing the effects of the environmental or noise variables on the development (design) of a product or process. In the management of flow in compact inlets, the environmental or noise variables can be identified with the mission variables. Therefore this paper formulates a statistical design methodology that minimizes the impact of variations in the mission variables on inlet performance and demonstrates that these statistical design concepts can lead to simpler inlet flow management systems.

  2. Design Evolution and Performance Characterization of the GTX Air-Breathing Launch Vehicle Inlet

    NASA Technical Reports Server (NTRS)

    DeBonis, J. R.; Steffen, C. J., Jr.; Rice, T.; Trefny, C. J.

    2002-01-01

    The design and analysis of a second version of the inlet for the GTX rocket-based combine-cycle launch vehicle is discussed. The previous design did not achieve its predicted performance levels due to excessive turning of low-momentum comer flows and local over-contraction due to asymmetric end-walls. This design attempts to remove these problems by reducing the spike half-angle to 10- from 12-degrees and by implementing true plane of symmetry end-walls. Axisymmetric Reynolds-Averaged Navier-Stokes simulations using both perfect gas and real gas, finite rate chemistry, assumptions were performed to aid in the design process and to create a comprehensive database of inlet performance. The inlet design, which operates over the entire air-breathing Mach number range from 0 to 12, and the performance database are presented. The performance database, for use in cycle analysis, includes predictions of mass capture, pressure recovery, throat Mach number, drag force, and heat load, for the entire Mach range. Results of the computations are compared with experimental data to validate the performance database.

  3. Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

    PubMed Central

    2014-01-01

    Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the

  4. Optimal Micro-Vane Flow Control for Compact Air Vehicle Inlets

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Miller, Daniel N.; Addington, Gregory A.; Agrell, Johan

    2004-01-01

    The purpose of this study on micro-vane secondary flow control is to demonstrate the viability and economy of Response Surface Methodology (RSM) to optimally design micro-vane secondary flow control arrays, and to establish that the aeromechanical effects of engine face distortion can also be included in the design and optimization process. These statistical design concepts were used to investigate the design characteristics of "low unit strength" micro-effector arrays. "Low unit strength" micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion. Therefore, this report examines optimal micro-vane secondary flow control array designs for compact inlets through a Response Surface Methodology.

  5. Management of Total Pressure Recovery, Distortion and High Cycle Fatigue in Compact Air Vehicle Inlets

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Baust, Henry D.; Agrell, Johan

    2002-01-01

    It is the purpose of this study to demonstrate the viability and economy of Response Surface Methods (RSM) and Robustness Design Concepts (RDC) to arrive at micro-secondary flow control installation designs that maintain optimal inlet performance over a range of the mission variables. These statistical design concepts were used to investigate the robustness properties of 'low unit strength' micro-effector installations. 'Low unit strength' micro-effectors are micro-vanes set at very low angles-of-incidence with very long chord lengths. They were designed to influence the near wall inlet flow over an extended streamwise distance, and their advantage lies in low total pressure loss and high effectiveness in managing engine face distortion.

  6. Optimal Micro-Jet Flow Control for Compact Air Vehicle Inlets

    NASA Technical Reports Server (NTRS)

    Anderson, Bernhard H.; Miller, Daniel N.; Addington, Gregory A.; Agrell, Johan

    2004-01-01

    The purpose of this study on micro-jet secondary flow control is to demonstrate the viability and economy of Response Surface Methodology (RSM) to optimally design micro-jet secondary flow control arrays, and to establish that the aeromechanical effects of engine face distortion can also be included in the design and optimization process. These statistical design concepts were used to investigate the design characteristics of "low mass" micro-jet array designs. The term "low mass" micro-jet may refers to fluidic jets with total (integrated) mass flow ratios between 0.10 and 1.0 percent of the engine face mass flow. Therefore, this report examines optimal micro-jet array designs for compact inlets through a Response Surface Methodology.

  7. Apparatus and Method for Measuring Air Temperature Ahead of an Aircraft for Controlling a Variable Inlet/Engine Assembly

    NASA Technical Reports Server (NTRS)

    Gary, Bruce L. (Inventor)

    2001-01-01

    The apparatus and method employ remote sensing to measure the air temperature a sufficient distance ahead of the aircraft to allow time for a variable inlet/engine assembly to be reconfigured in response to the measured temperature, to avoid inlet unstart and/or engine compressor stall. In one embodiment, the apparatus of the invention has a remote sensor for measuring at least one air temperature ahead of the vehicle and an inlet control system for varying the inlet. The remote sensor determines a change in temperature value using at least one temperature measurement and prior temperature measurements corresponding to the location of the aircraft. The control system uses the change in air temperature value to vary the inlet configuration to maintain the position of the shock wave during the arrival of the measured air in the inlet. In one embodiment, the method of the invention includes measuring at least one air temperature ahead of the vehicle, determining an air temperature at the vehicle from prior air temperature measurements, determining a change in temperature value using the air temperature at the vehicle and the at least one air temperature measurement ahead of the vehicle, and using the change in temperature value to-reposition the airflow inlet, to cause the shock wave to maintain substantially the same position within the inlet as the airflow temperature changes within the inlet.

  8. Novel inlet-airframe integration methodology for hypersonic waverider vehicles

    NASA Astrophysics Data System (ADS)

    Ding, Feng; Liu, Jun; Shen, Chi-bing; Huang, Wei

    2015-06-01

    With the aim of integrating a ramjet or scramjet with an airframe, a novel inlet-airframe integration methodology for the hypersonic waverider vehicle is proposed. For this newly proposed design concept and for the specified flight conditions, not only the forebody of the vehicle but also its engine cowl and wings can ride on the bow shock wave, causing the bow shock wave to remain attached to the leading edge for the entire length of the vehicle. Thus, this integrated vehicle can take full advantage of the waverider's high lift-to-drag ratio characteristics and the ideal pre-compression surface for the engine. In this work, a novel inlet-airframe integrated axisymmetric basic flow model that accounts for both external and internal flows is first designed using the method of characteristics and the streamline tracing technique. Subsequently, the design of the inlet-airframe integrated waverider vehicle is generated from the integrated axisymmetric basic flow model using the streamline tracing technique. Then, the design methodologies of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are verified by a computational numerical method. Finally, the viscous effects and performance of both the integrated axisymmetric basic flow model and the integrated waverider vehicle are analysed under the design condition using the numerical computation. The obtained results show that the proposed approach is effective in designing the integrated hypersonic waverider vehicle.

  9. Euler Calculations at Off-Design Conditions for an Inlet of Inward Turning RBCC-SSTO Vehicle

    NASA Technical Reports Server (NTRS)

    Takashima, N.; Kothari, A. P.

    1998-01-01

    The inviscid performance of an inward turning inlet design is calculated computationally for the first time. Hypersonic vehicle designs based on the inward turning inlets have been shown analytically to have increased effective specific impulse and lower heat load than comparably designed vehicles with two-dimensional inlets. The inward turning inlets are designed inversely from inviscid stream surfaces of known flow fields. The computational study is performed on a Mach 12 inlet design to validate the performance predicted by the design code (HAVDAC) and calculate its off-design Mach number performance. The three-dimensional Euler equations are solved for Mach 4, 8, and 12 using a software package called SAM, which consists of an unstructured mesh generator (SAMmesh), a three-dimensional unstructured mesh flow solver (SAMcfd), and a CAD-based software (SAMcad). The computed momentum averaged inlet throat pressure is within 6% of the design inlet throat pressure. The mass-flux at the inlet throat is also within 7 % of the value predicted by the design code thereby validating the accuracy of the design code. The off-design Mach number results show that flow spillage is minimal, and the variation in the mass capture ratio with Mach number is comparable to an ideal 2-D inlet. The results from the inviscid flow calculations of a Mach 12 inward turning inlet indicate that the inlet design has very good on and off-design performance which makes it a promising design candidate for future air-breathing hypersonic vehicles.

  10. Nuclear air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    The state-of-the-art of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant is identified. Using mission studies and cost estimates, some of the advantages of nuclear power for large air cushion vehicles are described. The technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies are summarized.

  11. Efficiency of dust sampling inlets in calm air.

    PubMed

    Breslin, J A; Stein, R L

    1975-08-01

    Measurement of airborne dust concentrations usually involves drawing a sample of the dust-laden air into the measuring instrument through an inlet. Even if the surrounding air is calm, theoretical calculations predict that large particles may not be sampled accurately due to the combined effects of gravity and inertia on the particles near the sampling inlet. Tests were conducted to determine the conditions of particle size, inlet radius, and flow rare necessary for accurate dust sampling. A coal-dust aerosol was sampled simultaneously through inlets of different diameters at the same volume flow-rate and collected on filters. The dust was removed from the filters and the particles were counted and sized with a Coulter counter. Results showed that published criteria for inlet conditions for correct sampling are overly restrictive and that respirable-size particles are sampled correctly in the normal range or operation of most dust sampling instruments. PMID:1227283

  12. Nuclear air cushion vehicles.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    This paper serves several functions. It identifies the 'state-of-the-art' of the still-conceptual nuclear air cushion vehicle, particularly the nuclear powerplant. Using mission studies and cost estimates, the report describes some of the advantages of nuclear power for large air cushion vehicles. The paper also summarizes the technology studies on mobile nuclear powerplants and conceptual ACV systems/missions studies that have been performed at NASA Lewis Research Center.

  13. Alpha-environmental continuous air monitor inlet

    DOEpatents

    Rodgers, John C.

    2003-01-01

    A wind deceleration and protective shroud that provides representative samples of ambient aerosols to an environmental continuous air monitor (ECAM) has a cylindrical enclosure mounted to an input on the continuous air monitor, the cylindrical enclosure having shrouded nozzles located radially about its periphery. Ambient air flows, often along with rainwater flows into the nozzles in a sampling flow generated by a pump in the continuous air monitor. The sampling flow of air creates a cyclonic flow in the enclosure that flows up through the cylindrical enclosure until the flow of air reaches the top of the cylindrical enclosure and then is directed downward to the continuous air monitor. A sloped platform located inside the cylindrical enclosure supports the nozzles and causes any moisture entering through the nozzle to drain out through the nozzles.

  14. 47. View of "dry air inlets" to waveguides entering scanner ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    47. View of "dry air inlets" to waveguides entering scanner building 105. Dried air is generated under pressure by Ingersoll-Rand dehumidified/dessicator and compressor system. View is at entrance from passageway that links into corner of scanner building. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  15. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook Inlet Intrastate Air Quality Control Region (Alaska) consists of the territorial area encompassed by the boundaries... 40 Protection of Environment 17 2010-07-01 2010-07-01 false Cook Inlet Intrastate Air...

  16. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook Inlet Intrastate Air Quality Control Region (Alaska) consists of the territorial area encompassed by the boundaries... 40 Protection of Environment 17 2011-07-01 2011-07-01 false Cook Inlet Intrastate Air...

  17. Design of Modular, Shape-transitioning Inlets for a Conical Hypersonic Vehicle

    NASA Technical Reports Server (NTRS)

    Gollan, Rowan J.; Smart, Michael K.

    2010-01-01

    For a hypersonic vehicle, propelled by scramjet engines, integration of the engines and airframe is highly desirable. Thus, the forward capture shape of the engine inlet should conform to the vehicle body shape. Furthermore, the use of modular engines places a constraint on the shape of the inlet sidewalls. Finally, one may desire a combustor cross- section shape that is different from that of the inlet. These shape constraints for the inlet can be accommodated by employing a streamline-tracing and lofting technique. This design technique was developed by Smart for inlets with a rectangular-to-elliptical shape transition. In this paper, we generalise that technique to produce inlets that conform to arbitrary shape requirements. As an example, we show the design of a body-integrated hypersonic inlet on a winged-cone vehicle, typical of what might be used in a three-stage orbital launch system. The special challenge of inlet design for this conical vehicle at an angle-of-attack is also discussed. That challenge is that the bow shock sits relatively close to the vehicle body.

  18. Inlet Development for a Rocket Based Combined Cycle, Single Stage to Orbit Vehicle Using Computational Fluid Dynamics

    NASA Technical Reports Server (NTRS)

    DeBonis, J. R.; Trefny, C. J.; Steffen, C. J., Jr.

    1999-01-01

    Design and analysis of the inlet for a rocket based combined cycle engine is discussed. Computational fluid dynamics was used in both the design and subsequent analysis. Reynolds averaged Navier-Stokes simulations were performed using both perfect gas and real gas assumptions. An inlet design that operates over the required Mach number range from 0 to 12 was produced. Performance data for cycle analysis was post processed using a stream thrust averaging technique. A detailed performance database for cycle analysis is presented. The effect ot vehicle forebody compression on air capture is also examined.

  19. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 18 2014-07-01 2014-07-01 false Cook Inlet Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook...

  20. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 18 2013-07-01 2013-07-01 false Cook Inlet Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook...

  1. 40 CFR 81.54 - Cook Inlet Intrastate Air Quality Control Region.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 18 2012-07-01 2012-07-01 false Cook Inlet Intrastate Air Quality...) AIR PROGRAMS (CONTINUED) DESIGNATION OF AREAS FOR AIR QUALITY PLANNING PURPOSES Designation of Air Quality Control Regions § 81.54 Cook Inlet Intrastate Air Quality Control Region. The Cook...

  2. Investigation of Aerodynamic and Icing Characteristics of a Flush Alternate Inlet Induction System Air Scoop

    NASA Technical Reports Server (NTRS)

    Lewis, James P.

    1953-01-01

    An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet. The investigation was made over a range of mass-air- flow ratios of 0 to 0.8, angles of attack of 0 and 4 deg airspeeds of 150 to 270 miles per hour, air temperatures of 0 and 25 F various liquid-water contents, and droplet sizes. The ram inlet gave good pressure recovery in both clear air and icing but rapid blockage of the top-deck screen occurred during icing. The flush alternate inlet had poor pressure recovery in both clear air and icing. The greatest decreases in the alternate-inlet pressure recovery were obtained at icing conditions of low air temperature and high liquid-water content. No serious screen icing was observed with the alternate inlet. Pressure and temperature distributions on the carburetor top deck were determined using the preheat-air supply with the preheat- and alternate-inlet doors in various positions. No screen icing occurred when the preheat-air system was operated in combination with alternate-inlet air flow.

  3. Air cushion vehicles: A briefing

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Finnegan, P. M.

    1971-01-01

    Experience and characteristics; the powering, uses, and implications of large air cushion vehicles (ACV); and the conceptual design and operation of a nuclear powered ACV freighter and supporting facilities are described.

  4. Swozzle based burner tube premixer including inlet air conditioner for low emissions combustion

    DOEpatents

    Tuthill, Richard Sterling; Bechtel, II, William Theodore; Benoit, Jeffrey Arthur; Black, Stephen Hugh; Bland, Robert James; DeLeonardo, Guy Wayne; Meyer, Stefan Martin; Taura, Joseph Charles; Battaglioli, John Luigi

    2002-01-01

    A burner for use in a combustion system of a heavy-duty industrial gas turbine includes a fuel/air premixer having an air inlet, a fuel inlet, and an annular mixing passage. The fuel/air premixer mixes fuel and air into a uniform mixture for injection into a combustor reaction zone. The burner also includes an inlet flow conditioner disposed at the air inlet of the fuel/air premixer for controlling a radial and circumferential distribution of incoming air. The pattern of perforations in the inlet flow conditioner is designed such that a uniform air flow distribution is produced at the swirler inlet annulus in both the radial and circumference directions. The premixer includes a swozzle assembly having a series of preferably air foil shaped turning vanes that impart swirl to the airflow entering via the inlet flow conditioner. Each air foil contains internal fuel flow passages that introduce natural gas fuel into the air stream via fuel metering holes that pass through the walls of the air foil shaped turning vanes. By injecting fuel in this manner, an aerodynamically clean flow field is maintained throughout the premixer. By injecting fuel via two separate passages, the fuel/air mixture strength distribution can be controlled in the radial direction to obtain optimum radial concentration profiles for control of emissions, lean blow outs, and combustion driven dynamic pressure activity as machine and combustor load are varied.

  5. Optimal air-breathing launch vehicle design

    NASA Technical Reports Server (NTRS)

    Hattis, P. D.

    1981-01-01

    A generalized two-point boundary problem methodology, similar to techniques used in deterministic optimal control studies, is applied to the design and flight analysis of a two-stage air-breathing launch vehicle. Simultaneous consideration is given to configuration and trajectory by treating geometry, dynamic discontinuities, and time-dependent flight variables all as controls to be optimized with respect to a single mathematical performance measure. While minimizing fuel consumption, inequality constraints are applied to dynamic pressure and specific force. The optimal system fuel consumption and staging Mach number are found to vary little with changes in the inequality constraints due to substantial geometry and trajectory adjustments. Staging, from an air-breathing first stage to a rocket-powered second stage, consistently occurs near Mach 3.5. The dynamic pressure bound has its most pronounced effects on vehicle geometry, particularly the air-breathing propulsion inlet area, and on the first-stage altitude profile. The specific force has its greatest influence on the second-stage thrust history.

  6. Summary of Inlet Characteristics of the F/A-18A High Alpha Research Vehicle

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin; Steenken, William; Williams, John

    1998-01-01

    Effects of high-angle-of-attack flight on aircraft inlet aerodynamic characteristics were investigated at NASA Dryden Flight Research Center as part of NASA's High Alpha Technology Program. The highly instrumented F/A-18A High Alpha Research Vehicle was used for this research. A newly designed inlet total-pressure rake was installed in front of the right-hand F404-GE-400 engine to measure inlet recovery and distortion characteristics. Objectives included: (1) determining the inlet total-pressure characteristics at steady high-angle-of-attack conditions; (2) assessing if inlet distortion is significantly different between rapid angle-of-attack maneuvers and corresponding steady aerodynamic conditions; (3) assessing inlet characteristics during aircraft departures; (4) providing data for developing and verifying computational fluid dynamic codes; and (5) calculating engine airflow using four methods for comparison with a reference method. This paper describes the results obtained from this investigation. These data and the associated database were rigorously validated to establish the foundation for understanding inlet characteristics at high angle of attack.

  7. Aerodynamic characteristics of a series of twin-inlet air-breathing missile configurations. 3: Axisymmetric and two-dimensional inlets at subsonic-transonic speeds

    NASA Technical Reports Server (NTRS)

    Hayes, C.

    1983-01-01

    A series of air-breathing missile configurations was investigated to provide a data base for the design of such missiles. The model could be configurated with either twin axisymmetric or two dimensional inlets. Three circumferential inlet locations were investigated: 90 deg, 115 deg, and 135 deg from the top center. Two vertical wing locations, as well as wingless configurations, were used. Three tail configurations were formed by locating the tail surfaces either on the inlet fairing or on the inlet fairing or on fairings on the body. The surfaces were used to provide pitch control. Two dimensional inlets with extended compression surfaces, used to improve the angle-of-attack performance of the inlets for wingless configurations, were also investigated. The twin axisymmetric two dimensional inlet types without internal flow are covered, and the boost configuration of an air-breathing missile is simulated.

  8. Intelligence Applied to Air Vehicles

    NASA Technical Reports Server (NTRS)

    Rosen, Robert; Gross, Anthony R.; Fletcher, L. Skip; Zornetzer, Steven (Technical Monitor)

    2000-01-01

    The exponential growth in information technology has provided the potential for air vehicle capabilities that were previously unavailable to mission and vehicle designers. The increasing capabilities of computer hardware and software, including new developments such as neural networks, provide a new balance of work between humans and machines. This paper will describe several NASA projects, and review results and conclusions from ground and flight investigations where vehicle intelligence was developed and applied to aeronautical and space systems. In the first example, flight results from a neural network flight control demonstration will be reviewed. Using, a highly-modified F-15 aircraft, a NASA/Dryden experimental flight test program has demonstrated how the neural network software can correctly identify and respond to changes in aircraft stability and control characteristics. Using its on-line learning capability, the neural net software would identify that something in the vehicle has changed, then reconfigure the flight control computer system to adapt to those changes. The results of the Remote Agent software project will be presented. This capability will reduce the cost of future spacecraft operations as computers become "thinking" partners along with humans. In addition, the paper will describe the objectives and plans for the autonomous airplane program and the autonomous rotorcraft project. Technologies will also be developed.

  9. Aerodynamic characteristics of a series of twin-inlet air-breathing missile configurations. 2: Two-dimensional inlets at supersonic speeds

    NASA Technical Reports Server (NTRS)

    Hayes, C.

    1983-01-01

    A series of air-breathing missile configurations was investigated to provide a data base for the design of such missiles. The model could be configured with either twin axisymmetric or two dimensional inlets. Three circumferential inlet locations were investigated: 90 deg, 115 deg, and 135 deg from the top center. Two vertical wing locations, as well as wingless configurations, were used. Three tail configurations were formed by locating the tail surfaces either on the inlet fairings or on fairings on the body. The surfaces were used to provide pitch control. Two dimensional inlets with extended compression surfaces, used to improve the angle-of-attack performance of the inlets for wingless configurations, were also investigated. The two dimensional inlet configurations are covered.

  10. Air lifted and propelled vehicle

    SciTech Connect

    Jones, T.E.; Johnson, R.A.

    1987-02-17

    This patent describes a vehicle which rides on air cushion and which is propelled by air, comprising: upper deck means, having a bottom edge which defines the periphery of an area; a thin, flexible sheet located below the upper deck means, extending beneath the bottom edge and secured beneath the bottom edge for defining a plenum that is defined by and closed off by the upper deck means and the sheet. The deck means is shaped within the area defined by its bottom edge for causing the plenum to always be an open space and the upper deck means is rigid enough to maintain that open condition of the plenum; the sheet being secured in a manner permitting the sheet to pillow when air is pressurized in the plenum; and the sheet being perforated below the upper deck means for permitting exit of air from the plenum at a controllable rate through the perforations; the sheet having a large plurality of the perforations dispersed over most of its area below the upper deck means; each of the perforations being a hole.

  11. Aerodynamic characteristics of a series of single-inlet air-breathing missile configurations

    NASA Technical Reports Server (NTRS)

    Hayes, C.

    1983-01-01

    A series of air-breathing missile configurations was investigated to provide a data base for the design of such missiles. The model could be configured with either a single axisymmetric or a two dimensional inlet located at the bottom of the body. Two tail configurations were investigated: a tri-tail and an X-tail. The tail surfaces could be deflected to provide pitch control. A wing could be located above the inlet on the center line of the model. Tests were made at supersonic Mach numbers with the inlet open and internal flow, and at subsonic-transonic Mach numbers with the internal duct closed and no internal flow.

  12. Effect of inlet-air humidity on the formation of oxides of nitrogen in a gas-turbine combustor

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.

    1973-01-01

    Tests were conducted to determine the effect of inlet-air humidity on the formation of oxides of nitrogen from a gas-turbine combustor. Combustor inlet-air temperature ranged from 450 F to 1050 F. The tests were run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NO sub x emission index was found to decrease with increasing inlet-air humidity at a constant exponential rate of 19 percent per mass percent water vapor in the air. This decrease of NO sub x emission index with increasing humidity was found to be independent of inlet-air temperature.

  13. Inlet Aerodynamics and Ram Drag of Laser-Propelled Lightcraft Vehicles

    NASA Astrophysics Data System (ADS)

    Langener, Tobias; Myrabo, Leik; Rusak, Zvi

    2010-05-01

    Numerical simulations are used to study the aerodynamic inlet properties of three axisymmetric configurations of laser-propelled Lightcraft vehicles operating at subsonic, transonic and supersonic speeds up to Mach 5. The 60 cm vehicles were sized for launching 0.1-1.0 kg nanosatellites with combined-cycle airbreathing/rocket engines, transitioning between propulsion modes at roughly Mach 5-6. Results provide the pressure, temperature, density, and velocity flowfields around and through the three representative vehicle/engine configurations, as well as giving the resulting ram drag and total drag coefficients—all as a function of flight Mach number. Simulations with rotating boundaries were also carried out, since for stability reasons, Lightcraft are normally spun up before lift-off. Given the three alternatives, it is demonstrated that the optimal geometry for minimum drag is the configuration with a parabola nose; hence, these inlet flow conditions are being applied in subsequent "direct connect" 2D laser propulsion experiments in a small transonic flow facility.

  14. Improving the performance of a compression ignition engine by directing flow of inlet air

    NASA Technical Reports Server (NTRS)

    Kemper, Carlton

    1946-01-01

    The object of this report is to present the results of tests performed by the National Advisory Committee for Aeronautics to determine the effect on engine performance of directing the flow of the inlet air to a 5-inch by 7-inch cylinder, solid injection, compression ignition engine, After a few preliminary tests, comparative runs were made at a speed of 1500 r.p.m. with and without directed air flow. It was found that directing the flow of the inlet air toward the fuel injection valve gave steadier engine operation, and an appreciable increase in power, and decreased fuel consumption. The results indicate the possibility of improving the performance of a given type of combustion chamber without changing its shape and with no change in valve timing. They would also seem to prove that directional turbulence, set up before the inlet valve of a four-stroke cycle engine, continues in the engine cylinder throughout the compression stroke.

  15. Aerodynamic effect of combustor inlet-air pressure on fuel jet atomization

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1984-01-01

    Mean drop diameters were measured with a recently developed scanning radiometer in a study of the atomization of liquid jets injected cross stream in high velocity and high pressure airflows. At constant inlet air pressure, reciprocal mean drop diameter, was correlated with airflow mass velocity. Over a combustor inlet-air pressure range of 1 to 21 atmospheres, the ratio of orifice to mean drop diameter, D(O)/D(M), was correlated with the product of Weber and Reynolds number, WeRe, and with the molecular scale momentum transfer ratio of gravitational to inertial forces.

  16. Aerodynamic effect of combustor inlet-air pressure on fuel jet atomization

    NASA Technical Reports Server (NTRS)

    Ingebo, R. D.

    1984-01-01

    Mean drop diameters were measured with a recently developed scanning radiometer in a study of the atomization of liquid jets injected cross stream in high velocity and high pressure airflows. At constant inlet air pressure, reciprocal mean drop diameter was correlated with airflow mass velocity. Over a combustor inlet-air pressure range of 1 to 21 atmospheres, the ratio of orifice to mean drop diameter, D(O)/D(M), was correlated with the product of Weber and Reynolds number, WeRe, and with the molecular scale momentum transfer ratio of gravitational to inertial forces. Previously announced in STAR as N84-22910

  17. Evaluation of biological air filters for livestock ventilation air by membrane inlet mass spectrometry.

    PubMed

    Feilberg, Anders; Adamsen, Anders P S; Lindholst, Sabine; Lyngbye, Merete; Schäfer, Annette

    2010-01-01

    Biological air filters have been proposed as a cost-effective technology for reducing odor emissions from intensive swine production facilities. In this work we present results from the application of membrane inlet mass spectrometry (MIMS) for continuously monitoring the removal of odorous compounds in biological air filters. The sensitivity and selectivity were tested on synthetic samples of selected odorous compounds, and linearity and detection limits in the lower ppb range were demonstrated for all compounds tested (methanethiol, dimethyl sulfide, carboxylic acids, 4-methylphenol, aldehydes, indole, and skatole) except trimethylamine. The method was applied in situ at two full-scale filters installed at swine houses. The results have been compared with analyses by thermal desorption gas chromatography-mass spectrometry (TD-GC/MS), and odor was measured by olfactometry. By comparison with TD-GC/MS, observed MIMS signals were assigned to 4-methylphenol, 4-ethylphenol, indole, skatole, the sum of volatile reduced organic sulfur compounds (ROS), and three subgroups of carboxylic acids. The removal rates were observed to be related to air-water partitioning with removal efficiencies in the range of 0 to 50% for low-soluble organic sulfur compounds and high removal efficiencies (typically 80-100%) for more soluble phenols and carboxylic acids. Based on the results and published odor threshold values, it is estimated that the low removal efficiency of ROS is the main limitation for achieving a higher odor reduction. PMID:20400604

  18. An evaluation of thermal energy storage options for precooling gas turbine inlet air

    SciTech Connect

    Antoniak, Z.I.; Brown, D.R.; Drost, M.K.

    1992-12-01

    Several approaches have been used to reduce the temperature of gas turbine inlet air. One of the most successful uses off-peak electric power to drive vapor-compression-cycle ice makers. The ice is stored until the next time high ambient temperature is encountered, when the ice is used in a heat exchanger to cool the gas turbine inlet air. An alternative concept would use seasonal thermal energy storage to store winter chill for inlet air cooling. The objective of this study was to compare the performance and economics of seasonal thermal energy storage in aquifers with diurnal ice thermal energy storage for gas turbine inlet air cooling. The investigation consisted of developing computer codes to model the performance of a gas turbine, energy storage system, heat exchangers, and ancillary equipment. The performance models were combined with cost models to calculate unit capital costs and levelized energy costs for each concept. The levelized energy cost was calculated for three technologies in two locations (Minneapolis, Minnesota and Birmingham, Alabama). Precooling gas turbine inlet air with cold water supplied by an aquifer thermal energy storage system provided lower cost electricity than simply increasing the size of the turbine for meteorological and geological conditions existing in the Minneapolis vicinity. A 15 to 20% cost reduction resulted for both 0.05 and 0.2 annual operating factors. In contrast, ice storage precooling was found to be between 5 and 20% more expensive than larger gas turbines for the Minneapolis location. In Birmingham, aquifer thermal energy storage precooling was preferred at the higher capacity factor and ice storage precooling was the best option at the lower capacity factor. In both cases, the levelized cost was reduced by approximately 5% when compared to larger gas turbines.

  19. Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

    NASA Astrophysics Data System (ADS)

    Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

    2016-08-01

    The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

  20. Operational test report for 241-AW tank inlet air control stations

    SciTech Connect

    Minteer, D.J., Westinghouse Hanford

    1996-07-03

    This document reports the results of operational testing on tank inlet air control stations in 241-AW tank farm. An air control station was installed on each of the six AW tanks. Operational testing consisted of a simple functional test of each station`s air flow controller, aerosol testing of each station`s HEPA filter, and final ventilation system balancing (i.e., tank airflows and vacuum level) using the air control stations. The test was successful and the units were subsequently placed into operation.

  1. Application technology progress report: Evaluation of PM-10 commercial inlets and development of an inlet for new Rocky Flats Plant surveillance air sampler, January 1986-December 1986

    SciTech Connect

    Langer, G.; Deitesfeld, C.A. (ed.0

    1987-09-10

    Work during 1986 was concerned with developing a new PM-10 inlet for use at Rocky Flats Plant (RFP), Golden, Colorado. The commercial units that we evaluated did not allow for recovery of the >10-..mu..m dust fraction as may be required by EPA and DOE for nuclear installations. One of them, the Wedding PM-10 Inlet, did not meet the PM-10 cut-point requirement, because of the build-up of vegetative fibers in the cyclone type separator. Therefore, we developed a new PM-10 inlet (patent applied for) to meet our needs, and especially one that is adaptable to our existing 60 surveillance air samplers at minimum cost. The inlet utilizes a modified slotted impactor design. This device is directly adaptable to existing EPA high-volume samplers. 9 refs., 5 figs., 1 tab.

  2. A new integration method based on the coupling of mutistage osculating cones waverider and Busemann inlet for hypersonic airbreathing vehicles

    NASA Astrophysics Data System (ADS)

    Wang, Xu-dong; Wang, Jiang-feng; Lyu, Zhen-jun

    2016-09-01

    This paper proposes a new design method employed for a practical integration of multistage compression osculating cones waverider and Busemann inlet. The singularity based on Taylor-Maccoll equations for Busemann inlet is vertified to result in the failure to directly integrate mutistage waverider and Busemann inlet. In order to avoid this limitation, a revised transition portion is incorporated into the integration, which achieves the objective to integrate multistage compression waverider with Busemann inlet in geometrical configuration. Aerodynamic characteristics of the integration and a compared three-stage compression osculating cones waverider are compared and analyzed in the same design conditions with the same leading edge of the forebody. The research results show that the integration with a Busemann inlet as its third-stage compression surface has greater lift-to-drag ratio, more uniform airbreathing inflow at the inlet entrance, and greater total pressure recovery coefficient with the same mass flowrate. And the performance can satisfy the requirements of the forebody-inlet compression for hypersonic vehicles.

  3. Benefits of compressor inlet air cooling for gas turbine cogeneration plants

    SciTech Connect

    De Lucia, M.; Lanfranchi, C.; Boggio, V.

    1996-07-01

    Compressor inlet air cooling is an effective method for enhancing the performance of gas turbine plants. This paper presents a comparative analysis of different solutions for cooling the compressor inlet air for the LM6000 gas turbine in a cogeneration plant operated in base load. Absorption and evaporative cooling systems are considered and their performance and economic benefits compared for the dry low-NO{sub x} LM6000 version. Reference is made to two sites in Northern and Southern Italy, whose climate data series for modeling the variations in ambient temperature during the single day were used to account for the effects of climate in the simulation. The results confirmed the advantages of inlet air cooling systems. In particular, evaporative cooling proved to be cost effective, though capable of supplying only moderate cooling, while absorption systems have a higher cost but are also more versatile and powerful in base-load operation. An integration of the two systems proved to be able to give both maximum performance enhancement and net economic benefit.

  4. Wind-Tunnel Investigation of Air Inlet and Outlet Openings on a Streamline Body

    NASA Technical Reports Server (NTRS)

    Becker, John V

    1951-01-01

    In connection with the general problem of providing air flow to an aircraft power plant located within a fuselage, an investigation was conducted in the Langley 8-foot high-speed tunnel to determine the effect on external drag and pressure distribution of air inlet openings located at the nose of a streamline body. Air outlet openings located at the tail and at the 21-percent and 63-percent stations of the body were also investigated. Boundary layer transition measurements were made and correlated with the force and the pressure data. Individual openings were investigated with the aid of a blower and then practicable combinations of inlet and outlet openings were tested. Various modifications to the internal duct shape near the inlet opening and the aerodynamic effects of a simulated gun in the duct were also studied. The results of the tests suggested that outlet openings should be designed so that the static pressure of the internal flow at the outlet would be the same as the static pressure of the external flow in the vicinity of the opening.

  5. Aerodynamics for Revolutionary Air Vehicles

    NASA Technical Reports Server (NTRS)

    Sellers, William L., III; Singer, Bart A.; Leavitt, Laurence D.

    2003-01-01

    Aeronautics research has seriously declined partly because of the perception that it is a mature science and only incremental improvements are possible. Recent aeronautics roadmapping activities at NASA Langley paint a different picture of the future. Breakthroughs are still felt to be possible if we expand the current design space of today's vehicles and optimize the airspace and vehicles as a system. The paper describes some of the challenges that the aircraft and airline industry face. These challenges include political, technical and environmental issues. Examples of the opportunities and technologies that could provide a different vision for the future are discussed.

  6. Numerical study of innovative scramjet inlets coupled to combustors using hydrocarbon-air mixture

    NASA Astrophysics Data System (ADS)

    Malo-Molina, Faure Joel

    The research objective is to use high-fidelity multi-physics Computational Fluid Dynamics (CFD) analysis to characterize 3-D scramjet flowfields in two novel streamline traced circular configurations without axisymmetric profiles. This work builds on a body of research conducted over the past several years. In addition, this research provides the modeling and simulation support, prior to ground (wind tunnel) and flight experiment programs. Two innovative inlets, Jaws and Scoop, are analyzed and compared to a Baseline inlet, a current state of the art rectangular inlet used as a baseline for on/off-design conditions. The flight trajectory conditions selected were Mach 6 and a dynamic pressure of 1,500 psf (71.82 kPa), corresponding to a static pressure of 43.7 psf (2.09 kPa) and temperature of 400.8 R° (222.67 C°). All inlets are designed for equal flight conditions, equal contraction ratios and exit cross-sectional areas, thus facilitating their comparison and integration to a common combustor design. Analysis of these hypersonic inlets was performed to investigate distortion effects downstream in common generic combustors. These combustors include a single cavity acting as flame holder and strategically positioned fuel injection ports. This research not only seeks to identify the most successful integrated scramjet inlet/combustor design, but also investigates the flow physics and quantifies the integrated performance impact of the two novel scramjet inlet designs. It contributes to the hypersonic air-breathing community by providing analysis and predictions on directly-coupled combustor numerical experiments for developing pioneering inlets or nozzles for scramjets. Several validations and verifications of General Propulsion Analysis Chemical-kinetic and Two-phase (GPACT), the CFD tool, were conducted throughout the research. In addition, this study uses 13 gaseous species and 20 reactions for an Ethylene/air finite-rate chemical model. The key conclusions of

  7. Evaluation of Air Capture Ratio of Scramjet Inlet by Multi-Point Pressure Measurement

    NASA Astrophysics Data System (ADS)

    Kitamura, Eijiro; Mitani, Tohru; Sakuranaka, Noboru; Izumikawa, Muneo; Watanabe, Syuichi; Masuya, Goro

    A method to evaluate aerodynamic performances of scramjet engines by using multi-probe rakes was proposed. The aerodynamic tests were carried out under Mach 4 flight conditions. The Pitot and static pressures were measured at 250 points in the cross sectional area of the engine exit by the rakes. Local mass flux and thrust function were evaluated from the pressure measurement at each point and integrations of these values enabled to obtain the mass flow rate and the stream thrust at the engine exit. The air capture ratios were independently measured by the rakes and a conventional choked flowmeter. The air capture ratios measured by these two methods agreed within 2%. It was found that the rakes enabled to measure the air capture ratio more simply than the flowmeter. Additionally, the effect of boundary layer ingestion to an internal drag was investigated by the rakes. The decrease of air capture ratio measured by the rakes showed that the ingested boundary layers were separated in the inlet. The pressure drag of inlet increased by the separation and the pressure thrust decreased by the decrease of air capture ratio. As a result, the internal drag increased when the forebody boundary layer was ingested.

  8. Flexible-Wing-Based Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Jenkins, David A.; Ettinger, Scott; Lian, Yong-Sheng; Shyy, Wei; Waszak, Martin R.

    2002-01-01

    This paper documents the development and evaluation of an original flexible-wing-based Micro Air Vehicle (MAV) technology that reduces adverse effects of gusty wind conditions and unsteady aerodynamics, exhibits desirable flight stability, and enhances structural durability. The flexible wing concept has been demonstrated on aircraft with wingspans ranging from 18 inches to 5 inches. Salient features of the flexible-wing-based MAV, including the vehicle concept, flexible wing design, novel fabrication methods, aerodynamic assessment, and flight data analysis are presented.

  9. A Low-speed Investigation of an Annular Transonic Air Inlet

    NASA Technical Reports Server (NTRS)

    Nichols, Mark R; Rinkoski, Donald W

    1952-01-01

    Low-speed wind-tunnel tests were conducted as preliminary steps in the study of fuselage-air-inlet arrangements believed suitable for use at transonic speeds. The forward part of the model consisted of an NACA 1-85-050 cowling located at the base of the long protruding fuselage nose designed to maintain substream surface velocities everywhere ahead of the entrance and thereby to avoid or minimize adverse boundary-layer-shock interaction effects up to low supersonic speeds. Pressure-recovery and surface-pressure measurements are presented for the model with three fuselage nose shapes for ranges of angle of attack and inlet-velocity ratio useful for high-speed flight

  10. Design of an air ejector for boundary-layer bleed of an acoustically treated turbofan engine inlet during ground testing

    NASA Technical Reports Server (NTRS)

    Stakolich, E. G.

    1978-01-01

    An air ejector was designed and built to remove the boundary-layer air from the inlet a turbofan engine during an acoustic ground test program. This report describes; (1) how the ejector was sized; (2) how the ejector performed; and (3) the performance of a scale model ejector built and tested to verify the design. With proper acoustic insulation, the ejector was effective in reducing boundary layer thickness in the inlet of the turbofan engine while obtaining the desired acoustic test conditions.

  11. Environmental continuous air monitor inlet with combined preseparator and virtual impactor

    DOEpatents

    Rodgers, John C.

    2007-06-19

    An inlet for an environmental air monitor is described wherein a pre-separator interfaces with ambient environment air and removes debris and insects commonly associated with high wind outdoors and a deflector plate in communication with incoming air from the pre-separator stage, that directs the air radially and downward uniformly into a plurality of accelerator jets located in a manifold of a virtual impactor, the manifold being cylindrical and having a top, a base, and a wall, with the plurality of accelerator jets being located in the top of the manifold and receiving the directed air and accelerating directed air, thereby creating jets of air penetrating into the manifold, where a major flow is deflected to the walls of the manifold and extracted through ports in the walls. A plurality of receiver nozzles are located in the base of the manifold coaxial with the accelerator jets, and a plurality of matching flow restrictor elements are located in the plurality of receiver nozzles for balancing and equalizing the total minor flow among all the plurality of receiver nozzles, through which a lower, fractional flow extracts large particle constituents of the air for collection on a sample filter after passing through the plurality of receiver nozzles and the plurality of matching flow restrictor elements.

  12. Biofuels, vehicle emissions, and urban air quality.

    PubMed

    Wallington, Timothy J; Anderson, James E; Kurtz, Eric M; Tennison, Paul J

    2016-07-18

    Increased biofuel content in automotive fuels impacts vehicle tailpipe emissions via two mechanisms: fuel chemistry and engine calibration. Fuel chemistry effects are generally well recognized, while engine calibration effects are not. It is important that investigations of the impact of biofuels on vehicle emissions consider the impact of engine calibration effects and are conducted using vehicles designed to operate using such fuels. We report the results of emission measurements from a Ford F-350 fueled with either fossil diesel or a biodiesel surrogate (butyl nonanoate) and demonstrate the critical influence of engine calibration on NOx emissions. Using the production calibration the emissions of NOx were higher with the biodiesel fuel. Using an adjusted calibration (maintaining equivalent exhaust oxygen concentration to that of the fossil diesel at the same conditions by adjusting injected fuel quantities) the emissions of NOx were unchanged, or lower, with biodiesel fuel. For ethanol, a review of the literature data addressing the impact of ethanol blend levels (E0-E85) on emissions from gasoline light-duty vehicles in the U.S. is presented. The available data suggest that emissions of NOx, non-methane hydrocarbons, particulate matter (PM), and mobile source air toxics (compounds known, or suspected, to cause serious health impacts) from modern gasoline and diesel vehicles are not adversely affected by increased biofuel content over the range for which the vehicles are designed to operate. Future increases in biofuel content when accomplished in concert with changes in engine design and calibration for new vehicles should not result in problematic increases in emissions impacting urban air quality and may in fact facilitate future required emissions reductions. A systems perspective (fuel and vehicle) is needed to fully understand, and optimize, the benefits of biofuels when blended into gasoline and diesel. PMID:27112132

  13. Covert air vehicle 2003 LDRD final report.

    SciTech Connect

    Spletzer, Barry Louis; Callow, Diane Schafer; Salton, Jonathan Robert; Fischer, Gary John

    2003-11-01

    This report describes the technical work carried out under a 2003 Laboratory Directed Research and Development project to develop a covert air vehicle. A mesoscale air vehicle that mimics a bird offers exceptional mobility and the possibility of remaining undetected during flight. Although some such vehicles exist, they are lacking in key areas: unassisted landing and launching, true mimicry of bird flight to remain covert, and a flapping flight time of any real duration. Current mainstream technology does not have the energy or power density necessary to achieve bird like flight for any meaningful length of time; however, Sandia has unique combustion powered linear actuators with the unprecedented high energy and power density needed for bird like flight. The small-scale, high-pressure valves and small-scale ignition to make this work have been developed at Sandia. We will study the feasibility of using this to achieve vehicle takeoff and wing flapping for sustained flight. This type of vehicle has broad applications for reconnaissance and communications networks, and could prove invaluable for military and intelligence operations throughout the world. Initial tests were conducted on scaled versions of the combustion-powered linear actuator. The tests results showed that heat transfer and friction effects dominate the combustion process at 'bird-like' sizes. The problems associated with micro-combustion must be solved before a true bird-like ornithopter can be developed.

  14. The spatial-temporal variability of air-sea momentum fluxes observed at a tidal inlet

    NASA Astrophysics Data System (ADS)

    Ortiz-Suslow, D. G.; Haus, B. K.; Williams, N. J.; Laxague, N. J. M.; Reniers, A. J. H. M.; Graber, H. C.

    2015-02-01

    Coastal waters are an aerodynamically unique environment that has been little explored from an air-sea interaction point of view. Consequently, most studies must assume that open ocean-derived parameterizations of the air-sea momentum flux are representative of the nearshore wind forcing. Observations made at the New River Inlet in North Carolina, during the Riverine and Estuarine Transport experiment (RIVET), were used to evaluate the suitability of wind speed-dependent, wind stress parameterizations in coastal waters. As part of the field campaign, a small, agile research vessel was deployed to make high-resolution wind velocity measurements in and around the tidal inlet. The eddy covariance method was employed to recover direct estimates of the 10 m neutral atmospheric drag coefficient from the three-dimensional winds. Observations of wind stress angle, near-surface currents, and heat flux were used to analyze the cross-shore variability of wind stress steering off the mean wind azimuth. In general, for onshore winds above 5 m/s, the drag coefficient was observed to be two and a half times the predicted open ocean value. Significant wind stress steering is observed within 2 km of the inlet mouth, which is observed to be correlated with the horizontal current shear. Other mechanisms such as the reduction in wave celerity or depth-limited breaking could also play a role. It was determined that outside the influence of these typical coastal processes, the open ocean parameterizations generally represent the wind stress field. The nearshore stress variability has significant implications for observations and simulations of coastal transport, circulation, mixing, and general surf-zone dynamics.

  15. Nonuniform air flow in inlets: the effect on filter deposits in the fiber sampling cassette.

    PubMed

    Baron, P A; Chen, C C; Hemenway, D R; O'Shaughnessy, P

    1994-08-01

    Smoke stream studies were combined with a new technique for visualizing a filter deposit from samples used to monitor asbestos or other fibers. Results clearly show the effect of secondary flow vortices within the sampler under anisoaxial sampling conditions. The vortices observed at low wind velocities occur when the inlet axis is situated at angles between 45 degrees and 180 degrees to the motion of the surrounding air. It is demonstrated that the vortices can create a complex nonuniform pattern in the filter deposit, especially when combined with particle settling or electrostatic interactions between the particles and the sampler. Inertial effects also may play a role in the deposit nonuniformity, as well as causing deposition on the cowl surfaces. Changes in the sampler, such as its placement, may reduce these biases. The effects noted are not likely to occur in all sampling situations, but may explain some reports of high variability on asbestos fiber filter samples. The flow patterns observed in this study are applicable to straight, thin-walled inlets. Although only compact particles were used, the air flow patterns and forces involved will have similar effects on fibers of the same aerodynamic diameter. PMID:7942509

  16. 49 CFR 179.220-17 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Gauging devices, top loading and unloading devices, venting and air inlet devices. 179.220-17 Section 179.220-17 Transportation Other Regulations Relating to... and 115AW) § 179.220-17 Gauging devices, top loading and unloading devices, venting and air...

  17. 49 CFR 179.220-17 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Gauging devices, top loading and unloading devices, venting and air inlet devices. 179.220-17 Section 179.220-17 Transportation Other Regulations Relating to... and 115AW) § 179.220-17 Gauging devices, top loading and unloading devices, venting and air...

  18. 49 CFR 179.220-17 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Gauging devices, top loading and unloading devices, venting and air inlet devices. 179.220-17 Section 179.220-17 Transportation Other Regulations Relating to... and 115AW) § 179.220-17 Gauging devices, top loading and unloading devices, venting and air...

  19. 49 CFR 179.220-17 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Gauging devices, top loading and unloading devices, venting and air inlet devices. 179.220-17 Section 179.220-17 Transportation Other Regulations Relating to... and 115AW) § 179.220-17 Gauging devices, top loading and unloading devices, venting and air...

  20. Performance and economic enhancement of cogeneration gas turbines through compressor inlet air cooling

    NASA Astrophysics Data System (ADS)

    Delucia, M.; Bronconi, R.; Carnevale, E.

    1994-04-01

    Gas turbine air cooling systems serve to raise performance to peak power levels during the hot months when high atmospheric temperatures cause reductions in net power output. This work describes the technical and economic advantages of providing a compressor inlet air cooling system to increase the gas turbine's power rating and reduce its heat rate. The pros and cons of state-of-the-art cooling technologies, i.e., absorption and compression refrigeration, with and without thermal energy storage, were examined in order to select the most suitable cooling solution. Heavy-duty gas turbine cogeneration systems with and without absorption units were modeled, as well as various industrial sectors, i.e., paper and pulp, pharmaceuticals, food processing, textiles, tanning, and building materials. The ambient temperature variations were modeled so the effects of climate could be accounted for in the simulation. The results validated the advantages of gas turbine cogeneration with absorption air cooling as compared to other systems without air cooling.

  1. Motor Vehicles, Air Pollution, and Climate Change

    NASA Astrophysics Data System (ADS)

    Mark, Jason

    2000-04-01

    Despite years of technical progress, motor vehicles continue to be a leading cause of environmental damage in the United States. For example, today's cars and trucks are the largest source of air pollution in many urban areas. US motor vehicles also account for 25 percent of the nation's carbon emissions, more than most countries emit from all sources combined. Fortunately, a host of technical improvements are emerging that could go a long ways towards taking vehicles out of the pollution picture. In the near-term, improving on the century-old internal combustion engine can deliver much-needed incremental gains. But electric drive vehicles--whether powered by batteries, small engines in hybrid configuration, or fuel cells--ultimately offer the greatest promise. Such technologies could dramatically reduce energy use, greenhouse gas emissions, and key air pollutants. The bulk of technical attention in recent years has been focused on improving the passenger vehicle, which will be the dominant energy consumer in the transportation sector for years to come. But freight trucks are also of growing concern, both because their contribution to global warming is on the rise and because serious questions are being raised about the public health impact of diesel technology. As a result, heavy trucks are emerging as a priority issue. Capitalizing on the opportunity presented by new technologies will not only require continued technical innovation but also policy action. As research into improved engines, fuels, and drive systems bears fruit over the coming years, aggressive and prudent policies will ensure that these new options make it onto the road and deliver on their environmental promise.

  2. Effect of Fuel-Air Ratio, Inlet Temperature, and Exhaust Pressure on Detonation

    NASA Technical Reports Server (NTRS)

    Taylor, E S; Leary, W A; Diver, J R

    1940-01-01

    An accurate determination of the end-gas condition was attempted by applying a refined method of analysis to experimental results. The results are compared with those obtained in Technical Report no. 655. The experimental technique employed afforded excellent control over the engine variables and unusual cyclic reproducibility. This, in conjunction with the new analysis, made possible the determination of the state of the end-gas at any instant to a fair degree of precision. Results showed that for any given maximum pressure the maximum permissible end-gas temperature increased as the fuel-air ratio was increased. The tendency to detonate was slightly reduced by an increase in residual gas content resulting from an increase in exhaust backpressure with inlet pressure constant.

  3. Diode laser-based air mass flux sensor for subsonic aeropropulsion inlets.

    PubMed

    Miller, M F; Kessler, W J; Allen, M G

    1996-08-20

    An optical air mass flux sensor based on a compact, room-temperature diode laser in a fiber-coupled delivery system has been tested on a full-scale gas turbine engine. The sensor is based on simultaneous measurements of O(2) density and Doppler-shifted velocity along a line of sight across the inlet duct. Extensive tests spanning engine power levels from idle to full afterburner demonstrate accuracy and precision of the order of 1-2% of full scale in density, velocity, and mass flux. The precision-limited velocity at atmospheric pressure was as low as 40 cm/s. Multiple data-reduction procedures are quantitatively compared to suggest optimal strategies for flight sensor packages. PMID:21102916

  4. Diode laser-based air mass flux sensor for subsonic aeropropulsion inlets

    NASA Astrophysics Data System (ADS)

    Miller, Michael F.; Kessler, William J.; Allen, Mark G.

    1996-08-01

    An optical air mass flux sensor based on a compact, room-temperature diode laser in a fiber-coupled delivery system has been tested on a full-scale gas turbine engine. The sensor is based on simultaneous measurements of O 2 density and Doppler-shifted velocity along a line of sight across the inlet duct. Extensive tests spanning engine power levels from idle to full afterburner demonstrate accuracy and precision of the order of 1 2 of full scale in density, velocity, and mass flux. The precision-limited velocity at atmospheric pressure was as low as 40 cm s. Multiple data-reduction procedures are quantitatively compared to suggest optimal strategies for flight sensor packages.

  5. The comparative performance of an aviation engine at normal and high inlet air temperatures

    NASA Technical Reports Server (NTRS)

    Gardiner, Arthur W; Schey, Oscar W

    1928-01-01

    This report presents some results obtained during an investigation to determine the effect of high inlet air temperature on the performance of a Liberty 12 aviation engine. The purpose of this investigation was to ascertain, for normal service carburetor adjustments and a fixed ignition advance, the relation between power and temperature for the range of carburetor air temperatures that may be encountered when supercharging to sea level pressure at altitudes of over 20,000 feet and without intercooling when using plain aviation gasoline and mixtures of benzol and gasoline. The results show that for the conditions of test, both the brake and indicated power decrease with increase in air temperature at a faster rate than given by the theoretical assumption that power varies inversely as the square root of the absolute temperature. On a brake basis, the order of the difference in power for a temperature difference of 120 degrees F. Is 3 to 5 per cent. The observed relation between power and temperature when using the 30-70 blend was found to be linear. But, although these differences are noted, the above theoretical assumption may be considered as generally applicable except where greater precision over a wide range of temperatures is desired, in which case it appears necessary to test the particular engine under the given conditions. (author)

  6. Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

    2003-01-01

    The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic air- breathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjetkcramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demon- strate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and develop ment cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

  7. Air cushion vehicles - Any potential for Canada?

    NASA Astrophysics Data System (ADS)

    Laframboise, J. F.

    1987-09-01

    The present evaluation of air cushion vehicle (ACV) operational and commercial suitability in the Canadian context notes that the most successful and durable ACV applications are those in which only ACVs can perform the required mission. An important factor is the reliability of the craft being tested in a given field of operations. Because of their low ground pressure, ACVs can operate over low-cost trails with an efficiency that compares with that of trucks over conventional roads; this renders them especially attractive for transportation networks in the North West Territories.

  8. 49 CFR 179.200-16 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Gauging devices, top loading and unloading devices... and 115AW) § 179.200-16 Gauging devices, top loading and unloading devices, venting and air inlet...). In no case shall the wall thickness be less than that specified in § 179.201-1. (f) When top...

  9. 49 CFR 179.220-17 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Gauging devices, top loading and unloading devices, venting and air inlet devices. 179.220-17 Section 179.220-17 Transportation Other Regulations Relating to... DOT-111AW and 115AW) § 179.220-17 Gauging devices, top loading and unloading devices, venting and...

  10. 49 CFR 179.200-16 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Gauging devices, top loading and unloading devices... and 115AW) § 179.200-16 Gauging devices, top loading and unloading devices, venting and air inlet...). In no case shall the wall thickness be less than that specified in § 179.201-1. (f) When top...

  11. 49 CFR 179.200-16 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Gauging devices, top loading and unloading devices... and 115AW) § 179.200-16 Gauging devices, top loading and unloading devices, venting and air inlet...). In no case shall the wall thickness be less than that specified in § 179.201-1. (f) When top...

  12. 49 CFR 179.200-16 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Gauging devices, top loading and unloading devices... and 115AW) § 179.200-16 Gauging devices, top loading and unloading devices, venting and air inlet...). In no case shall the wall thickness be less than that specified in § 179.201-1. (f) When top...

  13. Zinc air battery development for electric vehicles

    NASA Astrophysics Data System (ADS)

    Putt, R. A.; Merry, G. W.

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this 'soluble' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (greater than 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high resistance failure of the cell. The Phase 1 program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/sq cm. By the end of the Phase 1 program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase 2 program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  14. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.A.; Merry, G.W. )

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this soluble'' zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  15. Affordable Flight Demonstration of the GTX Air-Breathing SSTO Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Krivanek, Thomas M.; Roche, Joseph M.; Riehl, John P.; Kosareo, Daniel N.

    2002-01-01

    The rocket based combined cycle (RBCC) powered single-stage-to-orbit (SSTO) reusable launch vehicle has the potential to significantly reduce the total cost per pound for orbital payload missions. To validate overall system performance, a flight demonstration must be performed. This paper presents an overview of the first phase of a flight demonstration program for the GTX SSTO vehicle concept. Phase 1 will validate the propulsion performance of the vehicle configuration over the supersonic and hypersonic airbreathing portions of the trajectory. The focus and goal of Phase 1 is to demonstrate the integration and performance of the propulsion system flowpath with the vehicle aerodynamics over the air-breathing trajectory. This demonstrator vehicle will have dual mode ramjet/scramjets, which include the inlet, combustor, and nozzle with geometrically scaled aerodynamic surface outer mold lines (OML) defining the forebody, boundary layer diverter, wings, and tail. The primary objective of this study is to demonstrate propulsion system performance and operability including the ram to scram transition, as well as to validate vehicle aerodynamics and propulsion airframe integration. To minimize overall risk and development cost the effort will incorporate proven materials, use existing turbomachinery in the propellant delivery systems, launch from an existing unmanned remote launch facility, and use basic vehicle recovery techniques to minimize control and landing requirements. A second phase would demonstrate propulsion performance across all critical portions of a space launch trajectory (lift off through transition to all-rocket) integrated with flight-like vehicle systems.

  16. Air cushion vehicles for arctic operation

    NASA Astrophysics Data System (ADS)

    Koleser, J.; Lavis, D. R.

    1986-09-01

    Attention is given to the results of the NAVSEA FY85 Surface Ship Concept Formulation Design Study for an initial operational capability year-2000 air cushion vehicle (ACV) suitable for logistics and general search/rescue duties in the Arctic. Two designs were developed during the study; the first utilized an ACV design synthesis math model while the second evolved as a derivative of an existing U.S. production craft. Both are regarded as feasible from an engineering and naval architectural standpoint. Results of performance and cost trade-off studies suggest that, for an Arctic ACV, gas turbines are the preferred power plant choice and an aluminum alloy is the preferred hull structural material choice. The most appropriate skirt height is approximately 12 ft.

  17. Development and Characterization Testing of an Air Pulsation Valve for a Pulse Detonation Engine Supersonic Parametric Inlet Test Section

    NASA Technical Reports Server (NTRS)

    Tornabene, Robert

    2005-01-01

    In pulse detonation engines, the potential exists for gas pulses from the combustor to travel upstream and adversely affect the inlet performance of the engine. In order to determine the effect of these high frequency pulses on the inlet performance, an air pulsation valve was developed to provide air pulses downstream of a supersonic parametric inlet test section. The purpose of this report is to document the design and characterization tests that were performed on a pulsation valve that was tested at the NASA Glenn Research Center 1x1 Supersonic Wind Tunnel (SWT) test facility. The high air flow pulsation valve design philosophy and analyses performed are discussed and characterization test results are presented. The pulsation valve model was devised based on the concept of using a free spinning ball valve driven from a variable speed electric motor to generate air flow pulses at preset frequencies. In order to deliver the proper flow rate, the flow port was contoured to maximize flow rate and minimize pressure drop. To obtain sharp pressure spikes the valve flow port was designed to be as narrow as possible to minimize port dwell time.

  18. Achieving Acceptable Air Quality: Some Reflections on Controlling Vehicle Emissions

    NASA Astrophysics Data System (ADS)

    Calvert, J. G.; Heywood, J. B.; Sawyer, R. F.; Seinfeld, J. H.

    1993-07-01

    Motor vehicle emissions have been and are being controlled in an effort to abate urban air pollution. This article addresses the question: Will the vehicle exhaust emission control and fuel requirements in the 1990 Clean Air Act Amendments and the California Air Resources Board regulations on vehicles and fuels have a significant impact? The effective control of in-use vehicle emissions is the key to a solution to the motor vehicle part of the urban air pollution problem for the next decade or so. It is not necessary, except perhaps in Southern California, to implement extremely low new car emission standards before the end of the 20th century. Some of the proposed gasoline volatility and composition changes in reformulated gasoline will produce significant reductions in vehicle emissions (for example, reduced vapor pressure, sulfur, and light olefin and improved high end volatility), whereas others (such as substantial oxygenate addition and aromatics reduction) will not.

  19. Navier-Stokes predictions of dynamic stability derivatives for air-breathing hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Liu, Xu; Liu, Wei; Zhao, Yunfei

    2016-01-01

    Dynamic derivatives are important parameters for designing vehicle trajectory and attitude control system that directly decide the divergence behavior of vibration of the aircraft open-loop system under interference. After calibration model validation, the dynamic behavior of air-breathing hypersonic vehicle WR-A is characterized. The unsteady flow field of aircraft forced simple harmonic vibration (SHV) is simulated using N-S equation. The direct damping derivatives, cross derivatives, acceleration derivatives and rotary derivatives of WR-A under different frequencies, amplitudes and positions of centroid are obtained. Research demonstrates that the proportion of acceleration derivatives, which represents the flow time lag effect, in the direct damping derivatives can be as high as 40% but is opposite to the damping derivative value symbols in some cases, contributing to dynamic instability. Numerical simulation on large-amplitude forced vibration of WR-A indicates that the aerodynamic behavior predicted by the dynamic derivative model agrees well with unsteady calculations. The inlet performance parameter derivatives are solved using the Etkin theory. The inlet performance parameters under large-amplitude vibration are successfully predicted using the dynamic derivative model. This offers a guideline for characterizing the dynamic internal flow field and unsteady inlet performance.

  20. Air-Conditioning for Electric Vehicles

    NASA Technical Reports Server (NTRS)

    Popinski, Z.

    1984-01-01

    Combination of ammonia-absorption refrigerator, roof-mounted solar collectors, and 200 degrees C service electric-vehicle motor provides evaporative space-heating/space cooling system for electric-powered and hybrid fuel/electric vehicles.

  1. The induction of water to the inlet air as a means of internal cooling in aircraft-engine cylinders

    NASA Technical Reports Server (NTRS)

    Rothrock, Addison M; Krsek, Alois, Jr; Jones, Anthony W

    1943-01-01

    Report presents the results of investigations conducted on a full-scale air-cooled aircraft-engine cylinder of 202-cubic inch displacement to determine the effects of internal cooling by water induction on the maximum permissible power and output of an internal-combustion engine. For a range of fuel-air and water-fuel ratios, the engine inlet pressure was increased until knock was detected aurally, the power was then decreased 7 percent holding the ratios constant. The data indicated that water was a very effective internal coolant, permitting large increases in engine power as limited by either knock or by cylinder temperatures.

  2. Zinc air battery development for electric vehicles

    SciTech Connect

    Putt, R.A. )

    1990-05-01

    This document reports the progress and accomplishments of a 16 month program to develop a rechargeable zinc-air battery for electric vehicle propulsion, from October 1988 through January 1990. The program was the first stage in the transition of alkaline zinc electrode technology, invented at Lawrence Berkeley Laboratory, to private industry. The LBL invention teaches the use of a copper metal foam substrate for the zinc electrode, in combination with forced convection of electrolyte through the foam during battery operation. Research at LBL showed promise that this approach would avoid shape change (densification and dendrite growth), the primary failure mode of this electrode. The program comprised five tasks; (1) cell design, (2) capacity maximization, (3) cycle testing, (4) materials qualification, and (5) a cost/design study. The cell design contemplates a plate and frame stack, with alternating zinc and oxygen electrode frame assemblies between rigid end plates. A 200 Ah cell, as may be required for the EV application, would comprise a stack of five zinc and six oxygen electrode frame/assemblies. 8 figs., 2 tabs.

  3. Effect of inlet-air humidity, temperature, pressure, and reference Mach number on the formation of oxides of nitrogen in a gas turbine combustor

    NASA Technical Reports Server (NTRS)

    Marchionna, N. R.; Diehl, L. A.; Trout, A. M.

    1973-01-01

    Tests were conducted to determine the effect of inlet air humidity on the formation of oxides of nitrogen (NOx) from a gas turbine combustor. Combustor inlet air temperature ranged from 506 K (450 F) to 838 K (1050 F). The tests were primarily run at a constant pressure of 6 atmospheres and reference Mach number of 0.065. The NOx emission index was found to decrease with increasing inlet air humidity at a constant exponential rate: NOx = NOx0e-19H (where H is the humidity and the subscript 0 denotes the value at zero humidity). the emission index increased exponentially with increasing normalized inlet air temperature to the 1.14 power. Additional tests made to determine the effect of pressure and reference Mach number on NOx showed that the NOx emission index varies directly with pressure to the 0.5 power and inversely with reference Mach number.

  4. Stability and control characteristics of an air-breathing missile configuration having a forward located inlet

    NASA Technical Reports Server (NTRS)

    Sawyer, W. C.; Hayes, C.

    1976-01-01

    An investigation was made to determine the aerodynamic characteristics of an airbreathing missile configuration having a forward located inlet. Control was provided by cruciform tail surfaces. Aerodynamic data were obtained for the body-tail configuration alone and with planar or cruciform wings. At Mach numbers from 2.86 to 4.63, the model had internal flow. At Mach numbers from 1.70 to 2.86, the internal duct was closed, and an inlet fairing was installed to simulate boost conditions.

  5. Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Offutt Air Force Base, Looking Glass Airborne Command Post, Vehicle Refueling Station, Northeast of AGE Storage Facility at far northwest end of Project Looking Glass Historic District, Bellevue, Sarpy County, NE

  6. Interior view Beale Air Force Base, Perimeter Acquisition Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior view - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  7. Looking north Beale Air Force Base, Perimeter Acquisition Vehicle ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking north - Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  8. Robotic air vehicle. Blending artificial intelligence with conventional software

    NASA Technical Reports Server (NTRS)

    Mcnulty, Christa; Graham, Joyce; Roewer, Paul

    1987-01-01

    The Robotic Air Vehicle (RAV) system is described. The program's objectives were to design, implement, and demonstrate cooperating expert systems for piloting robotic air vehicles. The development of this system merges conventional programming used in passive navigation with Artificial Intelligence techniques such as voice recognition, spatial reasoning, and expert systems. The individual components of the RAV system are discussed as well as their interactions with each other and how they operate as a system.

  9. Gust Mitigation of Micro Air Vehicles Using Passive Articulated Wings

    PubMed Central

    Slegers, Nathan

    2014-01-01

    Birds and insects naturally use passive flexing of their wings to augment their stability in uncertain aerodynamic environments. In a similar manner, micro air vehicle designers have been investigating using wing articulation to take advantage of this phenomenon. The result is a class of articulated micro air vehicles where artificial passive joints are designed into the lifting surfaces. In order to analyze how passive articulation affects performance of micro air vehicles in gusty environments, an efficient 8 degree-of-freedom model is developed. Experimental validation of the proposed mathematical model was accomplished using flight test data of an articulated micro air vehicle obtained from a high resolution indoor tracking facility. Analytical investigation of the gust alleviation properties of the articulated micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes. Simulations show that passive articulation in micro air vehicles can increase their robustness to gusts within a range of joint compliance. It is also shown that if articulation joints are made too compliant that gust mitigation performance is degraded when compared to a rigid system. PMID:24516368

  10. Heat transfer to two-phase air/water mixtures flowing in small tubes with inlet disequilibrium

    NASA Technical Reports Server (NTRS)

    Janssen, J. M.; Florschuetz, L. W.; Fiszdon, J. P.

    1986-01-01

    The cooling of gas turbine components was the subject of considerable research. The problem is difficult because the available coolant, compressor bleed air, is itself quite hot and has relatively poor thermophysical properties for a coolant. Injecting liquid water to evaporatively cool the air prior to its contact with the hot components was proposed and studied, particularly as a method of cooling for contingency power applications. Injection of a small quantity of cold liquid water into a relatively hot coolant air stream such that evaporation of the liquid is still in process when the coolant contacts the hot component was studied. No approach was found whereby heat transfer characteristics could be confidently predicted for such a case based solely on prior studies. It was not clear whether disequilibrium between phases at the inlet to the hot component section would improve cooling relative to that obtained where equilibrium was established prior to contact with the hot surface.

  11. Hypersonic Inlet for a Laser Powered Propulsion System

    NASA Astrophysics Data System (ADS)

    Harrland, Alan; Doolan, Con; Wheatley, Vincent; Froning, Dave

    2011-11-01

    Propulsion within the lightcraft concept is produced via laser induced detonation of an incoming hypersonic air stream. This process requires suitable engine configurations that offer good performance over all flight speeds and angles of attack to ensure the required thrust is maintained. Stream traced hypersonic inlets have demonstrated the required performance in conventional hydrocarbon fuelled scramjet engines, and has been applied to the laser powered lightcraft vehicle. This paper will outline the current methodology employed in the inlet design, with a particular focus on the performance of the lightcraft inlet at angles of attack. Fully three-dimensional turbulent computational fluid dynamics simulations have been performed on a variety of inlet configurations. The performance of the lightcraft inlets have been evaluated at differing angles of attack. An idealized laser detonation simulation has also been performed to validate that the lightcraft inlet does not unstart during the laser powered propulsion cycle.

  12. Wind-Tunnel Investigation of Air Inlet and Outlet Openings for Aircraft, Special Report

    NASA Technical Reports Server (NTRS)

    Rogallo, Francis M.; Gauvain, William E.

    1938-01-01

    An investigation was made in the NACA 5-foot vertical wind tunnel of a large variety of duct inlets and outlets to obtain information relative to their design for the cooling or the ventilation systems on aircraft. Most of the tests were of openings in a flat plate but, in order to determine the best locations and the effects of interference, a few tests were made of openings in an airfoil. The best inlet location for a system not including a blower was found to be at the forward stagnation point; for one including a blower, the best location was found to be in the region of lowest total head, probably in the boundary layer near the trailing edge. Design recommendations are given, and it is shown that correct design demands a knowledge of the external flow and of the internal requirements in addition to that obtained from the results of the wind tunnel tests.

  13. Multiple Unmanned Air Vehicles Control Using Neurobiologically Inspired Algorithms

    NASA Astrophysics Data System (ADS)

    Zhang, Yong; Wang, Li

    In order to develop and evaluate future Unmanned Air Vehicles for the hazardous environmental monitoring, the comprehensive simulation test and analysis of new advanced concepts is imperative. This paper details an on-going proof of concept focused on development of a neurobiologically-inspired system for the high level control of a Air Vehicle team. This study, entitled Neurobiologically Enabled Autonomous Vehicle Operations, will evaluate initial System-Under-Test concept data by selecting well defined tasks, and evaluating performance based on assignment effectiveness, cooperation, and adaptability of the system. The system will be tested thoroughly in simulation, and if mature, will be implemented in hardware.

  14. Effect of inlet temperature on the performance of a catalytic reactor. [air pollution control

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1978-01-01

    A 12 cm diameter by 15 cm long catalytic reactor was tested with No. 2 diesel fuel in a combustion test rig at inlet temperatures of 700, 800, 900, and 1000 K. Other test conditions included pressures of 3 and 6 x 10 to the 5th power Pa, reference velocities of 10, 15, and 20 m/s, and adiabatic combustion temperatures in the range 1100 to 1400 K. The combustion efficiency was calculated from measurements of carbon monoxide and unburned hydrocarbon emissions. Nitrogen oxide emissions and reactor pressure drop were also measured. At a reference velocity of 10 m/s, the CO and unburned hydrocarbons emissions, and, therefore, the combustion efficiency, were independent of inlet temperature. At an inlet temperature of 1000 K, they were independent of reference velocity. Nitrogen oxides emissions resulted from conversion of the small amount (135 ppm) of fuel-bound nitrogen in the fuel. Up to 90 percent conversion was observed with no apparent effect of any of the test variables. For typical gas turbine operating conditions, all three pollutants were below levels which would permit the most stringent proposed automotive emissions standards to be met.

  15. Honeywell's organic air vehicle chemical-biological sensing platform

    NASA Astrophysics Data System (ADS)

    Cole, Barry E.; Krafthefer, Brian; Knee, Daniel; Fulton, Vaughn M.; Law, Kristen

    2004-12-01

    Unmanned air vehicles (UAVs) today are mostly used for reconnaissance and sometimes weapons delivery. Remote sensing of chemical-biological (CB) agents is another beneficial use of UAVs. While remote sensing of CB agents can be done by LIDAR spectroscopy, this technology is less spatially precise and less sensitive than actual measurements on a collected sample. One family of UAVs of particularly unique benefit for CB sampling and in-flight analysis is the Honeywell family of Organic Air Vehicles (OAVs). This vehicle with its ability to hover and stare has the unique ability among UAVs to collect and analyze chem-bio samples from a specific location over extended periods of time. Such collections are not possible with other micro-air-vehicles (MAVs) that only operate in fly-by mode. This paper describes some of the Honeywell OAV features that are conducive to CB detection.

  16. 78 FR 20881 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-08

    ... AGENCY 40 CFR Part 80 RIN 2060-AQ86 Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle... hearings to be held for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule is hereinafter referred to as ``Tier 3''),...

  17. Missions and vehicle concepts for modern, propelled, lighter-than-air vehicles

    NASA Technical Reports Server (NTRS)

    Ardema, M. D.

    1984-01-01

    The results of studies conducted over the last 15 years to assess missions and vehicle concepts for modern, propelled, lighter-than-air vehicles (airships) were surveyed. Rigid and non-rigid airship concepts are considered. The use of airships for ocean patrol and surveillance is discussed along with vertical heavy lift airships. Military and civilian needs for high altitude platforms are addressed.

  18. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOEpatents

    Farrington, Robert B.; Anderson, Ren

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  19. Interactions between Flight Dynamics and Propulsion Systems of Air-Breathing Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Dalle, Derek J.

    The development and application of a first-principles-derived reduced-order model called MASIV (Michigan/AFRL Scramjet In Vehicle) for an air-breathing hypersonic vehicle is discussed. Several significant and previously unreported aspects of hypersonic flight are investigated. A fortunate coupling between increasing Mach number and decreasing angle of attack is shown to extend the range of operating conditions for a class of supersonic inlets. Detailed maps of isolator unstart and ram-to-scram transition are shown on the flight corridor map for the first time. In scram mode the airflow remains supersonic throughout the engine, while in ram mode there is a region of subsonic flow. Accurately predicting the transition between these two modes requires models for complex shock interactions, finite-rate chemistry, fuel-air mixing, pre-combustion shock trains, and thermal choking, which are incorporated into a unified framework here. Isolator unstart occurs when the pre-combustion shock train is longer than the isolator, which blocks airflow from entering the engine. Finally, cooptimization of the vehicle design and trajectory is discussed. An optimal control technique is introduced that greatly reduces the number of computations required to optimize the simulated trajectory.

  20. Flexible Wing Base Micro Aerial Vehicles: Assessment of Controllability of Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Jenkins, David A.; Ifju, Peter G.; Abdulrahim, Mujahid; Olipra, Scott

    2002-01-01

    In the last several years, we have developed unique types of micro air vehicles that utilize flexible structures and extensible covering materials. These MAVs can be operated with maximum dimensions as small as 6 inches and carry reasonable payloads, such as video cameras and transmitters. We recently demonstrated the potential of these vehicles by winning the Fourth International Micro Air Vehicle Competition, held at Ft. Huachucha, Arizona in May 2000. The pilots report that these vehicles have unusually smooth flying characteristics and are relatively easy to fly, both in the standard RC mode and "through the camera" when at greater distances. In comparison, they find that similar sized vehicles with more conventional rigid construction require much more input from the pilot just to maintain control. To make these subjective observations more quantitative, we have devised a system that can conveniently record a complete history of all the RC transmitter stick movements during a flight. Post-flight processing of the stick movement data allows for direct comparisons between different types of MAVs when flown by the same pilot, and also comparisons between pilots. Eventually, practical micro air vehicles will be autonomously controlled, but we feel that the smoothest flying and easiest to fly embodiments will also be the most successful in the long run. Comparisons between several types of micro air vehicles will be presented, along with interpretations of the data.

  1. Australian Air Breathing Propulsion Research for Hypersonic, Beamed Energy-Propelled Vehicles

    NASA Astrophysics Data System (ADS)

    Froning, David

    2010-05-01

    A three year laser-propelled vehicle analysis and design investigation has been begun in June, 2009 by Faculty and graduate students at the University of Adelaide under a Grant/Cooperative Agreement Award to the University of Adelaide by the Asian Office of Aerospace Research and Development (AOARD). The major objectives of thsis investigation are: (a) development of hypersonic, air breathing "lightcraft" with innovative air inlets that enable acceptable airflow capture and combustion, and acceptable cowl-lip heating rates during hot, high-speed, high angle-of-attack hypersonic flight; (b) yest of the most promising lightcraft and inlet design in the high power laser beam that is part of the shock tunnel facility at CTO Instituto in Brazil; and (c) plan a series of laser guided and propelled flights that achieve supersonic or higher speed at the Woomera Test Facility (WTF) in South Australia—using the existing WTF launching and tracking facilities and sponsor-provided laser pointing and tracking and illumination systems.

  2. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    SciTech Connect

    Norman, Kevin M; Huff, Shean P; West, Brian H

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  3. Prototype air bag restraint for use in patrol vehicles

    SciTech Connect

    Marts, D.J.; Barker, S.G.

    1995-03-01

    An air bag has been designed and laboratory tested for use in existing police vehicles that will restrain a person if he or she becomes violent. The device will prevent self-injury and protect the vehicle and officer. The device does not pose a suffocation hazard and can be quickly and easily inflated or deflated by the officer from the front seat. The device is ready for field testing.

  4. An inlet air washer/chiller system for combined cycle planet repowering

    SciTech Connect

    Sengupta, U.; Soroka, G. )

    1989-01-01

    A conditioning method to achieve increased output at any relative humidity condition is an air washer and absorption chiller arrangement. At elevated temperatures and low humidity, the air washer operates as an evaporative cooler without the chiller in operation. In this mode, the air washer will give similar results as a media type evaporative cooler at a fraction of the pressure loss. In the air washer plus chiller operating mode the chiller maintains cooling effectiveness of the air washer during periods of high relative humidity. This makes such a system very appropriate anywhere relative humidity is high. Many combined cycle plants utilize supplemental firing of the heat recovery steam generators to offset the loss of gas turbine power at high ambient temperatures. This paper shows that in contrast to supplementary firing, the combination air washer/chiller system can generate power more efficiently and at lower cost.

  5. Northwest passage: Trade route for large air cushion vehicles

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.

    1973-01-01

    A conceptual vehicle and powerplant (10,000-ton) nuclear-powered air-cushion vehicle (ACV) that could open the Northwest Passage and other Arctic passages to commercial traffic is identified. The report contains a description of the conceptual vehicle, including the powerplant and operations, an assessment of technical feasibility, estimates of capital and operating costs, and identification of eligible cargo and markets. A comparison of the nuclear ACV freighter with nuclear container ships shows that for containerized or roll-on/roll-off cargo the ACV would provide greatly reduced transit time between North Atlantic and North Pacific ports at a competitive cost.

  6. The aluminum-air battery for electric vehicles - An update

    NASA Astrophysics Data System (ADS)

    1980-11-01

    The development of aluminum-air batteries as mechanically rechargeable power sources to be used in electric vehicles is discussed. The chemistry of the aluminum-air battery, which has a potential for providing the range, acceleration and rapid refueling capability of contemporary automobiles and is based on the reaction of aluminum metal with atmospheric oxygen in the presence of an aqueous sodium hydroxide/sodium aluminate electrolyte, is examined, and it is pointed out that the electric vehicle would be practically emissionless. The battery development program at the Lawrence Livermore National Laboratory, which includes evaluations of electrochemical and chemical phenomena, studies of the economics and energy balance of a transportation system based on aluminum, and power cell design and performance analysis, is presented. It is concluded that although difficult problems must be overcome before the technical and economic feasibility of aluminum-air batteries for electric vehicles can be established, projections indicate that the aluminum-air vehicle is potentially competitive with internal combustion vehicles powered by synthetic liquid fuels.

  7. Yaw rate control of an air bearing vehicle

    NASA Technical Reports Server (NTRS)

    Walcott, Bruce L.

    1989-01-01

    The results of a 6 week project which focused on the problem of controlling the yaw (rotational) rate the air bearing vehicle used on NASA's flat floor facility are summarized. Contained within is a listing of the equipment available for task completion and an evaluation of the suitability of this equipment. The identification (modeling) process of the air bearing vehicle is detailed as well as the subsequent closed-loop control strategy. The effectiveness of the solution is discussed and further recommendations are included.

  8. Electric Vehicle Preparedness - Implementation Approach for Electric Vehicles at Naval Air Station Whidbey Island. Task 4

    SciTech Connect

    Schey, Stephen; Francfort, Jim

    2015-06-01

    Several U.S. Department of Defense base studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). This study is focused on the Naval Air Station Whidbey Island (NASWI) located in Washington State. Task 1 consisted of a survey of the non-tactical fleet of vehicles at NASWI to begin the review of vehicle mission assignments and types of vehicles in service. In Task 2, daily operational characteristics of vehicles were identified to select vehicles for further monitoring and attachment of data loggers. Task 3 recorded vehicle movements in order to characterize the vehicles’ missions. The results of the data analysis and observations were provided. Individual observations of the selected vehicles provided the basis for recommendations related to PEV adoption, i.e., whether a battery electric vehicle (BEV) or plug-in hybrid electric vehicle (PHEV) (collectively PEVs) can fulfill the mission requirements. It also provided the basis for recommendations related to placement of PEV charging infrastructure. This report focuses on an implementation plan for the near-term adoption of PEVs into the NASWI fleet.

  9. Integration of air separation membrane and coalescing filter for use on an inlet air system of an engine

    DOEpatents

    Moncelle, Michael E.

    2003-01-01

    An intake air separation system suitable for combustion air of an internal combustion engine. An air separation device of the system includes a plurality of fibers, each fiber having a tube with a permeation barrier layer on the outer surface thereof and a coalescing layer on the inner surface thereof, to restrict fluid droplets from contacting the permeation barrier layer.

  10. Unmanned Air Vehicle -Version 1.0

    SciTech Connect

    Fred Oppel, SNL 06134

    2013-04-17

    This package contains modules that model the mobility of systems such as helicopters and fixed wing flying in the air. This package currently models first order physics - basically a velocity integrator. UAV mobility uses an internal clock to maintain stable, high-fidelity simulations over large time steps This package depends on interface that reside in the Mobility package.

  11. Air-Breathing Launch Vehicle Technology Being Developed

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    2003-01-01

    Of the technical factors that would contribute to lowering the cost of space access, reusability has high potential. The primary objective of the GTX program is to determine whether or not air-breathing propulsion can enable reusable single-stage-to-orbit (SSTO) operations. The approach is based on maturation of a reference vehicle design with focus on the integration and flight-weight construction of its air-breathing rocket-based combined-cycle (RBCC) propulsion system.

  12. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D. , Inc., Cambridge, MA )

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an [open quotes]upsized[close quotes] condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  13. Study of long term options for electric vehicle air conditioning

    SciTech Connect

    Dieckmann, J.; Mallory, D.

    1991-07-01

    There are strong incentives in terms of national energy and environmental policy to encourage the commercialization of electrically powered vehicles in the U.S. Among these incentives are reduced petroleum consumption, improved electric generation capacity utilization, reduced IC engine emissions, and, depending on the primary fuel used for electric power generation, reduced emissions of carbon dioxide. A basic requirement for successfully commercializing any motor vehicle in the US is provision of adequate passenger comfort heating and air conditioning (cooling). Although air conditioning is generally sold as optional equipment, in excess of 80% of the automobiles and small trucks sold in the US have air conditioning systems. In current, pre-commercial electric vehicles, comfort heating is provided by a liquid fuel fired heater that heats water which is circulated through the standard heater core in the conventional interior air handling unit. Air conditioning is provided by electric motor driven compressors, installed in a system having, perhaps, an {open_quotes}upsized{close_quotes} condenser and a standard evaporator (front and rear evaporators in some instances) installed in the conventional interior air handler. Although this approach is adequate in the near term for initial commercialization efforts, a number of shortcomings of this arrangement, as well as longer range concerns need to be addressed. In this project, the long term alternatives for cooling and heating electric vehicles effectively, efficiently (with minimum range penalties), and without adverse environmental impacts have been examined. Identification of options that can provide both heating and cooling is important, in view of the disadvantages of carrying separate heating and cooling systems in the vehicle.

  14. Collaborative tactical behaviors for autonomous ground and air vehicles

    NASA Astrophysics Data System (ADS)

    Albus, James; Barbera, Anthony; Scott, Harry; Balakirsky, Stephen

    2005-05-01

    Tactical behaviors for autonomous ground and air vehicles are an area of high interest to the Army. They are critical for the inclusion of robots in the Future Combat System (FCS). Tactical behaviors can be defined at multiple levels: at the Company, Platoon, Section, and Vehicle echelons. They are currently being defined by the Army for the FCS Unit of Action. At all of these echelons, unmanned ground vehicles, unmanned air vehicles, and unattended ground sensors must collaborate with each other and with manned systems. Research being conducted at the National Institute of Standards and Technology (NIST) and sponsored by the Army Research Lab is focused on defining the Four Dimensional Real-time Controls System (4D/RCS) reference model architecture for intelligent systems and developing a software engineering methodology for system design, integration, test and evaluation. This methodology generates detailed design requirements for perception, knowledge representation, decision making, and behavior generation processes that enable complex military tactics to be planned and executed by unmanned ground and air vehicles working in collaboration with manned systems.

  15. Mechanically refuelable zinc/air electric vehicle cells

    NASA Astrophysics Data System (ADS)

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  16. Mechanically refuelable zinc/air electric vehicle cells

    SciTech Connect

    Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J.F.

    1992-12-01

    Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration -- factors which define the essential functions of common automobiles. Such a electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described in this report focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

  17. Simulation study of plane motion of air cushion vehicle

    NASA Astrophysics Data System (ADS)

    Zhao, Shu-Qin; Shi, Xiao-Cheng; Shi, Yi-Long; Bian, Xin-Qian

    2003-12-01

    This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV’s voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV’s movement characteristic basically.

  18. An Adaptive Path Planning Algorithm for Cooperating Unmanned Air Vehicles

    SciTech Connect

    Cunningham, C.T.; Roberts, R.S.

    2000-09-12

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  19. Adaptive path planning algorithm for cooperating unmanned air vehicles

    SciTech Connect

    Cunningham, C T; Roberts, R S

    2001-02-08

    An adaptive path planning algorithm is presented for cooperating Unmanned Air Vehicles (UAVs) that are used to deploy and operate land-based sensor networks. The algorithm employs a global cost function to generate paths for the UAVs, and adapts the paths to exceptions that might occur. Examples are provided of the paths and adaptation.

  20. A zinc-air battery and flywheel zero emission vehicle

    SciTech Connect

    Tokarz, F.; Smith, J.R.; Cooper, J.; Bender, D.; Aceves, S.

    1995-10-03

    In response to the 1990 Clean Air Act, the California Air Resources Board (CARB) developed a compliance plan known as the Low Emission Vehicle Program. An integral part of that program was a sales mandate to the top seven automobile manufacturers requiring the percentage of Zero Emission Vehicles (ZEVs) sold in California to be 2% in 1998, 5% in 2001 and 10% by 2003. Currently available ZEV technology will probably not meet customer demand for range and moderate cost. A potential option to meet the CARB mandate is to use two Lawrence Livermore National Laboratory (LLNL) technologies, namely, zinc-air refuelable batteries (ZARBs) and electromechanical batteries (EMBs, i. e., flywheels) to develop a ZEV with a 384 kilometer (240 mile) urban range. This vehicle uses a 40 kW, 70 kWh ZARB for energy storage combined with a 102 kW, 0.5 kWh EMB for power peaking. These technologies are sufficiently near-term and cost-effective to plausibly be in production by the 1999-2001 time frame for stationary and initial vehicular applications. Unlike many other ZEVs currently being developed by industry, our proposed ZEV has range, acceleration, and size consistent with larger conventional passenger vehicles available today. Our life-cycle cost projections for this technology are lower than for Pb-acid battery ZEVs. We have used our Hybrid Vehicle Evaluation Code (HVEC) to simulate the performance of the vehicle and to size the various components. The use of conservative subsystem performance parameters and the resulting vehicle performance are discussed in detail.

  1. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    NASA Astrophysics Data System (ADS)

    Othman, M. N. K.; Zuradzman, M. Razlan; Hazry, D.; Khairunizam, Wan; Shahriman, A. B.; Yaacob, S.; Ahmed, S. Faiz; Hussain, Abadalsalam T.

    2014-12-01

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  2. Internal air flow analysis of a bladeless micro aerial vehicle hemisphere body using computational fluid dynamic

    SciTech Connect

    Othman, M. N. K. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Hazry, D. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Khairunizam, Wan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Shahriman, A. B. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Yaacob, S. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; and others

    2014-12-04

    This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.

  3. the nature of air flow near the inlets of blunt dust sampling probes

    NASA Astrophysics Data System (ADS)

    Vincent, J. H.; Hutson, D.; Mark, D.

    This paper sets out to describe the nature of air flow near blunt dust samplers in a way which allows a relatively simple assessment of their performances for collecting dust particles. Of particular importance is the shape of the limiting stream surface which divides the sampled air from that which passes outside the sampler, and how this is affected by the free-stream air velocity, the sampling flow rate, and the shape of the sampler body. This was investigated for two-dimensional and axially-symmetric sampler systems by means of complementary experiments using electrolytic tank potential flow analogues and a wind tunnel respectively. For extreme conditions the flow of air entering the sampling orifice may be wholly divergent or wholly convergent. For a wide range of intermediate conditions, however, the flow first diverges then converges, exhibiting a so-called "spring onion effect". Whichever of these applies for a particular situation, the flow may be considered to consist of two parts, the outer one dominated by the flow about the sampler body and the inner one dominated by the flow into the sampling orifice. Particle transport in this two-part flow may be assessed using ideas borrowed from thin-walled probe theory.

  4. Inlet technology

    NASA Technical Reports Server (NTRS)

    Kutschenreuter, Paul

    1992-01-01

    At hypersonic flight Mach numbers, particularly above Mo = 10, the inlet compression process is no longer adiabatic, real gas chemistry takes on extra importance, and the combined effects of entropy layer and viscous effects lead to highly nonuniform flow profile characteristics at the combustor entrance. Under such conditions, traditional inlet efficiency parameters can be unnecessarily cumbersome and/or lacking in the ability to appropriately characterize the inlet flow and to provide insight into propulsion system performance. Recent experience suggests that the use of inlet entropy increases inlet efficiency in hypersonic applications.

  5. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles §...

  6. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles §...

  7. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles §...

  8. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles §...

  9. 40 CFR 86.1832-01 - Optional equipment and air conditioning for test vehicles.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... VEHICLES AND ENGINES General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1832-01...

  10. Air cushion vehicle conductive/semiconductive flexible skirt, and method

    NASA Astrophysics Data System (ADS)

    Cavenagh, Richard A.; Dyke, Raymond W.

    1990-03-01

    Discussed here is a method for dissipating static electrical energy from air cushion vehicles when operating more particularly in cold, low humidity environments, which method involves fabricating the skirt assembly from a flexible sheet material of at least semiconductive character, which will provide a suitable dissipating grounding pathway to discharge potential static electrical energy generated during the aforesaid operation. The method includes using a coated flexible fabric material having at least one of its opposite surfaces coated with an elastomeric abrasion-resistant material, and embedding a plurality of electrically conductive flexible strands at least partially within said flexible fabric material, or alternatively embedding electrically conductive particles or fibers in a generally uniformly manner throughout a forming of its elastomeric composition. The invention also is directed specifically to/on an air cushion vehicle skirt component comprised of electrically conductive composite flexible sheet material having sufficient conductive characteristics to provide a near constant dissipation grounding pathway from said vehicle for any substantial build up of generated static electrical energy, more particularly when the air cushion vehicle is operating in cold, low humidity environments.

  11. Prospects for future hypersonic air-breathing vehicles

    NASA Technical Reports Server (NTRS)

    Beach, H. L., Jr.; Blankson, Isaiah M.

    1991-01-01

    The age of hypersonics is (almost) here. This is evident from the amount of activity in the United States, Europe, the USSR and Japan; this activity is a reflection of technical progress in key areas which will enable new vehicle systems, as well as renewed interest in the utilization of these systems. The current situation, at least in the United States, is the product of an interesting history which is briefly reviewed here. The context for hypersonic applications is discussed, but the emphasis is on hypersonic technology issues and needs, particularly for propulsion and technology integration. The paper concludes with prospects for accomplishing the objective of air-breathing hypersonic vehicle systems.

  12. Powering future vehicles with the refuelable zinc/air battery

    SciTech Connect

    1995-10-01

    A recent road test at LLNL underscored the zinc/air battery`s capacity to give electric vehicles some of the attractive features of gas-driven cars: a 400-km range between refueling, 10-minute refueling, and highway-safe acceleration. Developed at Lawrence Livermore National Laboratory, the battery weights only one-sixth as much as standard lead/acid batteries and occupies one-third the space, yet costs less per mile to operate. What`s more, because the battery is easily refuelable, it promises trouble-free, nearly 24-hour-a-day operation for numerous kinds of electric vehicles, from forklifts to delivery vans and possibly, one day, personal automobiles. The test of a Santa Barbara Municipal Transit bus with a hybrid of zinc/air and lead/acid batteries capped a short development period for the zinc/air battery. The test run indicated the zinc/air battery`s potential savings in vehicle weight from 5.7 to 4.0 metric tons, in battery weight from 2.0 to 0.3 metric tons, in battery volume from 0.79 to 0.25 m{sup 3}, and in electricity cost from 5.6 cents per mile to 4.7 cents per mile. The power, however, remains the same.

  13. Effect of Inlet Air Distortion on the Steady-State and Surge Characteristics of an Axial-Flow Turbojet Compressor

    NASA Technical Reports Server (NTRS)

    Ciepluch, Carl C.

    1948-01-01

    An investigation was conducted in an altitude test chamber to determine the effects of inlet airflow distortion on the compressor steady-state and surge characteristics of a high-pressure ratio, axial-flow turbojet engine. Circumferential-type inlet flow distortions were investigated, which covered a range of distortion sector angles from 20 deg to 168 deg and distortion levels up to 22 percent. The presence of inlet airflow distortions at the compressor face resulted in a substantial increase in the local pressure ratio in the distorted region, primarily for the inlet stages. The local pressure ratio in the distorted region for the inlet stages increased as either the distortion sector angle decreased or the percent distortion increased. The average compressor-surge pressure ratio was much more sensitive to inlet airflow distortions at lower engine speeds than at engine speeds near rated. Hence, compressor-surge margin reduction due to inlet airflow distortion was quite severe at the lower engine speeds. Although the average compressor-surge pressure ratio was generally reduced with inlet flow distortion, local pressure ratios across the distorted sector of the compressor were obtained during surge and were significantly greater than the normal compressor-surge pressure ratio. This was a result of increased loading of the inlet stages in the distorted region.

  14. Numerical Simulation of Flows in a Cyclone Chamber with Different Conditions of Air Inlet and Outlet

    NASA Astrophysics Data System (ADS)

    Pitsukha, E. A.

    2014-09-01

    A numerical investigation of flows in a cyclone chamber has been carried out at the fraction of bottom blast φ =0-0.5, at the values of the dimensionless pinch diameter dout/D =0.7 with different locations and configurations of nozzles for air intake. In the simulation of swirling flows, the well-known k-ɛ and k-ω turbulence models, as well as the laminar flow model, were used. A satisfactory agreement between the results of numerical simulation and experimental data at dout/D =0.5-0.7 is obtained. For a chamber with a relative pinch diameter dout/D =0.3 the calculated flow parameters differ substantially from experimental values.

  15. Biofiltration of air contaminated by styrene: Effect of nitrogen supply, gas flow rate, and inlet concentration

    SciTech Connect

    Jorio, H.; Bibeau, L.; Heitz, M.

    2000-05-01

    The biofiltration process is a promising technology for the treatment of dilute styrene emissions in air. The efficiency of this process is however strongly dependent upon various operational parameters such as the filter bed characteristics, nutrient supplies, input contaminant concentrations, and gas flow rates. The biofiltration of air containing styrene vapors was therefore investigated, employing a novel biomass filter material, in two identical but separate laboratory scale biofiltration units (units 1 and 2), both biofilters being initially inoculated with a microbial consortium. Each biofilter was irrigated with a nutrient solution supplying nitrogen in one of two forms; i.e., mainly as ammonia for unit 1 and exclusively as nitrate for unit 2. The experimental results have revealed that greater styrene elimination rates are achieved in the biofilter supplied with ammonia as the major nitrogen source in comparison to the lesser elimination performance obtained with the nitrate provided biofilter. However, in achieving the high styrene removal rates in the ammonia supplied biofilter, the excess of biomass accumulates on the filtering pellets and causes progressive clogging of the filter media. Furthermore, the effectiveness of nitrate supply as the sole nitrogen nutrient form, on reducing or controlling the biomass accumulation in the filter media in comparison to ammonia, could not be satisfactorily demonstrated because the two biofilters operated with very different styrene elimination capacities. The monitoring of the carbon dioxide concentration profile through both biofilters revealed that the ratio of carbon dioxide produced to the styrene removed was approximately 3/1, which confirms the complete biodegradation of removed styrene, given that some of the organic carbon consumed is also used for the microbial growth. The effects of the most important design parameters, namely styrene input concentrations and gas flow rates, were investigated for each

  16. Developments in skirt systems for air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  17. Episodic air quality impacts of plug-in electric vehicles

    NASA Astrophysics Data System (ADS)

    Razeghi, Ghazal; Carreras-Sospedra, Marc; Brown, Tim; Brouwer, Jack; Dabdub, Donald; Samuelsen, Scott

    2016-07-01

    In this paper, the Spatially and Temporally Resolved Energy and Environment Tool (STREET) is used in conjunction with University of California Irvine - California Institute of Technology (UCI-CIT) atmospheric chemistry and transport model to assess the impact of deploying plug-in electric vehicles and integrating wind energy into the electricity grid on urban air quality. STREET is used to generate emissions profiles associated with transportation and power generation sectors for different future cases. These profiles are then used as inputs to UCI-CIT to assess the impact of each case on urban air quality. The results show an overall improvement in 8-h averaged ozone and 24-h averaged particulate matter concentrations in the South Coast Air Basin (SoCAB) with localized increases in some cases. The most significant reductions occur northeast of the region where baseline concentrations are highest (up to 6 ppb decrease in 8-h-averaged ozone and 6 μg/m3 decrease in 24-h-averaged PM2.5). The results also indicate that, without integration of wind energy into the electricity grid, the temporal vehicle charging profile has very little to no effect on urban air quality. With the addition of wind energy to the grid mix, improvement in air quality is observed while charging at off-peak hours compared to the business as usual scenario.

  18. Air liquefaction and enrichment system propulsion in reusable launch vehicles

    SciTech Connect

    Bond, W.H.; Yi, A.C.

    1994-07-01

    A concept is shown for a fully reusable, Earth-to-orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high-speed acceleration, both using liquid hydrogen for fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90% pure liquid oxygen as its oxidizer that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. This article shows an approach and the corresponding technology needs for using air liquefaction and enrichment system propulsion in a single-stage-to-orbit (SSTO) vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, in a direct substitution for aluminum or aluminum-lithium alloy, is critical to meet the structure weight objective for SSTO. Configurations that utilize `waverider` aerodynamics show great promise to reduce the vehicle weight. 5 refs.

  19. In-vehicle particle air pollution and its mitigation

    NASA Astrophysics Data System (ADS)

    Tartakovsky, L.; Baibikov, V.; Czerwinski, J.; Gutman, M.; Kasper, M.; Popescu, D.; Veinblat, M.; Zvirin, Y.

    2013-01-01

    This work presents results of particle mass, number and size measurements inside passenger cars (PCs), vans and urban buses. Effects of the in-cabin air purifier on particle concentrations and average size inside a vehicle are studied. Use of the air purifier leads to a dramatic reduction, by 95-99%, in the measured ultrafine particles number concentration inside a vehicle compared with outside readings. Extremely low particle concentrations may be reached without a danger of vehicle occupants' exposure to elevated CO2 levels. The lowest values of particle concentrations inside a PC without air purifier are registered under the recirculation ventilation mode, but the issue of CO2 accumulation limits the use of this mode to very short driving events. Lower PM concentrations are found inside newer cars, if this ventilation mode is used. Great differences by a factor of 2.5-3 in PM10 concentrations are found between the PCs and the buses. Smoking inside a car leads to a dramatic increase, by approximately 90 times, in PM2.5 concentrations.

  20. Effect of Gas/Steam Turbine Inlet Temperatures on Combined Cycle Having Air Transpiration Cooled Gas Turbine

    NASA Astrophysics Data System (ADS)

    Kumar, S.; Singh, O.

    2012-10-01

    Worldwide efforts are being made for further improving the gas/steam combined cycle performance by having better blade cooling technology in topping cycle and enhanced heat recovery in bottoming cycle. The scope of improvement is possible through turbines having higher turbine inlet temperatures (TITs) of both gas turbine and steam turbine. Literature review shows that a combined cycle with transpiration cooled gas turbine has not been analyzed with varying gas/steam TITs. In view of above the present study has been undertaken for thermodynamic study of gas/steam combined cycle with respect to variation in TIT in both topping and bottoming cycles, for air transpiration cooled gas turbine. The performance of combined cycle with dual pressure heat recovery steam generator has been evaluated for different cycle pressure ratios (CPRs) varying from 11 to 23 and the selection diagrams presented for TIT varying from 1,600 to 1,900 K. Both the cycle efficiency and specific work increase with TIT for each pressure ratio. For each TIT there exists an optimum pressure ratio for cycle efficiency and specific work. For the CPR of 23 the best cycle performance is seen at a TIT of 1,900 K for maximum steam temperature of 570 °C, which gives the cycle efficiency of 60.9 % with net specific work of 909 kJ/kg.

  1. 78 FR 32223 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... AGENCY 40 CFR Parts 80, 85, 86, 600, 1036, 1037, 1065, and 1066 RIN 2060-A0 Control of Air Pollution From... (``EPA'') is announcing an extension of the public comment period for the proposed rule ``Control of Air Pollution from Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards'' (the proposed rule...

  2. Potential impacts of electric vehicles on air quality in Taiwan.

    PubMed

    Li, Nan; Chen, Jen-Ping; Tsai, I-Chun; He, Qingyang; Chi, Szu-Yu; Lin, Yi-Chiu; Fu, Tzung-May

    2016-10-01

    The prospective impacts of electric vehicle (EV) penetration on the air quality in Taiwan were evaluated using an air quality model with the assumption of an ambitious replacement of current light-duty vehicles under different power generation scenarios. With full EV penetration (i.e., the replacement of all light-duty vehicles), CO, VOCs, NOx and PM2.5 emissions in Taiwan from a fleet of 20.6 million vehicles would be reduced by 1500, 165, 33.9 and 7.2Ggyr(-1), respectively, while electric sector NOx and SO2 emissions would be increased by up to 20.3 and 12.9Ggyr(-1), respectively, if the electricity to power EVs were provided by thermal power plants. The net impacts of these emission changes would be to reduce the annual mean surface concentrations of CO, VOCs, NOx and PM2.5 by about 260, 11.3, 3.3ppb and 2.1μgm(-3), respectively, but to increase SO2 by 0.1ppb. Larger reductions tend to occur at time and place of higher ambient concentrations and during high pollution events. Greater benefits would clearly be attained if clean energy sources were fully encouraged. EV penetration would also reduce the mean peak-time surface O3 concentrations by up to 7ppb across Taiwan with the exception of the center of metropolitan Taipei where the concentration increased by <2ppb. Furthermore, full EV penetration would reduce annual days of O3 pollution episodes by ~40% and PM2.5 pollution episodes by 6-10%. Our findings offer important insights into the air quality impacts of EV and can provide useful information for potential mitigation actions. PMID:27285533

  3. Analytical evaluation of effect of equivalence ratio inlet-air temperature and combustion pressure on performance of several possible ram-jet fuels

    NASA Technical Reports Server (NTRS)

    Tower, Leonard K; Gammon, Benson E

    1953-01-01

    The results of an analytical investigation of the theoretical air specific impulse performance and adiabatic combustion temperatures of several possible ram-jet fuels over a range of equivalence ratios, inlet-air temperatures, and combustion pressures, is presented herein. The fuels include octane-1, 50-percent-magnesium slurry, boron, pentaborane, diborane, hydrogen, carbon, and aluminum. Thermal effects from high combustion temperatures were found to effect considerably the combustion performance of all the fuels. An increase in combustion pressure was beneficial to air specific impulse at high combustion temperatures. The use of these theoretical data in engine operation and in the evaluation of experimental data is described.

  4. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets. PMID:19406910

  5. Investigation at supersonic and subsonic Mach numbers of auxiliary inlets supplying secondary air flow to ejector exhaust nozzles

    NASA Technical Reports Server (NTRS)

    Hearth, Donald P; Cubbison, Robert W

    1956-01-01

    The results indicated increases in auxiliary-inlet pressure recovery with increases in scoop height relative to the boundary-layer thickness. The pressure recovery increased at about the same rate as theoretically predicted for an inlet in a boundary layer having a one-seventh power profile, but was only about 0.68 to 0.75 of the theoretically obtainable values. Under some operating conditions, flow from the primary jet was exhausted through the auxiliary inlet. This phenomenon could be predicted from the ejector pumping characteristics.

  6. Conceptual design of flapping-wing micro air vehicles.

    PubMed

    Whitney, J P; Wood, R J

    2012-09-01

    Traditional micro air vehicles (MAVs) are miniature versions of full-scale aircraft from which their design principles closely follow. The first step in aircraft design is the development of a conceptual design, where basic specifications and vehicle size are established. Conceptual design methods do not rely on specific knowledge of the propulsion system, vehicle layout and subsystems; these details are addressed later in the design process. Non-traditional MAV designs based on birds or insects are less common and without well-established conceptual design methods. This paper presents a conceptual design process for hovering flapping-wing vehicles. An energy-based accounting of propulsion and aerodynamics is combined with a one degree-of-freedom dynamic flapping model. Important results include simple analytical expressions for flight endurance and range, predictions for maximum feasible wing size and body mass, and critical design space restrictions resulting from finite wing inertia. A new figure-of-merit for wing structural-inertial efficiency is proposed and used to quantify the performance of real and artificial insect wings. The impact of these results on future flapping-wing MAV designs is discussed in detail. PMID:22498507

  7. Projection Moire Interferometry Measurements of Micro Air Vehicle Wings

    NASA Technical Reports Server (NTRS)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-01-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat s wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  8. Projection moire interferometry measurements of micro air vehicle wings

    NASA Astrophysics Data System (ADS)

    Fleming, Gary A.; Bartram, Scott M.; Waszak, Martin R.; Jenkins, Luther N.

    2001-11-01

    Projection Moire Interferometry (PMI) has been used to measure the structural deformation of micro air vehicle (MAV) wings during a series of wind tunnel tests. The MAV wings had a highly flexible wing structure, generically reminiscent of a bat's wing, which resulted in significant changes in wing shape as a function of MAV angle-of-attack and simulated flight speed. This flow-adaptable wing deformation is thought to provide enhanced vehicle stability and wind gust alleviation compared to rigid wing designs. Investigation of the potential aerodynamic benefits of a flexible MAV wing required measurement of the wing shape under aerodynamic loads. PMI was used to quantify the aerodynamically induced changes in wing shape for three MAV wings having different structural designs and stiffness characteristics. This paper describes the PMI technique, its application to MAV testing, and presents a portion of the PMI data acquired for the three different MAV wings tested.

  9. EPA evaluation of the 'Pass Master Vehicle Air Conditioner Cut-Off' Device. Technical report

    SciTech Connect

    Penninga, T.J.

    1980-08-01

    The conclusions of the EPA evaluation of the 'Pass Master Vehicle Air Conditioner Compressor Cut-Off Device' under the provisions of Section 511 of the Motor Vehicle Information and Cost Savings Act are announced. The Pass Master device disengages the air conditioning compressor during hard vehicle acceleration modes. The reduced engine loading will result in some fuel savings.

  10. The effect of different inlet conditions of air in a rectangular channel on convection heat transfer: Turbulence flow

    SciTech Connect

    Kurtbas, Irfan

    2008-10-15

    Theoretical and empirical correlations for duct flow are given for hydrodynamically and thermally developed flow in most of previous studies. However, this is commonly not a realistic inlet configuration for heat exchanger, in which coolant flow generally turns through a serpentine shaped passage before entering heat sinks. Accordingly, an experimental investigation was carried out to determine average heat transfer coefficients in uniformly heated rectangular channel with 45 and 90 turned flow, and with wall mounted a baffle. The channel was heated through bottom side with the baffle. In present work, a detailed study was conducted for three different height of entry channel (named as the ratio of the height of entry channel to the height of test section (anti H{sub c}=h{sub c}/H)) by varying Reynolds number (Re{sub Dh}). Another variable parameter was the ratio of the baffle height to the channel height (anti H{sub b}=h{sub b}/H). Only one baffle was attached on the bottom (heating) surface. The experimental procedure was validated by comparing the data for the straight channel with no baffle. Reynolds number (Re{sub Dh}) was varied from 2800 to 30,000, so the flow was considered as only turbulent regime. All experiments were conduced with air accordingly; Prandtl number (Pr) was approximately fixed at 0.71. The results showed that average Nusselt number for {theta}=45 and {theta}=90 were 9% and 30% higher, respectively, than that of the straight channel without baffle. Likewise, the pressure drop increased up to 4.4 to 5.3 times compare to the straight channel. (author)

  11. Creating new cities through the large air-cushion vehicle.

    NASA Technical Reports Server (NTRS)

    Anderson, J. L.; Finnegan, P. M.

    1972-01-01

    The air-cushion vehicle (ACV) can travel over concrete roads, grass, sand, mud, swamp, snow, ice, and water. This mobility makes possible a totally new geographical freedom in choosing transportation routes, locating ports, and laying out a city. By the 1980s fleets of large ACV freighters could begin carrying ocean-going cargo. The mobility of an ACV fleet would allow placing hoverports away from areas now crowded. New cities could rise along shallow or reef-bound seacoasts and rivers, just as cities once rose around deep-water seaports.

  12. Thirty years of research and development of air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Bertelsen, William R.

    This paper describes the conception of the air cushion vehicle (ACV) from experiments with the ground effect of a VTOL aircraft model. Then it describes the evolution of the ultimate ACV drive system through building and testing many models and 16 full-scale ACV to arrive at complete controllability. Adequate control of the frictionless craft, which are without inherent yaw stability, requires control force of the order of magnitude of propulsion. The derived gimbal fans provide such control force in the form of direct thrust, which is instantly available in any of 360 degrees, meterable, instantly cancelable, and reversible.

  13. Research of autonomous landing control of unmanned combat air vehicle

    NASA Astrophysics Data System (ADS)

    Li, Shaoyan; Chen, Zongji

    2003-09-01

    This paper is to present a robust controller design method for developing autonomous landing systems of Unmanned Combat Air Vehicle (UCAV). We first analyze the characteristic of autonomous landing of UCAV, and put forward its landing performance specifications. Structure singular value μ| synthesis is used to develop autonomous landing systems to accurately follow the pre-designed ideal landing track or online generated optimal landing track. The robust performance of system is analyzed. The simulation results demonstrate that the designed autonomous landing system satisfies the performance requirements of autonomous landing of UCAV when there are uncertainties of UCAV aircraft model, measurement noises and exogenous disturbances.

  14. CARS Temperature and Species Measurements For Air Vehicle Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Gord, James R.; Grisch, Frederic; Klimenko, Dmitry; Clauss, Walter

    2005-01-01

    The coherent anti-Stokes Raman spectroscopy (CARS) method has recently been used in the United States and Europe to probe several different types of propulsion systems for air vehicles. At NASA Langley Research Center in the United States, CARS has been used to simultaneously measure temperature and the mole fractions of N2, O2 and H2 in a supersonic combustor, representative of a scramjet engine. At Wright- Patterson Air Force Base in the United States, CARS has been used to simultaneously measure temperature and mole fractions of N2, O2 and CO2, in the exhaust stream of a liquid-fueled, gas-turbine combustor. At ONERA in France and the DLR in Germany researchers have used CARS to measure temperature and species concentrations in cryogenic LOX-H2 rocket combustion chambers. The primary aim of these measurements has been to provide detailed flowfield information for computational fluid dynamics (CFD) code validation.

  15. Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

    SciTech Connect

    Thomas, John F; Huff, Shean P; West, Brian H; Norman, Kevin M

    2012-01-01

    Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Four of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.

  16. Updraft Model for Development of Autonomous Soaring Uninhabited Air Vehicles

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2006-01-01

    Large birds and glider pilots commonly use updrafts caused by convection in the lower atmosphere to extend flight duration, increase cross-country speed, improve range, or simply to conserve energy. Uninhabited air vehicles may also have the ability to exploit updrafts to improve performance. An updraft model was developed at NASA Dryden Flight Research Center (Edwards, California) to investigate the use of convective lift for uninhabited air vehicles in desert regions. Balloon and surface measurements obtained at the National Oceanic and Atmospheric Administration Surface Radiation station (Desert Rock, Nevada) enabled the model development. The data were used to create a statistical representation of the convective velocity scale, w*, and the convective mixing-layer thickness, zi. These parameters were then used to determine updraft size, vertical velocity profile, spacing, and maximum height. This paper gives a complete description of the updraft model and its derivation. Computer code for running the model is also given in conjunction with a check case for model verification.

  17. GPS Auto-Navigation Design for Unmanned Air Vehicles

    NASA Technical Reports Server (NTRS)

    Nilsson, Caroline C. A.; Heinzen, Stearns N.; Hall, Charles E., Jr.; Chokani, Ndaona

    2003-01-01

    A GPS auto-navigation system is designed for Unmanned Air Vehicles. The objective is to enable the air vehicle to be used as a test-bed for novel flow control concepts. The navigation system uses pre-programmed GPS waypoints. The actual GPS position, heading, and velocity are collected by the flight computer, a PC104 system running in Real-Time Linux, and compared with the desired waypoint. The navigator then determines the necessity of a heading correction and outputs the correction in the form of a commanded bank angle, for a level coordinated turn, to the controller system. This controller system consists of 5 controller! (pitch rate PID, yaw damper, bank angle PID, velocity hold, and altitude hold) designed for a closed loop non-linear aircraft model with linear aerodynamic coefficients. The ability and accuracy of using GPS data, is validated by a GPS flight. The autopilots are also validated in flight. The autopilot unit flight validations show that the designed autopilots function as designed. The aircraft model, generated on Matlab SIMULINK is also enhanced by the flight data to accurately represent the actual aircraft.

  18. Low Earth Orbit Raider (LER) winged air launch vehicle concept

    NASA Technical Reports Server (NTRS)

    Feaux, Karl; Jordan, William; Killough, Graham; Miller, Robert; Plunk, Vonn

    1989-01-01

    The need to launch small payloads into low earth orbit has increased dramatically during the past several years. The Low Earth orbit Raider (LER) is an answer to this need. The LER is an air-launched, winged vehicle designed to carry a 1500 pound payload into a 250 nautical mile orbit. The LER is launched from the back of a 747-100B at 35,000 feet and a Mach number of 0.8. Three staged solid propellant motors offer safe ground and flight handling, reliable operation, and decreased fabrication cost. The wing provides lift for 747 separation and during the first stage burn. Also, aerodynamic controls are provided to simplify first stage maneuvers. The air-launch concept offers many advantages to the consumer compared to conventional methods. Launching at 35,000 feet lowers atmospheric drag and other loads on the vehicle considerably. Since the 747 is a mobile launch pad, flexibility in orbit selection and launch time is unparalleled. Even polar orbits are accessible with a decreased payload. Most importantly, the LER launch service can come to the customer, satellites and experiments need not be transported to ground based launch facilities. The LER is designed to offer increased consumer freedom at a lower cost over existing launch systems. Simplistic design emphasizing reliability at low cost allows for the light payloads of the LER.

  19. Experimental Evaluation of the Effect of Angle-of-attack on the External Aerodynamics and Mass Capture of a Symmetric Three-engine Air-breathing Launch Vehicle Configuration at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Kim, Hyun D.; Frate, Franco C.

    2001-01-01

    A subscale aerodynamic model of the GTX air-breathing launch vehicle was tested at NASA Glenn Research Center's 10- by 10-Foot Supersonic Wind Tunnel from Mach 2.0 to 3.5 at various angles-of-attack. The objective of the test was to investigate the effect of angle-of-attack on inlet mass capture, inlet diverter effectiveness, and the flowfield at the cowl lip plane. The flow-through inlets were tested with and without boundary-layer diverters. Quantitative measurements such as inlet mass flow rates and pitot-pressure distributions in the cowl lip plane are presented. At a 3deg angle-of-attack, the flow rates for the top and side inlets were within 8 percent of the zero angle-of-attack value, and little distortion was evident at the cowl lip plane. Surface oil flow patterns showing the shock/boundary-layer interaction caused by the inlet spikes are shown. In addition to inlet data, vehicle forebody static pressure distributions, boundary-layer profiles, and temperature-sensitive paint images to evaluate the boundary-layer transition are presented. Three-dimensional parabolized Navier-Stokes computational fluid dynamics calculations of the forebody flowfield are presented and show good agreement with the experimental static pressure distributions and boundary-layer profiles. With the boundary-layer diverters installed, no adverse aerodynamic phenomena were found that would prevent the inlets from operating at the required angles-of-attack. We recommend that phase 2 of the test program be initiated, where inlet contraction ratio and diverter geometry variations will be tested.

  20. Experimental Investigation of Actuators for Flow Control in Inlet Ducts

    NASA Astrophysics Data System (ADS)

    Vaccaro, John; Elimelech, Yossef; Amitay, Michael

    2010-11-01

    Attractive to aircraft designers are compact inlets, which implement curved flow paths to the compressor face. These curved flow paths could be employed for multiple reasons. One of which is to connect the air intake to the engine embedded in the aircraft body. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic purpose of inlets is to decelerate the oncoming flow before reaching the engine while minimizing total pressure loss, unsteadiness and distortion. Low length-to-diameter ratio inlets have a high degree of curvature, which inevitably causes flow separation and secondary flows. Currently, the length of the propulsion system is constraining the overall size of Unmanned Air Vehicles (UAVs), thus, smaller more efficient aircrafts could be realized if the propulsion system could be shortened. Therefore, active flow control is studied in a compact (L/D=1.5) inlet to improve performance metrics. Actuation from a spanwise varying coanda type ejector actuator and a hybrid coanda type ejector / vortex generator jet actuator is investigated. Special attention will be given to the pressure recovery at the AIP along with unsteady pressure signatures along the inlet surface and at the AIP.

  1. Effect of Water Spray Evaporative Cooling at the Inlet of Regeneration Air Stream on the Performance of an Adsorption Desiccant Cooling Process

    NASA Astrophysics Data System (ADS)

    Ando, Kosuke; Kodama, Akio; Hirose, Tsutomu; Goto, Motonobu; Okano, Hiroshi

    This paper shows an influence of evaporative cooler at the inlet of regeneration air stream of an adsorptive desiccant cooling process on the cooling/dehumidifying performance. This evaporative cooling was expected to cause humidity increase in regeneration air reducing the dehumidifying performance of the honeycomb absorber, while the evaporative cooling plays an important role to produce a lower temperature in supply air. Two different airs to be used for the regeneration of the desiccant wheel were considered. One was fresh outside air (OA mode) and the other was air ventilated from the room (RA mode). Experimental results showed that the amount of dehumidified water obtained at the process without water spray evaporative cooler was actually larger than that of process with water spray evaporative cooler. This behavior was mainly due to increase of humidity or relative humidity in the regeneration air as expected. However, temperature of supply air produced by the process with the evaporator was rather lower than that of the other because of the cooled return air, resulting higher CE value. Regarding the operating mode, the evaporative cooler at the OA-mode was no longer useful at higher ambient humidity because of the difficulty of the evaporation of the water in such high humidity. It was also found that its dehumidifying performance was remarkably decreased at higher ambient humidity and lower regeneration temperature since the effective adsorption capacity at the resulting high relative humidity of the regeneration air decreased.

  2. Attic inlet technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rising fuel costs have driven development of alternative heat sources for poultry growers. Attic inlets are employed to pre-heat incoming ventilation air to reduce fuel usage. Attic temperatures are at least 10 °F warmer than the outside temperature at least 80% of the time and offers a source of...

  3. Flexible Wing Base Micro Aerial Vehicles: Micro Air Vehicles (MAVs) for Surveillance and Remote Sensor Delivery

    NASA Technical Reports Server (NTRS)

    Ifju, Peter

    2002-01-01

    Micro Air Vehicles (MAVs) will be developed for tracking individuals, locating terrorist threats, and delivering remote sensors, for surveillance and chemical/biological agent detection. The tasks are: (1) Develop robust MAV platform capable of carrying sensor payload. (2) Develop fully autonomous capabilities for delivery of sensors to remote and distant locations. The current capabilities and accomplishments are: (1) Operational electric (inaudible) 6-inch MAVs with novel flexible wing, providing superior aerodynamic efficiency and control. (2) Vision-based flight stability and control (from on-board cameras).

  4. Investigation of the impact of imposed air inlet velocity oscillations on the formation and oxidation of soot using simultaneous 2-Colour-TIRE-LII

    NASA Astrophysics Data System (ADS)

    Aleksandrov, A.; Suntz, R.; Bockhorn, H.

    2015-05-01

    The response of non-premixed swirling flames to acoustic perturbations at various frequencies (0-350 Hz) and the impact of imposed air inlet velocity oscillations on the formation and oxidation of soot are investigated. The results obtained from these flames are of special interest for "rich-quenched-lean" (RQL) combustion concepts applied in modern gas turbines. In RQL combustion, the fuel is initially oxidized by air under fuel-rich conditions in a first stage followed by a fuel-lean combustion step in a second stage. To mimic soot formation and oxidation in RQL combustion, soot particle measurements in highly turbulent, non-premixed swirling natural gas/ethylene-confined flames at imposed air inlet velocity oscillations are performed using simultaneous 2-Colour-Time-Resolved-Laser-Induced Incandescence (simultaneous 2-Colour-TIRE-LII). The latter technique is combined with line-of-sight averaged OH*-chemiluminescence imaging, measurements of the velocity field by high-speed particle imaging velocimetry under reactive combustion conditions and measurements of the mean temperature field obtained by a thermocouple. A natural gas/ethylene mixture (Φ = 1.56, 42 % C2H4, 58 % natural gas, P th = 17.6 kW at atmospheric pressure) is used as a fuel, which is oxidized by air under fuel-rich conditions in the first combustion chamber.

  5. Vehicle expectations in air transportation for the year 2000

    NASA Technical Reports Server (NTRS)

    Hearth, D. P.

    1980-01-01

    This paper is intended to provide an overview of the air transportation system for the year 2000 in terms of vehicle expectations. Emphasis is placed on civil air transportation with the time period approached from the standpoint of evolutionary changes for the near term and also with the assumption of more revolutionary changes for the far term. The view along the evolutionary path begins with a historical review of airline market growth and the impact that technologies have had on airplane designs. Projections of the life expectancy of existing, derivative, and new airplanes are examined in terms of their productivity and fuel efficiency in view of the present and projected fuel usage and availability. The factors influencing airline growth are outlined and some views on whether another new generation of subsonic airplanes are in the offing are given along with an assessment of the economic viability of an advanced commercial supersonic transport in terms of its higher speed, higher productivity, and higher fuel usage. With regard to revolutionary changes, major technology breakthroughs are assumed to occur at a specified date. As an example, the impact of a dramatic reduction in skin friction drag is examined in terms of its effect on the airplane configuration, its propulsion systems, it projected fuel usage, and the air transportation system in which it must operate.

  6. Zinc air battery development for electric vehicles. Final report

    SciTech Connect

    Putt, R.A.; Merry, G.W.

    1991-07-01

    This report summarizes the results of research conducted during the sixteen month continuation of a program to develop rechargeable zinc-air batteries for electric vehicles. The zinc-air technology under development incorporates a metal foam substrate for the zinc electrode, with flow of electrolyte through the foam during battery operation. In this ``soluble`` zinc electrode the zincate discharge product dissolves completely in the electrolyte stream. Cycle testing at Lawrence Berkeley Laboratory, where the electrode was invented, and at MATSI showed that this approach avoids the zinc electrode shape change phenomenon. Further, electrolyte flow has been shown to be necessary to achieve significant cycle life (> 25 cycles) in this open system. Without it, water loss through the oxygen electrode results in high-resistance failure of the cell. The Phase I program, which focused entirely on the zinc electrode, elucidated the conditions necessary to increase electrode capacity from 75 to as much as 300 mAh/cm{sup 2}. By the end of the Phase I program over 500 cycles had accrued on one of the zinc-zinc half cells undergoing continuous cycle testing. The Phase II program continued the half cell cycle testing and separator development, further refined the foam preplate process, and launched into performance and cycle life testing of zinc-air cells.

  7. A novel zinc-air battery for electric vehicles

    SciTech Connect

    Ross, P.N.

    1995-07-01

    A new type of zinc electrode is matched with new bifunctional air electrodes to produce a zinc-air battery of a novel design. The zinc electrode is a flow-thru type made from copper foam-metal. The air electrode uses corrosion resistant carbon black as a high area support for a highly dispersed spinel oxide electrocatalyst. The battery design employs flowing electrolyte, 12 M KOH saturated or supersaturated with zincate. Single cells as large as 200 cm{sup 2} (1/5 EV design scale) having a capacity of 20 AH have been tested with C/4--C/16 constant current cycling. More extensive and realistic life cycle testing was done with 2 Ah cells, including the Simplified Federal Urban Driving Schedule (SFUDS) cycle. This testing has confirmed that these cells can provide the necessary transient power response required for urban EV applications. The cells achieved an average of 72 SFUDS repetitions (7.2 hrs) per discharge cycle, more than twice the number with a sealed lead acid EV battery in similar testing. The full scale (30 kWh) EV battery design based on these single cell tests indicate an energy density of 90--100 Wh/kg, 60--80 W/kg, and a very low materials cost ($50 per kWh). These results indicate this battery would provide at least twice the vehicle range of a lead acid battery of the same volume at a comparable or even lower materials cost.

  8. Flexible Wing Base Micro Aerial Vehicles: Composite Materials for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ifju, Peter G.; Ettinger, Scott; Jenkins, David; Martinez, Luis

    2002-01-01

    This paper will discuss the development of the University of Florida's Micro Air Vehicle concept. A series of flexible wing based aircraft that possess highly desirable flight characteristics were developed. Since computational methods to accurately model flight at the low Reynolds numbers associated with this scale are still under development, our effort has relied heavily on trial and error. Hence a time efficient method was developed to rapidly produce prototype designs. The airframe and wings are fabricated using a unique process that incorporates carbon fiber composite construction. Prototypes can be fabricated in around five man-hours, allowing many design revisions to be tested in a short period of time. The resulting aircraft are far more durable, yet lighter, than their conventional counterparts. This process allows for thorough testing of each design in order to determine what changes were required on the next prototype. The use of carbon fiber allows for wing flexibility without sacrificing durability. The construction methods developed for this project were the enabling technology that allowed us to implement our designs. The resulting aircraft were the winning entries in the International Micro Air Vehicle Competition for the past two years. Details of the construction method are provided in this paper along with a background on our flexible wing concept.

  9. Computer-aided conceptual design of Air Cushion Vehicles

    NASA Astrophysics Data System (ADS)

    Band, E. G. U.; Lavis, D. R.

    This paper describes the development and use of a computer-aided design tool which has been used to explore preferred options for amphibious Air-Cushion Vehicle (ACV) and Surface-Effect Ship (SES) designs in support of U.S. Navy and U.S. Army programs. The tool, referred to as the ACV Design Synthesis Model (ADSM), is an interactive computer program which provides a description of feasible ACV or SES concepts that could be developed, by a competent design team, to perform the mission described by the input parameters. The paper discusses how the program was used to explore parametrically the design of a range of self-propelled hoverbarges to meet requirements of the U.S. Army Logistics Over the Shore (LOTS) phases of an amphibious landing. Examples of results are presented to illustrate the method used in determining design and performance trade-offs.

  10. Flow Analysis over Batten Reinforced Wings for Micro Air Vehicles

    NASA Astrophysics Data System (ADS)

    Townsend, Kurtis; Hicks, Travis; Hubner, James P.

    2008-11-01

    Flexible membrane wings modify the flow separation of low Reynolds number micro air vehicles (MAVs). A specific type of fixed-wing geometry is a batten-reinforced configuration in which the membrane is attached to a rigid frame with chordwise battens, allowing the vibration of the membrane at the trailing-edge. In this study, smoke-wire visualization and hot-wire anemometry, both near the trailing-edge and further downstream in the wake, are used to quantify the frequency and energy of these fluctuations for various cell geometries and flow angles-of-attack. Improvement in the wake momentum deficit will be analyzed to determine preferred membrane cell geometries for MAV flight conditions.

  11. Air pollution and health risks due to vehicle traffic.

    PubMed

    Zhang, Kai; Batterman, Stuart

    2013-04-15

    Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, "U" shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2-NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must

  12. Integration of an Autopilot for a Micro Air Vehicle

    NASA Technical Reports Server (NTRS)

    Platanitis, George; Shkarayev, Sergey

    2005-01-01

    Two autopilots providing autonomous flight capabilities are presented herein. The first is the Pico-Pilot, demonstrated for the 12-inch size class of micro air vehicles. The second is the MicroPilot MP2028(sup g), where its integration into a 36-inch Zagi airframe (tailless, elevons only configuration) is investigated and is the main focus of the report. Analytical methods, which include the use of the Advanced Aircraft Analysis software from DARCorp, were used to determine the stability and control derivatives, which were then validated through wind tunnel experiments. From the aerodynamic data, the linear, perturbed equations of motion from steady-state flight conditions may be cast in terms of these derivatives. Using these linear equations, transfer functions for the control and navigation systems were developed and feedback control laws based on Proportional, Integral, and Derivative (PID) control design were developed to control the aircraft. The PID gains may then be programmed into the autopilot software and uploaded to the microprocessor of the autopilot. The Pico-Pilot system was flight tested and shown to be successful in navigating a 12-inch MAV through a course defined by a number of waypoints with a high degree of accuracy, and in 20 mph winds. The system, though, showed problems with control authority in the roll and pitch motion of the aircraft: causing oscillations in these directions, but the aircraft maintained its heading while following the prescribed course. Flight tests were performed in remote control mode to evaluate handling, adjust trim, and test data logging for the Zagi with integrated MP2028(sup g). Ground testing was performed to test GPS acquisition, data logging, and control response in autonomous mode. Technical difficulties and integration limitations with the autopilot prevented fully autonomous flight from taking place, but the integration methodologies developed for this autopilot are, in general, applicable for unmanned air

  13. H-CANYON AIR EXHAUST TUNNEL INSPECTION VEHICLE DEVELOPMENT

    SciTech Connect

    Minichan, R.; Fogle, R.; Marzolf, A.

    2011-05-24

    The H-Canyon at Savannah River Site is a large concrete structure designed for chemical separation processes of radioactive material. The facility requires a large ventilation system to maintain negative pressure in process areas for radioactive contamination control and personnel protection. The ventilation exhaust is directed through a concrete tunnel under the facility which is approximately five feet wide and 8 feet tall that leads to a sand filter and stack. Acidic vapors in the exhaust have had a degrading effect on the surface of the concrete tunnels. Some areas have been inspected; however, the condition of other areas is unknown. Experience from historical inspections with remote controlled vehicles will be discussed along with the current challenge of inspecting levels below available access points. The area of interest in the exhaust tunnel must be accessed through a 14 X 14 inch concrete plug in the floor of the hot gang valve corridor. The purpose for the inspection is to determine the condition of the inside of the air tunnel and establish if there are any structural concerns. Various landmarks, pipe hangers and exposed rebar are used as reference points for the structural engineers when evaluating the current integrity of the air tunnel.

  14. Impact of Solar Control PVB Glass on Vehicle Interior Temperatures, Air-Conditioning Capacity, Fuel Consumption, and Vehicle Range

    SciTech Connect

    Rugh, J.; Chaney, L.; Venson, T.; Ramroth, L.; Rose, M.

    2013-04-01

    The objective of the study was to assess the impact of Saflex1 S-series Solar Control PVB (polyvinyl butyral) configurations on conventional vehicle fuel economy and electric vehicle (EV) range. The approach included outdoor vehicle thermal soak testing, RadTherm cool-down analysis, and vehicle simulations. Thermal soak tests were conducted at the National Renewable Energy Laboratory's Vehicle Testing and Integration Facility in Golden, Colorado. The test results quantified interior temperature reductions and were used to generate initial conditions for the RadTherm cool-down analysis. The RadTherm model determined the potential reduction in air-conditioning (A/C) capacity, which was used to calculate the A/C load for the vehicle simulations. The vehicle simulation tool identified the potential reduction in fuel consumption or improvement in EV range between a baseline and modified configurations for the city and highway drive cycles. The thermal analysis determined a potential 4.0% reduction in A/C power for the Saflex Solar PVB solar control configuration. The reduction in A/C power improved the vehicle range of EVs and fuel economy of conventional vehicles and plug-in hybrid electric vehicles.

  15. Air-Sea Interaction Measurements from the Controlled Towed Vehicle

    NASA Astrophysics Data System (ADS)

    Khelif, D.; Bluth, R. T.; Jonsson, H.; Barge, J.

    2014-12-01

    The Controlled Towed Vehicle (CTV) uses improved towed drone technology to actively maintain via a radar altimeter and controllable wing a user-set height that can be as low as the canonical reference height of 10 m above the sea surface. After take-off, the drone is released from the tow aircraft on a ~700-m stainless steel cable. We have instrumented the 0.23 m diameter and 2.13 m long drone with high fidelity instruments to measure the means and turbulent fluctuations of 3-D wind vector, temperature, humidity, pressure, CO2 and IR sea surface temperature. Data are recorded internally at 40 Hz and simultaneously transmitted to the tow aircraft via dedicated wireless Ethernet link. The CTV accommodates 40 kg of instrument payload and provides it with 250 W of continuous power through a ram air propeller-driven generator. Therefore its endurance is only limited by that of the tow aircraft.We will discuss the CTV development, the engineering challenges and solutions that have been successfully implemented to overcome them. We present results from recent flights as low as 9 m over the coastal ocean and comparisons of profiles and turbulent fluxes from the CTV and the tow aircraft. Manned aircraft operation at low-level boundary-layer flights is very limited. Dropsondes and UAS (Unmanned Aerial Systems) and UAS are alternates for measurements near the ocean surface. However, dropsondes have limited sensor capability and do not measure fluxes, and most present UAS vehicles do not have the payload and power capacity nor the low-flying ability in high winds over the oceans. The CTV therefore, fills a needed gap between the dropsondes, in situ aircraft, and UAS. The payload, capacity and power of the CTV makes it suitable for a variety of atmospheric research measurements. Other sensors to measure aerosol, chemistry, radiation, etc., could be readily accommodated in the CTV.

  16. Inlet Performance Analysis Code Developed

    NASA Technical Reports Server (NTRS)

    Jules, Kenol; Barnhart, Paul J.

    1998-01-01

    The design characteristics of an inlet very much depend on whether the inlet is to be flown at subsonic, supersonic, or hypersonic speed. Whichever the case, the primary function of an inlet is to deliver free-stream air to the engine face at the highest stagnation pressure possible and with the lowest possible variation in both stagnation pressure and temperature. At high speeds, this is achieved by a system of oblique and/or normal shock waves, and possibly some isentropic compression. For both subsonic and supersonic flight, current design practice indicates that the inlet should deliver the air to the engine face at approximately Mach 0.45. As a result, even for flight in the high subsonic regime, the inlet must retard (or diffuse) the air substantially. Second, the design of an inlet is influenced largely by the compromise between high performance and low weight. This compromise involves tradeoffs between the mission requirements, flight trajectory, airframe aerodynamics, engine performance, and weight-all of which, in turn, influence each other. Therefore, to study the effects of some of these influential factors, the Propulsion System Analysis Office of the NASA Lewis Research Center developed the Inlet Performance Analysis Code (IPAC). This code uses oblique shock and Prandtl-Meyer expansion theory to predict inlet performance. It can be used to predict performance for a given inlet geometric design such as pitot, axisymmetric, and two-dimensional. IPAC also can be used to design preliminary inlet systems and to make subsequent performance analyses. It computes the total pressure, the recovery, the airflow, and the drag coefficients. The pressure recovery includes losses associated with normal and oblique shocks, internal and external friction, the sharp lip, and diffuser components. Flow rate includes captured, engine, spillage, bleed, and bypass flows. The aerodynamic drag calculation includes drags associated with spillage, cowl lip suction, wave, bleed

  17. Partial camera automation in an unmanned air vehicle.

    PubMed

    Korteling, J E; van der Borg, W

    1997-03-01

    The present study focused on an intelligent, semiautonomous, interface for a camera operator of a simulated unmanned air vehicle (UAV). This interface used system "knowledge" concerning UAV motion in order to assist a camera operator in tracking an object moving through the landscape below. The semiautomated system compensated for the translations of the UAV relative to the earth. This compensation was accompanied by the appropriate joystick movements ensuring tactile (haptic) feedback of these system interventions. The operator had to superimpose self-initiated joystick manipulations over these system-initiated joystick motions in order to track the motion of a target (a driving truck) relative to the terrain. Tracking data showed that subjects performed substantially better with the active system. Apparently, the subjects had no difficulty in maintaining control, i.e., "following" the active stick while superimposing self-initiated control movements over the system-interventions. Furthermore, tracking performance with an active interface was clearly superior relative to the passive system. The magnitude of this effect was equal to the effect of update-frequency (2-5 Hz) of the monitor image. The benefits of update frequency enhancement and semiautomated tracking were the greatest under difficult steering conditions. Mental workload scores indicated that, for the difficult tracking-dynamics condition, both semiautomation and update frequency increase resulted in less experienced mental effort. For the easier dynamics this effect was only seen for update frequency. PMID:11541093

  18. Aerial networking communication solutions using Micro Air Vehicle (MAV)

    NASA Astrophysics Data System (ADS)

    Balasubramanian, Shyam; de Graaf, Maurits; Hoekstra, Gerard; Corporaal, Henk; Wijtvliet, Mark; Cuadros Linde, Javier

    2014-10-01

    The application of a Micro Air Vehicle (MAV) for wireless networking is slowly gaining significance in the field of network robotics. Aerial transport of data requires efficient network protocols along with accurate positional adjustment of the MAV to minimize transaction times. In our proof of concept, we develop an Aerial networking protocol for data transfer using the technology of Disruption Tolerant Networks (DTN), a store-and-forward approach for environments that deals with disrupted connectivity. Our results show that close interaction between networking and flight behavior helps in efficient data exchange. Potential applications are in areas where network infrastructure is minimal or unavailable and distances may be large. For example, forwarding video recordings during search and rescue, agriculture, swarm communication, among several others. A practical implementation and validation, as described in this paper, presents the complex dynamics of wireless environments and poses new challenges that are not addressed in earlier work on this topic. Several tests are evaluated in a practical setup to display the networking MAV behavior during such an operation.

  19. Correlation of Forced-convection Heat-transfer Data for Air Flowing in Smooth Platinum Tube with Long-approach Entrance at High Surface and Inlet-air Temperatures

    NASA Technical Reports Server (NTRS)

    Desmon, Leland G; Sams, Eldon W

    1950-01-01

    A heat-transfer investigation was conducted with air in an electrically heated platinum tube with long-approach entrance, inside diameter of 0.525 inch, and effective heat-transfer length of 24 inches over ranges of Reynolds number up to 320,000, average inside-tube-wall temperature up to 3053 degrees R, and inlet-air temperature up to 1165 degrees R. Correlation of data by the conventional Nusselt relation resulted in separation of data with tube-wall temperature. Good correlation was obtained, however, by use of a modified Reynolds number.

  20. Transportation vehicle energy intensities. A joint DOT/NASA reference paper. [energy consumption of air and ground vehicles

    NASA Technical Reports Server (NTRS)

    Mascy, A. C.; Paullin, R. L.

    1974-01-01

    A compilation of data on the energy consumption of air and ground vehicles is presented. The ratio BTU/ASM, British Thermal Units/Available Seat Mile, is used to express vehicle energy intensiveness, and related to the energy consumed directly in producing seat-mile or ton-mile productivity. Data is presented on passenger and freight vehicles which are in current use or which are about to enter service, and advanced vehicles which may be operational in the 1980's and beyond. For the advanced vehicles, an estimate is given of the date of initial operational service, and the performance characteristics. Other key considerations in interpreting energy intensiveness for a given mode are discussed, such as: load factors, operations, overhead energy consumption, and energy investments in new structure and equipment.

  1. 40 CFR 90.407 - Engine inlet and exhaust systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine...

  2. 40 CFR 90.407 - Engine inlet and exhaust systems.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine...

  3. 40 CFR 90.407 - Engine inlet and exhaust systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine...

  4. 40 CFR 90.407 - Engine inlet and exhaust systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... exhaust emission compliance over the full range of air inlet filter systems and exhaust muffler systems. (b) The air inlet filter system and exhaust muffler system combination used on the test engine...

  5. Preliminary performance estimates of an oblique, all-wing, remotely piloted vehicle for air-to-air combat

    NASA Technical Reports Server (NTRS)

    Nelms, W. P., Jr.; Bailey, R. O.

    1974-01-01

    A computerized aircraft synthesis program has been used to assess the effects of various vehicle and mission parameters on the performance of an oblique, all-wing, remotely piloted vehicle (RPV) for the highly maneuverable, air-to-air combat role. The study mission consists of an outbound cruise, an acceleration phase, a series of subsonic and supersonic turns, and a return cruise. The results are presented in terms of both the required vehicle weight to accomplish this mission and the combat effectiveness as measured by turning and acceleration capability. This report describes the synthesis program, the mission, the vehicle, and results from sensitivity studies. An optimization process has been used to establish the nominal RPV configuration of the oblique, all-wing concept for the specified mission. In comparison to a previously studied conventional wing-body canard design for the same mission, this oblique, all-wing nominal vehicle is lighter in weight and has higher performance.

  6. A Computational and Experimental Study of Coflow Laminar Methane/Air Diffusion Flames: Effects of Fuel Dilution, Inlet Velocity, and Gravity

    NASA Technical Reports Server (NTRS)

    Cao, S.; Ma, B.; Bennett, B. A. V.; Giassi, D.; Stocker, D. P.; Takahashi, F.; Long, M. B.; Smooke, M. D.

    2014-01-01

    The influences of fuel dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH4-air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity (mu g) and normal gravity (1g) conditions with CH4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity-velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1g counterparts; the effect of fuel dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the fuel mass flow rate, and the effects from fuel dilution and inlet velocity are secondary.

  7. Development of Micro Air Vehicle Technology With In-Flight Adaptive-Wing Structure

    NASA Technical Reports Server (NTRS)

    Waszak, Martin R. (Technical Monitor); Shkarayev, Sergey; Null, William; Wagner, Matthew

    2004-01-01

    This is a final report on the research studies, "Development of Micro Air Vehicle Technology with In-Flight Adaptrive-Wing Structure". This project involved the development of variable-camber technology to achieve efficient design of micro air vehicles. Specifically, it focused on the following topics: 1) Low Reynolds number wind tunnel testing of cambered-plate wings. 2) Theoretical performance analysis of micro air vehicles. 3) Design of a variable-camber MAV actuated by micro servos. 4) Test flights of a variable-camber MAV.

  8. Liquefied Bleed for Stability and Efficiency of High Speed Inlets

    NASA Technical Reports Server (NTRS)

    Saunders, J. David; Davis, David; Barsi, Stephen J.; Deans, Matthew C.; Weir, Lois J.; Sanders, Bobby W.

    2014-01-01

    A mission analysis code was developed to perform a trade study on the effectiveness of liquefying bleed for the inlet of the first stage of a TSTO vehicle. By liquefying bleed, the vehicle weight (TOGW) could be reduced by 7 to 23%. Numerous simplifying assumptions were made and lessons were learned. Increased accuracy in future analyses can be achieved by: Including a higher fidelity model to capture the effect of rescaling (variable vehicle TOGW). Refining specific thrust and impulse models ( T m a and Isp) to preserve fuel-to-air ratio. Implementing LH2 for T m a and Isp. Correlating baseline design to other mission analyses and correcting vehicle design elements. Implementing angle-of-attack effects on inlet characteristics. Refining aerodynamic performance (to improve L/D ratio at higher Mach numbers). Examining the benefit with partial cooling or densification of the bleed air stream. Incorporating higher fidelity weight estimates for the liquefied bleed system (heat exchange and liquid storage versus bleed duct weights) could be added when more fully developed. Adding trim drag or 6-degree-of-freedom trajectory analysis for higher fidelity. Investigating vehicle optimization for each of the bleed configurations.

  9. Hover and wind-tunnel testing of shrouded rotors for improved micro air vehicle design

    NASA Astrophysics Data System (ADS)

    Pereira, Jason L.

    The shrouded-rotor configuration has emerged as the most popular choice for rotary-wing Micro Air Vehicles (MAVs), because of the inherent safety of the design and the potential for significant performance improvements. However, traditional design philosophies based on experience with large-scale ducted propellers may not apply to the low-Reynolds-number (˜20,000) regime in which MAVs operate. An experimental investigation of the effects of varying the shroud profile shape on the performance of MAV-scale shrouded rotors has therefore been conducted. Hover tests were performed on seventeen models with a nominal rotor diameter of 16 cm (6.3 in) and various values of diffuser expansion angle, diffuser length, inlet lip radius and blade tip clearance, at various rotor collective angles. Compared to the baseline open rotor, the shrouded rotors showed increases in thrust by up to 94%, at the same power consumption, or reductions in power by up to 62% at the same thrust. These improvements surpass those predicted by momentum theory, due to the additional effect of the shrouds in reducing the non-ideal power losses of the rotor. Increasing the lip radius and decreasing the blade tip clearance caused performance to improve, while optimal values of diffuser angle and length were found to be 10 and 50% of the shroud throat diameter, respectively. With the exception of the lip radius, the effects of changing any of the shrouded-rotor parameters on performance became more pronounced as the values of the other parameters were changed to degrade performance. Measurements were also made of the wake velocity profiles and the shroud surface pressure distributions. The uniformity of the wake was improved by the presence of the shrouds and by decreasing the blade tip clearance, resulting in lower induced power losses. For high net shroud thrust, a favorable pressure distribution over the inlet was seen to be more important than in the diffuser. Strong suction pressures were observed

  10. Unmanned air vehicle (UAV) ultra-persitence research

    SciTech Connect

    Dron, S. B.

    2012-03-01

    Sandia National Laboratories and Northrop Grumman Corporation Integrated Systems, Unmanned Systems (NGIS UMS) collaborated to further ultra-persistence technologies for unmanned air vehicles (UAVs). The greatest shortfalls in UAV capabilities have been repeatedly identified as (1) insufficient flight persistence or 'hang time,' (2) marginal electrical power for running higher power avionics and payload systems, and (3) inadequate communications bandwidth and reach. NGIS UMS requested support from Sandia to develop an ultra-persistent propulsion and power system (UP3S) for potential incorporation into next generation UAV systems. The team members tried to determine which energy storage and power generation concepts could most effectively push UAV propulsion and electrical power capabilities to increase UAV sortie duration from days to months while increasing available electrical power at least two-fold. Primary research and development areas that were pursued included these goals: perform general system engineering and integration analyses; develop initial thermal and electrical power estimates; provide mass, volume, dimensional, and balance estimates; conduct preliminary safety assessments; assess logistics support requirements; perform, preliminary assessments of any security and safeguards; evaluate options for removal, replacement, and disposition of materials; generally advance the potential of the UP3S concept. The effort contrasted and compared eight heat sources technologies, three power conversion, two dual cycle propulsion system configurations, and a single electrical power generation scheme. Overall performance, specific power parameters, technical complexities, security, safety, and other operational features were successfully investigated. Large and medium sized UAV systems were envisioned and operational flight profiles were developed for each concept. Heat source creation and support challenges for domestic and expeditionary operations were

  11. Target location by self-organizing autonomous air vehicles

    NASA Astrophysics Data System (ADS)

    Brown, Kim; Bowyer, Richard S.; Koks, Don

    2002-08-01

    Target location is a problem where the application of multiple sensors that are geographically distributed can determine or improve the location estimate of a target. If these sensors are capable of cooperative behaviour then the information from each sensor can be autonomously fused to provide an estimate of the target position. The individual sensors may be quite unsophisticated, yet the observation system that is created through cooperation and adaptive networking of these sensors provides sufficient process gain to achieve target location accuracies similar to those of expensive centralized sensor systems. The accuracy of target location estimates depends heavily on the separation distance between the sensors. Large baseline geometry takes advantage of many seemingly unsophisticated bearing measurements that are organised into a coordinated observation system to locate a target. Team formation is one method to address coordination of distributed sensors, data fusion, sensor resource and energy management, and communication link control based on the concept of cooperating machines1,2,3. We apply an algorithm for agent team formation4 inspired by the self-organising behaviour observed in colonies of ants, to the problem of integrating the sensors of a group of networked mini-Autonomous Air Vehicles (AAVs). The mini-AAVs are tasked to locate targets within a region of interest. The challenge we address is to make the location estimation system adaptive to a dynamic environment and robust to failure. Simulation results are presented which address issues in distributed data fusion, sensor resource and energy management, and communication link control, for a group of mini-AAVs.

  12. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Satellite Communications Terminal, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  13. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Electric Substation, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  14. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Civil Engineering Storage Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  15. Venus Atmospheric Maneuverable Platform (VAMP) — Air Vehicle Concept and Entry CONOPs

    NASA Astrophysics Data System (ADS)

    Sokol, D.; Lee, G.; Polidan, R.; Bolisay, L.; Barnes, N.

    2014-06-01

    This presentation discusses the continued development of the Northrop Grumman/L’GARDE team’s long-lived, maneuverable platform to explore the Venus upper atmosphere. It focuses on the air vehicle design and entry CONOPs and their interdependencies.

  16. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Techinical Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  17. Beale Air Force Base, Perimeter Acquisition Vehicle Entry PhasedArray Warning ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Beale Air Force Base, Perimeter Acquisition Vehicle Entry Phased-Array Warning System, Microwave Equipment Building, End of Spencer Paul Road, north of Warren Shingle Road (14th Street), Marysville, Yuba County, CA

  18. Fugitive particulate air emissions from off-road vehicle maneuvers at military training lands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Military training lands used for off-road vehicle maneuvers may be subject to severe soil loss and air quality degradation as a result of severe wind erosion. The objective of this study was to measure suspended particulate matter resulting from various different vehicle training scenarios. Soil s...

  19. Assessing the Link between Environmental Concerns and Consumers' Decisions to Use Clean-Air Vehicles

    ERIC Educational Resources Information Center

    Plax, Timothy G.; Kearney, Patricia; Ross, Ted J.; Jolly, J. Christopher

    2008-01-01

    A consulting contract with the California Air Resources Board led to a project examining how California drivers' and fleet managers' perceptions, attitudes, and consumer behavior regarding Clean Vehicle Technologies influenced their own energy choices when it came to purchasing vehicles. The consultants examined archival research, conducted focus…

  20. [Impact of heavy-duty diesel vehicles on air quality and control of their emissions].

    PubMed

    Zhou, Lei; Wang, Bo-Guang; Tang, Da-Gang

    2011-08-01

    Through an analysis of the characteristics of diesel vehicle emissions and motor vehicle emissions inventories, this paper examines the impact of heavy-duty diesel vehicles on air quality in China as well as issues related to the control of their emissions. Heavy-duty diesel vehicles emit large amounts of nitrogen oxides and particulate matter. Nitrogen oxides is one of the important precursors for the formation of secondary particles and ozone in the atmosphere, causing regional haze. Diesel particulate matter is a major toxic air pollutant with adverse effect on human health, and in particular, the ultrafine particles in 30-100 nm size range can pose great health risks because of its extremely small sizes. Motor vehicles have become a major source of air pollution in many metropolitan areas and city cluster in China, and among them the heavy-duty diesel vehicles are a dominant contributor of nitrogen oxides and particulate matter emissions. Hence, controlling heavy-duty diesel vehicle emissions should be a key component of an effective air quality management plan, and a number of issues related to heavy-duty diesel vehicle emissions need to be addressed. PMID:22619934

  1. CFD Analysis to Study Effect of Circular Vortex Generator Placed in Inlet Section to Investigate Heat Transfer Aspects of Solar Air Heater

    PubMed Central

    Gawande, Vipin B.; Dhoble, A. S.; Zodpe, D. B.

    2014-01-01

    CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate. PMID:25254251

  2. CFD analysis to study effect of circular vortex generator placed in inlet section to investigate heat transfer aspects of solar air heater.

    PubMed

    Gawande, Vipin B; Dhoble, A S; Zodpe, D B

    2014-01-01

    CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤ P/e ≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate. PMID:25254251

  3. Two-dimensional symmetrical inlets with external compression

    NASA Technical Reports Server (NTRS)

    Ruden, P

    1950-01-01

    The purpose of inlets like, for instance, those of air-cooled radiators and scoops is to take a certain air quantity out of the free stream and to partly convert the free-stream velocity into pressure. In the extreme case this pressure conversion may occur either entirely in the interior of the inlet (inlet with internal compression) or entirely in the free stream ahead of the inlet (inlet with external compression). In this report a theory for two-dimensional inlets with external compression is developed and illustrated by numerical examples. Intermediary forms between inlets with internal and external compression which can be derived from the latter are briefly discussed.

  4. Autoignition in a premixing-prevaporizing fuel duct using 3 different fuel injection systems at inlet air temperatures to 1250 K

    NASA Technical Reports Server (NTRS)

    Tacina, R. R.

    1983-01-01

    Conditions were determined in a continuous-flow, premixing-prevaporizing duct at which autoignition occurred. Test conditions were representative of an advanced, regenerative-cycle, automotive gas turbine. The test conditions inlet air temperatures from 600 to 1250 K (a vitiated preheater was used), pressures from 170 to 600 kPa, air velocities of 10 to 30 m/sec, equivalence ratios from 0.3 to 1.0, mixing lengths from 10 to 60 cm, and residence times of 2 to 100 ms. The fuel was diesel number 2. The duct was insulated and had an inside diameter of 12 cm. Three different fuel injection systems were used: One was a single simplex pressure atomizer, and the other two were multiple-source injectors. The data obtained with the simplex and one of the multiple-source injectors agreed satisfactorily with the references and correlated with an Arrenhius expression. The data obtained with the other multiple source injector, which used multiple cones to improve the fuel-air distribution, did not correlate well with residence time.

  5. The promise of air cargo: System aspects and vehicle design

    NASA Technical Reports Server (NTRS)

    Whitehead, A. H., Jr.

    1976-01-01

    The current operation of the air cargo system is reviewed. An assessment of the future of air cargo is provided by: (1) analyzing statistics and trends, (2) by noting system problems and inefficiencies, (3) by analyzing characteristics of 'air eligible' commodities, and (4) by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. The following topics are discussed: (1) air cargo demand forecasts; (2) economics of air cargo transport; (3) the integrated air cargo system; (4) evolution of airfreighter design; and (5) the span distributed load concept.

  6. Proposed architecture for the UAV family of air vehicles

    NASA Astrophysics Data System (ADS)

    Marinelli, Louis; Bazow, Steve

    1993-12-01

    As an integral part of the Unmanned Aerial Vehicle (UAV) interoperability and commonality program, Vitro Corporation and the UAV Systems Engineering Directorate developed a UAV family architecture which lays the foundation for future UAV systems.

  7. Wind tunnel tests of a zero length, slotted-lip engine air inlet for a fixed nacelle V/STOL aircraft

    NASA Technical Reports Server (NTRS)

    Woollett, R. R.; Beck, W. E., Jr.; Glasgow, E. R.

    1982-01-01

    Zero length, slotted lip inlet performance and associated fan blade stresses were determined during model tests using a 20 inch diameter fan simulator in the NASA-LeRC 9 by 15 foot low speed wind tunnel. The model configuration variables consisted of inlet contraction ratio, slot width, circumferential extent of slot fillers, and length of a constant area section between the inlet throat and fan face. The inlet performance was dependent on slot gap width and relatively independent of inlet throat/fan face spacer length and slot flow blockage created by 90 degree slot fillers. Optimum performance was obtained at a slot gap width of 0.36 inch. The zero length, slotted lip inlet satisfied all critical low speed inlet operating requirements for fixed horizontal nacelles subsonic V/STOL aircraft.

  8. 49 CFR 179.200-16 - Gauging devices, top loading and unloading devices, venting and air inlet devices.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Gauging devices, top loading and unloading devices... DOT-111AW and 115AW) § 179.200-16 Gauging devices, top loading and unloading devices, venting and air...). In no case shall the wall thickness be less than that specified in § 179.201-1. (f) When top...

  9. Air quality impacts of motor vehicle emissions in the south coast air basin: Current versus more stringent control scenario

    NASA Astrophysics Data System (ADS)

    Collet, Susan; Kidokoro, Toru; Sonoda, Yukihiro; Lohman, Kristen; Karamchandani, Prakash; Chen, Shu-Yun; Minoura, Hiroaki

    2012-02-01

    States are working to comply with the ozone National Ambient Air Quality Standards (NAAQS). Often, regulations restricting vehicle emissions are promulgated in order to attain compliance with the NAAQS. Currently, more stringent vehicle emission regulations are being considered by government agencies. This paper compares emissions from passenger cars and light duty trucks under the current California Low Emission Vehicle (LEV II) standards to a control scenario which was anticipated in 2008 to become LEV III (referred to as "more stringent control" in this paper) and determines if the scenario would result in additional improvements to air quality in California's South Coast Air Basin. The air quality modeling was performed using the Community Multi-scale Air Quality Model (CMAQ) for years 2005, 2014 and 2020. The more stringent control sensitivity study simulated a scenario in which all new passenger cars and light duty trucks in the California South Coast Air Basin in year 2016 achieve Super Ultra-Low Emission Vehicle (SULEV) tail pipe emissions, zero evaporative emissions and more stringent aggressive driving requirements. The total on-road vehicles emissions difference when averaged across the South Coast Air Basin showed the more stringent scenario compared to LEV II to have reductions of 1% for oxides of nitrogen (NO x), 1% for as reactive organic gases (ROG) and 5% for carbon monoxide (CO) in 2030. LEV II modeled ozone levels in the western areas of the basin increased in 2014 and 2020 as compared to 2005, because these areas are VOC-sensitive and the reductions in NO x emissions in these regions are larger than the VOC reductions. In other areas of the South Coast Basin, ozone is reduced by 1.5% or less. The more stringent control scenario modeled levels of ozone have a maximum decrease from LEV II levels by 1% or less in 2014 and 1.5% or less in 2020.

  10. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... constructed and maintained in a manner to prevent the ingress of engine exhaust fumes and gases from...

  11. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... constructed and maintained in a manner to prevent the ingress of engine exhaust fumes and gases from...

  12. 9 CFR 3.114 - Primary conveyances (motor vehicle, rail, air and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ..., rail, air and marine). 3.114 Section 3.114 Animals and Animal Products ANIMAL AND PLANT HEALTH... conveyances (motor vehicle, rail, air and marine). (a) The animal cargo space of primary conveyances used in... animal cargo space must be constructed and maintained in a manner that will prevent the ingress of...

  13. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... constructed and maintained in a manner to prevent the ingress of engine exhaust fumes and gases from...

  14. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH... (motor vehicle, rail, air, and marine). (a) The animal cargo space of primary conveyances used in... constructed and maintained in a manner to prevent the ingress of engine exhaust fumes and gases from...

  15. Overview of the SAMPSON smart inlet

    NASA Astrophysics Data System (ADS)

    Dunne, James P.; Hopkins, Mark A.; Baumann, Erwin W.; Pitt, Dale M.; White, Edward V.

    1999-07-01

    The SAMPSON program will demonstrate the application of Smart Materials and Structures to large-scale aircraft and marine propulsion systems and show that smart materials can be used to significantly enhance vehicle performance, thereby enabling new missions and/or expanding current missions. Two demonstrations will be executed in relevant environments and at scales representations of actual vehicle components. The demonstrations will serve to directly address questions of scalability and technology readiness, thereby improving the opportunities and reducing the risk for transitioning the technology into applications. The aircraft application to be examined is the in-flight structural variation of a fighter engine inlet. Smart technologies will be utilized to actively deform the inlet into predetermined configurations to improve the performance of the inlet at all flight conditions. The inlet configurations to be investigated consists of capture area control, compression ramp generation, leading edge blunting, and porosity control. The operation and demonstration of this Smart Inlet is described in detail.

  16. Micro air vehicle motion tracking and aerodynamic modeling

    NASA Astrophysics Data System (ADS)

    Uhlig, Daniel V.

    Aerodynamic performance of small-scale fixed-wing flight is not well understood, and flight data are needed to gain a better understanding of the aerodynamics of micro air vehicles (MAVs) flying at Reynolds numbers between 10,000 and 30,000. Experimental studies have shown the aerodynamic effects of low Reynolds number flow on wings and airfoils, but the amount of work that has been conducted is not extensive and mostly limited to tests in wind and water tunnels. In addition to wind and water tunnel testing, flight characteristics of aircraft can be gathered through flight testing. The small size and low weight of MAVs prevent the use of conventional on-board instrumentation systems, but motion tracking systems that use off-board triangulation can capture flight trajectories (position and attitude) of MAVs with minimal onboard instrumentation. Because captured motion trajectories include minute noise that depends on the aircraft size, the trajectory results were verified in this work using repeatability tests. From the captured glide trajectories, the aerodynamic characteristics of five unpowered aircraft were determined. Test results for the five MAVs showed the forces and moments acting on the aircraft throughout the test flights. In addition, the airspeed, angle of attack, and sideslip angle were also determined from the trajectories. Results for low angles of attack (less than approximately 20 deg) showed the lift, drag, and moment coefficients during nominal gliding flight. For the lift curve, the results showed a linear curve until stall that was generally less than finite wing predictions. The drag curve was well described by a polar. The moment coefficients during the gliding flights were used to determine longitudinal and lateral stability derivatives. The neutral point, weather-vane stability and the dihedral effect showed some variation with different trim speeds (different angles of attack). In the gliding flights, the aerodynamic characteristics

  17. Design criteria for light high speed desert air cushion vehicles

    NASA Astrophysics Data System (ADS)

    Abulnaga, B. E.

    An evaluation is made of the applicability and prospective performance of ACVs in trans-Saharan cargo transport, in view of the unique characteristics of the dry sand environment. The lightweight/high-speed ACV concept envisioned is essentially ground effect aircraftlike, with conventional wheels as a low-speed backup suspension system. A propeller is used in ground effect cruise. Attention is given to the effects on vehicle stability and performance of sandy surface irregularities of the desert topography and of cross-winds from various directions relative to vehicle movement.

  18. Consequential life cycle air emissions externalities for plug-in electric vehicles in the PJM interconnection

    NASA Astrophysics Data System (ADS)

    Weis, Allison; Jaramillo, Paulina; Michalek, Jeremy

    2016-02-01

    We perform a consequential life cycle analysis of plug-in electric vehicles (PEVs), hybrid electric vehicles (HEVs), and conventional gasoline vehicles in the PJM interconnection using a detailed, normative optimization model of the PJM electricity grid that captures the change in power plant operations and related emissions due to vehicle charging. We estimate and monetize the resulting human health and environmental damages from life cycle air emissions for each vehicle technology. We model PJM using the most recent data available (2010) as well as projections of the PJM grid in 2018 and a hypothetical scenario with increased wind penetration. We assess a range of sensitivity cases to verify the robustness of our results. We find that PEVs have higher life cycle air emissions damages than gasoline HEVs in the recent grid scenario, which has a high percentage of coal generation on the margin. In particular, battery electric vehicles with large battery capacity can produce two to three times as much air emissions damage as gasoline HEVs, depending on charge timing. In our future 2018 grid scenarios that account for predicted coal plant retirements, PEVs would produce air emissions damages comparable to or slightly lower than HEVs.

  19. Proposal for a Vehicle Level Test Procedure to Measure Air Conditioning Fuel Use

    SciTech Connect

    Rugh, J. P.

    2010-04-01

    The air-conditioning (A/C) compressor load significantly impacts the fuel economy of conventional vehicles and the fuel use/range of plug-in hybrid electric vehicles (PHEV). A National Renewable Energy Laboratory (NREL) vehicle performance analysis shows the operation of the air conditioner reduces the charge depletion range of a 40-mile range PHEV from 18% to 30% in a worst case hot environment. Designing for air conditioning electrical loads impacts PHEV and electric vehicle (EV) energy storage system size and cost. While automobile manufacturers have climate control procedures to assess A/C performance, and the U.S. EPA has the SCO3 drive cycle to measure indirect A/C emissions, there is no automotive industry consensus on a vehicle level A/C fuel use test procedure. With increasing attention on A/C fuel use due to increased regulatory activities and the development of PHEVs and EVs, a test procedure is needed to accurately assess the impact of climate control loads. A vehicle thermal soak period is recommended, with solar lamps that meet the SCO3 requirements or an alternative heating method such as portable electric heaters. After soaking, the vehicle is operated over repeated drive cycles or at a constant speed until steady-state cabin air temperature is attained. With this method, the cooldown and steady-state A/C fuel use are measured. This method can be run at either different ambient temperatures to provide data for the GREEN-MAC-LCCP model temperature bins or at a single representative ambient temperature. Vehicles with automatic climate systems are allowed to control as designed, while vehicles with manual climate systems are adjusted to approximate expected climate control settings. An A/C off test is also run for all drive profiles. This procedure measures approximate real-world A/C fuel use and assess the impact of thermal load reduction strategies.

  20. Prospects for future hypersonic air-breathing vehicles

    NASA Technical Reports Server (NTRS)

    Beach, H. L., Jr.; Blankson, Isaiah M.

    1991-01-01

    An overview of the technical progress achieved in key areas of hypersonic airbreathing vehicle development is presented. The context for hypersonic applications is discussed with emphasis placed on technology issues and requirements, particularly for propulsion and technology integration. Attention is given to CFD technology which allows the consideration of configurations and extrapolations to flight conditions that cannot be simulated on the ground.

  1. Modeling and analysis of an articulated winged micro air vehicle for gust mitigation

    NASA Astrophysics Data System (ADS)

    Oduyela, Adetunji Y.

    Articulated micro air vehicles are a class of micro air vehicles comprised of a main center body attached to outer wings on both sides. As in the case of a single rigid micro air vehicle, the center body and the attached bodies in the articulated case are all responsible for the generation of aerodynamic forces and moments during flight resulting in a multibody system. While many approaches have been taken in the literature to model the system of equations resulting from such a complicated multibody system, this dissertation presents an approach based on a Newton-Euler multibody dynamics formulation where the multiple bodies are attached together with suitable joints. The number and type of joints determines the level of articulation and total degree of freedom for the entire system. Unlike most articulated air vehicle model formulations available in the literature, the final model formulation presented in this work provides joint force and moment data acting on the articulated MAV during flight. This feature allows such information to be available during the vehicle design and development stage where appropriate spring and dampers for the system are selected based on mission requirements. Experimental validation of the proposed mathematical model using experimental flight test data obtained from UAHuntsville's Autonomous Tracking and Optical Measurements laboratory allowed the comparison of the flight test results and model simulations. Analytical investigation of the gust alleviation properties of the articulated 8 degree-of-freedom micro air vehicle model was carried out using simulations with varying crosswind gust magnitudes and shows that the passive articulation in micro air vehicles increases their robustness to gusts when suitable joint parameters are selected.

  2. Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits.

    PubMed

    Michalek, Jeremy J; Chester, Mikhail; Jaramillo, Paulina; Samaras, Constantine; Shiau, Ching-Shin Norman; Lave, Lester B

    2011-10-01

    We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO(2) emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent. PMID:21949359

  3. Valuation of plug-in vehicle life-cycle air emissions and oil displacement benefits

    PubMed Central

    Michalek, Jeremy J.; Chester, Mikhail; Jaramillo, Paulina; Samaras, Constantine; Shiau, Ching-Shin Norman; Lave, Lester B.

    2011-01-01

    We assess the economic value of life-cycle air emissions and oil consumption from conventional vehicles, hybrid-electric vehicles (HEVs), plug-in hybrid-electric vehicles (PHEVs), and battery electric vehicles in the US. We find that plug-in vehicles may reduce or increase externality costs relative to grid-independent HEVs, depending largely on greenhouse gas and SO2 emissions produced during vehicle charging and battery manufacturing. However, even if future marginal damages from emissions of battery and electricity production drop dramatically, the damage reduction potential of plug-in vehicles remains small compared to ownership cost. As such, to offer a socially efficient approach to emissions and oil consumption reduction, lifetime cost of plug-in vehicles must be competitive with HEVs. Current subsidies intended to encourage sales of plug-in vehicles with large capacity battery packs exceed our externality estimates considerably, and taxes that optimally correct for externality damages would not close the gap in ownership cost. In contrast, HEVs and PHEVs with small battery packs reduce externality damages at low (or no) additional cost over their lifetime. Although large battery packs allow vehicles to travel longer distances using electricity instead of gasoline, large packs are more expensive, heavier, and more emissions intensive to produce, with lower utilization factors, greater charging infrastructure requirements, and life-cycle implications that are more sensitive to uncertain, time-sensitive, and location-specific factors. To reduce air emission and oil dependency impacts from passenger vehicles, strategies to promote adoption of HEVs and PHEVs with small battery packs offer more social benefits per dollar spent. PMID:21949359

  4. Combatting urban air pollution through Natural Gas Vehicle (NGV) analysis, testing, and demonstration

    SciTech Connect

    1995-03-01

    Deteriorating urban air quality ranks as a top concern worldwide, since air pollution adversely affects both public health and the environment. The outlook for improving air quality in the world`s megacities need not be bleak, however, The use of natural gas as a transportation fuel can measurably reduce urban pollution levels, mitigating chronic threats to health and the environment. Besides being clean burning, natural gas vehicles (NGVs) are economical to operate and maintain. The current cost of natural gas is lower than that of gasoline. Natural gas also reduces the vehicle`s engine wear and noise level, extends engine life, and decreases engine maintenance. Today, about 700,000 NGVs operate worldwide, the majority of them converted from gasoline or diesel fuel. This article discusses the economic, regulatory and technological issues of concern to the NGV industry.

  5. An Expert Fault Diagnosis System for Vehicle Air Conditioning Product Development

    NASA Astrophysics Data System (ADS)

    Tan, C. F.; Tee, B. T.; Khalil, S. N.; Chen, W.; Rauterberg, G. W. M.

    2015-09-01

    The paper describes the development of the vehicle air-conditioning fault diagnosis system in automotive industries with expert system shell. The main aim of the research is to diagnose the problem of new vehicle air-conditioning system development process and select the most suitable solution to the problems. In the vehicle air-conditioning manufacturing industry, process can be very costly where an expert and experience personnel needed in certain circumstances. The expert of in the industry will retire or resign from time to time. When the expert is absent, their experience and knowledge is difficult to retrieve or lost forever. Expert system is a convenient method to replace expert. By replacing the expert with expert system, the accuracy of the processes will be increased compared to the conventional way. Therefore, the quality of product services that are produced will be finer and better. The inputs for the fault diagnosis are based on design data and experience of the engineer.

  6. Multi-Disciplinary Design Optimization of Hypersonic Air-Breathing Vehicle

    NASA Astrophysics Data System (ADS)

    Wu, Peng; Tang, Zhili; Sheng, Jianda

    2016-06-01

    A 2D hypersonic vehicle shape with an idealized scramjet is designed at a cruise regime: Mach number (Ma) = 8.0, Angle of attack (AOA) = 0 deg and altitude (H) = 30kms. Then a multi-objective design optimization of the 2D vehicle is carried out by using a Pareto Non-dominated Sorting Genetic Algorithm II (NSGA-II). In the optimization process, the flow around the air-breathing vehicle is simulated by inviscid Euler equations using FLUENT software and the combustion in the combustor is modeled by a methodology based on the well known combination effects of area-varying pipe flow and heat transfer pipe flow. Optimization results reveal tradeoffs among total pressure recovery coefficient of forebody, lift to drag ratio of vehicle, specific impulse of scramjet engine and the maximum temperature on the surface of vehicle.

  7. Distributed pheromone-based swarming control of unmanned air and ground vehicles for RSTA

    NASA Astrophysics Data System (ADS)

    Sauter, John A.; Mathews, Robert S.; Yinger, Andrew; Robinson, Joshua S.; Moody, John; Riddle, Stephanie

    2008-04-01

    The use of unmanned vehicles in Reconnaissance, Surveillance, and Target Acquisition (RSTA) applications has received considerable attention recently. Cooperating land and air vehicles can support multiple sensor modalities providing pervasive and ubiquitous broad area sensor coverage. However coordination of multiple air and land vehicles serving different mission objectives in a dynamic and complex environment is a challenging problem. Swarm intelligence algorithms, inspired by the mechanisms used in natural systems to coordinate the activities of many entities provide a promising alternative to traditional command and control approaches. This paper describes recent advances in a fully distributed digital pheromone algorithm that has demonstrated its effectiveness in managing the complexity of swarming unmanned systems. The results of a recent demonstration at NASA's Wallops Island of multiple Aerosonde Unmanned Air Vehicles (UAVs) and Pioneer Unmanned Ground Vehicles (UGVs) cooperating in a coordinated RSTA application are discussed. The vehicles were autonomously controlled by the onboard digital pheromone responding to the needs of the automatic target recognition algorithms. UAVs and UGVs controlled by the same pheromone algorithm self-organized to perform total area surveillance, automatic target detection, sensor cueing, and automatic target recognition with no central processing or control and minimal operator input. Complete autonomy adds several safety and fault tolerance requirements which were integrated into the basic pheromone framework. The adaptive algorithms demonstrated the ability to handle some unplanned hardware failures during the demonstration without any human intervention. The paper describes lessons learned and the next steps for this promising technology.

  8. Comparisons of rocket and air-breathing vehicle concepts for earth-to-orbit transportarion

    NASA Astrophysics Data System (ADS)

    Dorrington, G. E.

    1990-07-01

    To illustrate that there is ample room for improvement in earth-to-orbit reliability, transportation cost and environmental cleanliness, some future European launch vehicle concepts are presented. Varying assumptions of technology level and operational strategy offer a wide range of system/subsystem options for consideration. Specific examples cited include: the advanced reusable single-stage VTOL all-rocket vehicles, the all-liquid hydrogen-oxygen variants of Ariane 5, and the advanced one-and-a-half-stage horizontal take-off air-breathing vehicles.

  9. Actuated Attic Inlets: A Progress Report

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Attic inlets are being widely employed by poultry growers to alleviate high fuel costs during the brooding period. Pre-heated inlet air can reduce fuel usage and estimates for fuel savings were derived from field reports. Fuel usage was estimated for both large and small bird flocks for one year’...

  10. Experimental investigation of a quad-rotor biplane micro air vehicle

    NASA Astrophysics Data System (ADS)

    Bogdanowicz, Christopher Michael

    Micro air vehicles are expected to perform demanding missions requiring efficient operation in both hover and forward flight. This thesis discusses the development of a hybrid air vehicle which seamlessly combines both flight capabilities: hover and high-speed forward flight. It is the quad-rotor biplane, which weighs 240 grams and consists of four propellers with wings arranged in a biplane configuration. The performance of the vehicle system was investigated in conditions representative of flight through a series of wind tunnel experiments. These studies provided an understanding of propeller-wing interaction effects and system trim analysis. This showed that the maximum speed of 11 m/s and a cruise speed of 4 m/s were achievable and that the cruise power is approximately one-third of the hover power. Free flight testing of the vehicle successfully highlighted its ability to achieve equilibrium transition flight. Key design parameters were experimentally investigated to understand their effect on overall performance. It was found that a trade-off between efficiency and compactness affects the final choice of the design. Design improvements have allowed for decreases in vehicle weight and ground footprint, while increasing structural soundness. Numerous vehicle designs, models, and flight tests have proven system scalability as well as versatility, including an upscaled model to be utilized in an extensive commercial package delivery system. Overall, the quad-rotor biplane is proven to be an efficient and effective multi-role vehicle.

  11. Indoor-outdoor air quality relationships in vehicle: effect of driving environment and ventilation modes

    NASA Astrophysics Data System (ADS)

    Chan, Andy T.; Chung, Michael W.

    Nitrogen oxides and carbon monoxide concentration were measured inside and outside of a light-goods-vehicle at different locations and driving conditions for a 6-month period. To investigate the exposure of the vehicle passenger to the specified outdoor pollutant, the indoor-outdoor air quality (IO) relationships under various driving conditions, namely traffic density, ventilation modes and type of roadway were studied. Four main types of driving environments were selected: highway, countryside, urban street and tunnel. The vehicle was driven under the three main types of ventilation conditions: air-conditioning with air-recirculation, air-conditioning with fresh air intake and natural ventilation. It is found that the IO ratio is not specific only to the mode of ventilation but also depends on the driving environment. The IO value can vary drastically even using the same ventilation mode when the vehicle is travelling in a different environment. It is found that using fresh-air ventilation mode, the IO can change from approximately 0.5-3 as it commutes from a highway to the countryside. The results also indicate that indoor NO level increased as the traffic density increases. The fluctuation of indoor NO level of naturally ventilated vehicle followed the variation of outdoor NO concentration with the IO value varying from 0.5 to 5. The results also show that even in an air-conditioned van, the indoor NO and CO concentration is significantly affected by that outdoor. It suggests the use of different ventilation mode when commuting in different environment.

  12. Configuration Studies of Personal Air Vehicles. Personal Air Vehicle and Flying Jeep Concepts: A Commentary on Promising Approaches or What Goes Around Comes Around (About Every Twenty Years)

    NASA Technical Reports Server (NTRS)

    Hall, David W.

    2001-01-01

    The NASA/Langley Personal Air Vehicle (PAV) Exploration (PAVE) and the DARPA (Defense Advanced Research Projects Agency) Dual Air/Road Transportation System (DARTS) projects were established to investigate the feasibility of creating vehicles which could replace, or at the very least augment, personal ground and air transportation schemes. This overall goal implies integrating several technology areas with practical everyday transportation requirements to design a class of vehicles which will achieve the following goals: (1) Vertical, Extremely Short, or Short Takeoff and Landing (VTOL, ESTOL, STOL) capability; (2) Operation at block speeds markedly faster than current combinations of land and air transportation, particularly in critical market areas; (3) Unit cost comparable to current luxury cars and small general aviation aircraft; (4) Excellent reliability; (5) Excellent safety; (6) Ability to integrate with existing land and air transportation systems. The conclusions of these configuration studies are summarized as follows: (1) Creation of the five assigned configurations prompted added explorations, some of which were dead-ends; (2) Some components could be common to all configurations such as avionics and dual-mode suspension schemes; (3) Single-Mode PAVs can be created by removing dual-mode-specific items; (4) Aviation history provided some intriguing starting points, as in what goes around comes around; (5) CTOL (Conventional Take-off and Landing) and STOL dual-mode PAVs look feasible with single-mode PAVs being simplifications of the dual-mode approach; (6) VTOL PAVs will require development; (7) More exotic collapsing mechanisms mechanisms need development; (8) As a teaching tool, PAVs are not yet a well-enough bounded design problem.

  13. Propulsion integration of hypersonic air-breathing vehicles utilizing a top-down design methodology

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, Brad Kenneth

    In recent years, a focus of aerospace engineering design has been the development of advanced design methodologies and frameworks to account for increasingly complex and integrated vehicles. Techniques such as parametric modeling, global vehicle analyses, and interdisciplinary data sharing have been employed in an attempt to improve the design process. The purpose of this study is to introduce a new approach to integrated vehicle design known as the top-down design methodology. In the top-down design methodology, the main idea is to relate design changes on the vehicle system and sub-system level to a set of over-arching performance and customer requirements. Rather than focusing on the performance of an individual system, the system is analyzed in terms of the net effect it has on the overall vehicle and other vehicle systems. This detailed level of analysis can only be accomplished through the use of high fidelity computational tools such as Computational Fluid Dynamics (CFD) or Finite Element Analysis (FEA). The utility of the top-down design methodology is investigated through its application to the conceptual and preliminary design of a long-range hypersonic air-breathing vehicle for a hypothetical next generation hypersonic vehicle (NHRV) program. System-level design is demonstrated through the development of the nozzle section of the propulsion system. From this demonstration of the methodology, conclusions are made about the benefits, drawbacks, and cost of using the methodology.

  14. Vehicle height and posture control of the electronic air suspension system using the hybrid system approach

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Chen, Long; Liu, Yanling; Wang, Shaohua

    2016-03-01

    The electronic air suspension (EAS) system can improve ride comfort, fuel economy and handling safety of vehicles by adjusting vehicle height. This paper describes the development of a novel controller using the hybrid system approach to adjust the vehicle height (height control) and to regulate the roll and pitch angles of the vehicle body during the height adjustment process (posture control). The vehicle height adjustment system of EAS poses challenging hybrid control problems, since it features different discrete modes of operation, where each mode has an associated linear continuous-time dynamic. In this paper, we propose a novel approach to the modelling and controller design problem for the vehicle height adjustment system of EAS. The system model is described firstly in the hybrid system description language (HYSDEL) to obtain a mixed logical dynamical (MLD) hybrid model. For the resulting model, a hybrid model predictive controller is tuned to improve the vehicle height and posture tracking accuracy and to achieve the on-off statuses direct control of solenoid valves. The effectiveness and performance of the proposed approach are demonstrated by simulations and actual vehicle tests.

  15. Improving the aluminum-air battery system for use in electrical vehicles

    NASA Astrophysics Data System (ADS)

    Yang, Shaohua

    The objectives of this study include improvement of the efficiency of the aluminum/air battery system and demonstration of its ability for vehicle applications. The aluminum/air battery system can generate enough energy and power for driving ranges and acceleration similar to that of gasoline powered cars. Therefore has the potential to be a power source for electrical vehicles. Aluminum/air battery vehicle life cycle analysis was conducted and compared to that of lead/acid and nickel-metal hydride vehicles. Only the aluminum/air vehicles can be projected to have a travel range comparable to that of internal combustion engine vehicles (ICE). From this analysis, an aluminum/air vehicle is a promising candidate compared to ICE vehicles in terms of travel range, purchase price, fuel cost, and life cycle cost. We have chosen two grades of Al alloys (Al alloy 1350, 99.5% and Al alloy 1199, 99.99%) in our study. Only Al 1199 was studied extensively using Na 2SnO3 as an electrolyte additive. We then varied concentration and temperature, and determined the effects on the parasitic (corrosion) current density and open circuit potential. We also determined cell performance and selectivity curves. To optimize the performance of the cell based on our experiments, the recommended operating conditions are: 3--4 N NaOH, about 55°C, and a current density of 150--300 mA/cm2. We have modeled the cell performance using the equations we developed. The model prediction of cell performance shows good agreement with experimental data. For better cell performance, our model studies suggest use of higher electrolyte flow rate, smaller cell gap, higher conductivity and lower parasitic current density. We have analyzed the secondary current density distributions in a two plane, parallel Al/air cell and a wedge-type Al/air cell. The activity of the cathode has a large effect on the local current density. With increases in the cell gap, the local current density increases, but the increase is

  16. Axisymmetric inlet minimum weight design method

    NASA Technical Reports Server (NTRS)

    Nadell, Shari-Beth

    1995-01-01

    An analytical method for determining the minimum weight design of an axisymmetric supersonic inlet has been developed. The goal of this method development project was to improve the ability to predict the weight of high-speed inlets in conceptual and preliminary design. The initial model was developed using information that was available from inlet conceptual design tools (e.g., the inlet internal and external geometries and pressure distributions). Stiffened shell construction was assumed. Mass properties were computed by analyzing a parametric cubic curve representation of the inlet geometry. Design loads and stresses were developed at analysis stations along the length of the inlet. The equivalent minimum structural thicknesses for both shell and frame structures required to support the maximum loads produced by various load conditions were then determined. Preliminary results indicated that inlet hammershock pressures produced the critical design load condition for a significant portion of the inlet. By improving the accuracy of inlet weight predictions, the method will improve the fidelity of propulsion and vehicle design studies and increase the accuracy of weight versus cost studies.

  17. Autonomous Soaring for Improved Endurance of a Small Uninhabited Air Vehicle

    NASA Technical Reports Server (NTRS)

    Allen, Michael J.

    2005-01-01

    A relatively unexplored method to improve the endurance of an autonomous aircraft is to use buoyant plumes of air found in the lower atmosphere called thermals or updrafts. Glider pilots and birds commonly use updrafts to improve range, endurance, or cross-country speed. This report presents a quantitative analysis of a small electric-powered uninhabited air vehicle using updrafts to extend its endurance over a target location. A three-degree-of-freedom simulation of the uninhabited air vehicle was used to determine the yearly effect of updrafts on performance. Surface radiation and rawinsonde balloon measurements taken at Desert Rock, Nevada, were used to determine updraft size, strength, spacing, shape, and maximum height for the simulation. A fixed-width spiral path was used to search for updrafts at the same time as maintaining line-of-sight to the surface target position. Power was used only when the aircraft was flying at the lower-altitude limit in search of updrafts. Results show that an uninhabited air vehicle with a nominal endurance of 2 hours can fly a maximum of 14 hours using updrafts during the summer and a maximum of 8 hours during the winter. The performance benefit and the chance of finding updrafts both depend on what time of day the uninhabited air vehicle is launched. Good endurance and probability of finding updrafts during the year was obtained when the uninhabited air vehicle was launched 30 percent into the daylight hours after sunrise each day. Yearly average endurance was found to be 8.6 hours with these launch times.

  18. Design and analysis of aluminum/air battery system for electric vehicles

    NASA Astrophysics Data System (ADS)

    Yang, Shaohua; Knickle, Harold

    Aluminum (Al)/air batteries have the potential to be used to produce power to operate cars and other vehicles. These batteries might be important on a long-term interim basis as the world passes through the transition from gasoline cars to hydrogen fuel cell cars. The Al/air battery system can generate enough energy and power for driving ranges and acceleration similar to gasoline powered cars. From our design analysis, it can be seen that the cost of aluminum as an anode can be as low as US 1.1/kg as long as the reaction product is recycled. The total fuel efficiency during the cycle process in Al/air electric vehicles (EVs) can be 15% (present stage) or 20% (projected) comparable to that of internal combustion engine vehicles (ICEs) (13%). The design battery energy density is 1300 Wh/kg (present) or 2000 Wh/kg (projected). The cost of battery system chosen to evaluate is US 30/kW (present) or US$ 29/kW (projected). Al/air EVs life-cycle analysis was conducted and compared to lead/acid and nickel metal hydride (NiMH) EVs. Only the Al/air EVs can be projected to have a travel range comparable to ICEs. From this analysis, Al/air EVs are the most promising candidates compared to ICEs in terms of travel range, purchase price, fuel cost, and life-cycle cost.

  19. Development of Micro Air Reconnaissance Vehicle as a Test Bed for Advanced Sensors and Electronics

    NASA Technical Reports Server (NTRS)

    Shams, Qamar A.; Vranas, Thomas L.; Fox, Robert L.; Kuhn, Theodore R.; Ingham, John; Logan, Michael J.; Barnes, Kevin N.; Guenther, Benjamin F.

    2002-01-01

    This paper describes the development of a Micro/Mini Air Reconnaissance Vehicle for advanced sensors and electronics at NASA Langley Research Center over the last year. This vehicle is expected to have a total weight of less than four pounds, a design velocity of 40 mph, an endurance of 15-20 minutes, and a maximum range of 5km. The vehicle has wings that are simple to detach yet retain the correct alignment. The upper fuselage surface has a quick release hatch used to access the interior and also to mount the varying propulsion systems. The sensor suite developed for this vehicle consists of a Pitot-static measurement system for determining air speed, an absolute pressure measurement for determining altitude, magnetic direction measurement, and three orthogonal gyros to determine body angular rates. Swarming GPS-guidance and in-flight maneuvering is discussed, as well as design and installation of some other advance sensors like MEMS microphones, infrared cameras, GPS, humidity sensors, and an ultrasonic sonar sensor. Also low cost, small size, high performance control and navigation system for the Micro Air Vehicle is discussed. At the end, laboratory characterization of different sensors, motors, propellers, and batteries will be discussed.

  20. Internal Performance of Several Auxiliary Air Inlets Immersed in a Turbulent Boundary Layer at Mach Numbers of 1.3, 1.5, and 2.0

    NASA Technical Reports Server (NTRS)

    Huff, Ronald G; Anderson, Arthur R

    1957-01-01

    Internal performance of normal-shock rectangular, circular, and scoop inlets and of external-compression inlets experimentally obtained with varying immersion in a turbulent boundary layer. Recoveries varied from about 95 percent of theoretical in the free stream to 80 percent with complete immersion, while the corresponding mass flows were usually above 95 percent of theoretical. Turning of the flow through 10 degrees caused losses in pressure recovery of 0.03 to 0.07. External compression did not improve pressure recovery in the boundary layer. Average distortion at critical operation for all inlets was 5 percent.

  1. Design of an air sampler for a small unmanned aerial vehicle.

    PubMed

    Peräjärvi, K; Lehtinen, J; Pöllänen, R; Toivonen, H

    2008-01-01

    In the aftermath of a nuclear accident or malevolent act, it is of paramount importance to have the capability to monitor airborne radioactive substances by collecting air samples. For potentially dangerous missions, the Radiation and Nuclear Safety Authority of Finland (STUK) has developed an air sampler to be used on a small unmanned aerial vehicle. When a Petrianov or Fluoropore filter is used in the sampler and the air velocity is 71 km h(-1), the air flow rate through the filter is 0.73 m(3) h(-1) or 0.23 m(3) h(-1), respectively. The present article introduces the developed air sampler using fluid dynamic simulations and wind tunnel data. The operation of the system was validated by collecting airborne radioactive aerosols from air. PMID:19091809

  2. CFD based aerodynamic modeling to study flight dynamics of a flapping wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Rege, Alok Ashok

    The demand for small unmanned air vehicles, commonly termed micro air vehicles or MAV's, is rapidly increasing. Driven by applications ranging from civil search-and-rescue missions to military surveillance missions, there is a rising level of interest and investment in better vehicle designs, and miniaturized components are enabling many rapid advances. The need to better understand fundamental aspects of flight for small vehicles has spawned a surge in high quality research in the area of micro air vehicles. These aircraft have a set of constraints which are, in many ways, considerably different from that of traditional aircraft and are often best addressed by a multidisciplinary approach. Fast-response non-linear controls, nano-structures, integrated propulsion and lift mechanisms, highly flexible structures, and low Reynolds aerodynamics are just a few of the important considerations which may be combined in the execution of MAV research. The main objective of this thesis is to derive a consistent nonlinear dynamic model to study the flight dynamics of micro air vehicles with a reasonably accurate representation of aerodynamic forces and moments. The research is divided into two sections. In the first section, derivation of the nonlinear dynamics of flapping wing micro air vehicles is presented. The flapping wing micro air vehicle (MAV) used in this research is modeled as a system of three rigid bodies: a body and two wings. The design is based on an insect called Drosophila Melanogaster, commonly known as fruit-fly. The mass and inertial effects of the wing on the body are neglected for the present work. The nonlinear dynamics is simulated with the aerodynamic data published in the open literature. The flapping frequency is used as the control input. Simulations are run for different cases of wing positions and the chosen parameters are studied for boundedness. Results show a qualitative inconsistency in boundedness for some cases, and demand a better

  3. An Analysis of Skill Requirements for Operators of Amphibious Air Cushion Vehicles (ACVs).

    ERIC Educational Resources Information Center

    McKnight, A. James; And Others

    This report describes the skills required in the operation of an amphibious air cushion vehicle (ACV) in Army tactical and logistic missions. The research involved analyzing ACV characteristics, operating requirements, environmental effects, and results of a simulation experiment. The analysis indicates that ACV operation is complicated by an…

  4. 9 CFR 3.37 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.37 Section 3.37 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation of...

  5. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.62 Section 3.62 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment and Transportation of...

  6. 9 CFR 3.138 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Primary conveyances (motor vehicle, rail, air, and marine). 3.138 Section 3.138 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE STANDARDS Specifications for the Humane Handling, Care, Treatment, and Transportation...

  7. CRITERIA AND AIR TOXIC EMISSIONS FROM IN-USE, LOW EMISSION VEHICLES (LEVS)

    EPA Science Inventory

    The U.S. Environmental Protection Agency implemented a program to identify tailpipe emissions of criteria and air toxic contaminants from in-use, light-duty Low Emission Vehicles (LEVs). EPA recruited twenty-five LEVs in 2002, and measured emissions on a chassis dynamometer usin...

  8. Rehabilitation of the Rocket Vehicle Integration Test Stand at Edwards Air Force Base

    NASA Technical Reports Server (NTRS)

    Jones, Daniel S.; Ray, Ronald J.; Phillips, Paul

    2005-01-01

    Since initial use in 1958 for the X-15 rocket-powered research airplane, the Rocket Engine Test Facility has proven essential for testing and servicing rocket-powered vehicles at Edwards Air Force Base. For almost two decades, several successful flight-test programs utilized the capability of this facility. The Department of Defense has recently demonstrated a renewed interest in propulsion technology development with the establishment of the National Aerospace Initiative. More recently, the National Aeronautics and Space Administration is undergoing a transformation to realign the organization, focusing on the Vision for Space Exploration. These initiatives provide a clear indication that a very capable ground-test stand at Edwards Air Force Base will be beneficial to support the testing of future access-to-space vehicles. To meet the demand of full integration testing of rocket-powered vehicles, the NASA Dryden Flight Research Center, the Air Force Flight Test Center, and the Air Force Research Laboratory have combined their resources in an effort to restore and upgrade the original X-15 Rocket Engine Test Facility to become the new Rocket Vehicle Integration Test Stand. This report describes the history of the X-15 Rocket Engine Test Facility, discusses the current status of the facility, and summarizes recent efforts to rehabilitate the facility to support potential access-to-space flight-test programs. A summary of the capabilities of the facility is presented and other important issues are discussed.

  9. Challenges for micro-scale flapping-wing micro air vehicles

    NASA Astrophysics Data System (ADS)

    Wood, Robert J.; Finio, Benjamin; Karpelson, Michael; Pérez-Arancibia, Nestor O.; Sreetharan, Pratheev; Whitney, John P.

    2012-06-01

    The challenges for successful flight of insect-scale micro air vehicles encompass basic questions of fabrication, design, propulsion, actuation, control, and power - topics that have in general been answered for larger aircraft. When developing a flying robot on the scale of flies and bees, all hardware must be developed from scratch as there are no "off-the-shelf" sensors, actuators, or microcontrollers that can satisfy the extreme mass and power limitations imposed by such vehicles. Similar challenges exist for fabrication and assembly of the structural and aeromechanical components of insect-scale micro air vehicles that neither macro-scale techniques nor MEMS can adequately solve. With these challenges in mind, this paper presents progress in the essential technologies for micro-scale flapping-wing robots.

  10. Feasibility report: Operation of light air cushion vehicle at McMurdo Sound, Antarctica

    NASA Astrophysics Data System (ADS)

    Dibbern, J. S.

    1987-02-01

    This report explores the viability of the use of an air cushion vehicle (ACV) or hovercraft to perform logistic and scientific support in the area of McMurdo Station, Antarctica. After a review of personnel assets and facilities at McMurdo Station to support the ACV plus a reconnaissance of the five major routes selected, it appears that an air cushion vehicle in the 1 to 1 1/2 ton payload class would be of significant value to support operations. It would reduce transit times for surface vehicle traverses on the routes selected and reduce requirements for expenditure of helicopter flight time in others. Of major significance is the ability to handle passenger/shuttle requirements between the Scott Base transition and Williams Field Skiway. Use of the ACV for high frequency passenger operations would help preserve the snow road for cargo operations during periods of road deterioration.

  11. Ancillary benefits for climate change mitigation and air pollution control in the world's motor vehicle fleets.

    PubMed

    Walsh, Michael P

    2008-01-01

    The global motor vehicle population has grown very rapidly in the past half century and is expected to continue to grow rapidly for the next several decades, especially in developing countries. As a result, vehicles are a major source of urban air pollution in many cities and are the fastest-growing source of greenhouse emissions. Strategies exist to reduce both problems, but many countries emphasize one over the other rather than pursuing strategies that reduce both concerns. Using diesel as an example, this article illustrates that it is now possible not only to reduce carbon dioxide with the increased use of diesel vehicles but also to improve urban air pollution. Doing so requires both stringent emissions regulations and clean fuels. Several principles contained in the Bellagio Memorandum are highlighted as guides for policy makers. PMID:18173380

  12. Space Shuttle Solid Rocket Booster decelerator subsystem - Air drop test vehicle/B-52 design

    NASA Technical Reports Server (NTRS)

    Runkle, R. E.; Drobnik, R. F.

    1979-01-01

    The air drop development test program for the Space Shuttle Solid Rocket Booster Recovery System required the design of a large drop test vehicle that would meet all the stringent requirements placed on it by structural loads, safety considerations, flight recovery system interfaces, and sequence. The drop test vehicle had to have the capability to test the drogue and the three main parachutes both separately and in the total flight deployment sequence and still be low-cost to fit in a low-budget development program. The design to test large ribbon parachutes to loads of 300,000 pounds required the detailed investigation and integration of several parameters such as carrier aircraft mechanical interface, drop test vehicle ground transportability, impact point ground penetration, salvageability, drop test vehicle intelligence, flight design hardware interfaces, and packaging fidelity.

  13. Zinc/air fuel cell for electric vehicles

    SciTech Connect

    Cherepy, N. J.; Krueger, R.; Cooper, J. F.

    1999-01-01

    We are conducting tests of an advanced zinc/air fuel cell design to determine effectiveness in various commercial applications. Our 322-cm2 cell uses gravity-fed zinc pellets as the anode, 12 M KOH electrolyte, and an air cathode catalyzed by a cobalt-porphyrin complex on carbon black. A single 322 cm2 cell runs at a standard operating power of 38 W (1200 W/m2) at 39 A (1245 A/m2) and 0.96 V with a power density of 2400 W/m2 at 0.67 V. With improved current collection hardware, already demonstrated in the laboratory, power generation increases to -3600 W/m2 at 1V. We conducted a 50-hour test in which a cell generated 587 Ah and 569 Wh. The power that may be generated increases by a factor of 2.5 between T = 28 °C and 52 °C. Electrolyte capacity, without stabilization additives, was measured at 147 Ah/L

  14. Geometry Modeling and Adaptive Control of Air-Breathing Hypersonic Vehicles

    NASA Astrophysics Data System (ADS)

    Vick, Tyler Joseph

    Air-breathing hypersonic vehicles have the potential to provide global reach and affordable access to space. Recent technological advancements have made scramjet-powered flight achievable, as evidenced by the successes of the X-43A and X-51A flight test programs over the last decade. Air-breathing hypersonic vehicles present unique modeling and control challenges in large part due to the fact that scramjet propulsion systems are highly integrated into the airframe, resulting in strongly coupled and often unstable dynamics. Additionally, the extreme flight conditions and inability to test fully integrated vehicle systems larger than X-51 before flight leads to inherent uncertainty in hypersonic flight. This thesis presents a means to design vehicle geometries, simulate vehicle dynamics, and develop and analyze control systems for hypersonic vehicles. First, a software tool for generating three-dimensional watertight vehicle surface meshes from simple design parameters is developed. These surface meshes are compatible with existing vehicle analysis tools, with which databases of aerodynamic and propulsive forces and moments can be constructed. A six-degree-of-freedom nonlinear dynamics simulation model which incorporates this data is presented. Inner-loop longitudinal and lateral control systems are designed and analyzed utilizing the simulation model. The first is an output feedback proportional-integral linear controller designed using linear quadratic regulator techniques. The second is a model reference adaptive controller (MRAC) which augments this baseline linear controller with an adaptive element. The performance and robustness of each controller are analyzed through simulated time responses to angle-of-attack and bank angle commands, while various uncertainties are introduced. The MRAC architecture enables the controller to adapt in a nonlinear fashion to deviations from the desired response, allowing for improved tracking performance, stability, and

  15. Investigation of Unsteady Flow Interaction Between an Ultra-Compact Inlet and a Transonic Fan

    NASA Technical Reports Server (NTRS)

    Hah, Chunill; Rabe, Douglas; Scribben, Angie

    2015-01-01

    In the present study, unsteady flow interaction between an ultra-compact inlet and a transonic fan stage is investigated. Future combat aircraft require ultra-compact inlet ducts as part of an integrated, advanced propulsion system to improve air vehicle capability and effectiveness to meet future mission needs. The main purpose of the study is to advance the current understanding of the flow interaction between two different ultra-compact inlets and a transonic fan for future design applications. Both URANS and LES approaches are used to calculate the unsteady flow field and are compared with the available measured data. The present study indicates that stall inception is mildly affected by the distortion pattern generated by the inlet with the current test set-up. The numerical study indicates that the inlet distortion pattern decays significantly before it reaches the fan face for the current configuration. Numerical results with a shorter distance between the inlet and fan show that counter-rotating vortices near the rotor tip due to the serpentine diffuser affects fan characteristics significantly.

  16. Design analysis of an aluminum-air battery for vehicle operations. Transportation systems research

    SciTech Connect

    Behrin, E.; Wood, R.L.; Salisbury, J.D.; Whisler, D.J.; Hudson, C.L.

    1983-03-18

    The objective of the study reported was to perform a detailed configuration analysis of an aluminum-air battery, evaluate various automobile propulsion systems utilizing the Al-air battery, and estimate the performance and cost of vehicles incorporating these propulsion systems. A preliminary engineering design is performed. A physical model and a cell-performance model of a conceptual mass-produced Al-air battery were constructed and work together to characterize the battery system. The physical battery model is based on a specific battery design concept and defines the mass and volume of a complete Al-air battery system. The cell-performance model simulates the electrical and electrochemical characteristics of the battery. The physical model and two versions of the cell-performance model - near-term and optimistic - were used in a vehicle-conversion analysis to evaluate three automotive propulsion systems - Al-air battery only, Al-air battery/secondary battery, and Al-air battery/flywheel. (LEW)

  17. Tests of Hypersonic Inlet Oscillatory Flows in a Shock Tunnel

    NASA Astrophysics Data System (ADS)

    Li, Zhufei; Gao, Wenzhi; Jiang, Hongliang; Yang, Jiming

    For efficient operation, hypersonic air breathing engine requires the inlet to operate in a starting mode [1]. High backpressure induced by the combustion may cause the inlet to unstart in the engine actual operation [2].When unstarted, shock wave oscillations are typically observed in the inlet, a phenomenon known as buzz.

  18. Concentrations of air toxics in motor vehicle-dominated environments.

    PubMed

    Fujita, Eric M; Campbell, David E; Zielinska, Barbara; Arnott, William P; Chow, Judith C

    2011-02-01

    We at the Desert Research Institute (DRI*) measured volatile organic compounds (VOCs), including several mobile-source air toxics (MSATs), particulate matter with a mass mean aerodynamic diameter < or = 2.5 pm (PM2.5), black carbon (BC), nitrogen oxides (NOx), particulate matter (PM), and carbon monoxide (CO) on highways in Los Angeles County during summer and fall 2004, to characterize the diurnal and seasonal variations in measured concentrations related to volume and mix of traffic. Concentrations of on-road pollutants were then compared to corresponding measurements at fixed monitoring sites. The on-road concentrations of CO and MSATs were higher in the morning under stable atmospheric conditions and during periods of higher traffic volumes. In contrast, BC concentrations, measured as particulate light absorption, were higher on truck routes during the midday sampling periods despite more unstable atmospheric conditions. Compared to the measurements at the three near-road sites, the 1-hour averages of on-road BC concentrations were as much as an order of magnitude higher. The peak 1-minute average concentrations were two orders of magnitude higher for BC and were between two and six times higher for PM2.5 mass. The on-road concentrations of benzene, toluene, ethylbenzene, and xylenes (BTEX) during the summer were 3.5 +/- 0.7 and 1.2 +/- 0.6 times higher during morning and afternoon commuting periods, respectively, compared to annual average 24-hour concentrations measured at air toxic monitoring network sites. These ratios were higher during the fall, with smaller diurnal differences (4.8 +/- 0.7 and 3.9 +/- 0.6 for morning and afternoon commuting periods, respectively). Ratios similar to those for BTEX were obtained for 1,3-butadiene (BD) and styrene. On-road concentrations of formaldehyde and acetaldehyde were up to two times higher than at air toxics monitoring sites, with fall ratios slightly higher than summer ratios. Chemical mass balance (CMB) receptor

  19. Effect of vehicle type on the performance of second generation air bags for child occupants.

    PubMed

    Arbogast, Kristy B; Durbin, Dennis R; Kallan, Michael J; Winston, Flaura K

    2003-01-01

    Passenger air bags experienced considerable design modification in the late 1990s, principally to mitigate risks to child passengers. This study utilized Data from the Partners for Child Passenger Safety study, a large-scale child-focused crash surveillance system, to examine the effect of vehicle type on the differential performance of first and second generation air bags on injuries to restrained children in frontal impact crashes. Our results show that the benefit of second-generation air bags was seen in passenger cars - those children exposed to second-generation air bags were half as likely to sustain a serious injury - and minivans. However, in SUVs the data suggest no reduction in injury risk with the new designs. This field data provides crucial real-world experience to the automotive industry as they work towards the next generation of air bag designs. PMID:12941218

  20. Performance Validation Approach for the GTX Air-Breathing Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.; Roche, Joseph M.

    2002-01-01

    The primary objective of the GTX effort is to determine whether or not air-breathing propulsion can enable a launch vehicle to achieve orbit in a single stage. Structural weight, vehicle aerodynamics, and propulsion performance must be accurately known over the entire flight trajectory in order to make a credible assessment. Structural, aerodynamic, and propulsion parameters are strongly interdependent, which necessitates a system approach to design, evaluation, and optimization of a single-stage-to-orbit concept. The GTX reference vehicle serves this purpose, by allowing design, development, and validation of components and subsystems in a system context. The reference vehicle configuration (including propulsion) was carefully chosen so as to provide high potential for structural and volumetric efficiency, and to allow the high specific impulse of air-breathing propulsion cycles to be exploited. Minor evolution of the configuration has occurred as analytical and experimental results have become available. With this development process comes increasing validation of the weight and performance levels used in system performance determination. This paper presents an overview of the GTX reference vehicle and the approach to its performance validation. Subscale test rigs and numerical studies used to develop and validate component performance levels and unit structural weights are outlined. The sensitivity of the equivalent, effective specific impulse to key propulsion component efficiencies is presented. The role of flight demonstration in development and validation is discussed.

  1. Impact of aeroelasticity on propulsion and longitudinal flight dynamics of an air-breathing hypersonic vehicle

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Mcminn, John D.; Pototzky, Anthony S.; Wooley, Christine L.

    1993-01-01

    Many air-breathing hypersonic aerospacecraft design concepts incorporate an elongated fuselage forebody acting as the aerodynamic compression surface for a hypersonic combustion module, or scram jet. This highly integrated design approach creates the potential for an unprecedented form of aero-propulsive-elastic interaction in which deflections of the vehicle fuselage give rise to propulsion transients, producing force and moment variations that may adversely impact the rigid body flight dynamics and/or further excite the fuselage bending modes. To investigate the potential for such interactions, a math model was developed which included the longitudinal flight dynamics, propulsion system, and first seven elastic modes of a hypersonic air-breathing vehicle. Perturbation time histories from a simulation incorporating this math model are presented that quantify the propulsive force and moment variations resulting from aeroelastic vehicle deflections. Root locus plots are presented to illustrate the effect of feeding the propulsive perturbations back into the aeroelastic model. A concluding section summarizes the implications of the observed effects for highly integrated hypersonic air-breathing vehicle concepts.

  2. Cloud-Droplet Ingestion in Engine Inlets with Inlet Velocity Ratios of 1.0 and 0.7

    NASA Technical Reports Server (NTRS)

    Brun, Rinaldo J

    1957-01-01

    The paths of cloud droplets into two engine inlets have been calculated for a wide range of meteorological and flight conditions. The amount of water in droplet form ingested by the inlets and the amount and distribution of water impinging on the inlet walls are obtained from these droplet-trajectory calculations. In both types of inlet, a prolate ellipsoid of revolution represents either part or all of the forebody at the center of an annular inlet to an engine. The configurations can also represent a fuselage of an airplane with side ram-scoop inlets. The studies were made at an angle of attack of 0 degree. The principal difference between the two inlets studied is that the inlet-air velocity of one is 0.7 that of the other. The studies of the two velocity ratios lead to some important general concepts of water ingestion in inlets.

  3. Concentrations of vehicle-related air pollutants in an urban parking garage.

    PubMed

    Kim, Sung R; Dominici, Francesca; Buckley, Timothy J

    2007-11-01

    There is growing evidence that traffic-related air pollution poses a public health threat, yet the dynamics of human exposure are not well understood. The urban parking garage is a microenvironment that is of concern but has not been characterized. Using time-resolved measurement methods, we evaluated air toxics levels within an urban parking garage and assessed the influence of vehicle activity and type on their levels. Carbon monoxide (CO) and particle-bound polycyclic aromatic hydrocarbons (pPAH) were measured with direct-reading instruments. Volatile organic compounds (VOCs) were measured in 30 min intervals using a sorbent tube loaded sequential sampler. Vehicle volume and type were evaluated by video recording. Sampling was conducted from June 24 to July 17, 2002. We observed garage traffic median volumes of 71 counts/h on weekdays and 6 counts/h on weekends. The 12-fold reduction in traffic volume from weekday to weekend corresponded with a decrease in median air pollution that varied from a minimum 2- (CO) to a maximum 7 (pPAH)-fold. The actual 30-min median weekday and weekend values were: CO--2.6/1.2 ppm; pPAH--19/2.6 ng/m(3); 1,3-butadiene-0.5/0.2 microg/m(3), MTBE-7.4/0.4 microg/m(3); and benzene-2.7/0.3 microg/m(3). The influence of traffic was quantified using longitudinal models. The pollutant coefficients provide an indication of the average air pollution vehicle source contribution and ranged from 0.31 (CO) to 1.08 (pPAH) percent increase/vehicle count. For some pollutants, a slightly higher (0.5-0.6%) coefficient was observed for light-trucks relative to cars. This study has public health relevance in providing a unique assessment of air pollution levels and source contribution for the urban parking garage. PMID:17716646

  4. Determining air quality and greenhouse gas impacts of hydrogen infrastructure and fuel cell vehicles.

    PubMed

    Stephens-Romero, Shane; Carreras-Sospedra, Marc; Brouwer, Jacob; Dabdub, Donald; Samuelsen, Scott

    2009-12-01

    Adoption of hydrogen infrastructure and hydrogen fuel cell vehicles (HFCVs) to replace gasoline internal combustion engine (ICE) vehicles has been proposed as a strategy to reduce criteria pollutant and greenhouse gas (GHG) emissions from the transportation sector and transition to fuel independence. However, it is uncertain (1) to what degree the reduction in criteria pollutants will impact urban air quality, and (2) how the reductions in pollutant emissions and concomitant urban air quality impacts compare to ultralow emission gasoline-powered vehicles projected for a future year (e.g., 2060). To address these questions, the present study introduces a "spatially and temporally resolved energy and environment tool" (STREET) to characterize the pollutant and GHG emissions associated with a comprehensive hydrogen supply infrastructure and HFCVs at a high level of geographic and temporal resolution. To demonstrate the utility of STREET, two spatially and temporally resolved scenarios for hydrogen infrastructure are evaluated in a prototypical urban airshed (the South Coast Air Basin of California) using geographic information systems (GIS) data. The well-to-wheels (WTW) GHG emissions are quantified and the air quality is established using a detailed atmospheric chemistry and transport model followed by a comparison to a future gasoline scenario comprised of advanced ICE vehicles. One hydrogen scenario includes more renewable primary energy sources for hydrogen generation and the other includes more fossil fuel sources. The two scenarios encompass a variety of hydrogen generation, distribution, and fueling strategies. GHG emissions reductions range from 61 to 68% for both hydrogen scenarios in parallel with substantial improvements in urban air quality (e.g., reductions of 10 ppb in peak 8-h-averaged ozone and 6 mug/m(3) in 24-h-averaged particulate matter concentrations, particularly in regions of the airshed where concentrations are highest for the gasoline scenario

  5. Cleaning the air and improving health with hydrogen fuel-cell vehicles

    SciTech Connect

    Jacobson, M.Z.; Colella, W.G.; Golden, D.M.

    2005-06-24

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

  6. Cleaning the Air and Improving Health with Hydrogen Fuel-Cell Vehicles

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2005-06-01

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline.

  7. The Digital Twin Paradigm for Future NASA and U.S. Air Force Vehicles

    NASA Technical Reports Server (NTRS)

    Glaessgen, Edward H.; Stargel, D. S.

    2012-01-01

    Future generations of NASA and U.S. Air Force vehicles will require lighter mass while being subjected to higher loads and more extreme service conditions over longer time periods than the present generation. Current approaches for certification, fleet management and sustainment are largely based on statistical distributions of material properties, heuristic design philosophies, physical testing and assumed similitude between testing and operational conditions and will likely be unable to address these extreme requirements. To address the shortcomings of conventional approaches, a fundamental paradigm shift is needed. This paradigm shift, the Digital Twin, integrates ultra-high fidelity simulation with the vehicle s on-board integrated vehicle health management system, maintenance history and all available historical and fleet data to mirror the life of its flying twin and enable unprecedented levels of safety and reliability.

  8. Cleaning the air and improving health with hydrogen fuel-cell vehicles.

    PubMed

    Jacobson, M Z; Colella, W G; Golden, D M

    2005-06-24

    Converting all U.S. onroad vehicles to hydrogen fuel-cell vehicles (HFCVs) may improve air quality, health, and climate significantly, whether the hydrogen is produced by steam reforming of natural gas, wind electrolysis, or coal gasification. Most benefits would result from eliminating current vehicle exhaust. Wind and natural gas HFCVs offer the greatest potential health benefits and could save 3700 to 6400 U.S. lives annually. Wind HFCVs should benefit climate most. An all-HFCV fleet would hardly affect tropospheric water vapor concentrations. Conversion to coal HFCVs may improve health but would damage climate more than fossil/electric hybrids. The real cost of hydrogen from wind electrolysis may be below that of U.S. gasoline. PMID:15976300

  9. An Air-Breathing Launch Vehicle Concept for Single-Stage-to-Orbit

    NASA Technical Reports Server (NTRS)

    Trefny, Charles J.

    1999-01-01

    The "Trailblazer" is a 300-lb payload, single-stage-to-orbit launch vehicle concept that uses air-breathing propulsion to reduce the required propellant fraction. The integration of air-breathing propulsion is done considering performance, structural and volumetric efficiency, complexity, and design risk. The resulting configuration is intended to be viable using near-term materials and structures. The aeropropulsion performance goal for the Trailblazer launch vehicle is an equivalent effective specific impulse (I*) of 500 sec. Preliminary analysis shows that this requires flight in the atmosphere to about Mach 10, and that the gross lift-off weight is 130,000 lb. The Trailblazer configuration and proposed propulsion system operating modes are described. Preliminary performance results are presented, and key technical issues are highlighted. An overview of the proposed program plan is given.

  10. Emissions of halocarbons from mobile vehicle air conditioning system in Hong Kong.

    PubMed

    Yan, H H; Guo, H; Ou, J M

    2014-08-15

    During the implementation of Montreal Protocol, emission inventories of halocarbons in different sectors at regional scale are fundamental to the formulation of relevant management strategy and inspection of the implementation efficiency. This study investigated the emission profile of halocarbons used in the mobile vehicle air conditioning system, the leading sector of refrigeration industry in terms of the refrigerant bank, market and emission, in the Hong Kong Special Administrative Region, using a bottom-up approach developed by 2006 IPCC Good Practice Guidance. The results showed that emissions of CFC-12 peaked at 53 tons ODP (Ozone Depletion Potential) in 1992 and then gradually diminished, whereas HFC-134a presented an increasing emission trend since 1990s and the emissions of HFC-134a reached 65,000 tons CO2-equivelant (CO2-eq) by the end of 2011. Uncertainty analysis revealed relatively high levels of uncertainties for special-purpose vehicles and government vehicles. Moreover, greenhouse gas (GHG) abatements under different scenarios indicated that potential emission reduction of HFC-134a ranged from 4.1 to 8.4 × 10(5)tons CO2-eq. The findings in this study advance our knowledge of halocarbon emissions from mobile vehicle air conditioning system in Hong Kong. PMID:24997256

  11. Optimum Aeroelastic Design of Resonance Type Flapping Wing for Micro Air Vehicles

    NASA Astrophysics Data System (ADS)

    Isogai, Koji; Kamisawa, Yuichi; Sato, Hiroyuki

    The optimum aeroelastic design method for a resonance-type flapping wing for a Micro Air Vehicle (MAV) is presented. It uses Complex Method and 3D Navier-Stokes code to determine the optimum structural and aerodynamic parameters of a 2 DOF flapping wing system. The method is used to design a dragonfly-type MAV, and numerical simulation shows that the designed flapping wings can generate sufficient lift to sustain the weight and sufficient thrust to overcome the body drag.

  12. The system integration and verification testing of an orbital maneuvering vehicle for an air bearing floor

    NASA Technical Reports Server (NTRS)

    Shields, N. L., Jr.; Martin, M. F.; Paulukaitis, K. R.; Haslam, J. W., Jr.; Henderson, D. E.

    1986-01-01

    The teleoperator and Robotics Evaluation Facility (TOREF) is composed of a 4,000 square foot precision air bearing floor, the Teleoperator Motion Base, the Target Motion and Support Simulator, the mock-ups of the Hubble Space Telescope, Multi-mission Modular Spacecraft, and the Orbital Maneuvering Vehicle (OMV). The TOREF and its general capabilities to support the OMV and other remote system simulations; the facility operating procedures and requirements; and the results of generic OMV investigations are summarized.

  13. Flexible Wing Base Micro Aerial Vehicles: Towards Flight Autonomy: Vision-Based Horizon Detection for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Nechyba, Michael C.; Ettinger, Scott M.; Ifju, Peter G.; Wazak, Martin

    2002-01-01

    Recently substantial progress has been made towards design building and testifying remotely piloted Micro Air Vehicles (MAVs). This progress in overcoming the aerodynamic obstacles to flight at very small scales has, unfortunately, not been matched by similar progress in autonomous MAV flight. Thus, we propose a robust, vision-based horizon detection algorithm as the first step towards autonomous MAVs. In this paper, we first motivate the use of computer vision for the horizon detection task by examining the flight of birds (biological MAVs) and considering other practical factors. We then describe our vision-based horizon detection algorithm, which has been demonstrated at 30 Hz with over 99.9% correct horizon identification, over terrain that includes roads, buildings large and small, meadows, wooded areas, and a lake. We conclude with some sample horizon detection results and preview a companion paper, where the work discussed here forms the core of a complete autonomous flight stability system.

  14. A hybrid approach to modeling and control of vehicle height for electronically controlled air suspension

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoqiang; Cai, Yingfeng; Wang, Shaohua; Liu, Yanling; Chen, Long

    2016-01-01

    The control problems associated with vehicle height adjustment of electronically controlled air suspension (ECAS) still pose theoretical challenges for researchers, which manifest themselves in the publications on this subject over the last years. This paper deals with modeling and control of a vehicle height adjustment system for ECAS, which is an example of a hybrid dynamical system due to the coexistence and coupling of continuous variables and discrete events. A mixed logical dynamical (MLD) modeling approach is chosen for capturing enough details of the vehicle height adjustment process. The hybrid dynamic model is constructed on the basis of some assumptions and piecewise linear approximation for components nonlinearities. Then, the on-off statuses of solenoid valves and the piecewise approximation process are described by propositional logic, and the hybrid system is transformed into the set of linear mixed-integer equalities and inequalities, denoted as MLD model, automatically by HYSDEL. Using this model, a hybrid model predictive controller (HMPC) is tuned based on online mixed-integer quadratic optimization (MIQP). Two different scenarios are considered in the simulation, whose results verify the height adjustment effectiveness of the proposed approach. Explicit solutions of the controller are computed to control the vehicle height adjustment system in realtime using an offline multi-parametric programming technology (MPT), thus convert the controller into an equivalent explicit piecewise affine form. Finally, bench experiments for vehicle height lifting, holding and lowering procedures are conducted, which demonstrate that the HMPC can adjust the vehicle height by controlling the on-off statuses of solenoid valves directly. This research proposes a new modeling and control method for vehicle height adjustment of ECAS, which leads to a closed-loop system with favorable dynamical properties.

  15. Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

    NASA Astrophysics Data System (ADS)

    Wang, J. M.; Jeong, C.-H.; Zimmerman, N.; Healy, R. M.; Wang, D. K.; Ke, F.; Evans, G. J.

    2015-03-01

    An automated identification and integration method has been developed to investigate in-use vehicle emissions under real-world conditions. This technique was applied to high time resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada during four seasons, through month-long campaigns in 2013-2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number, black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg-1 and 7.7 × 1014 kg-1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25%) contributed significantly to total fleet emissions; 95, 93, 76, and 75% for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter. However, regulatory strategies to more efficiently target multi-pollutants mixtures may be better developed by considering the co

  16. Plume-based analysis of vehicle fleet air pollutant emissions and the contribution from high emitters

    NASA Astrophysics Data System (ADS)

    Wang, J. M.; Jeong, C.-H.; Zimmerman, N.; Healy, R. M.; Wang, D. K.; Ke, F.; Evans, G. J.

    2015-08-01

    An automated identification and integration method has been developed for in-use vehicle emissions under real-world conditions. This technique was applied to high-time-resolution air pollutant measurements of in-use vehicle emissions performed under real-world conditions at a near-road monitoring station in Toronto, Canada, during four seasons, through month-long campaigns in 2013-2014. Based on carbon dioxide measurements, over 100 000 vehicle-related plumes were automatically identified and fuel-based emission factors for nitrogen oxides; carbon monoxide; particle number; black carbon; benzene, toluene, ethylbenzene, and xylenes (BTEX); and methanol were determined for each plume. Thus the automated identification enabled the measurement of an unprecedented number of plumes and pollutants over an extended duration. Emission factors for volatile organic compounds were also measured roadside for the first time using a proton transfer reaction time-of-flight mass spectrometer; this instrument provided the time resolution required for the plume capture technique. Mean emission factors were characteristic of the light-duty gasoline-dominated vehicle fleet present at the measurement site, with mean black carbon and particle number emission factors of 35 mg kg fuel-1 and 7.5 × 1014 # kg fuel-1, respectively. The use of the plume-by-plume analysis enabled isolation of vehicle emissions, and the elucidation of co-emitted pollutants from similar vehicle types, variability of emissions across the fleet, and the relative contribution from heavy emitters. It was found that a small proportion of the fleet (< 25 %) contributed significantly to total fleet emissions: 100, 100, 81, and 77 % for black carbon, carbon monoxide, BTEX, and particle number, respectively. Emission factors of a single pollutant may help classify a vehicle as a high emitter; however, regulatory strategies to more efficiently target multi-pollutant mixtures may be better developed by considering the co

  17. Air quality and climate impacts due to CNG conversion of motor vehicles in Dhaka, Bangladesh.

    PubMed

    Wadud, Zia; Khan, Tanzila

    2013-12-17

    Dhaka had recently experienced rapid conversion of its motor vehicle fleet to run on compressed natural gas (CNG). This paper quantifies ex-post the air quality and climate benefits of the CNG conversion policy, including monetary valuations, through an impact pathway approach. Around 2045 (1665) avoided premature deaths in greater Dhaka (City Corporation) can be attributed to air quality improvements from the CNG conversion policy in 2010, resulting in a saving of around USD 400 million. Majority of these health benefits resulted from the conversion of high-emitting diesel vehicles. CNG conversion was clearly detrimental from climate change perspective using the changes in CO2 and CH4 only (CH4 emissions increased); however, after considering other global pollutants (especially black carbon), the climate impact was ambiguous. Uncertainty assessment using input distributions and Monte Carlo simulation along with a sensitivity analysis show that large uncertainties remain for climate impacts. For our most likely estimate, there were some climate costs, valued at USD 17.7 million, which is an order of magnitude smaller than the air quality benefits. This indicates that such policies can and should be undertaken on the grounds of improving local air pollution alone and that precautions should be taken to reduce the potentially unintended increases in GHG emissions or other unintended effects. PMID:24195736

  18. High Altitude Long Endurance Air Vehicle Analysis of Alternatives and Technology Requirements Development

    NASA Technical Reports Server (NTRS)

    Nickol, Craig L.; Guynn, Mark D.; Kohout, Lisa L.; Ozoroski, Thomas A.

    2007-01-01

    The objective of this study was to develop a variety of High Altitude Long Endurance (HALE) Unmanned Aerial Vehicle (UAV) conceptual designs for two operationally useful missions (hurricane science and communications relay) and compare their performance and cost characteristics. Sixteen potential HALE UAV configurations were initially developed, including heavier-than-air (HTA) and lighter-than-air (LTA) concepts with both consumable fuel and solar regenerative (SR) propulsion systems. Through an Analysis of Alternatives (AoA) down select process, the two leading consumable fuel configurations (one each from the HTA and LTA alternatives) and an HTA SR configuration were selected for further analysis. Cost effectiveness analysis of the consumable fuel configurations revealed that simply maximizing vehicle endurance can lead to a sub-optimum system solution. An LTA concept with a hybrid propulsion system (solar arrays and a hydrogen-air proton exchange membrane fuel cell) was found to have the best mission performance; however, an HTA diesel-fueled wing-body-tail configuration emerged as the preferred consumable fuel concept because of the large size and technical risk of the LTA concept. The baseline missions could not be performed by even the best HTA SR concept. Mission and SR technology trade studies were conducted to enhance understanding of the potential capabilities of such a vehicle. With near-term technology SR-powered HTA vehicles are limited to operation in favorable solar conditions, such as the long days and short nights of summer at higher latitudes. Energy storage system specific energy and solar cell efficiency were found to be the key technology areas for enhancing HTA SR performance.

  19. Stepped inlet optical panel

    DOEpatents

    Veligdan, James T.

    2001-01-01

    An optical panel includes stacked optical waveguides having stepped inlet facets collectively defining an inlet face for receiving image light, and having beveled outlet faces collectively defining a display screen for displaying the image light channeled through the waveguides by internal reflection.

  20. Attic Inlet Technology Update

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Attic inlets are a popular addition for new construction and energy saving retrofits. Proper management of attic inlets is necessary to get maximum benefits from the system and reduce the likelihood of moisture-related problems in the structure. Solar energy levels were determined for the continen...

  1. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives

    PubMed Central

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D.; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research. PMID:27420065

  2. Indoor air as a vehicle for human pathogens: Introduction, objectives, and expectation of outcome.

    PubMed

    Sattar, Syed A

    2016-09-01

    Airborne spread of pathogens can be rapid, widespread, and difficult to prevent. In this international workshop, a panel of 6 experts will expound on the following: (1) the potential for indoor air to spread a wide range of human pathogens, plus engineering controls to reduce the risk for exposure to airborne infectious agents; (2) the behavior of aerosolized infectious agents indoors and the use of emerging air decontamination technologies; (3) a survey of quantitative methods to recover infectious agents and their surrogates from indoor air with regard to survival and inactivation of airborne pathogens; (4) mathematical models to predict the movement of pathogens indoors and the use of such information to optimize the benefits of air decontamination technologies; and (5) synergy between different infectious agents, such as legionellae and fungi, in the built environment predisposing to possible transmission-related health impacts of aerosolized biofilm-based opportunistic pathogens. After the presentations, the panel will address a set of preformulated questions on selection criteria for surrogate microbes to study the survival and inactivation of airborne human pathogens, desirable features of technologies for microbial decontamination of indoor air, knowledge gaps, and research needs. It is anticipated that the deliberations of the workshop will provide the attendees with an update on the significance of indoor air as a vehicle for transmitting human pathogens with a brief on what is currently being done to mitigate the risks from airborne infectious agents. PMID:27590701

  3. An Overview of Small Unmanned Aerial Vehicles for Air Quality Measurements: Present Applications and Future Prospectives.

    PubMed

    Villa, Tommaso Francesco; Gonzalez, Felipe; Miljievic, Branka; Ristovski, Zoran D; Morawska, Lidia

    2016-01-01

    Assessment of air quality has been traditionally conducted by ground based monitoring, and more recently by manned aircrafts and satellites. However, performing fast, comprehensive data collection near pollution sources is not always feasible due to the complexity of sites, moving sources or physical barriers. Small Unmanned Aerial Vehicles (UAVs) equipped with different sensors have been introduced for in-situ air quality monitoring, as they can offer new approaches and research opportunities in air pollution and emission monitoring, as well as for studying atmospheric trends, such as climate change, while ensuring urban and industrial air safety. The aims of this review were to: (1) compile information on the use of UAVs for air quality studies; and (2) assess their benefits and range of applications. An extensive literature review was conducted using three bibliographic databases (Scopus, Web of Knowledge, Google Scholar) and a total of 60 papers was found. This relatively small number of papers implies that the field is still in its early stages of development. We concluded that, while the potential of UAVs for air quality research has been established, several challenges still need to be addressed, including: the flight endurance, payload capacity, sensor dimensions/accuracy, and sensitivity. However, the challenges are not simply technological, in fact, policy and regulations, which differ between countries, represent the greatest challenge to facilitating the wider use of UAVs in atmospheric research. PMID:27420065

  4. OCTAVE: a bioinspired visuo-motor control system for the guidance of micro-air-vehicles

    NASA Astrophysics Data System (ADS)

    Ruffier, Franck; Franceschini, Nicolas

    2003-04-01

    We have developed a visually based autopilot for Micro Air Vehicles (MAV), which we have called OCTAVE (Optical altitude Control sysTem for Autonomous VEhicles). First we built a miniature MAV and an indoor test-bed. The mini-helicopter is tethered to a whirling arm and rotates around a central pole equipped with ground-truth positioning sensors for experimental evaluation. The 100-gram rotorcraft lifts itself by means of a single rotor that can also be tilted forward (pitch) to give the craft a horizontal thrust component (propulsive force). The helicopter"s eye is automatically oriented downwards over an environment composed of contrasting features randomly arranged on the floor. Here we show the feasibility of a ground avoiding system based on a low complexity opto-electronic system. The latter relies on an Elementary Motion Detector (EMD) that estimates the optic flow in the downward direction. The EMD functional structure is directly inspired by that of the fly"s EMDs, the functional scheme of which has been elucidated at our Laboratory by performing electrophysiological recordings while applying optical microstimuli to the retina. The OCTAVE autopilot makes the aircraft capable of effective terrain following at various speeds: the MAV performs reproducible manoeuvers such as smooth cruise flight over a planar ground and hill climbing. The overall processing electronics is very light-weight, which makes it highly suitable for mounting on-board micro air vehicles with an avionic payload in the order of only a few grams.

  5. Prospects for utilization of air liquefaction and enrichment system (ALES) propulsion in fully reusable launch vehicles

    NASA Technical Reports Server (NTRS)

    Bond, W. H.; Yi, A. C.

    1993-01-01

    A concept is shown for a fully reusable, earth to orbit launch vehicle with horizontal takeoff and landing, employing an air-turborocket for low speed and a rocket for high speed acceleration, both using LH2 fuel. The turborocket employs a modified liquid air cycle to supply the oxidizer. The rocket uses 90 percent pure LOX that is collected from the atmosphere, separated, and stored during operation of the turborocket from about Mach 2 to Mach 5 or 6. The takeoff weight and the thrust required at takeoff are markedly reduced by collecting the rocket oxidizer in-flight. The paper shows an approach and the corresponding technology needs for using ALES propulsion in a SSTO vehicle. Reducing the trajectory altitude at the end of collection reduces the wing area and increases payload. The use of state-of-the-art materials, such as graphite polyimide, is critical to meet the structure weight objective for SSTO. Configurations that utilize 'waverider' aerodynamics show great promise to reduce the vehicle weight.

  6. Design of a Flush Airdata System (FADS) for the Hypersonic Air Launched Option (HALO) Vehicle

    NASA Technical Reports Server (NTRS)

    Whitmore, Stephen A.; Moes, Timothy R.; Deets, Dwain A. (Technical Monitor)

    1994-01-01

    This paper presents a design study for a pressure based Flush airdata system (FADS) on the Hypersonic Air Launched Option (HALO) Vehicle. The analysis will demonstrate the feasibility of using a pressure based airdata system for the HALO and provide measurement uncertainty estimates along a candidate trajectory. The HALO is a conceived as a man-rated vehicle to be air launched from an SR-71 platform and is proposed as a testbed for an airbreathing hydrogen scramjet. A feasibility study has been performed and indicates that the proposed trajectory is possible with minimal modifications to the existing SR71 vehicle. The mission consists of launching the HALO off the top of an SR-71 at Mach 3 and 80,000 ft. A rocket motor is then used to accelerate the vehicle to the test condition. After the scramjet test is completed the vehicle will glide to a lakebed runway landing. This option provides reusability of the vehicle and scramjet engine. The HALO design will also allow for various scramjet engine and flowpath designs to be flight tested. For the HALO flights, measurements of freestream airdata are considered to be a mission critical to perform gain scheduling and trajectory optimization. One approach taken to obtaining airdata involves measurement of certain parameters such as external atmospheric winds, temperature, etc to estimate the airdata quantities. This study takes an alternate approach. Here the feasibility of obtaining airdata using a pressure-based flush airdata system (FADS) methods is assessed. The analysis, although it is performed using the HALO configuration and trajectory, is generally applicable to other hypersonic vehicles. The method to be presented offers the distinct advantage of inferring total pressure, Mach number, and flow incidence angles, without stagnating the freestream flow. This approach allows for airdata measurements to be made using blunt surfaces and significantly diminishes the heating load at the sensor. In the FADS concept a

  7. Utilizing adaptive wing technology in the control of a micro air vehicle

    NASA Astrophysics Data System (ADS)

    Null, William R.; Wagner, Matthew G.; Shkarayev, Sergey V.; Jouse, Wayne C.; Brock, Keith M.

    2002-07-01

    Evolution of the design of micro air vehicles (MAVs) towards miniaturization has been severely constrained by the size and mass of the electronic components needed to control the vehicles. Recent research, experimentation, and development in the area of smart materials have led to the possibility of embedding control actuators, fabricated from smart materials, in the wing of the vehicle, reducing both the size and mass of these components. Further advantages can be realized by developing adaptive wing structures. Small size and mass, and low airspeeds, can lead to considerable buffeting during flight, and may result in a loss of flight control. In order to counter these effects, we are developing a thin, variable-cambered airfoil design with actuators embedded within the wing. In addition to reducing the mass and size of the vehicle or, conversely, increasing its available payload, an important benefit from the adaptive wing concept is the possibility of in-flight modification of the flight envelope. Reduced airspeeds, which are crucial during loiter, can be realized by an in-flight increase in wing camber. Conversely, decreases in camber provide for an airframe best suited for rapid ingress/egress and extension of the mission range.

  8. Investigation of Unsteady Flow Interaction Between an Ultra-Compact Inlet and a Transonic Fan

    NASA Technical Reports Server (NTRS)

    Hah, Chunill; Rabe, Douglas; Scribben, Angie

    2015-01-01

    In the study presented, unsteady flow interaction between an ultra-compact inlet and a transonic fan stage is investigated. Future combat aircraft engines require ultra-compact inlet ducts as part of an integrated, advanced propulsion system to improve air vehicle capability and effectiveness to meet future mission needs. The main purpose of the current study is to advance the understanding of the flow interaction between a modern ultra-compact inlet and a transonic fan for future design applications. Many experimental/ analytical studies have been reported on the aerodynamics of compact inlets in aircraft engines. On the other hand, very few studies have been reported on the effects of flow distortion from these inlets on the performance of the following fan/compressor stages. The primary goal of the study presented is to investigate how flow interaction between an ultra-compact inlet and a transonic compressor influence the operating margin of the compressor. Both Unsteady Reynolds-averaged Navier-Stokes (URANS) and Large Eddy Simulation (LES) approaches are used to calculate the unsteady flow field, and the numerical results are used to study the flow interaction. The present study indicates that stall inception of the following compressor stage is affected directly based on how the distortion pattern evolves before it interacts with the fan/compressor face. For the present compressor, the stall initiates at the tip section with clean inlet flow and distortion pattern away from the casing itself seems to have limited impacts on the stall inception of the compressor. A counter-rotating swirl, which is generated due to flow separation inside the s-shaped compact duct, generates an increased flow angle near the blade tip. This increased flow angle near the rotor tip due to the secondary flow from the counter-rotating vortices is the primary reason for the reduced compressor stall margin.

  9. Comprehensive modeling and control of flexible flapping wing micro air vehicles

    NASA Astrophysics Data System (ADS)

    Nogar, Stephen Michael

    Flapping wing micro air vehicles hold significant promise due to the potential for improved aerodynamic efficiency, enhanced maneuverability and hover capability compared to fixed and rotary configurations. However, significant technical challenges exist to due the lightweight, highly integrated nature of the vehicle and coupling between the actuators, flexible wings and control system. Experimental and high fidelity analysis has demonstrated that aeroelastic effects can change the effective kinematics of the wing, reducing vehicle stability. However, many control studies for flapping wing vehicles do not consider these effects, and instead validate the control strategy with simple assumptions, including rigid wings, quasi-steady aerodynamics and no consideration of actuator dynamics. A control evaluation model that includes aeroelastic effects and actuator dynamics is developed. The structural model accounts for geometrically nonlinear behavior using an implicit condensation technique and the aerodynamic loads are found using a time accurate approach that includes quasi-steady, rotational, added mass and unsteady effects. Empirically based parameters in the model are fit using data obtained from a higher fidelity solver. The aeroelastic model and its ingredients are compared to experiments and computations using models of higher fidelity, and indicate reasonable agreement. The developed control evaluation model is implemented in a previously published, baseline controller that maintains stability using an asymmetric wingbeat, known as split-cycle, along with changing the flapping frequency and wing bias. The model-based controller determines the control inputs using a cycle-averaged, linear control design model, which assumes a rigid wing and no actuator dynamics. The introduction of unaccounted for dynamics significantly degrades the ability of the controller to track a reference trajectory, and in some cases destabilizes the vehicle. This demonstrates the

  10. Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

    NASA Technical Reports Server (NTRS)

    Arnold, James O.; Deiwert, George S.

    1997-01-01

    This paper surveys the use of aerothermodynamic facilities which have been useful in the study of external flows and propulsion aspects of hypersonic, air-breathing vehicles. While the paper is not a survey of all facilities, it covers the utility of shock tunnels and conventional hypersonic blow-down facilities which have been used for hypersonic air-breather studies. The problems confronting researchers in the field of aerothermodynamics are outlined. Results from the T5 GALCIT tunnel for the shock-on lip problem are outlined. Experiments on combustors and short expansion nozzles using the semi-free jet method have been conducted in large shock tunnels. An example which employed the NASA Ames 16-Inch shock tunnel is outlined, and the philosophy of the test technique is described. Conventional blow-down hypersonic wind tunnels are quite useful in hypersonic air-breathing studies. Results from an expansion ramp experiment, simulating the nozzle on a hypersonic air-breather from the NASA Ames 3.5 Foot Hypersonic wind tunnel are summarized. Similar work on expansion nozzles conducted in the NASA Langley hypersonic wind tunnel complex is cited. Free-jet air-frame propulsion integration and configuration stability experiments conducted at Langley in the hypersonic wind tunnel complex on a small generic model are also summarized.

  11. Spatially- and Temporally-Resolved Measurements of Roadway Air Pollution Using a Zero-Emission Electric Vehicle

    EPA Science Inventory

    Vehicle-related air pollution has an intrinsically dynamic nature. Recent field measurements and modeling work have demonstrated that near-road topography may modify levels of air pollutants reaching populations residing and working in close proximity to roadways. However, the ma...

  12. Structural Sizing of a 25,000-lb Payload, Air-breathing Launch Vehicle for Single-stage-to-orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.

    2001-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (five to ten years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  13. Structural Sizing of a 25,000-lb Payload, Air-Breathing Launch Vehicle For Single-Stage-To-Orbit

    NASA Technical Reports Server (NTRS)

    Roche, Joseph M.; Kosareo, Daniel N.; Palac, Don (Technical Monitor)

    2000-01-01

    In support of NASA's Air-Breathing Launch Vehicle (ABLV) study, a 25,000-lb payload version of the GTX (formerly Trailblazer) reference vehicle concept was developed. The GTX is a vertical lift-off, reusable, single-stage-to-orbit launch vehicle concept that uses hypersonic air-breathing propulsion in a rocket-based combined-cycle (RBCC) propulsion system to reduce the required propellant fraction. To achieve this goal the vehicle and propulsion system must be well integrated both aerodynamically and structurally to reduce weight. This study demonstrates the volumetric and structural efficiency of a vertical takeoff, horizontal landing, hypersonic vehicle with a circular cross section. A departure from the lifting body concepts, this design philosophy is even extended to the engines, which have semicircular nacelles symmetrically mounted on the vehicle. Material candidates with a potential for lightweight and simplicity have been selected from a set of near term technologies (5 to 10 years). To achieve the mission trajectory, preliminary weight estimates show the vehicle's gross lift-off weight is 1.26 x 10(exp 6) lb. The structural configuration of the GTX vehicle and its propulsion system are described. The vehicle design benefits are presented, and key technical issues are highlighted.

  14. Design of an airborne launch vehicle for an air launched space booster

    NASA Astrophysics Data System (ADS)

    Chao, Chin; Choi, Rich; Cohen, Scott; Dumont, Brian; Gibin, Mauricius; Jorden, Rob; Poth, Stefan

    1993-12-01

    A conceptual design is presented for a carrier vehicle for an air launched space booster. This airplane is capable of carrying a 500,000 pound satellite launch system to an altitude over 40,000 feet for launch. The airplane features a twin fuselage configuration for improved payload and landing gear integration, a high aspect ratio wing for maneuverability at altitude, and is powered by six General Electric GE-90 engines. The analysis methods used and the systems employed in the airplane are discussed. Launch costs are expected to be competitive with existing launch systems.

  15. Model Update of a Micro Air Vehicle (MAV) Flexible Wing Frame with Uncertainty Quantification

    NASA Technical Reports Server (NTRS)

    Reaves, Mercedes C.; Horta, Lucas G.; Waszak, Martin R.; Morgan, Benjamin G.

    2004-01-01

    This paper describes a procedure to update parameters in the finite element model of a Micro Air Vehicle (MAV) to improve displacement predictions under aerodynamics loads. Because of fabrication, materials, and geometric uncertainties, a statistical approach combined with Multidisciplinary Design Optimization (MDO) is used to modify key model parameters. Static test data collected using photogrammetry are used to correlate with model predictions. Results show significant improvements in model predictions after parameters are updated; however, computed probabilities values indicate low confidence in updated values and/or model structure errors. Lessons learned in the areas of wing design, test procedures, modeling approaches with geometric nonlinearities, and uncertainties quantification are all documented.

  16. Design of an airborne launch vehicle for an air launched space booster

    NASA Technical Reports Server (NTRS)

    Chao, Chin; Choi, Rich; Cohen, Scott; Dumont, Brian; Gibin, Mauricius; Jorden, Rob; Poth, Stefan

    1993-01-01

    A conceptual design is presented for a carrier vehicle for an air launched space booster. This airplane is capable of carrying a 500,000 pound satellite launch system to an altitude over 40,000 feet for launch. The airplane features a twin fuselage configuration for improved payload and landing gear integration, a high aspect ratio wing for maneuverability at altitude, and is powered by six General Electric GE-90 engines. The analysis methods used and the systems employed in the airplane are discussed. Launch costs are expected to be competitive with existing launch systems.

  17. Operational benefits from the Terminal Configured Vehicle. [aircraft equipment for air traffic improvement

    NASA Technical Reports Server (NTRS)

    Reeder, J. P.; Schmitz, R. A.

    1978-01-01

    The objective of Terminal Configured Vehicle (TCV) research activity is to provide improvements which lead to increased airport and runway capacity, increasing air traffic controller productivity, energy efficient terminal area operations, reduced weather minima with safety, and reduced community noise by use of appropriate measures. Some early results of this research activity are discussed, and present and future research needs to meet the broad research objectives are defined. Particular consideration is given to the development of the TCV B-737 aircraft, the integration of the TCV with MLS, and avionics configurations, flight profiles, and manually controlled approaches for TCV. Some particular test demonstrations are discussed.

  18. Flexible Wing Base Micro Aerial Vehicles: Vision-Guided Flight Stability and Autonomy for Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Ettinger, Scott M.; Nechyba, Michael C.; Ifju, Peter G.; Wazak, Martin

    2002-01-01

    Substantial progress has been made recently towards design building and test-flying remotely piloted Micro Air Vehicle's (MAVs). We seek to complement this progress in overcoming the aerodynamic obstacles to.flight at very small scales with a vision stability and autonomy system. The developed system based on a robust horizon detection algorithm which we discuss in greater detail in a companion paper. In this paper, we first motivate the use of computer vision for MAV autonomy arguing that given current sensor technology, vision may he the only practical approach to the problem. We then briefly review our statistical vision-based horizon detection algorithm, which has been demonstrated at 30Hz with over 99.9% correct horizon identification. Next we develop robust schemes for the detection of extreme MAV attitudes, where no horizon is visible, and for the detection of horizon estimation errors, due to external factors such as video transmission noise. Finally, we discuss our feed-back controller for self-stabilized flight, and report results on vision autonomous flights of duration exceeding ten minutes.

  19. Multi-Reflex Propulsion Systems for Space and Air Vehicles and Energy Transfer for Long Distance

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    The purpose of this article is to call attention to the revolutionary idea of light multi-reflection. This idea allows the design of new engines, space and air propulsion systems, storage (of a beam and solar energy), transmitters of energy (to millions of kilometers), creation of new weapons, etc. This method and the main innovations were offered by the author in 1983 in the former USSR. Now the author shows in a series of articles the immense possibilities of this idea in many fields of engineering - astronautics, aviation, energy, optics, direct converter of light (laser beam) energy to mechanical energy (light engine), to name a few. This article considers the multi-reflex propulsion systems for space and air vehicles and energy transmitter for long distances in space.

  20. Progress report on Bertelsen research and development of an air cushion crawler all-terrain vehicle

    NASA Astrophysics Data System (ADS)

    Bertelsen, W. R.

    1987-06-01

    The ACV is an exceptional amphibian but it is not, nor is any other existing craft, an all-terrain vehicle (ATV). Using the best elements of the ACV in an air-cushion crawler tractor, a true ATV can be attained. A conventional crawler drive train will propel two tracks as pressurized, propulsive pontoons. The key to a successful ATV is in perfecting efficient, durable, sliding seals to allow the belt to move in its orbit around the track unit and maintain its internal pressure. After deriving the adequate seal, a 12 inch wide x 86 inch long endless rubber belt was fitted bilateral seals and slide plates with internal guide wheels fore and aft with a 21 inch wheel base. From this approximately one-quarter scale model, full-scale air track crawlers, true ATVs, of any size and capacity can be produced.

  1. Formation of photochemical air pollution in central California 1. Development of a revised motor vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Marr, Linsey C.; Black, Douglas R.; Harley, Robert A.

    2002-03-01

    Photochemical air pollution problems have proved difficult to understand and control in central California. A major source of uncertainty is the rate of precursor volatile organic compounds and NOx emissions, especially from motor vehicles. We develop alternative emissions estimates for on-road motor vehicles in 1990, using fuel sales data, emission factors measured in on-road studies, and ambient pollutant ratios, for a region that includes the San Francisco Bay and San Joaquin Valley air basins and Sacramento County. Fuel-based emissions estimates are compared with predictions of California's most recent motor vehicle emission factor model (EMFAC) and with an inventory that has been used in previous regional-scale photochemical modeling studies. The fuel-based inventory contains 10-50% less CO, 40-100% more nonmethane organic compounds, and 10-20% less NOx than estimated both by EMFAC and the photochemical modeling inventory. We also describe new temporal distributions of vehicle emissions by hour and day of week. Diesel trucks, a major source of NOx, have a broad midday peak in emissions on weekdays, in contrast to passenger vehicles, which show morning and afternoon commuter peaks. While passenger vehicle travel is similar on weekdays and weekends, diesel truck activity and emissions decrease by 70-80% on weekends. Vehicle emission rates and their temporal patterns are linked to a regional photochemical air pollution episode that spans a weekend in August 1990.

  2. Survey of Aerothermodynamics Facilities Useful for the Design of Hypersonic Vehicles Using Air-Breathing Propulsion

    NASA Technical Reports Server (NTRS)

    Arnold, James O.; Deiwert, G. S.

    1997-01-01

    The dream of producing an air-breathing, hydrogen fueled, hypervelocity aircraft has been before the aerospace community for decades. However, such a craft has not yet been realized, even in an experimental form. Despite the simplicity and beauty of the concept, many formidable problems must be overcome to make this dream a reality. This paper summarizes the aero/aerothermodynamic issues that must be addressed to make the dream a reality and discusses how aerothermodynamics facilities and their modem companion, real-gas computational fluid dynamics (CFD), can help solve the problems blocking the way to realizing the dream. The approach of the paper is first to outline the concept of an air-breathing hypersonic vehicle and then discuss the nose-to-tail aerothermodynamics issues and special aerodynamic problems that arise with such a craft. Then the utility of aerothermodynamic facilities and companion CFD analysis is illustrated by reviewing results from recent United States publications wherein these problems have been addressed. Papers selected for the discussion have k e n chosen such that the review will serve to survey important U.S. aero/aerothermodynamic real gas and conventional wind tunnel facilities that are useful in the study of hypersonic, hydrogen propelled hypervelocity vehicles.

  3. Linear Heave Dynamics of an Air-Cushion Vehicle Bag-and-Finger Skirt

    NASA Astrophysics Data System (ADS)

    Chung, Joon; Sullivan, Phillip A.

    Results from a linear analysis of the heave dynamics of an air-cushion vehicle equipped with a bag-and-finger skirt are described. A two-dimensional section of the cushion is subject to pure heave or long-wave surface motion inputs. The skirt mass is lumped in the fingers, with the bag being modelled as a combination of massless inelastic membranes and links. The airflows from bag to cushion and from cushion to atmosphere are assumed quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. For a configuration representative of a 37t vehicle, frequency response characteristics show the effect of skirt geometry and mass changes, and cushion capacitance. The results suggest that changes in skirt geometry cannot be used to radically modify an undesirable heave response, but reducing the skirt mass may be effective. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent at the low cushion-flow rates now used in practice.

  4. Characterization of on-road vehicle emission factors and microenvironmental air quality in Beijing, China

    NASA Astrophysics Data System (ADS)

    Westerdahl, Dane; Wang, Xing; Pan, Xiaochuan; Zhang, K. Max

    In this paper, we report the results and analysis of a recent field campaign in August 2007 investigating the impacts of emissions from transportation on air quality and community concentrations in Beijing, China. We conducted measurements in three different environments, on-road, roadside and ambient. The carbon monoxide, black carbon and ultrafine particle number emission factors for on-road light-duty vehicles are derived to be 95 g kg -1-fuel, 0.3 g kg -1-fuel and 1.8 × 10 15 particles kg -1-fuel, respectively. The emission factors for on-road heavy-duty vehicles are 50 g kg -1-fuel, 1.3 g kg -1-fuel and 1.1 × 10 16 particles kg -1-fuel, respectively. The carbon monoxide emission factors from this study agree with those derived from remote sensing and on-board vehicle emission testing systems in China. The on-road black carbon and particle number emission factors for Chinese vehicles are reported for the first time in the literature. Strong traffic impacts can be observed from the concentrations measured in these different environments. Most clear is a reflection of diesel truck traffic activity in black carbon concentrations. The comparison of the particle size distributions measured at the three environments suggests that the traffic is a major source of ultrafine particles. A four-day traffic control experiment conducted by the Beijing Government as a pilot to test the effectiveness of proposed controls was found to be effective in reducing extreme concentrations that occurred at both on-road and ambient environments.

  5. Theoretical investigation of heave dynamics of an air cushion vehicle bag and finger skirt

    NASA Astrophysics Data System (ADS)

    Chung, Joon

    This thesis describes a theoretical investigation of the nonlinear and linear heave dynamics of an air cushion vehicle (ACV) equipped with a bag and finger skirt system with the purpose of understanding the skirt's effect on the vehicle heave dynamics. Throughout the course of this work, the pure heave motion of a two dimensional section of the skirt is investigated using several mathematical models. Both the nonlinear and linearized analyses include a detailed model of the skirt geometry, which is modelled as a combination of inelastic membranes and links. Air flow processes from the bag to the cushion and from the cushion to the atmosphere are assumed to be quasisteady, and the bag and cushion volumes are modelled as lumped pneumatic capacitances. The modulation of the escaping cushion air by skirt-ground contact is also included. The nonlinear simulations reveal that characteristically nonlinear dynamical phenomena such as period doubling and chaos can be expected to occur during the normal operation of ACVs. Furthermore, a configuration representative of a 37 tonne vehicle shows a resonance at frequencies in the range for which humans are most sensitive. Although these results thus show that some aspects of the bag and finger skirt heave dynamics can be highly nonlinear, they indicate that under certain circumstances, standard linear techniques can yield useful insights. Results from the linear analysis suggest that changes in skirt geometry cannot be used to radically modify the undesirable heave response of the bag and finger skirt, but reducing the skirt mass is quite effective. The pneumatic capacitance of the bag and cushion volume proves to be an important factor in the heave response. In particular, it contributes to heave instability. The air compressibility also affects heave response at high frequencies, with the effect becoming more prominent as the flow rate is reduced. The importance of unsteady fan effects on ACV dynamics is investigated by the

  6. Investigation of REST-Class Hypersonic Inlet Designs

    NASA Technical Reports Server (NTRS)

    Gollan, Rowan; Ferlemann, Paul G.

    2011-01-01

    Rectangular-to-elliptical shape-transition (REST) inlets are of interest for use on scramjet engines because they are efficient and integrate well with the forebody of a planar vehicle. The classic design technique by Smart for these inlets produces an efficient inlet but the complex three-dimensional viscous effects are only approximately included. Certain undesirable viscous features often occur in these inlets. In the present work, a design toolset has been developed which allows for rapid design of REST-class inlet geometries and the subsequent Navier-Stokes analysis of the inlet performance. This gives the designer feedback on the complex viscous effects at each design iteration. This new tool is applied to design an inlet for on-design operation at Mach 8. The tool allows for rapid investigation of design features that was previously not possible. The outcome is that the inlet shape can be modified to affect aspects of the flow field in a positive way. In one particular example, the boundary layer build-up on the bodyside of the inlet was reduced by 20% of the thickness associated with the classically designed inlet shape.

  7. The potential impacts of electric vehicles on air quality in the urban areas of Barcelona and Madrid (Spain)

    NASA Astrophysics Data System (ADS)

    Soret, A.; Guevara, M.; Baldasano, J. M.

    2014-12-01

    This work analyses the potential air quality improvements resulting from three fleet electrification scenarios (∼13, 26 and 40%) by replacing conventional vehicles with Electric Battery Vehicles (EBVs), Plug-in Hybrid Electric Vehicles (PHEVs) and Hybrid Electric Vehicles (HEVs). This study has been performed for the cities of Barcelona and Madrid (Spain), where road transport is the primary emission source. In these urban areas, several air quality problems are present, mainly related to NO2 and particulate matter. The WRF-ARW/HERMESv2/CMAQ model system has been applied at high spatial (1 × 1 km2) and temporal (1 h) resolution. The results show that fleet electrification offers a potential for emission abatement, especially related to NOx and CO. Regarding the more ambitious scenario (∼40% fleet electrification), reductions of 11% and 17% of the total NOx emissions are observed in Barcelona and Madrid respectively. These emissions reductions involve air quality improvements in NO2 maximum hourly values up to 16%: reductions up to 30 and 35 μg m-3 in Barcelona and Madrid, respectively. Furthermore, an additional scenario has been defined considering electric generation emissions associated with EBVs and PHEVs charging from a combined-cycle power plant. These charging emissions would produce slight NO2 increases in the downwind areas of <3 μg m-3. Thus, fleet electrification would improve urban air quality even when considering emissions associated with charging electric vehicles. However, two further points should be considered. First, fleet electrification cannot be considered a unique solution, and other management strategies may be defined. This is especially important with respect to particulate matter emissions, which are not significantly reduced by fleet electrification (<5%) due to the high weight of non-exhaust emissions. Second, a significant introduction of electric vehicles (26-40%) involving all vehicle categories is required to improve urban

  8. Mach 6.5 air induction system design for the Beta II Two-Stage-to-Orbit booster vehicle

    NASA Technical Reports Server (NTRS)

    Midea, Anthony C.

    1991-01-01

    A preliminary, two-dimensional, mixed compression air induction system is designed for the Beta II Two-Stage-to-Orbit booster vehicle to minimize installation losses and efficiently deliver the required airflow. Design concepts, such as an external isentropic compression ramp and a bypass system, are developed and evaluated for performance benefits. The design is optimized by maximizing installed propulsion/vehicle system performance, and the resulting system design operating characteristics and performance are presented. The air induction system design has significantly lower transonic drag than similar designs, and only requires approximately 1/3 of the bleed extraction. In addition, the design efficiently provides the integrated system required airflow, while maintaining adequate levels of total pressure recovery. The excellent performance of this highly integrated air induction system is essential for the successful completion of the Beta II booster vehicle mission.

  9. Mach 6.5 air induction system design for the Beta 2 two-stage-to-orbit booster vehicle

    NASA Technical Reports Server (NTRS)

    Midea, Anthony C.

    1991-01-01

    A preliminary, two-dimensional, mixed compression air induction system is designed for the Beta II Two Stage to Orbit booster vehicle to minimize installation losses and efficiently deliver the required airflow. Design concepts, such as an external isentropic compression ramp and a bypass system were developed and evaluated for performance benefits. The design was optimized by maximizing installed propulsion/vehicle system performance. The resulting system design operating characteristics and performance are presented. The air induction system design has significantly lower transonic drag than similar designs and only requires about 1/3 of the bleed extraction. In addition, the design efficiently provides the integrated system required airflow, while maintaining adequate levels of total pressure recovery. The excellent performance of this highly integrated air induction system is essential for the successful completion of the Beta II booster vehicle mission.

  10. Experimental Investigation of a Shrouded Rotor Micro Air Vehicle in Hover and in Edgewise Gusts

    NASA Astrophysics Data System (ADS)

    Hrishikeshavan, Vikram

    Due to the hover capability of rotary wing Micro Air Vehicles (MAVs), it is of interest to improve their aerodynamic performance, and hence hover endurance (or payload capability). In this research, a shrouded rotor configuration is studied and implemented, that has the potential to offer two key operational benefits: enhanced system thrust for a given input power, and improved structural rigidity and crashworthiness of an MAV platform. The main challenges involved in realising such a system for a lightweight craft are: design of a lightweight and stiff shroud, and increased sensitivity to external flow disturbances that can affect flight stability. These key aspects are addressed and studied in order to assess the capability of the shrouded rotor as a platform of choice for MAV applications. A fully functional shrouded rotor vehicle (disk loading 60 N/ m2) was designed and constructed with key shroud design variables derived from previous studies on micro shrouded rotors. The vehicle weighed about 280 g (244 mm rotor diameter). The shrouded rotor had a 30% increase in power loading in hover compared to an unshrouded rotor. Due to the stiff, lightweight shroud construction, a net payload benefit of 20-30 g was achieved. The different components such as the rotor, stabilizer bar, yaw control vanes and the shroud were systematically studied for system efficiency and overall aerodynamic improvements. Analysis of the data showed that the chosen shroud dimensions was close to optimum for a design payload of 250 g. Risk reduction prototypes were built to sequentially arrive at the final configuration. In order to prevent periodic oscillations in ight, a hingeless rotor was incorporated in the shroud. The vehicle was successfully ight tested in hover with a proportional-integralderivative feedback controller. A flybarless rotor was incorporated for efficiency and control moment improvements. Time domain system identification of the attitude dynamics of the flybar and

  11. Improving commercial broiler attic inlet ventilation thorugh CFD analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of solar heated attic air is an area of increasing interest in commercial poultry production. Attic inlets satisfy the demand for alternative heating while being simple to implement in an existing poultry house. A number of demonstration projects have suggested that attic inlets may decrease...

  12. Q-learning approach to automated unmanned air vehicle (UAV) demining

    NASA Astrophysics Data System (ADS)

    Ferrari, Silvia; Daugherty, Greyson

    2010-04-01

    This paper develops a Q-learning approach to Unmanned Air Vehicle (UAV) navigation, or path planning, for sensing applications in which an infrared (IR) sensor or camera is installed onboard the UAV for the purpose of detecting and classifying multiple, stationary ground targets. The problem can be considered as a geometric sensor-path planning problem, because the geometry and position of the sensor's field of view (FOV) determines what targets can be detected and classified at any given time. The advantage of this approach over existing path planning techniques is that the optimal guidance policy is learned via the Q-function, without explicit knowledge of the system models and environmental conditions. The approach is demonstrated through a demining application in which a UAV-based IR sensor is capable of determining the optimal altitude for properly detecting and classifying targets buried in a complex region of interest.

  13. Continuous high order sliding mode controller design for a flexible air-breathing hypersonic vehicle.

    PubMed

    Wang, Jie; Zong, Qun; Su, Rui; Tian, Bailing

    2014-05-01

    This paper investigates the problem of tracking control with uncertainties for a flexible air-breathing hypersonic vehicle (FAHV). In order to overcome the analytical intractability of this model, an Input-Output linearization model is constructed for the purpose of feedback control design. Then, the continuous finite time convergence high order sliding mode controller is designed for the Input-Output linearization model without uncertainties. In addition, a nonlinear disturbance observer is applied to estimate the uncertainties in order to compensate the controller and disturbance suppression, where disturbance observer and controller synthesis design is obtained. Finally, the synthesis of controller and disturbance observer is used to achieve the tracking for the velocity and altitude of the FAHV and simulations are presented to illustrate the effectiveness of the control strategies. PMID:24534328

  14. Monitoring of atmospheric aerosol emissions using a remotely piloted air vehicle (RPV)-Borne Sensor Suite

    SciTech Connect

    1996-05-01

    We have developed a small sensor system, the micro-atmospheric measurement system ({mu}-AMS), to monitor and track aerosol emissions. The system was developed to fly aboard a remotely piloted air vehicle, or other mobile platform, to provide real-time particle measurements in effluent plumes and to collect particles for chemical analysis. The {mu}-AMS instrument measures atmospheric parameters including particle mass concentration and size distribution, temperature, humidity, and airspeed, altitude and position (by GPS receiver) each second. The sensor data are stored onboard and are also down linked to a ground station in real time. The {mu}-AMS is battery powered, small (8 in. dia x 36 in.), and lightweight (15 pounds). Aerosol concentrations and size distributions from above ground explosive tests, airbone urban pollution, and traffic-produced particulates are presented.

  15. Improved Adaptive-Reinforcement Learning Control for morphing unmanned air vehicles.

    PubMed

    Valasek, John; Doebbler, James; Tandale, Monish D; Meade, Andrew J

    2008-08-01

    This paper presents an improved Adaptive-Reinforcement Learning Control methodology for the problem of unmanned air vehicle morphing control. The reinforcement learning morphing control function that learns the optimal shape change policy is integrated with an adaptive dynamic inversion control trajectory tracking function. An episodic unsupervised learning simulation using the Q-learning method is developed to replace an earlier and less accurate Actor-Critic algorithm. Sequential Function Approximation, a Galerkin-based scattered data approximation scheme, replaces a K-Nearest Neighbors (KNN) method and is used to generalize the learning from previously experienced quantized states and actions to the continuous state-action space, all of which may not have been experienced before. The improved method showed smaller errors and improved learning of the optimal shape compared to the KNN. PMID:18632393

  16. Robust tracking control for an air-breathing hypersonic vehicle with input constraints

    NASA Astrophysics Data System (ADS)

    Gao, Gang; Wang, Jinzhi; Wang, Xianghua

    2014-12-01

    The focus of this paper is on the design and simulation of robust tracking control for an air-breathing hypersonic vehicle (AHV), which is affected by high nonlinearity, uncertain parameters and input constraints. The linearisation method is employed for the longitudinal AHV model about a specific trim condition, and then considering the additive uncertainties of three parameters, the linearised model is just in the form of affine parameter dependence. From this point, the linear parameter-varying method is applied to design the desired controller. The poles for the closed-loop system of the linearised model are placed into a desired vertical strip, and the quadratic stability of the closed-loop system is guaranteed. Input constraints of the AHV are addressed by additional linear matrix inequalities. Finally, the designed controller is evaluated on the nonlinear AHV model and simulation results demonstrate excellent tracking performance with good robustness.

  17. NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan

    2010-01-01

    This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

  18. Linear analysis of the heave dynamics of a bag and finger air cushion vehicle skirt

    NASA Astrophysics Data System (ADS)

    Ma, T.; Sullivan, P. A.

    1986-09-01

    A linear analysis of the heave dynamics of an air-cushion vehicle bag and finger skirt is presented. A simplified geometry is considered; this is a two-dimensional section of the skirt without interior compartmentation. The bag is modeled as a membrane having distributed mass and viscoelasticity, and the fingers are modeled as rigid bodies having both mass and moment of inertia. A finite-element technique is used to discretize the equations of motion of the bag, but otherwise standard linear analysis techniques are used to obtain predictions of frequency response and stability characteristics. The stability results confirm the experimental observation that the dominant factor controlling the onset of skirt bounce is the bag-to-cushion pressure ratio.

  19. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, J. J.; Wu, L.; Mao, H. J.; Liu, H. L.; Jing, B. Y.; Yu, Y.; Ren, P. P.; Feng, C.; Liu, X. H.

    2015-07-01

    In a companion paper (Jing et al., 2015), a high temporal-spatial resolution vehicle emission inventory (HTSVE) for 2013 in Beijing has been established based on near real time (NRT) traffic data and bottom up methodology. In this study, based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modeling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing main urban areas in the periods of summer (July) and winter (December) 2013. Generally, CUACE model had good performance of pollutants concentration simulation. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes over moment. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2, while 5.4 and 10.5 % for PM2.5 in July and December 2013, respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than PM2.5 contribution rate for vehicle emission in total emission, which may be caused by easily dry deposition of PM2.5 from vehicle emission in near-surface layer compared to elevated source emission.

  20. A parallel expert system for the control of a robotic air vehicle

    NASA Technical Reports Server (NTRS)

    Shakley, Donald; Lamont, Gary B.

    1988-01-01

    Expert systems can be used to govern the intelligent control of vehicles, for example the Robotic Air Vehicle (RAV). Due to the nature of the RAV system the associated expert system needs to perform in a demanding real-time environment. The use of a parallel processing capability to support the associated expert system's computational requirement is critical in this application. Thus, algorithms for parallel real-time expert systems must be designed, analyzed, and synthesized. The design process incorporates a consideration of the rule-set/face-set size along with representation issues. These issues are looked at in reference to information movement and various inference mechanisms. Also examined is the process involved with transporting the RAV expert system functions from the TI Explorer, where they are implemented in the Automated Reasoning Tool (ART), to the iPSC Hypercube, where the system is synthesized using Concurrent Common LISP (CCLISP). The transformation process for the ART to CCLISP conversion is described. The performance characteristics of the parallel implementation of these expert systems on the iPSC Hypercube are compared to the TI Explorer implementation.

  1. The development of an experimental facility and investigation of rapidly maneuvering Micro-Air-Vehicle wings

    NASA Astrophysics Data System (ADS)

    Wilson, Lee Alexander

    Vertical Takeoff-and-Landing (VTOL) Micro Air Vehicles (MAVs) provide a versatile operational platform which combines the capabilities of fixed wing and rotary wing MAVs. In order to improve performance of these vehicles, a better understanding of the rapid transition between horizontal and vertical flight is required. This study examines the flow structures around the Mini-Vertigo VTOL MAV using flow visualization techniques. This will gives an understanding of the flow structures which dominate the flight dynamics of rapid pitching maneuvers. This study consists of three objectives: develop an experimental facility, use flow visualization to investigate the flow around the experimental subject during pitching, and analyze the results. The flow around the Mini-Vertigo VTOL MAV is dominated by the slipstream from its propellers. The slipstream delays LE separation and causes drastic deflection in the flow. While the frequency of the vortices shed from the LE and TE varies with flow speed, the non-dimensional frequency does not. It does, however, vary slightly with the pitching rate. These results are applicable across a wide range of flight conditions. The results correlate to previous research done to examine the aerodynamic forces on the MAV.

  2. Uncertainty analysis and robust trajectory linearization control of a flexible air-breathing hypersonic vehicle

    NASA Astrophysics Data System (ADS)

    Pu, Zhiqiang; Tan, Xiangmin; Fan, Guoliang; Yi, Jianqiang

    2014-08-01

    Flexible air-breathing hypersonic vehicles feature significant uncertainties which pose huge challenges to robust controller designs. In this paper, four major categories of uncertainties are analyzed, that is, uncertainties associated with flexible effects, aerodynamic parameter variations, external environmental disturbances, and control-oriented modeling errors. A uniform nonlinear uncertainty model is explored for the first three uncertainties which lumps all uncertainties together and consequently is beneficial for controller synthesis. The fourth uncertainty is additionally considered in stability analysis. Based on these analyses, the starting point of the control design is to decompose the vehicle dynamics into five functional subsystems. Then a robust trajectory linearization control (TLC) scheme consisting of five robust subsystem controllers is proposed. In each subsystem controller, TLC is combined with the extended state observer (ESO) technique for uncertainty compensation. The stability of the overall closed-loop system with the four aforementioned uncertainties and additional singular perturbations is analyzed. Particularly, the stability of nonlinear ESO is also discussed from a Liénard system perspective. At last, simulations demonstrate the great control performance and the uncertainty rejection ability of the robust scheme.

  3. A refuelable zinc/air battery for fleet electric vehicle propulsion

    NASA Astrophysics Data System (ADS)

    Cooper, John F.; Fleming, Dennis; Hargrove, Douglas; Koopman, Ronald; Peterman, Keith

    1995-04-01

    We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet's home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

  4. A refuelable zinc/air battery for fleet electric vehicle propulsion

    SciTech Connect

    Cooper, J.F.; Fleming, D.; Hargrove, D.; Koopman, R.; Peterman, K.

    1995-04-20

    We report the development and on-vehicle testing of an engineering prototype zinc/air battery. The battery is refueled by periodic exchange of spent electrolyte for zinc particles entrained in fresh electrolyte. The technology is intended to provide a capability for nearly continuous vehicle operation, using the fleet s home base for 10 minute refuelings and zinc recycling instead of commercial infrastructure. In the battery, the zinc fuel particles are stored in hoppers, from which they are gravity fed into individual cells and completely consumed during discharge. A six-celled (7V) engineering prototype battery was combined with a 6 V lead/acid battery to form a parallel hybrid unit, which was tested in series with the 216 V battery of an electric shuttle bus over a 75 mile circuit. The battery has an energy density of 140 Wh/kg and a mass density of 1.5 kg/L. Cost, energy efficiency, and alternative hybrid configurations are discussed.

  5. Preliminary development of a VTOL unmanned air vehicle for the close-range mission

    NASA Astrophysics Data System (ADS)

    Kress, Gregory A.

    1992-09-01

    The preliminary development of a full-scale Vertical Takeoff and Landing (VTOL) Unmanned Air Vehicle (UAV) for the Close-Range mission was completed at the Naval Postgraduate School (NPS). The vehicle was based on half-scale ducted-fan investigations performed at the UAV Flight Research Lab. The resulting design is a fixed-duct, tail-sitter UAV with a canard-configured horizontal stabilizer. Major airframe components are used from previous UAV's and include the wings from a U.S. Army Aquila and the ducted fan from the U.S. Marine Corps AROD. Accomplishments include: (1) the design and fabrication of a carry-through spar, and (2) the design and construction of an engine test stand. The through spar was designed using finite element analysis and constructed from composite materials. The purpose of the test stand is to measure torque, horsepower, and thrust of an entire ducted fan or an individual engine. Completion of this thesis will pave the way for future NPS research into the growing interest in VTOL UAV technology.

  6. The development of aluminum-air batteries for application in electric vehicles

    SciTech Connect

    Rudd, E.J. . Research and Development Center); Lott, S. )

    1990-12-01

    The recently concluded program, jointly funded by ELTECH Research Corporation and the Department of Energy, focused upon the development of an aluminum-air battery system for electric vehicle applications. The operation of the aluminum-air battery involves the dissolution of aluminum to produce a current and aluminate. Initially the objectives were to evaluate and optimize the battery design that was developed prior to this program (designated as the B300 cell) and to design and evaluate the components of the auxiliary system. During the program, three additional tasks were undertaken, addressing needs identified by ELTECH and by Sandia National Laboratories. First, the capability to produce aluminum alloys as relatively large ingots (100--150 lbs), with the required electrochemical performance, was considered essential to the development of the battery. The second additional task was the adoption of an advanced cell (designated as the AT400 cell), designed by ELTECH in a different program. Finally, it was recognized that a system model would allow evaluation of the interactions of the several unit operations involved in the battery. Therefore, the development of a mathematical model, based upon material and energy balances for the battery, was undertaken. At a systems level, sufficient information was obtained in the completion of this program to support the design, fabrication and operation of a batch'' or solids-free'' battery system. For the first time, the components of the auxiliary system, i.e., a heat exchanger, carbon dioxide scrubber and hydrogen disposal technology, have been defined for a vehicle battery. Progress on each component or system is summarized in the following sections.

  7. Estimation of road vehicle exhaust emissions from 1992 to 2010 and comparison with air quality measurements in Genoa, Italy

    NASA Astrophysics Data System (ADS)

    Zamboni, Giorgio; Capobianco, Massimo; Daminelli, Enrico

    An investigation into road transport exhaust emissions in the Genoa urban area was performed by comparing the quantities of carbon monoxide (CO), nitrogen oxides (NO x), nitrogen dioxide (NO 2) and particulate matter (PM) emitted by different vehicle categories with air quality measurements referred to the same pollutants. Exhaust emissions were evaluated by applying the PROGRESS (computer PROGramme for Road vehicle EmiSSions evaluation) code, developed by the Internal Combustion Engines Group of the University of Genoa, to eight different years (from 1992 to 2010), considering spark ignition and Diesel passenger cars and light duty vehicles, heavy duty vehicles and buses, motorcycles and mopeds. Changes in terms of vehicles number, mileage and total emissions are presented together with relative distributions among the various vehicle categories. By comparing 1992 and 2010 data, calculated trends show a 7% increase in the number of vehicles, with total mileage growing at a faster rate (approx. 22%); total emissions decrease considerably, by approximately 50% for NO x and PM, 70% for HC and 80% for CO, due to improvements in engines and fuels forced by the stricter European legislation and the fleet renewal, while primary NO 2 emission will be very close to 1992 level, after a decrease of about 18% in 2000. Air quality was analysed by selecting traffic and background measuring stations from the monitoring network managed by the Environmental Department of the Province of Genoa: average annual concentrations of considered pollutants from 1994 to 2007 were calculated in order to obtain the relative historical trends and compare them with European public health limits and with road vehicle emissions. Though an important reduction in pollutant concentrations has been achieved as a consequence of cleaner vehicles, some difficulties in complying with present and/or future NO 2 and PM 10 limits are also apparent, thus requiring suitable measures to be taken by the local

  8. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 2: Impact of vehicle emission on urban air quality

    NASA Astrophysics Data System (ADS)

    He, Jianjun; Wu, Lin; Mao, Hongjun; Liu, Hongli; Jing, Boyu; Yu, Ye; Ren, Peipei; Feng, Cheng; Liu, Xuehao

    2016-03-01

    A companion paper developed a vehicle emission inventory with high temporal-spatial resolution (HTSVE) with a bottom-up methodology based on local emission factors, complemented with the widely used emission factors of COPERT model and near-real-time (NRT) traffic data on a specific road segment for 2013 in urban Beijing (Jing et al., 2016), which is used to investigate the impact of vehicle pollution on air pollution in this study. Based on the sensitivity analysis method of switching on/off pollutant emissions in the Chinese air quality forecasting model CUACE, a modelling study was carried out to evaluate the contributions of vehicle emission to the air pollution in Beijing's main urban areas in the periods of summer (July) and winter (December) 2013. Generally, the CUACE model had good performance of the concentration simulation of pollutants. The model simulation has been improved by using HTSVE. The vehicle emission contribution (VEC) to ambient pollutant concentrations not only changes with seasons but also changes with time. The mean VEC, affected by regional pollutant transports significantly, is 55.4 and 48.5 % for NO2 and 5.4 and 10.5 % for PM2.5 in July and December 2013 respectively. Regardless of regional transports, relative vehicle emission contribution (RVEC) to NO2 is 59.2 and 57.8 % in July and December 2013, while it is 8.7 and 13.9 % for PM2.5. The RVEC to PM2.5 is lower than the PM2.5 contribution rate for vehicle emission in total emission, which may be due to dry deposition of PM2.5 from vehicle emission in the near-surface layer occuring more easily than from elevated source emission.

  9. Life cycle air emissions impacts and ownership costs of light-duty vehicles using natural gas as a primary energy source.

    PubMed

    Luk, Jason M; Saville, Bradley A; MacLean, Heather L

    2015-04-21

    This paper aims to comprehensively distinguish among the merits of different vehicles using a common primary energy source. In this study, we consider compressed natural gas (CNG) use directly in conventional vehicles (CV) and hybrid electric vehicles (HEV), and natural gas-derived electricity (NG-e) use in plug-in battery electric vehicles (BEV). This study evaluates the incremental life cycle air emissions (climate change and human health) impacts and life cycle ownership costs of non-plug-in (CV and HEV) and plug-in light-duty vehicles. Replacing a gasoline CV with a CNG CV, or a CNG CV with a CNG HEV, can provide life cycle air emissions impact benefits without increasing ownership costs; however, the NG-e BEV will likely increase costs (90% confidence interval: $1000 to $31 000 incremental cost per vehicle lifetime). Furthermore, eliminating HEV tailpipe emissions via plug-in vehicles has an insignificant incremental benefit, due to high uncertainties, with emissions cost benefits between -$1000 and $2000. Vehicle criteria air contaminants are a relatively minor contributor to life cycle air emissions impacts because of strict vehicle emissions standards. Therefore, policies should focus on adoption of plug-in vehicles in nonattainment regions, because CNG vehicles are likely more cost-effective at providing overall life cycle air emissions impact benefits. PMID:25825338

  10. Networking Multiple Autonomous Air and Ocean Vehicles for Oceanographic Research and Monitoring

    NASA Astrophysics Data System (ADS)

    McGillivary, P. A.; Borges de Sousa, J.; Rajan, K.

    2013-12-01

    Autonomous underwater and surface vessels (AUVs and ASVs) are coming into wider use as components of oceanographic research, including ocean observing systems. Unmanned airborne vehicles (UAVs) are now available at modest cost, allowing multiple UAVs to be deployed with multiple AUVs and ASVs. For optimal use good communication and coordination among vehicles is essential. We report on the use of multiple AUVs networked in communication with multiple UAVs. The UAVs are augmented by inferential reasoning software developed at MBARI that allows UAVs to recognize oceanographic fronts and change their navigation and control. This in turn allows UAVs to automatically to map frontal features, as well as to direct AUVs and ASVs to proceed to such features and conduct sampling via onboard sensors to provide validation for airborne mapping. ASVs can also act as data nodes for communication between UAVs and AUVs, as well as collecting data from onboard sensors, while AUVs can sample the water column vertically. This allows more accurate estimation of phytoplankton biomass and productivity, and can be used in conjunction with UAV sampling to determine air-sea flux of gases (e.g. CO2, CH4, DMS) affecting carbon budgets and atmospheric composition. In particular we describe tests in July 2013 conducted off Sesimbra, Portugal in conjunction with the Portuguese Navy by the University of Porto and MBARI with the goal of tracking large fish in the upper water column with coordinated air/surface/underwater measurements. A thermal gradient was observed in the infrared by a low flying UAV, which was used to dispatch an AUV to obtain ground truth to demonstrate the event-response capabilities using such autonomous platforms. Additional field studies in the future will facilitate integration of multiple unmanned systems into research vessel operations. The strength of hardware and software tools described in this study is to permit fundamental oceanographic measurements of both ocean

  11. Analysis of Scramjet Inlets

    NASA Technical Reports Server (NTRS)

    Kumar, A.

    1986-01-01

    NASCRIN analyzes two-dimensional flow fields in supersonic combustion ramjet (scramjet) inlets. Solves two-dimensional Euler or Navier-Strokes equations in conservative form by unsplit, explicit, two-step finitedifference method. More recent explicit/implicit, two-step scheme also incorporated for viscous flow analysis. Algebraic, two-layer eddy-viscosity model used for turbulent flow calculations.

  12. Explosives screening on a vehicle surface

    DOEpatents

    Parmeter, John E.; Brusseau, Charles A.; Davis, Jerry D.; Linker, Kevin L.; Hannum, David W.

    2005-02-01

    A system for detecting particles on the outer surface of a vehicle has a housing capable of being placed in a test position adjacent to, but not in contact with, a portion of the outer surface of the vehicle. An elongate sealing member is fastened to the housing along a perimeter surrounding the wall, and the elongate sealing member has a contact surface facing away from the wall to contact the outer surface of the vehicle to define a test volume when the wall is in the test position. A gas flow system has at least one gas inlet extending through the wall for providing a gas stream against the surface of the vehicle within the test volume. This gas stream, which preferably is air, dislodges particles from the surface of the vehicle covered by the housing. The gas stream exits the test volume through a gas outlet and particles in the stream are detected.

  13. Design and fabrication of microflap actuators for steering of micro air vehicles

    NASA Astrophysics Data System (ADS)

    Zimbru, George C.; Lee, Woo Ho; Popa, Dan O.

    2009-05-01

    This paper presents the design, analysis, and fabrication of an array of microflap actuators that can produce a substantial aerodynamic force for course corrections of Micro Air Vehicles (MAVs) and low speed projectiles. In the past, several actuation principles, including microjet, magnetic and bubble actuators, and flapping wings have been proposed, and had varying degrees of success. In this paper, we discuss the benefits and drawbacks of past attempts, and the technology that can be used to address the microflap steering problem. We propose a hybrid microflap actuation scheme that combines two types of actuators including: 1) a MEMS fabricated "active" microactuator connected to a microflap, and 2) a "passive" fluidic channel system that harvests the potential energy in the high pressure field on the leading edge of the MAV or high speed projectile to achieve a desired deflection. An array of microflap actuators was prototyped using silicon MEMS fabrication and microassembly. A Silicon On Insulator (SOI) wafer with 100 micron thick device layer was used to as a substrate material to fabricate microflap structures with springs. Front and back side DRIE process was used to etch and release the microstructures including microflaps. Then, the microactuator was assembled on top of the microflap. The static and dynamic behaviors of a microflap were measured using a laser displacement sensor and were compared to the analytic model. In the near future, a prototyped microflap will be tested inside of a wind tunnel to measure the lift and drag at various air speeds.

  14. Control and design of multiple unmanned air vehicles for persistent surveillance

    NASA Astrophysics Data System (ADS)

    Nigam, Nikhil

    Control of multiple autonomous aircraft for search and exploration, is a topic of current research interest for applications such as weather monitoring, geographical surveys, search and rescue, tactical reconnaissance, and extra-terrestrial exploration, and the need to distribute sensing is driven by considerations of efficiency, reliability, cost and scalability. Hence, this problem has been extensively studied in the fields of controls and artificial intelligence. The task of persistent surveillance is different from a coverage/exploration problem, in that all areas need to be continuously searched, minimizing the time between visitations to each region in the target space. This distinction does not allow a straightforward application of most exploration techniques to the problem, although ideas from these methods can still be used. The use of aerial vehicles is motivated by their ability to cover larger spaces and their relative insensitivity to terrain. However, the dynamics of Unmanned Air Vehicles (UAVs) adds complexity to the control problem. Most of the work in the literature decouples the vehicle dynamics and control policies, but their interaction is particularly interesting for a surveillance mission. Stochastic environments and UAV failures further enrich the problem by requiring the control policies to be robust, and this aspect is particularly important for hardware implementations. For a persistent mission, it becomes imperative to consider the range/endurance constraints of the vehicles. The coupling of the control policy with the endurance constraints of the vehicles is an aspect that has not been sufficiently explored. Design of UAVs for desirable mission performance is also an issue of considerable significance. The use of a single monolithic optimization for such a problem has practical limitations, and decomposition-based design is a potential alternative. In this research high-level control policies are devised, that are scalable, reliable

  15. Integration of Advanced Concepts and Vehicles Into the Next Generation Air Transportation System. Volume 1; Introduction, Key Messages, and Vehicle Attributes

    NASA Technical Reports Server (NTRS)

    Zellweger, Andres; Resnick, Herbert; Stevens, Edward; Arkind, Kenneth; Cotton William B.

    2010-01-01

    Raytheon, in partnership with NASA, is leading the way in ensuring that the future air transportation continues to be a key driver of economic growth and stability and that this system provides an environmentally friendly, safe, and effective means of moving people and goods. A Raytheon-led team of industry and academic experts, under NASA contract NNA08BA47C, looked at the potential issues and impact of introducing four new classes of advanced aircraft into the next generation air transportation system -- known as NextGen. The study will help determine where NASA should further invest in research to support the safe introduction of these new air vehicles. Small uncrewed or unmanned aerial systems (SUAS), super heavy transports (SHT) including hybrid wing body versions (HWB), very light jets (VLJ), and supersonic business jets (SSBJ) are the four classes of aircraft that we studied. Understanding each vehicle's business purpose and strategy is critical to assessing the feasibility of new aircraft operations and their impact on NextGen's architecture. The Raytheon team used scenarios created by aviation experts that depict vehicles in year 2025 operations along with scripts or use cases to understand the issues presented by these new types of vehicles. The information was then mapped into the Joint Planning and Development Office's (JPDO s) Enterprise Architecture to show how the vehicles will fit into NextGen's Concept of Operations. The team also identified significant changes to the JPDO's Integrated Work Plan (IWP) to optimize the NextGen vision for these vehicles. Using a proven enterprise architecture approach and the JPDO s Joint Planning Environment (JPE) web site helped make the leap from architecture to planning efficient, manageable and achievable. Very Light Jets flying into busy hub airports -- Supersonic Business Jets needing to climb and descend rapidly to achieve the necessary altitude Super-heavy cargo planes requiring the shortest common flight

  16. Micro-electro-mechanical flapping wing technology for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Hall, Asha J.; Riddick, Jaret C.

    2012-04-01

    Army combat operations have placed a high premium on reconnaissance missions for Unmanned Aerial Vehicles (UAVs) and Micro Air Vehicles (MAVs) (less than 15 cm in dimension and less than 20 g in mass). One approach for accomplishing this mission is to develop a biologically inspired flapping wing insect that can maneuver into confined areas and possess hovering capabilities. Analysis of insect flight indicates that in addition to the bending excitation (flapping), simultaneous excitation of the twisting degree-of-freedom (pitching) is required to manipulate the control surface adequately. Traditionally, bimorph piezoelectric PZT (Pb(Zr0.55Ti0.45)O3) actuators have been used in many applications to excite the bending degree-of-freedom. In laminated or layered structures, bend-twist coupling is governed by the existence of at least one anisotropic layer not aligned with the primary plate axes. By adding a layer of off-axis PZT segments to a PZT bimorph actuator, thereby producing a layered structure to be referred to as a functionally- modified bimorph, bend-twist coupling may be introduced to the flexural response of the layered PZT. Furthermore, by selectively charging off-axis layers in specific combinations with the bimorph, the response of the functionally-modified bimorph may be tailored yielding a biaxial actuator to actively control the flapping wing response. The present study presents an experimental investigation of both traditional bimorph and functionally-modified PZT bimorph designs intended for active bend-twist actuation of cm-scale flapping wing devices.

  17. Autonomous landing and ingress of micro-air-vehicles in urban environments based on monocular vision

    NASA Astrophysics Data System (ADS)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-06-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  18. Autonomous Landing and Ingress of Micro-Air-Vehicles in Urban Environments Based on Monocular Vision

    NASA Technical Reports Server (NTRS)

    Brockers, Roland; Bouffard, Patrick; Ma, Jeremy; Matthies, Larry; Tomlin, Claire

    2011-01-01

    Unmanned micro air vehicles (MAVs) will play an important role in future reconnaissance and search and rescue applications. In order to conduct persistent surveillance and to conserve energy, MAVs need the ability to land, and they need the ability to enter (ingress) buildings and other structures to conduct reconnaissance. To be safe and practical under a wide range of environmental conditions, landing and ingress maneuvers must be autonomous, using real-time, onboard sensor feedback. To address these key behaviors, we present a novel method for vision-based autonomous MAV landing and ingress using a single camera for two urban scenarios: landing on an elevated surface, representative of a rooftop, and ingress through a rectangular opening, representative of a door or window. Real-world scenarios will not include special navigation markers, so we rely on tracking arbitrary scene features; however, we do currently exploit planarity of the scene. Our vision system uses a planar homography decomposition to detect navigation targets and to produce approach waypoints as inputs to the vehicle control algorithm. Scene perception, planning, and control run onboard in real-time; at present we obtain aircraft position knowledge from an external motion capture system, but we expect to replace this in the near future with a fully self-contained, onboard, vision-aided state estimation algorithm. We demonstrate autonomous vision-based landing and ingress target detection with two different quadrotor MAV platforms. To our knowledge, this is the first demonstration of onboard, vision-based autonomous landing and ingress algorithms that do not use special purpose scene markers to identify the destination.

  19. Advanced Technology Inlet Design, NRA 8-21 Cycle II: DRACO Flowpath Hypersonic Inlet Design

    NASA Technical Reports Server (NTRS)

    Sanders, Bobby W.; Weir, Lois J.

    1999-01-01

    The report outlines work performed in support of the flowpath development for the DRACO engine program. The design process initiated to develop a hypersonic axisymmetric inlet for a Mach 6 rocket-based combined cycle (RBCC) engine is discussed. Various design parametrics were investigated, including design shock-on-lip Mach number, cone angle, throat Mach number, throat angle. length of distributed compression, and subsonic diffuser contours. Conceptual mechanical designs consistent with installation into the D-21 vehicle were developed. Additionally, program planning for an intensive inlet development program to support a Critical Design Review in three years was performed. This development program included both analytical and experimental elements and support for a flight-capable inlet mechanical design.

  20. Inlet nozzle assembly

    DOEpatents

    Christiansen, David W.; Karnesky, Richard A.; Precechtel, Donald R.; Smith, Bob G.; Knight, Ronald C.

    1987-01-01

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  1. Inlet nozzle assembly

    DOEpatents

    Christiansen, D.W.; Karnesky, R.A.; Knight, R.C.; Precechtel, D.R.; Smith, B.G.

    1985-09-09

    An inlet nozzle assembly for directing coolant into the duct tube of a fuel assembly attached thereto. The nozzle assembly includes a shell for housing separable components including an orifice plate assembly, a neutron shield block, a neutron shield plug, and a diffuser block. The orifice plate assembly includes a plurality of stacked plates of differently configurated and sized openings for directing coolant therethrough in a predesigned flow pattern.

  2. Emission factors of air pollutants from CNG-gasoline bi-fuel vehicles: Part II. CO, HC and NOx.

    PubMed

    Huang, Xiaoyan; Wang, Yang; Xing, Zhenyu; Du, Ke

    2016-09-15

    The estimation of emission factors (EFs) is the basis of accurate emission inventory. However, the EFs of air pollutants for motor vehicles vary under different operating conditions, which will cause uncertainty in developing emission inventory. Natural gas (NG), considered as a "cleaner" fuel than gasoline, is increasingly being used to reduce combustion emissions. However, information is scarce about how much emission reduction can be achieved by motor vehicles burning NG (NGVs) under real road driving conditions, which is necessary for evaluating the environmental benefits for NGVs. Here, online, in situ measurements of the emissions from nine bi-fuel vehicles were conducted under different operating conditions on the real road. A comparative study was performed for the EFs of black carbon (BC), carbon monoxide (CO), hydrocarbons (HCs) and nitrogen oxides (NOx) for each operating condition when the vehicles using gasoline and compressed NG (CNG) as fuel. BC EFs were reported in part I. The part II in this paper series reports the influence of operating conditions and fuel types on the EFs of CO, HC and NOx. Fuel-based EFs of CO showed good correlations with speed when burning CNG and gasoline. The correlation between fuel-based HC EFs and speed was relatively weak whether burning CNG or gasoline. The fuel-based NOx EFs moderately correlated with speed when burning CNG, but weakly correlated with gasoline. As for HC, the mileage-based EFs of gasoline vehicles are 2.39-12.59 times higher than those of CNG vehicles. The mileage-based NOx EFs of CNG vehicles are slightly higher than those of gasoline vehicles. These results would facilitate a detailed analysis of the environmental benefits for replacing gasoline with CNG in light duty vehicles. PMID:27219504

  3. Fully self-contained vision-aided navigation and landing of a micro air vehicle independent from external sensor inputs

    NASA Astrophysics Data System (ADS)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-06-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  4. Fully Self-Contained Vision-Aided Navigation and Landing of a Micro Air Vehicle Independent from External Sensor Inputs

    NASA Technical Reports Server (NTRS)

    Brockers, Roland; Susca, Sara; Zhu, David; Matthies, Larry

    2012-01-01

    Direct-lift micro air vehicles have important applications in reconnaissance. In order to conduct persistent surveillance in urban environments, it is essential that these systems can perform autonomous landing maneuvers on elevated surfaces that provide high vantage points without the help of any external sensor and with a fully contained on-board software solution. In this paper, we present a micro air vehicle that uses vision feedback from a single down looking camera to navigate autonomously and detect an elevated landing platform as a surrogate for a roof top. Our method requires no special preparation (labels or markers) of the landing location. Rather, leveraging the planar character of urban structure, the landing platform detection system uses a planar homography decomposition to detect landing targets and produce approach waypoints for autonomous landing. The vehicle control algorithm uses a Kalman filter based approach for pose estimation to fuse visual SLAM (PTAM) position estimates with IMU data to correct for high latency SLAM inputs and to increase the position estimate update rate in order to improve control stability. Scale recovery is achieved using inputs from a sonar altimeter. In experimental runs, we demonstrate a real-time implementation running on-board a micro aerial vehicle that is fully self-contained and independent from any external sensor information. With this method, the vehicle is able to search autonomously for a landing location and perform precision landing maneuvers on the detected targets.

  5. Air filtering device

    SciTech Connect

    Backus, A.L.

    1992-07-28

    This patent describes a room air cleaning device. It comprises: a box housing having an air inlet and an air outlet provided therein; a vertical baffle coupled to the box housing opposite the air outlet and spaced form the box housing such that an air egress outlet is formed between the vertical baffle and the box housing; air cleansing means substantially disposed within the box housing and cleansing air passing into the inlet and out of the air egress outlet; a fan disposed within the box housing, the fan providing air movement through the air inlet and the air egress outlet; wherein air exits the room air cleaning device through the air egress outlet as a vertical plane of moving air; and wherein formation of the vertical plane of moving air contributes to the formation of a low pressure area drawing impure air toward the air inlet.

  6. The effect of aircraft inlets on the behaviour of aero engine axial flow compressors

    NASA Astrophysics Data System (ADS)

    Freeman, Christopher J.

    The air inlet and its effect on turbocompressors are described, covering the following: the engine aircraft operating envelopes, inlet loading, interaction between inlet and compressor, compression distortion tolerance, response of compressor to inlet total pressure distortion, inlet and outlet static pressure distribution, and other threats to compressor stability due to inlet. The following conclusions are made: the aircraft operating envelope is demanding of the inlet when the pressures to reduce size cost, weight, and drag are obvious; the inlet separates at the edges of the envelope; the separation can be reduced by applying well known scaling laws; this asymmetric separation can degrade the compressor surge margin; and the stability margin of the engine can be affected by other features of the inlet.

  7. Measurement of Fine Particles From Mobile and Stationary Sources, and Reducing the Air Conditioner Power Consumption in Hybrid Electric Vehicles

    NASA Astrophysics Data System (ADS)

    Brewer, Eli Henry

    We study the PM2.5and ultrafine exhaust emissions from a new natural gas-fired turbine power facility to better understand air pollution in California. To characterize the emissions from new natural gas turbines, a series of tests were performed on a GE LMS100 gas turbine. These tests included PM2.5 and wet chemical tests for SO2/SO 3 and NH3, as well as ultrafine (less than 100 nm in diameter) particulate matter measurements. The turbine exhaust had an average particle number concentration that was 2.3x103 times higher than ambient air. The majority of these particles were nanoparticles; at the 100 nm size, stack particle concentrations were about 20 times higher than ambient, and increased to 3.9x104 times higher on average in the 2.5 - 3 nm particle size range. This study also found that ammonia emissions were higher than expected, but in compliance with permit conditions. This was possibly due to an ammonia imbalance entering the catalyst, some flue gas bypassing the catalyst, or not enough catalyst volume. SO3 accounted for an average of 23% of the total sulfur oxides emissions measured. Some of the SO3 is formed in the combustion process, it is likely that the majority formed as the SO2 in the combustion products passed across the oxidizing CO catalyst and SCR catalyst. The 100 MW turbine sampled in this study emitted particle loadings similar to those previously measured from turbines in the SCAQMD area, however, the turbine exhaust contained far more particles than ambient air. The power consumed by an air conditioner accounts for a significant fraction of the total power used by hybrid and electric vehicles especially during summer. This study examined the effect of recirculation of cabin air on power consumption of mobile air conditioners both in-lab and on-road. Real time power consumption and vehicle mileage were recorded by an On Board Diagnostic monitor and carbon balance method. Vehicle mileage improved with increased cabin air recirculation. The

  8. 4D metrology of flapping-wing micro air vehicle based on fringe projection

    NASA Astrophysics Data System (ADS)

    Zhang, Qican; Huang, Lei; Chin, Yao-Wei; Keong, Lau-Gih; Asundi, Anand

    2013-06-01

    Inspired by dominant flight of the natural flyers and driven by civilian and military purposes, micro air vehicle (MAV) has been developed so far by passive wing control but still pales in aerodynamic performance. Better understanding of flapping wing flight mechanism is eager to improve MAV's flight performance. In this paper, a simple and effective 4D metrology technique to measure full-field deformation of flapping membrane wing is presented. Based on fringe projection and 3D Fourier analysis, the fast and complex dynamic deformation, including wing rotation and wing stroke, of a flapping wing during its flight can be accurately reconstructed from the deformed fringe patterns recorded by a highspeed camera. An experiment was carried on a flapping-wing MAV with 5-cm span membrane wing beating at 30 Hz, and the results show that this method is effective and will be useful to the aerodynamicist or micro aircraft designer for visualizing high-speed complex wing deformation and consequently aid the design of flapping wing mechanism to enhanced aerodynamic performance.

  9. Fuel Cell Propulsion Systems for an All-Electric Personal Air Vehicle

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa L.

    2003-01-01

    There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

  10. An experimental study of a bio-inspired corrugated airfoil for micro air vehicle applications

    NASA Astrophysics Data System (ADS)

    Murphy, Jeffery T.; Hu, Hui

    2010-08-01

    An experimental study was conducted to investigate the aerodynamic characteristics of a bio-inspired corrugated airfoil compared with a smooth-surfaced airfoil and a flat plate at the chord Reynolds number of Re C = 58,000-125,000 to explore the potential applications of such bio-inspired corrugated airfoils for micro air vehicle designs. In addition to measuring the aerodynamic lift and drag forces acting on the tested airfoils, a digital particle image velocimetry system was used to conduct detailed flowfield measurements to quantify the transient behavior of vortex and turbulent flow structures around the airfoils. The measurement result revealed clearly that the corrugated airfoil has better performance over the smooth-surfaced airfoil and the flat plate in providing higher lift and preventing large-scale flow separation and airfoil stall at low Reynolds numbers (Re C < 100,000). While aerodynamic performance of the smooth-surfaced airfoil and the flat plate would vary considerably with the changing of the chord Reynolds numbers, the aerodynamic performance of the corrugated airfoil was found to be almost insensitive to the Reynolds numbers. The detailed flow field measurements were correlated with the aerodynamic force measurement data to elucidate underlying physics to improve our understanding about how and why the corrugation feature found in dragonfly wings holds aerodynamic advantages for low Reynolds number flight applications.

  11. Dynamic stability test results on an 0.024 scale B-1 air vehicle

    NASA Technical Reports Server (NTRS)

    Beeman, R. R.

    1972-01-01

    Dynamic longitudinal and lateral-directional stability characteristics of the B-1 air vehicle were investigated in three wind tunnels at the Langley Research Center. The main rotary derivatives were obtained for an angle of attack range of -3 degrees to +16 degrees for a Mach number range of 0.2 to 2.16. Damping in roll data could not be obtained at the supersonic Mach numbers. The Langley 7 x 10 foot high speed tunnel, the 8 foot transonic pressure tunnel, and the 4 foot Unitary Plan wind tunnel were the test sites. An 0.024 scale light-weight model was used on a forced oscillation type balance. Test Reynolds number varied from 474,000/ft to 1,550,000/ft. through the Mach number range tested. The results showed that the dynamic stability characteristics of the model in pitch and roll were generally satisfactory up to an angle attack of about +6 degrees. In the wing sweep range from 15 to 25 degrees the positive damping levels in roll deteriorated rapidly above +2 degrees angle of attack. This reduction in roll damping is believed to be due to the onset of separation over the wing as stall is approached.

  12. Conservation equations and physical models for hypersonic air flows over the aeroassist flight experiment vehicle

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.

    1989-01-01

    The code development and application program for the Langley Aerothermodynamic Upwind Relaxation Algorithm (LAURA), with emphasis directed toward support of the Aeroassist Flight Experiment (AFE) in the near term and Aeroassisted Space Transfer Vehicle (ASTV) design in the long term is reviewed. LAURA is an upwind-biased, point-implicit relaxation algorithm for obtaining the numerical solution to the governing equations for 3-D, viscous, hypersonic flows in chemical and thermal nonequilibrium. The algorithm is derived using a finite volume formulation in which the inviscid components of flux across cell walls are described with Roe's averaging and Harten's entropy fix with second-order corrections based on Yee's Symmetric Total Variation Diminishing scheme. Because of the point-implicit relaxation strategy, the algorithm remains stable at large Courant numbers without the necessity of solving large, block tri-diagonal systems. A single relaxation step depends only on information from nearest neighbors. Predictions for pressure distributions, surface heating, and aerodynamic coefficients compare well with experimental data for Mach 10 flow over an AFE wind tunnel model. Predictions for the hypersonic flow of air in chemical and thermal nonequilibrium over the full scale AFE configuration obtained on a multi-domain grid are discussed.

  13. Low Dimensional Tools for Flow-Structure Interaction Problems: Application to Micro Air Vehicles

    NASA Technical Reports Server (NTRS)

    Schmit, Ryan F.; Glauser, Mark N.; Gorton, Susan A.

    2003-01-01

    A low dimensional tool for flow-structure interaction problems based on Proper Orthogonal Decomposition (POD) and modified Linear Stochastic Estimation (mLSE) has been proposed and was applied to a Micro Air Vehicle (MAV) wing. The method utilizes the dynamic strain measurements from the wing to estimate the POD expansion coefficients from which an estimation of the velocity in the wake can be obtained. For this experiment the MAV wing was set at five different angles of attack, from 0 deg to 20 deg. The tunnel velocities varied from 44 to 58 ft/sec with corresponding Reynolds numbers of 46,000 to 70,000. A stereo Particle Image Velocimetry (PIV) system was used to measure the wake of the MAV wing simultaneously with the signals from the twelve dynamic strain gauges mounted on the wing. With 20 out of 2400 POD modes, a reasonable estimation of the flow flow was observed. By increasing the number of POD modes, a better estimation of the flow field will occur. Utilizing the simultaneously sampled strain gauges and flow field measurements in conjunction with mLSE, an estimation of the flow field with lower energy modes is reasonable. With these results, the methodology for estimating the wake flow field from just dynamic strain gauges is validated.

  14. Roof Modelling Potential of Unmanned Air Vehicle Point Clouds with Respect to Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Karakis, Serkan; Gunes Sefercik, Umut; Atalay, Can

    2016-07-01

    In parallel with the improvement of laser scanning technologies, dense point clouds which provide the detailed description of terrain and non-terrain objects became indispensable for remotely-sensed data users. Owing to the large demand, besides laser scanning, point clouds were started to achieve using photogrammetric images. Unmanned air vehicle (UAV) images are one of the most preferred data for creating dense point clouds by the advantage of low cost, rapid and periodically gain. In this study, we tried to assess the roof modelling potential of UAV point clouds by comparing three dimensional (3D) roof models produced from UAV and terrestrial laser scanning (TLS) point clouds. In the study, very popular low cost action camera SJ4000 and Faro Laser Scanner Focus3D X 330 were used to provide point clouds and the roof of Bulent Ecevit University Civil Aviation Academy building was utilized. For the validation of horizontal and vertical geolocation accuracies, standard deviation was used as the main indicator. The visual results demonstrated that UAV roof model is almost coherent with TLS roof model after the filtering-based refinement on noisy pixels and systematic bias correction. Moreover, the horizontal geolocation accuracy is approx. |5cm| both in X and Y directions and bias corrected vertical geolocation accuracy is approx. 17cm for zero roof slope.

  15. Design and verification of a smart wing for an extreme-agility micro-air-vehicle

    NASA Astrophysics Data System (ADS)

    Wickramasinghe, Viresh; Chen, Yong; Martinez, Marcias; Wong, Franklin; Kernaghan, Robert

    2011-12-01

    A special class of fixed-wing micro-air-vehicle (MAV) is currently being designed to fly and hover to provide range superiority as well as being able to hover through a flight maneuver known as prop-hanging to accomplish a variety of surveillance missions. The hover maneuver requires roll control of the wing through differential aileron deflection but a conventional system contributes significantly to the gross weight and complexity of a MAV. Therefore, it is advantageous to use smart structure approaches with active materials to design a lightweight, robust wing for the MAV. The proposed smart wing consists of an active trailing edge flap integrated with bimorph actuators with piezoceramic fibers. Actuation is enhanced by preloading the bimorph actuators with a compressive axial load. The preload is exerted on the actuators through a passive latex or electroactive polymer (EAP) skin that wraps around the airfoil. An EAP skin would further enhance the actuation by providing an electrostatic effect of the dielectric polymer to increase the deflection. Analytical modeling as well as finite element analysis show that the proposed concept could achieve the target bi-directional deflection of 30° in typical flight conditions. Several bimorph actuators were manufactured and an experimental setup was designed to measure the static and dynamic deflections. The experimental results validated the analytical technique and finite element models, which have been further used to predict the performance of the smart wing design for a MAV.

  16. Multi-terminal remote monitoring and warning system using Micro Air Vehicle for dangerous environment

    NASA Astrophysics Data System (ADS)

    Yu, Yanan; Wang, Xiaoxun; He, Chengcheng; Lai, Chenlong; Liu, Yuanchao

    2015-11-01

    For overcoming the problems such as remote operation and dangerous tasks, multi-terminal remote monitoring and warning system based on STC89C52 Micro Control Unit and wireless communication technique was proposed. The system with MCU as its core adopted multiple sets of sensor device to monitor environment parameters of different locations, such as temperature, humidity, smoke other harmful gas concentration. Data information collected was transmitted remotely by wireless transceiver module, and then multi-channel data parameter was processed and displayed through serial communication protocol between the module and PC. The results of system could be checked in the form of web pages within a local network which plays a wireless monitoring and warning role. In a remote operation, four-rotor micro air vehicle which fixed airborne data acquisition device was utilized as a middleware between collecting terminal and PC to increase monitoring scope. Whole test system has characteristics of simple construction, convenience, real time ability and high reliability, which could meet the requirements of actual use.

  17. Multisensor 3D tracking for counter small unmanned air vehicles (CSUAV)

    NASA Astrophysics Data System (ADS)

    Vasquez, Juan R.; Tarplee, Kyle M.; Case, Ellen E.; Zelnio, Anne M.; Rigling, Brian D.

    2008-04-01

    A variety of unmanned air vehicles (UAVs) have been developed for both military and civilian use. The typical large UAV is typically state owned, whereas small UAVs (SUAVs) may be in the form of remote controlled aircraft that are widely available. The potential threat of these SUAVs to both the military and civilian populace has led to research efforts to counter these assets via track, ID, and attack. Difficulties arise from the small size and low radar cross section when attempting to detect and track these targets with a single sensor such as radar or video cameras. In addition, clutter objects make accurate ID difficult without very high resolution data, leading to the use of an acoustic array to support this function. This paper presents a multi-sensor architecture that exploits sensor modes including EO/IR cameras, an acoustic array, and future inclusion of a radar. A sensor resource management concept is presented along with preliminary results from three of the sensors.

  18. Fuel Cell Propulsion Systems for an All-electric Personal Air Vehicle

    NASA Technical Reports Server (NTRS)

    Kohout, Lisa L.; Schmitz, Paul C.

    2003-01-01

    There is a growing interest in the use of fuel cells as a power source for all-electric aircraft propulsion as a means to substantially reduce or eliminate environmentally harmful emissions. Among the technologies under consideration for these concepts are advanced proton exchange membrane and solid oxide fuel cells, alternative fuels and fuel processing, and fuel storage. This paper summarizes the results of a first-order feasibility study for an all-electric personal air vehicle utilizing a fuel cell-powered propulsion system. A representative aircraft with an internal combustion engine was chosen as a baseline to provide key parameters to the study, including engine power and subsystem mass, fuel storage volume and mass, and aircraft range. The engine, fuel tank, and associated ancillaries were then replaced with a fuel cell subsystem. Various configurations were considered including: a proton exchange membrane (PEM) fuel cell with liquid hydrogen storage; a direct methanol PEM fuel cell; and a direct internal reforming solid oxide fuel cell (SOFC)/turbine hybrid system using liquid methane fuel. Each configuration was compared to the baseline case on a mass and range basis.

  19. Utilization Assessment of Target Electrification Vehicles at Naval Air Station Whidbey Island: Task 3

    SciTech Connect

    Schey, Steve

    2015-05-01

    Several U.S. Department of Defense based studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 2 involved identifying daily operational characteristics of select vehicles and initiating data logging of vehicle movements in order to characterize the vehicle’s mission. Individual observations of these selected vehicles provide the basis for recommendations related to PEV adoption and whether a battery electric vehicle or plug-in hybrid electric vehicle (collectively referred to as PEVs) can fulfill the mission requirements and provide observations related to placement of PEV charging infrastructure. This report provides the results of the data analysis and observations related to replacement of current vehicles with PEVs. This fulfills part of the Task 3 requirements. Task 3 also includes an assessment of the charging infrastructure required to support this replacement, which is the subject of a separate report.

  20. Dual rotor single- stator axial air gap PMSM motor/generator drive for high torque vehicles applications

    NASA Astrophysics Data System (ADS)

    Tutelea, L. N.; Deaconu, S. I.; Boldea, I.; Popa, G. N.

    2014-03-01

    The actual e - continuously variable transmission (e-CVT) solution for the parallel Hybrid Electric Vehicle (HEV) requires two electric machines, two inverters, and a planetary gear. A distinct electric generator and a propulsion electric motor, both with full power converters, are typical for a series HEV. In an effort to simplify the planetary-geared e-CVT for the parallel HEV or the series HEV we hereby propose to replace the basically two electric machines and their two power converters by a single, axial-air-gap, electric machine central stator, fed from a single PWM converter with dual frequency voltage output and two independent PM rotors, destined for hybrid electric vehicles (HEV) and military vehicles applications. The proposed topologies and the magneto-motive force analysis are the core of the paper.

  1. Analysis of Scramjet Inlets

    NASA Technical Reports Server (NTRS)

    Kumar, A.

    1987-01-01

    NASCRIN program analyzes two-dimensional flow fields in supersoniccombustion ramjet (scramjet) inlets. Solves two-dimensional Euler or Navier-Stokes equations in conservative form by unsplit, explicit, two-step finite-difference method. More recent explicit/implicit, two-step scheme incorporated by analysis of viscous flow. Algebraic, two-layer eddy-viscosity model used for turbulent-flow calculations. Vectorized version, written for CDC CYBER 205, whereas scalar version, can be run on CRAY or other scalar computers.

  2. Air-breathing hypersonic vehicle guidance and control studies: An integrated trajectory/control analysis methodology, phase 2

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    An integrated trajectory/control analysis algorithm has been used to generate trajectories and desired control strategies for two different hypersonic air-breathing vehicle models and orbit targets. Both models used cubic spline curve fit tabulated winged-cone accelerator vehicle representations. Near-fuel-optimal, horizontal takeoff trajectories, imposing a dynamic pressure limit of 1000 psf, were developed. The first model analysis case involved a polar orbit and included the dynamic effects of using elevons to maintain longitudinal trim. Analysis results indicated problems with the adequacy of the propulsion model and highlighted dynamic pressure/altitude instabilities when using vehicle angle of attack as a control variable. Also, the magnitude of computed elevon deflections to maintain trim suggested a need for alternative pitch moment management strategies. The second analysis case was reformulated to use vehicle pitch attitude relative to the local vertical as the control variable. A new, more realistic, air-breathing propulsion model was incorporated. Pitch trim calculations were dropped and an equatorial orbit was specified. Changes in flight characteristics due to the new propulsion model have been identified. Flight regimes demanding rapid attitude changes have been noted. Also, some issues that would affect design of closed-loop controllers were ascertained.

  3. Air-breathing hypersonic vehicle guidance and control studies; An integrated trajectory/control analysis methodology: Phase 1

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1991-01-01

    A tool which generates optimal trajectory/control histories in an integrated manner is generically adapted to the treatment of single-stage-to-orbit air-breathing hypersonic vehicles. The methodology is implemented as a two point boundary value problem solution technique. Its use permits an assessment of an entire near-minimum-fuel trajectory and desired control strategy from takeoff to orbit while satisfying physically derived inequality constraints and while achieving efficient propulsive mode phasing. A simpler analysis strategy that partitions the trajectory into several boundary condition matched segments is also included to construct preliminary trajectory and control history representations with less computational burden than is required for the overall flight profile assessment. A demonstration was accomplished using a tabulated example (winged-cone accelerator) vehicle model that is combined with a newly developed multidimensional cubic spline data smoothing routine. A constrained near-fuel-optimal trajectory, imposing a dynamic pressure limit of 1000 psf, was developed from horizontal takeoff to 20,000 ft/sec relative air speed while aiming for a polar orbit. Previously unspecified propulsive discontinuities were located. Flight regimes demanding rapid attitude changes were identified, dictating control effector and closed-loop controller authority was ascertained after evaluating effector use for vehicle trim. Also, inadequacies in vehicle model representations and specific subsystem models with insufficient fidelity were determined based on unusual control characteristics and/or excessive sensitivity to uncertainty.

  4. 78 FR 29815 - Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-21

    ... from inventories developed for the Final Cross-State Air Pollution Rule (76 FR 48208, August 8, 2011... reductions. \\7\\ 65 FR 6698 (February 10, 2000). The proposed Tier 3 standards include new light- and heavy... emissions standards.\\10\\ \\8\\ 77 FR 62623 (October 15, 2012). \\9\\ These states include Connecticut,...

  5. Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

    NASA Technical Reports Server (NTRS)

    McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

    2011-01-01

    Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

  6. Field test of the Electric Fuel{trademark} zinc-air refuelable battery system for electric vehicles

    SciTech Connect

    Goldstein, J.R.; Koretz, B.; Harats, Y.

    1996-12-31

    The Electric Fuel Limited (EFL) zinc-air refuelable battery system will be tested over the next two years in a number of electric vehicle demonstration projects, the largest of which is an $18-million, 64-vehicle, two-year test sponsored chiefly by Deutsche Post AG (the German Post Corporation). The German field test is the largest-ever EV fleet test of a single advanced-battery technology. It also represents a marked departure from other EV test and demonstration programs, in that it is being sponsored not by government or electric utility interests, but by large fleet operators committed to shifting significant proportions of their vehicles to electric over the next 5--10 years. The Electric Fuel battery has specific energy of 200 Wh/kg, an achievement that allows electric vehicles to go as far on a charge as conventionally fueled vehicles go on a tank of gasoline. Fast, convenient refueling eliminates the need for lengthy electrical recharging, and clean, centralized zinc regeneration plants ensure the most efficient and environment-friendly use of energy resources.

  7. Bio-inspired multi-mode optic flow sensors for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Park, Seokjun; Choi, Jaehyuk; Cho, Jihyun; Yoon, Euisik

    2013-06-01

    Monitoring wide-field surrounding information is essential for vision-based autonomous navigation in micro-air-vehicles (MAV). Our image-cube (iCube) module, which consists of multiple sensors that are facing different angles in 3-D space, can be applied to the wide-field of view optic flows estimation (μ-Compound eyes) and to attitude control (μ- Ocelli) in the Micro Autonomous Systems and Technology (MAST) platforms. In this paper, we report an analog/digital (A/D) mixed-mode optic-flow sensor, which generates both optic flows and normal images in different modes for μ- Compound eyes and μ-Ocelli applications. The sensor employs a time-stamp based optic flow algorithm which is modified from the conventional EMD (Elementary Motion Detector) algorithm to give an optimum partitioning of hardware blocks in analog and digital domains as well as adequate allocation of pixel-level, column-parallel, and chip-level signal processing. Temporal filtering, which may require huge hardware resources if implemented in digital domain, is remained in a pixel-level analog processing unit. The rest of the blocks, including feature detection and timestamp latching, are implemented using digital circuits in a column-parallel processing unit. Finally, time-stamp information is decoded into velocity from look-up tables, multiplications, and simple subtraction circuits in a chip-level processing unit, thus significantly reducing core digital processing power consumption. In the normal image mode, the sensor generates 8-b digital images using single slope ADCs in the column unit. In the optic flow mode, the sensor estimates 8-b 1-D optic flows from the integrated mixed-mode algorithm core and 2-D optic flows with an external timestamp processing, respectively.

  8. Electroactive polymers as a novel actuator technology for lighter-than-air vehicles

    NASA Astrophysics Data System (ADS)

    Michel, Silvain; Dürager, Christian; Zobel, Martin; Fink, Erich

    2007-04-01

    In this paper the worldwide first EAP actuated blimp will be presented. It consists of a slightly pressurized Helium filled body of a biologically inspired form with Dielectric Elastomer (DE) actuators driving a classical cross tail with two vertical and horizontal rudders for flight control. Two versions of actuators will be discussed: The first version consisted of "spring-roll" type of cylindrical actuators placed together with the electrical supply and control unit in the pay load gondola. The second version consisted of a configuration, where the actuators are placed between the control surfaces and the rudders. This novel type of EAP actuator named "active hinge" was developed and characterized first in the laboratory and afterwards optimized for minimum weight and finally integrated in the blimp structure. In the design phase a numerical simulation tool for the prediction of the DE actuators was developed based on a material model calibrated with the test results from cylindrical actuators. The electrical supply and control system was developed and optimized for minimum of weight. Special attention was paid to the electromagnetic systems compatibility of the high voltage electrical supply system of the DE actuators and the radio flight control system. The design and production of this 3.5 meter long Lighter-than-Air vehicle was collaboration between Empa Duebendorf Switzerland and the Technical University of Berlin. The first version of this EAP blimp first flew at an RC airship regatta hold on 24 th of June 2006 in Dresden Germany, while the second version had his maiden flight on 8 th of January 2007 in Duebendorf Switzerland. In both cases satisfactory flight control performances were demonstrated.

  9. Emerging Fuel Cell Technology Being Developed: Offers Many Benefits to Air Vehicles

    NASA Technical Reports Server (NTRS)

    Walker, James F.; Civinskas, Kestutis C.

    2004-01-01

    Fuel cells, which have recently received considerable attention for terrestrial applications ranging from automobiles to stationary power generation, may enable new aerospace missions as well as offer fuel savings, quiet operations, and reduced emissions for current and future aircraft. NASA has extensive experience with fuel cells, having used them on manned space flight systems over four decades. Consequently, the NASA Glenn Research Center has initiated an effort to investigate and develop fuel cell technologies for multiple aerospace applications. Two promising fuel cell types are the proton exchange membrane (PEM) and solid oxide fuel cell (SOFC). PEM technology, first used on the Gemini spacecraft in the sixties, remained unutilized thereafter until the automotive industry recently recognized the potential. PEM fuel cells are low-temperature devices offering quick startup time but requiring relatively pure hydrogen fuel. In contrast, SOFCs operate at high temperatures and tolerate higher levels of impurities. This flexibility allows SOFCs to use hydrocarbon fuels, which is an important factor considering our current liquid petroleum infrastructure. However, depending on the specific application, either PEM or SOFC can be attractive. As only NASA can, the Agency is pursuing fuel cell technology for civil uninhabited aerial vehicles (UAVs) because it offers enhanced scientific capabilities, including enabling highaltitude, long-endurance missions. The NASA Helios aircraft demonstrated altitudes approaching 100,000 ft using solar power in 2001, and future plans include the development of a regenerative PEM fuel cell to provide nighttime power. Unique to NASA's mission, the high-altitude aircraft application requires the PEM fuel cell to operate on pure oxygen, instead of the air typical of terrestrial applications.

  10. Evaluation of some significant issues affecting trajectory and control management for air-breathing hypersonic vehicles

    NASA Technical Reports Server (NTRS)

    Hattis, Philip D.; Malchow, Harvey L.

    1992-01-01

    Horizontal takeoff airbreathing-propulsion launch vehicles require near-optimal guidance and control which takes into account performance sensitivities to atmospheric characteristics while satisfying physically-derived operational constraints. A generic trajectory/control analysis tool that deepens insight into these considerations has been applied to two versions of a winged-cone vehicle model. Information that is critical to the design and trajectory of these vehicles is derived, and several unusual characteristics of the airbreathing propulsion model are shown to have potentially substantial effects on vehicle dynamics.

  11. Numerical Analysis of the Trailblazer Inlet Flowfield for Hypersonic Mach Numbers

    NASA Technical Reports Server (NTRS)

    Steffen, C. J., Jr.; DeBonis, J. R.

    1999-01-01

    A study of the Trailblazer vehicle inlet was conducted using the Global Air Sampling Program (GASP) code for flight Mach numbers ranging from 4-12. Both perfect gas and finite rate chemical analysis were performed with the intention of making detailed comparisons between the two results. Inlet performance was assessed using total pressure recovery and kinetic energy efficiency. These assessments were based upon a one-dimensional stream-thrust-average of the axisymmetric flowfield. Flow visualization utilized to examine the detailed shock structures internal to this mixed-compression inlet. Kinetic energy efficiency appeared to be the least sensitive to differences between the perfect gas and finite rate chemistry results. Total pressure recovery appeared to be the most sensitive discriminator between the perfect gas and finite rate chemistry results for flight Mach numbers above Mach 6. Adiabatic wall temperature was consistently overpredicted by the perfect gas model for flight Mach numbers above Mach 4. The predicted shock structures were noticeably different for Mach numbers from 6-12. At Mach 4, the perfect gas and finite rate chemistry models collapse to the same result.

  12. STS-32 OV-102 air revitalization system (ARS) humidity separator problem

    NASA Technical Reports Server (NTRS)

    1990-01-01

    During STS-32, onboard Columbia, Orbiter Vehicle (OV) 102, a leakage problem at environmental control and life support system (ECLSS) air revitalization system (ARS) humidity separator A below the middeck is solved with a plastic bag and a towel. The towel inserted inside a plastic bag absorbed the water that had collected at the separator inlet.

  13. Operating method for gas turbine with variable inlet vanes

    SciTech Connect

    Morishita, Susumu; Miyake, Yoshiyaki; Uchida, Seishi.

    1993-07-06

    A method is described of operating a gas turbine engine having a centrifugal compressor which is driven by a high-pressure turbine, and wherein the centrifugal compressor is the only compressor of the engine, comprising the steps of: positioning a variable inlet guide vane at an inlet air passage of the centrifugal compressor for adjusting the air flow rate through the engine; and changing the orientation of the guide vane while keeping the speed of rotation of the engine at a high level near its rated value to control the output of the engine by controlling the air flow rate through the engine.

  14. 78 FR 34911 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ...EPA is approving State Implementation Plan (SIP) revisions submitted by the State of Maryland on December 20, 2007, November 12, 2010, and June 22, 2011, as amended March 22, 2013. These SIP revisions pertain to adoption by Maryland of a Low Emission Vehicle (LEV) program, which incorporates by reference California's second generation Low Emission Vehicle (LEVII) program regulations.......

  15. 77 FR 75388 - Approval and Promulgation of Air Quality Implementation Plans; State of Colorado; Motor Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-20

    ...,'' by removing the light duty vehicle emission testing ] limits that went into effect on January 1, 2006... Emissions Inspection Program,'' by removing the light duty vehicle emission testing limits that went into... August 8, 2006, and provided an opportunity for public comment through February 13, 2012 (see 77 FR...

  16. High-resolution simulation of link-level vehicle emissions and concentrations for air pollutants in a traffic-populated eastern Asian city

    NASA Astrophysics Data System (ADS)

    Zhang, Shaojun; Wu, Ye; Huang, Ruikun; Wang, Jiandong; Yan, Han; Zheng, Yali; Hao, Jiming

    2016-08-01

    Vehicle emissions containing air pollutants created substantial environmental impacts on air quality for many traffic-populated cities in eastern Asia. A high-resolution emission inventory is a useful tool compared with traditional tools (e.g. registration data-based approach) to accurately evaluate real-world traffic dynamics and their environmental burden. In this study, Macau, one of the most populated cities in the world, is selected to demonstrate a high-resolution simulation of vehicular emissions and their contribution to air pollutant concentrations by coupling multimodels. First, traffic volumes by vehicle category on 47 typical roads were investigated during weekdays in 2010 and further applied in a networking demand simulation with the TransCAD model to establish hourly profiles of link-level vehicle counts. Local vehicle driving speed and vehicle age distribution data were also collected in Macau. Second, based on a localized vehicle emission model (e.g. the emission factor model for the Beijing vehicle fleet - Macau, EMBEV-Macau), this study established a link-based vehicle emission inventory in Macau with high resolution meshed in a temporal and spatial framework. Furthermore, we employed the AERMOD (AMS/EPA Regulatory Model) model to map concentrations of CO and primary PM2.5 contributed by local vehicle emissions during weekdays in November 2010. This study has discerned the strong impact of traffic flow dynamics on the temporal and spatial patterns of vehicle emissions, such as a geographic discrepancy of spatial allocation up to 26 % between THC and PM2.5 emissions owing to spatially heterogeneous vehicle-use intensity between motorcycles and diesel fleets. We also identified that the estimated CO2 emissions from gasoline vehicles agreed well with the statistical fuel consumption in Macau. Therefore, this paper provides a case study and a solid framework for developing high-resolution environment assessment tools for other vehicle-populated cities

  17. Control Volume Analysis of Boundary Layer Ingesting Propulsion Systems With or Without Shock Wave Ahead of the Inlet

    NASA Technical Reports Server (NTRS)

    Kim, Hyun Dae; Felder, James L.

    2011-01-01

    The performance benefit of boundary layer or wake ingestion on marine and air vehicles has been well documented and explored. In this article, a quasi-one-dimensional boundary layer ingestion (BLI) benefit analysis for subsonic and transonic propulsion systems is performed using a control volume of a ducted propulsion system that ingests the boundary layer developed by the external airframe surface. To illustrate the BLI benefit, a relationship between the amount of BLI and the net thrust is established and analyzed for two propulsor types. One propulsor is an electric fan, and the other is a pure turbojet. These engines can be modeled as a turbofan with an infinite bypass ratio for the electric fan, and with a zero bypass ratio for the pure turbojet. The analysis considers two flow processes: a boundary layer being ingested by an aircraft inlet and a shock wave sitting in front of the inlet. Though the two processes are completely unrelated, both represent a loss of total pressure and velocity. In real applications, it is possible to have both processes occurring in front of the inlet of a transonic vehicle. Preliminary analysis indicates that the electrically driven propulsion system benefits most from the boundary layer ingestion and the presence of transonic shock waves, whereas the benefit for the turbojet engine is near zero or negative depending on the amount of total temperature rise across the engine.

  18. Investigation of "6X" Scramjet Inlet Configurations

    NASA Technical Reports Server (NTRS)

    Alter, Stephen J.

    2012-01-01

    This work represents an initial attempt to determine what, if any, issues arise from scaling demonstration supersonic combustion scramjets to a flight scale making the engine a viable candidate for both military weapon and civilian access to space applications. The original vehicle sizes tested and flown to date, were designed to prove a concept. With the proven designs, use of the technology for applications as weapon systems or space flight are only possible at six to ten times the original scale. To determine effects of scaling, computations were performed with hypersonic inlets designed to operate a nominal Mach 4 and Mach 5 conditions that are possible within the eight foot high temperature tunnel at NASA Langley Research Center. The total pressure recovery for these inlets is about 70%, while maintaining self start conditions, and providing operable inflow to combustors. Based on this study, the primary scaling effect detected is the strength of a vortex created along the cowl edge causing adverse boundary layer growth in the inlet.

  19. Structural Sizing of a Horizontal Take-Off Launch Vehicle with an Air Collection and Enrichment System

    NASA Technical Reports Server (NTRS)

    McCurdy, David R.; Roche, Joseph M.

    2004-01-01

    In support of NASA's Next Generation Launch Technology (NGLT) program, the Andrews Gryphon booster was studied. The Andrews Gryphon concept is a horizontal lift-off, two-stage-to-orbit, reusable launch vehicle that uses an air collection and enrichment system (ACES). The purpose of the ACES is to collect atmospheric oxygen during a subsonic flight loiter phase and cool it to cryogenic temperature, ultimately resulting in a reduced initial take-off weight To study the performance and size of an air-collection based booster, an initial airplane like shape was established as a baseline and modeled in a vehicle sizing code. The code, SIZER, contains a general series of volume, surface area, and fuel fraction relationships that tie engine and ACES performance with propellant requirements and volumetric constraints in order to establish vehicle closure for the given mission. A key element of system level weight optimization is the use of the SIZER program that provides rapid convergence and a great deal of flexibility for different tank architectures and material suites in order to study their impact on gross lift-off weight. This paper discusses important elements of the sizing code architecture followed by highlights of the baseline booster study.

  20. Design and development of a biomimetic device for micro air vehicles

    NASA Astrophysics Data System (ADS)

    Bohorquez, Felipe; Pines, Darryll J.

    2002-07-01

    This paper presents the design and development of a pitching and plunging (flapping) mechanism for small-scale flight. In order to harness the unsteady lift mechanisms, used by most insects, a biologically inspired flapping/pitching device in conjunction with a rotary wing concept was developed and built. This mechanism attempts to replicate some of the aerodynamic phenomena that enhance the performance of small fliers, replacing the periodic translational motion with a unidirectional circular motion while actively flapping and pitching the rotor blades. In order to find the appropriate combination of phase, amplitude, frequency and rotational speed that leads to enhancement in lift, the device requires uncoupled independent pitch and flap actuation systems to permit the complete mapping of the parameter space. In the device under consideration the phase shift between the flapping and the pitching oscillations can be adjusted from 0 to 360 degrees over a wide range of rotational speeds. Maximum flapping and pitching amplitudes of +/- 23 degree(s) and +/- 20 degree(s) respectively can be attained. Linear displacements of two coaxial shafts are translated into the flapping and pitching motion of the rotor blades. The mechanism was designed to minimize the actuation stroke so that smart materials and conventional actuators such as motors and cams could be used. Kinematic analysis as well as experimental tests were performed. Using a customized test stand thrust and torque produced by the rotor were measured at different angles of attack, in steady-state and under periodical pitching actuation. The results showed that hover efficiency was considerably increased for a range of thrust coefficients. The device was developed based on the University of Maryland's rotary wing Micro Air vehicle (MAV) the MICOR (MIcro COaxial Rotorcraft), an electrically driven 100 g coaxial helicopter. It is anticipated that active flapping and/or pitching could be implemented in the

  1. Ice Protection of Turbojet Engines by Inertia Separation of Water III : Annular Submerged Inlets

    NASA Technical Reports Server (NTRS)

    Von Glahn, Uwe

    1948-01-01

    Aerodynamic and icing studies were conducted on a one-half-scale model of an annular submerged inlet for use with axial-flow turbojet engines. Pressure recoveries, screen radial-velocity profiles, circumferential mass-flow variations, and icing characteristics were determined at the compressor inlet. In order to be effective in maintaining water-free induction air, the inlet gap must be extremely small and ram-pressure recoveries consequently are low, the highest achieved being 65 percent at inlet-velocity ratio of 0.86. All inlets exhibited considerable screen icing. Severe mass-flow shifts occurred at angles of attack.

  2. Development of a high temporal-spatial resolution vehicle emission inventory based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, B. Y.; Wu, L.; Mao, H. J.; Gong, S. L.; He, J. J.; Zou, C.; Song, G. H.; Li, X. Y.; Wu, Z.

    2015-10-01

    As the ownership of vehicles and frequency of utilization increase, vehicle emissions have become an important source of air pollution in Chinese cities. An accurate emission inventory for on-road vehicles is necessary for numerical air quality simulation and the assessment of implementation strategies. This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near real time (NRT) traffic data on road segments to develop a high temporal-spatial resolution vehicle emission inventory (HTSVE) for the urban Beijing area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg, respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Additionally, the on-road vehicle emission inventory model and control effect assessment system in Beijing, a vehicle emission inventory model, was established based on this study in a companion paper (He et al., 2015).

  3. Active Flow Control on a Boundary-Layer-Ingesting Inlet

    NASA Technical Reports Server (NTRS)

    Gorton, Susan Althoff; Owens, Lewis R.; Jenkins, Luther N.; Allan, Brian G.; Schuster, Ernest P.

    2004-01-01

    Boundary layer ingestion (BLI) is explored as means to improve overall system performance for Blended Wing Body configuration. The benefits of BLI for vehicle system performance benefit are assessed with a process derived from first principles suitable for highly-integrated propulsion systems. This performance evaluation process provides framework within which to assess the benefits of an integrated BLI inlet and lays the groundwork for higher-fidelity systems studies. The results of the system study show that BLI provides a significant improvement in vehicle performance if the inlet distortion can be controlled, thus encouraging the pursuit of active flow control (AFC) as a BLI enabling technology. The effectiveness of active flow control in reducing engine inlet distortion was assessed using a 6% scale model of a 30% BLI offset, diffusing inlet. The experiment was conducted in the NASA Langley Basic Aerodynamics Research Tunnel with a model inlet designed specifically for this type of testing. High mass flow pulsing actuators provided the active flow control. Measurements were made of the onset boundary layer, the duct surface static pressures, and the mass flow through the duct and the actuators. The distortion was determined by 120 total pressure measurements located at the aerodynamic interface plane. The test matrix was limited to a maximum freestream Mach number of 0.15 with scaled mass flows through the inlet for that condition. The data show that the pulsed actuation can reduce distortion from 29% to 4.6% as measured by the circumferential distortion descriptor DC60 using less than 1% of inlet mass flow. Closed loop control of the actuation was also demonstrated using a sidewall surface static pressure as the response sensor.

  4. Ascent performance of an air-breathing horizontal-takeoff launch vehicle

    NASA Technical Reports Server (NTRS)

    Powell, Richard W.; Shaughnessy, John D.; Cruz, Christopher I.; Naftel, J. C.

    1991-01-01

    Simulations are conducted to investigate a proposed NASA launch vehicle that is fully reusable, takes off horizontally, and uses airbreathing propulsion in a single stage. The propulsion model is based on a cycle analysis method, and the vehicle is assumed to be a rigid structure with distributed fuel, operating under a range of atmospheric conditions. The program to optimize simulated trajectories (POST) is modified to include a predictor-corrector guidance capability and then used to generate the trajectories. Significant errors are encountered during the unpowered coast phase due to uncertainty in the atmospheric density profile. The amount of ascent propellant needed is shown to be directly related to the thrust-vector angle and the location of the center of gravity of the vehicle because of the importance of aim-drag losses to total ideal velocity.

  5. Fractional Order Modeling of Atmospheric Turbulence - A More Accurate Modeling Methodology for Aero Vehicles

    NASA Technical Reports Server (NTRS)

    Kopasakis, George

    2014-01-01

    The presentation covers a recently developed methodology to model atmospheric turbulence as disturbances for aero vehicle gust loads and for controls development like flutter and inlet shock position. The approach models atmospheric turbulence in their natural fractional order form, which provides for more accuracy compared to traditional methods like the Dryden model, especially for high speed vehicle. The presentation provides a historical background on atmospheric turbulence modeling and the approaches utilized for air vehicles. This is followed by the motivation and the methodology utilized to develop the atmospheric turbulence fractional order modeling approach. Some examples covering the application of this method are also provided, followed by concluding remarks.

  6. Numerical modeling of aerodynamics of airfoils of micro air vehicles in gusty environment

    NASA Astrophysics Data System (ADS)

    Gopalan, Harish

    The superior flight characteristics exhibited by birds and insects can be taken as a prototype of the most perfect form of flying machine ever created. The design of Micro Air Vehicles (MAV) which tries mimic the flight of birds and insects has generated a great deal of interest as the MAVs can be utilized for a number of commercial and military operations which is usually not easily accessible by manned motion. The size and speed of operation of a MAV results in low Reynolds number flight, way below the flying conditions of a conventional aircraft. The insensitivity to wind shear and gust is one of the required factors to be considered in the design of airfoil for MAVs. The stability of flight under wind shear is successfully accomplished in the flight of birds and insects, through the flapping motion of their wings. Numerous studies which attempt to model the flapping motion of the birds and insects have neglected the effect of wind gust on the stability of the motion. Also sudden change in flight conditions makes it important to have the ability to have an instantaneous change of the lift force without disturbing the stability of the MAV. In the current study, two dimensional rigid airfoil, undergoing flapping motion is studied numerically using a compressible Navier-Stokes solver discretized using high-order finite difference schemes. The high-order schemes in space and in time are needed to keep the numerical solution economic in terms of computer resources and to prevent vortices from smearing. The numerical grid required for the computations are generated using an inverse panel method for the streamfunction and potential function. This grid generating algorithm allows the creation of single-block orthogonal H-grids with ease of clustering anywhere in the domain and the easy resolution of boundary layers. The developed numerical algorithm has been validated successfully against benchmark problems in computational aeroacoustics (CAA), and unsteady viscous

  7. Rotor hover performance and system design of an efficient coaxial rotary wing micro air vehicle

    NASA Astrophysics Data System (ADS)

    Bohorquez, Felipe

    2007-12-01

    Rotary-wing Micro air vehicles (MAVs) due to their unique hovering and low-speed flight capabilities are specially suited for missions that require operation in constrained spaces. Size restrictions force MAVs to operate in a low Reynolds number aerodynamic regime where viscous effects are dominant. This results in poor aerodynamic performance of conventional airfoils and rotor configurations. This dissertation explores the design issues that affect the hover performance of small-scale rotors and the implementation of a working coaxial MAV prototype. A computerized hover test stand was used for the systematic testing of single and coaxial small-scale rotors. Thin circular arcs were chosen for blade manufacturing because of their good aerodynamic characteristics at low Reynolds numbers, and simplified parameterization. Influence of airfoil geometry on single rotor hover performance was studied on untwisted rectangular blades. Non rectangular blades were used to study coupled airfoil and blade parameters. Tip tapered geometries were manufactured by removing material from baseline rectangular blades producing a coupling between blade planform, twist distribution, and spanwise airfoil shape. Performance gains were obtained by introducing large negative twist angles over short radial distances at the blade tips. A parametric study of the blade geometries resulted in maximum figures of merit of 0.65. Coaxial rotor performance at torque equilibrium was explored for different trims and operating conditions. It was found that the upper rotor was marginally affected by the lower one at spacings larger than 35% of the rotor radius, and that it produced about 60% of the total thrust. Experiments showed that power loading was maximized when higher collectives were used at the lower rotor, resulting in sizable differences in rotational speed between rotors. The CFD solver INS2d was used for a two-dimensional parametric aerodynamic study of circular arc airfoils. Lift, drag, and

  8. On aerodynamic modelling of an insect-like flapping wing in hover for micro air vehicles.

    PubMed

    Zbikowski, Rafał

    2002-02-15

    This theoretical paper discusses recent advances in the fluid dynamics of insect and micro air vehicle (MAV) flight and considers theoretical analyses necessary for their future development. The main purpose is to propose a new conceptual framework and, within this framework, two analytic approaches to aerodynamic modelling of an insect-like flapping wing in hover in the context of MAVs. The motion involved is periodic and is composed of two half-cycles (downstroke and upstroke) which, in hover, are mirror images of each other. The downstroke begins with the wing in the uppermost and rearmost position and then sweeps forward while pitching up and plunging down. At the end of the half-cycle, the wing flips, so that the leading edge points backwards and the wing's lower surface becomes its upper side. The upstroke then follows by mirroring the downstroke kinematics and executing them in the opposite direction. Phenomenologically, the interpretation of the flow dynamics involved, and adopted here, is based on recent experimental evidence obtained by biologists from insect flight and related mechanical models. It is assumed that the flow is incompressible, has low Reynolds number and is laminar, and that two factors dominate: (i) forces generated by the bound leading-edge vortex, which models flow separation; and (ii) forces due to the attached part of the flow generated by the periodic pitching, plunging and sweeping. The first of these resembles the analogous phenomenon observed on sharp-edged delta wings and is treated as such. The second contribution is similar to the unsteady aerodynamics of attached flow on helicopter rotor blades and is interpreted accordingly. Theoretically, the fluid dynamic description is based on: (i) the superposition of the unsteady contributions of wing pitching, plunging and sweeping; and (ii) adding corrections due to the bound leading-edge vortex and wake distortion. Viscosity is accounted for indirectly by imposing the Kutta condition

  9. Smart actuation of inlet guide vanes for small turbine engine

    NASA Astrophysics Data System (ADS)

    Rusovici, Razvan; Kwok Choon, Stephen T.; Sepri, Paavo; Feys, Joshuo

    2011-04-01

    Unmanned Aerial Vehicles (UAVs) have gained popularity over the past few years to become an indispensable part of aerial missions that include reconnaissance, surveillance, and communication [1]. As a result, advancements in small jet-engine performance are needed to increase the performance (range, payload and efficiency) of the UAV. These jet engines designed especially for UAV's are characterized by thrust force on the order of 100N and due to their size and weight limitations, may lack advanced flow control devices such as IGV [2]. The goal of the current study was to present a conceptual design of an IGV smart-material based actuation mechanism that would be simple, compact and lightweight. The compressor section of an engine increases the pressure and conditions the flow before the air enters the combustion chamber [3]. The airflow entering the compressor is often turbulent due to the high angle of incidence between engine inlet and free-stream velocity, or existing atmospheric turbulence. Actuated IGV are used to help control the relative angle of incidence of the flow that enters the engine compressor, thereby preventing flow separation, compressor stall and thus extending the compressor's operating envelope [4]. Turbine jet- engines which employ variable IGV were developed by Rolls Royce (Trent DR-900) and General Electric (J79).

  10. Special problems and capabilities of high altitude lighter than air vehicles

    NASA Technical Reports Server (NTRS)

    Wessel, P. R.; Petrone, F. J.

    1975-01-01

    Powered LTA vehicles have historically been limited to operations at low altitudes. Conditions exist which may enable a remotely piloted unit to be operated at an altitude near 70,000 feet. Such systems will be launched like high altitude balloons, operate like nonrigid airships, and have mission capabilities comparable to a low altitude stationary satellite. The limited lift available and the stratospheric environment impose special requirements on power systems, hull materials and payloads. Potential nonmilitary uses of the vehicle include communications relay, environmental monitoring and ship traffic control.

  11. Variable Speed CMG Control of a Dual-Spin Stabilized Unconventional VTOL Air Vehicle

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.; Shin, J-Y.

    2004-01-01

    This paper describes an approach based on using both bias momentum and multiple control moment gyros for controlling the attitude of statically unstable thrust-levitated vehicles in hover or slow translation. The stabilization approach described in this paper uses these internal angular momentum transfer devices for stability, augmented by thrust vectoring for trim and other outer loop control functions, including CMG stabilization/ desaturation under persistent external disturbances. Simulation results show the feasibility of (1) improved vehicle performance beyond bias momentum assisted vector thrusting control, and (2) using control moment gyros to significantly reduce the external torque required from the vector thrusting machinery.

  12. The Effect of the Inlet Mach Number and Inlet-boundary-layer Thickness on the Performance of a 23 Degree Conical-diffuser-tail-pipe Combination

    NASA Technical Reports Server (NTRS)

    Persh, Jerome

    1950-01-01

    An investigation was conducted to determine the effect of the inlet Mach number and entrance-boundary-layer thickness on the performance of a 23 degree 21-inch conical-diffuser - tail-pipe combination with a 2:1 area ratio. The air flows used in this investigation covered an inlet Mach number range from 0.17 to 0.89 and corresponding Reynolds numbers of 1,700,000 to 7,070,000. Results are reported for two inlet-boundary-layer thicknesses. Over the entire range of flows, the mean value of the inlet displacement thickness is about 0.034 inch for the thinner inlet boundary layer and about 0.170 inch for the case of the thicker inlet boundary layer. The performance of the diffuser - tail-pipe combination is presented together with examples of longitudinal static-pressure distribution and the results of boundary-layer pressure surveys made at six points along the diffuser wall. The results indicated a progressive diminution of the static-pressure recovery and a steady increase in the total-pressure losses as the inlet Mach number was increased for both inlet-boundary-layer thicknesses. The ratio of actual static-pressure rise to that theoretically possible was much less and the total-pressure losses were greater for the case of the thicker inlet boundary layer throughout the speed range investigated. With the thinner inlet boundary layer, flow separation occurred at the diffuser exit at all inlet Mach numbers.Unseparated flow alternating with separated flow was observed near the inlet at the higher velocities. For the case of the thicker inlet boundary layer, the origin of the separated region occurred in the vicinity of the inlet-duct-diffuser junction section at all Mach numbers.

  13. Effect of end-wall boundary layer and inlet turbulence on the flow field structures in the turbine stage

    NASA Astrophysics Data System (ADS)

    Jelinek, Tomas; Straka, Petr; Uruba, Vaclav

    2016-06-01

    The article deals with the effects of the inlet flow parameters on the flow field structures in axial turbine stage. The experiment was performed on the axial turbine stage rig with an air as a working medium. The variable inlet channel produced the different inlet turbulence intensity and different inlet end-wall boundary layer thickness, resp. different inlet velocity distribution was applied. The turbulence was measured by CTA probes. The measured parameters of the inlet velocity distribution and turbulence intensity across the inlet channel height are presented. Based on the experimental inlet parameters the CFD fully turbulent calculation of the flow field was made. The differences in outlet kinetic energy loss, outlet vane angle and the turbulence distribution in the vane mid-span section are depicted. Changes of secondary flow structures with the different inlet end-wall boundary layer thickness were observed on the vane outlet parameters.

  14. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  15. Quasi 1D Modeling of Mixed Compression Supersonic Inlets

    NASA Technical Reports Server (NTRS)

    Kopasakis, George; Connolly, Joseph W.; Paxson, Daniel E.; Woolwine, Kyle J.

    2012-01-01

    The AeroServoElasticity task under the NASA Supersonics Project is developing dynamic models of the propulsion system and the vehicle in order to conduct research for integrated vehicle dynamic performance. As part of this effort, a nonlinear quasi 1-dimensional model of the 2-dimensional bifurcated mixed compression supersonic inlet is being developed. The model utilizes computational fluid dynamics for both the supersonic and subsonic diffusers. The oblique shocks are modeled utilizing compressible flow equations. This model also implements variable geometry required to control the normal shock position. The model is flexible and can also be utilized to simulate other mixed compression supersonic inlet designs. The model was validated both in time and in the frequency domain against the legacy LArge Perturbation INlet code, which has been previously verified using test data. This legacy code written in FORTRAN is quite extensive and complex in terms of the amount of software and number of subroutines. Further, the legacy code is not suitable for closed loop feedback controls design, and the simulation environment is not amenable to systems integration. Therefore, a solution is to develop an innovative, more simplified, mixed compression inlet model with the same steady state and dynamic performance as the legacy code that also can be used for controls design. The new nonlinear dynamic model is implemented in MATLAB Simulink. This environment allows easier development of linear models for controls design for shock positioning. The new model is also well suited for integration with a propulsion system model to study inlet/propulsion system performance, and integration with an aero-servo-elastic system model to study integrated vehicle ride quality, vehicle stability, and efficiency.

  16. Cabin air temperature of parked vehicles in summer conditions: life-threatening environment for children and pets calculated by a dynamic model

    NASA Astrophysics Data System (ADS)

    Horak, Johannes; Schmerold, Ivo; Wimmer, Kurt; Schauberger, Günther

    2016-07-01

    In vehicles that are parked, no ventilation and/or air conditioning takes place. If a vehicle is exposed to direct solar radiation, an immediate temperature rise occurs. The high cabin air temperature can threaten children and animals that are left unattended in vehicles. In the USA, lethal heat strokes cause a mean death rate of 37 children per year. In addition, temperature-sensitive goods (e.g. drugs in ambulances and veterinary vehicles) can be adversely affected by high temperatures. To calculate the rise of the cabin air temperature, a dynamic model was developed that is driven by only three parameters, available at standard meteorological stations: air temperature, global radiation and wind velocity. The transition from the initial temperature to the constant equilibrium temperature depends strongly on the configuration of the vehicle, more specifically on insulation, window area and transmission of the glass, as well as on the meteorological conditions. The comparison of the model with empirical data showed good agreement. The model output can be applied to assess the heat load of children and animals as well as temperature-sensitive goods, which are transported and/or stored in a vehicle.

  17. Maglev vehicles and superconductor technology: Integration of high-speed ground transportation into the air travel system

    SciTech Connect

    Johnson, L.R.; Rote, D.M.; Hull, J.R.; Coffey, H.T.; Daley, J.G.; Giese, R.F.

    1989-04-01

    This study was undertaken to (1) evaluate the potential contribution of high-temperature superconductors (HTSCs) to the technical and economic feasibility of magnetically levitated (maglev) vehicles, (2) determine the status of maglev transportation research in the United States and abroad, (3) identify the likelihood of a significant transportation market for high-speed maglev vehicles, and (4) provide a preliminary assessment of the potential energy and economic benefits of maglev systems. HTSCs should be considered as an enhancing, rather than an enabling, development for maglev transportation because they should improve reliability and reduce energy and maintenance costs. Superconducting maglev transportation technologies were developed in the United States in the late 1960s and early 1970s. Federal support was withdrawn in 1975, but major maglev transportation programs were continued in Japan and West Germany, where full-scale prototypes now carry passengers at speeds of 250 mi/h in demonstration runs. Maglev systems are generally viewed as very-high-speed train systems, but this study shows that the potential market for maglev technology as a train system, e.g., from one downtown to another, is limited. Rather, aircraft and maglev vehicles should be seen as complementing rather than competing transportation systems. If maglev systems were integrated into major hub airport operations, they could become economical in many relatively high-density US corridors. Air traffic congestion and associated noise and pollutant emissions around airports would also be reduced. 68 refs., 26 figs., 16 tabs.

  18. Quasi One-Dimensional Unsteady Modeling of External Compression Supersonic Inlets

    NASA Technical Reports Server (NTRS)

    Kopasakis, George; Connolly, Joseph W.; Kratz, Jonathan

    2012-01-01

    The AeroServoElasticity task under the NASA Supersonics Project is developing dynamic models of the propulsion system and the vehicle in order to conduct research for integrated vehicle dynamic performance. As part of this effort, a nonlinear quasi 1-dimensional model of an axisymmetric external compression supersonic inlet is being developed. The model utilizes compressible flow computational fluid dynamics to model the internal inlet segment as well as the external inlet portion between the cowl lip and normal shock, and compressible flow relations with flow propagation delay to model the oblique shocks upstream of the normal shock. The external compression portion between the cowl-lip and the normal shock is also modeled with leaking fluxes crossing the sonic boundary, with a moving CFD domain at the normal shock boundary. This model has been verified in steady state against tunnel inlet test data and it s a first attempt towards developing a more comprehensive model for inlet dynamics.

  19. Acute effects of motor vehicle traffic-related air pollution exposures on measures of oxidative stress in human airways

    PubMed Central

    Laumbach, Robert J.; Kipen, Howard M.

    2014-01-01

    Epidemiological studies have linked exposure to traffic-related air pollutants to increased respiratory and cardiovascular morbidity and mortality. Evidence from human, animal, and in vitro studies supports an important role for oxidative stress in the pathophysiological pathways underlying the adverse health effects of air pollutants. In controlled-exposure studies of animals and humans, emissions from diesel engines, a major source of traffic-related air pollutants, cause pulmonary and systemic inflammation that is mediated by redox-sensitive signaling pathways. Assessment of human responses to traffic-related air pollution under realistic conditions is challenging due to the complex, dynamic nature of near-roadway exposure. Noninvasive measurement of biomarkers in breath and breath condensate may be particularly useful for evaluating the role of oxidative stress in acute responses to exposures that occur in vehicles or during near-roadway activities. Promising biomarkers include nitric oxide in exhaled breath, and nitrite/nitrate, malondialdehyde, and F2-isoprostanes in exhaled breath condensate. PMID:20716291

  20. 77 FR 50969 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; Low Emission Vehicle...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-23

    ...-in hybrid electric vehicle conversions; and to adopt the national GHG emissions standards framework... Federal Register (88 FR 25324). This rule affects new passenger cars, light-duty trucks, and medium duty... Standard Has Been Revoked'' published in the August 3, 2005 Federal Register, 70 FR 4470). At the time...

  1. ANALYSIS OF MOTOR VEHICLE EMISSIONS IN A HOUSTON TUNNEL DURING THE TEXAS AIR QUALITY STUDY 2000

    EPA Science Inventory

    Measurements from a Houston tunnel were used to develop fuel consumption based emission factors for CO, NOx, and Non-Methane Organic Compound (NMOC) for on-road gasoline vehicles. The Houston NOx emission factor was at the low range of emission factors reported in previous (pr...

  2. Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles

    PubMed Central

    Abid, Haider J.; Chen, Jie; Nassar, Ameen A.

    2015-01-01

    This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system. PMID:27351020

  3. 9 CFR 3.62 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... rabbits shall be mechanically sound and provide fresh air by means of windows, doors, vents, or air... temperature in the animal cargo space is 75 °F (23.9 °C) or higher. The ambient temperature within the animal... temperature in the cargo space may be below 45 °F (7.2 °C) if the rabbits are accompanied by a certificate...

  4. A comparative study of turbulence models in predicting hypersonic inlet flows

    NASA Technical Reports Server (NTRS)

    Kapoor, Kamlesh

    1993-01-01

    A computational study has been conducted to evaluate the performance of various turbulence models. The NASA P8 inlet, which represents cruise condition of a typical hypersonic air-breathing vehicle, was selected as a test case for the study; the PARC2D code, which solves the full two dimensional Reynolds-averaged Navier-Stokes equations, was used. Results are presented for a total of six versions of zero- and two-equation turbulence models. Zero-equation models tested are the Baldwin-Lomax model, the Thomas model, and a combination of the two. Two-equation models tested are low-Reynolds number models (the Chien model and the Speziale model) and a high-Reynolds number model (the Launder and Spalding model).

  5. A Feasibility Study on the Control of a Generic Air Vehicle Using Control Moment Gyros

    NASA Technical Reports Server (NTRS)

    Lim, Kyong B.; Moerder, Daniel D.

    2006-01-01

    This paper examines feasibility and performance issues in using Control Moment Gyroscopes (CMGs) to control the attitude of a fixed-wing aircraft. The paper describes a control system structure that permits allocating control authority and bandwidth between a CMG system and conventional aerodynamic control surfaces to stabilize a vehicle with neutral aerodynamic stability. A simulation study explores the interplay between aerodynamic and CMG effects, and indicates desirable physical characteristics for a CMG system to be used for aircraft attitude control.

  6. Net air emissions from electric vehicles: the effect of carbon price and charging strategies.

    PubMed

    Peterson, Scott B; Whitacre, J F; Apt, Jay

    2011-03-01

    Plug-in hybrid electric vehicles (PHEVs) may become part of the transportation fleet on time scales of a decade or two. We calculate the electric grid load increase and emissions due to vehicle battery charging in PJM and NYISO with the current generation mix, the current mix with a $50/tonne CO(2) price, and this case but with existing coal generators retrofitted with 80% CO(2) capture. We also examine all new generation being natural gas or wind+gas. PHEV fleet percentages between 0.4 and 50% are examined. Vehicles with small (4 kWh) and large (16 kWh) batteries are modeled with driving patterns from the National Household Transportation Survey. Three charging strategies and three scenarios for future electric generation are considered. When compared to 2020 CAFE standards, net CO(2) emissions in New York are reduced by switching from gasoline to electricity; coal-heavy PJM shows somewhat smaller benefits unless coal units are fitted with CCS or replaced with lower CO(2) generation. NO(X) is reduced in both RTOs, but there is upward pressure on SO(2) emissions or allowance prices under a cap. PMID:21309508

  7. An air launched, highly responsive military transatmospheric vehicle (TAV), based on existing aerospace systems

    NASA Astrophysics Data System (ADS)

    Hampsten, Kenneth R.

    1996-03-01

    A novel vehicle design is presented that minimizes Research Development Test and Evaluation (RDT&E) cost. The proposed TAV can satisfy a broad range of military mission applications for the 21st century. TAV deployment is provided by a Rockwell B-1B bomber. Pre-launch orientation of the vehicle is centerline, underneath the B-1B forward weapon bays. Launch occurs at 30,000 ft, Mach 0.90, and at a flight path angle of 15-20 degrees. The TAV is a Two-Stage-To-Orbit (TSTO) vehicle utilizing Liquid Oxygen (LOX) and RP-1 (kerosene) propellants. The reusable upper stage, or TAV, incorporates a 130 cubic foot payload bay for mission specific equipment. The booster can either be expended, or potentially recovered for reuse. TAV reentry relies on a biconic aeroshell for the hypersonic flight phase and a parafoil for the subsonic, terminal recovery phase. Nominal mission performance is between 1,150-1,800 lbs of payload into a 100 nmi circular orbit.

  8. Improving an Inlet for Underwater Volatile Analyses

    NASA Astrophysics Data System (ADS)

    Chua, E.; Michel, A.; Wankel, S. D.; Kapit, J.

    2014-12-01

    Although the deep ocean remains a challenging place to study, recent progress in technologies such as advanced in situ chemical sensors is beginning to broaden the scope of ocean exploration by enabling more comprehensive measurements at higher spatial and temporal resolutions. Such sensors are designed to be compatible with remotely and human operated vehicles and thus shed light on the geochemical composition of, and processes occurring in, seafloor environments. Among these sensors is a recently-developed in situ laser-based analyzer which utilizes Off-Axis Integrated Cavity Output Spectroscopy (ICOS). This instrument is capable of measuring stable carbon isotope ratios of methane (δ13CCH4), making it a powerful tool for assessing biogeochemical activity in the deep sea. With the aim of improving the sensitivity of this membrane inlet-based chemical sensor, a Membrane Inlet Dissolved Gas Extractor (MIDGE) was developed. Recent work on the MIDGE focused on improving design elements with the aim of enhancing gas transport through the membrane and reducing water vapour in the gas stream. This was accomplished by implementing a newly-designed membrane flow-through inlet geometry, testing a variety of membrane materials, and incorporating an acidification module to evolve dissolved inorganic carbon (DIC) to gaseous CO2. We will report on results from a September 2014 research cruise, in which the MIDGE ICOS is to be deployed as part of an interdisciplinary mission conducting the first-ever in situ chemical and stable isotopic exploration of two seafloor sites in the Caribbean: the Barbados Mud Volcanoes and Kick 'em Jenny (KEJ). The goals of this project are to 1) use in situ measurements of methane and DIC carbon isotopes to enable biogeochemical exploration and mapping of methane seeps, and 2) measure the composition of bubble streams emanating from the crater of KEJ.

  9. Evaluation of inlets used for the airborne measurement of formaldehyde

    NASA Astrophysics Data System (ADS)

    Wert, B. P.; Fried, A.; Henry, B.; Cartier, S.

    2002-07-01

    The performance of three aircraft inlets used for sampling gas-phase formaldehyde (CH2O) was evaluated. These 1.5 m long inlets were operated with the National Center for Atmospheric Research Tunable Diode Laser Absorption Spectrometer (TDLAS) at flow rates between 7 and 9 standard liters per minute. Laboratory tests were performed on the 1997 North Atlantic Regional Experiment (NARE 97) TDLAS inlet, involving a wide range of sample temperatures (-40° to 25°C), pressures (250-625 torr), relative humidities (<1 to 85%), and CH2O concentrations (0-25 ppbv). Standard additions on ambient air were performed in the field with another inlet. Sampling artifacts were not observed in either case at CH2O levels less than about 10 ppbv to within the measurement precision (25-120 parts per trillion by volume (1 min, 1σ)) and/or accuracy of standard generation (+/-6%). Desorption associated with the Herriott Cell was measured under highly polluted conditions, and was largely corrected for by subtracting a frequently acquired instrument background. Inlet shielding and heating minimized error due to liquid water collection. Common inlet materials such as PFA Teflon and silica-coated steel efficiently transmitted CH2O.

  10. Some factors affecting the use of lighter than air systems. [economic and performance estimates for dirigibles and semi-buoyant hybrid vehicles

    NASA Technical Reports Server (NTRS)

    Havill, C. D.

    1974-01-01

    The uses of lighter-than-air vehicles are examined in the present day transportation environment. Conventional dirigibles were found to indicate an undesirable economic risk due to their low speeds and to uncertainties concerning their operational use. Semi-buoyant hybrid vehicles are suggested as an alternative which does not have many of the inferior characteristics of conventional dirigibles. Economic and performance estimates for hybrid vehicles indicate that they are competitive with other transportation systems in many applications, and unique in their ability to perform some highly desirable emergency missions.

  11. VEHICLE FOR SLAVE ROBOT

    DOEpatents

    Goertz, R.C.; Lindberg, J.F.

    1962-01-30

    A reeling device is designed for an electrical cable supplying power to the slave slde of a remote control manipulator mounted on a movable vehicle. As the vehicle carries the slave side about in a closed room, the device reels the cable in and out to maintain a variable length of the cable between the vehicle and a cable inlet in the wall of the room. The device also handles a fixed length of cable between the slave side and the vehicle, in spite of angular movement of the slave side with respect to the vehicle. (AEC)

  12. DESIGN AND PERFORMANCE OF A LOW FLOW RATE INLET

    EPA Science Inventory

    Several ambient air samplers that have been designated by the U. S. EPA as Federal Reference Methods (FRMs) for measuring particulate matter nominally less than 10 um (PM10) include the use of a particular inlet design that aspirates particulate matter from the atmosphere at 1...

  13. Experimental Surveys for Submerged Inlet

    NASA Astrophysics Data System (ADS)

    Jovanovic, Vasilije; Taskinoglu, Ezgi; Elliott, Gregory; Knight, Doyle

    2003-11-01

    The objective of the study is to define the Pareto set of designs for a subsonic submerged inlet that minimizes flow distortion and swirl at the engine face. A series of experimental surveys are performed to validate the accompanying computations and to provide additional information regarding the Pareto set. A stainless steel model with a removable submerged inlet (built using an FDM system) has been fabricated and installed in the Rutgers University subsonic wind tunnel. Boundary layer measurements upstream of the inlet are obtained by a computer-controlled traversing pitot tube. The estimated boundary layer thickness agrees closely with the computed profile. Detailed experiments are focused on the measurement of total pressure three diameters downstream of the exit of the inlet. A rotating multi-element pitot rack is fabricated and installed in the model, which is attached to the suction side of a blower to yield the appropriate mass flow rate through the inlet. Motion control, pressure and temperature data acquisition as well as management of the wind tunnel operations for all experiments are controlled by a LabView program developed at Rutgers University.

  14. Detailed investigation of flowfields within large scale hypersonic inlet models

    NASA Technical Reports Server (NTRS)

    Seebaugh, W. R.; Doran, R. W.; Decarlo, J. P.

    1971-01-01

    Analytical and experimental investigations were conducted to determine the characteristics of the internal flows in model passages representative of hypersonic inlets and also sufficiently large for meaningful data to be obtained. Three large-scale inlet models, each having a different compression ratio, were designed to provide high performance and approximately uniform static-pressure distributions at the throat stations. A wedge forebody was used to simulate the flowfield conditions at the entrance of the internal passages, thus removing the actual vehicle forebody from consideration in the design of the wind-tunnel models. Tests were conducted in a 3.5 foot hypersonic wind tunnel at a nominal test Mach number of 7.4 and freestream unit Reynolds number of 2,700,000 per foot. From flowfield survey data the inlet entrance, the entering inviscid and viscous flow conditions were determined prior to the analysis of the data obtained in the internal passages. Detailed flowfield survey data were obtained near the centerlines of the internal passages to define the boundary-layer development on the internal surfaces and the internal shock-wave configuration. Finally, flowfield data were measured across the throats of the inlet models to evaluate the internal performance of the internal passages. These data and additional results from surface instrumentation and flow visualization studies were utilized to determine the internal flowfield patterns and the inlet performance.

  15. HSI Guidelines Outline for the Air Vehicle Control Station. Version 2

    NASA Technical Reports Server (NTRS)

    2006-01-01

    This document provides guidance to the FAA and manufacturers on how to develop UAS Pilot Vehicle Interfaces to safely and effectively integrate UASs into the NAS. Preliminary guidelines are provided for Aviate, Communicate, Navigate and Avoid Hazard functions. The pilot shall have information and control capability so that pilot-UA interactions are not adverse, unfavorable, nor compromise safety. Unfavorable interactions include anomalous aircraft-pilot coupling (APC) interactions (closed loop), pilot-involved oscillations (categories I, II or III), and non-oscillatory APC events (e.g., divergence). - Human Systems Integration Pilot-Technology Interface Requirements for Command, Control, and Communications (C3)

  16. Experimental investigation of cavitation in pump inlet

    NASA Astrophysics Data System (ADS)

    Sikora, Roman; Bureček, Adam; Hružík, Lumír; Vašina, Martin

    2015-05-01

    The article deals with experimental research of cavitation development in inlet tube of hydraulic pump. The pressures in inlet and outlet tube of the pump and flow rate were measured. Mineral oil was used as working fluid. The cavitation was visually evaluated in transparent inlet tube. The inlet tube underpressure was achieved by throttle valve. The relationship between the generation of bubbles and the inlet pressure is evaluated.

  17. Investigation of Aerodynamic and Icing Characteristics of Water-Inertia-Separation Inlets for Turbojet Engines

    NASA Technical Reports Server (NTRS)

    VonGlahn, Uwe; Blatz, R. E.

    1950-01-01

    The results of an investigation of several internal water-inertia-separation inlets consisting of a main duct and an alternate duct designed to prevent automatically the entrance of large quantities of water into a turbojet engine in icing conditions are presented. Total-pressure losses and icing characteristics for a direct-ram inlet and the inertia-separation inlets are compared at similar aerodynamic and simulated icing conditions. Complete ice protection for inlet guide vanes could not be achieved with the inertia-separation inlets investigated. Approximately 8 percent of the volume of water entering the nacelles remained. In the air passing into the compressor inlet. Heavy alternate-duct-elbow ice formations caused by secondary inertia separation resulted in rapid total-pressure losses and decreases in mass flow. The duration in an icing condition for an inertia-separation- inlet, without local surface heating, was increased approximately four times above that for a direct-ram inlet with a compressor-inlet screen. For normal nonicing operation, the inertia-separation- inlet total-pressure losses were comparable to a direct-ram installation. The pressure losses and the circumferential uniformity of the mass flow in all the inlets were relatively independent of angle of attack. Use of an inertia-separation inlet would in most cases require a larger diameter nacelle than a direct-ram inlet in order to obtain an alternate duct sufficiently large to pass the required engine air flow at duct Mach numbers below 1.0 at the minimum area.

  18. Novel prescribed performance neural control of a flexible air-breathing hypersonic vehicle with unknown initial errors.

    PubMed

    Bu, Xiangwei; Wu, Xiaoyan; Zhu, Fujing; Huang, Jiaqi; Ma, Zhen; Zhang, Rui

    2015-11-01

    A novel prescribed performance neural controller with unknown initial errors is addressed for the longitudinal dynamic model of a flexible air-breathing hypersonic vehicle (FAHV) subject to parametric uncertainties. Different from traditional prescribed performance control (PPC) requiring that the initial errors have to be known accurately, this paper investigates the tracking control without accurate initial errors via exploiting a new performance function. A combined neural back-stepping and minimal learning parameter (MLP) technology is employed for exploring a prescribed performance controller that provides robust tracking of velocity and altitude reference trajectories. The highlight is that the transient performance of velocity and altitude tracking errors is satisfactory and the computational load of neural approximation is low. Finally, numerical simulation results from a nonlinear FAHV model demonstrate the efficacy of the proposed strategy. PMID:26456727

  19. On the Application of Rapid Prototyping Technology for the Fabrication of Flapping Wings for Micro Air Vehicles

    NASA Astrophysics Data System (ADS)

    Kraemer, Kurtis Leigh

    Micro air vehicles (MAV) are a class of small uninhabited aircraft with dimensions less than 15 cm (6 in) and mass less than 500g (1.1 lbs). The aim of this research was to develop a fast, accurate, low-cost, and repeatable fabrication process for flapping MAV wings. Through the use of the RepRap Mendel open-source fused-deposition modeling (FDM) rapid prototyping machine ("3-D printer"), various wing prototypes were designed and fabricated using a bio-inspired approach. Testing of the aerodynamic performance of both real locust wings and the 3-D printed wing prototypes was performed through axial spin testing. Bending stiffness measurements were also performed on the 3-D printed wings. Through the use of open-source rapid prototyping technology, a fast and low-cost fabrication process for flapping MAV wings has been developed, out of which further understanding of flapping wing design and fabrication has been gained.

  20. 9 CFR 3.37 - Primary conveyances (motor vehicle, rail, air, and marine).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... to transport guinea pigs or hamsters shall be mechanically sound and provide fresh air by means of... containing live guinea pigs or hamsters when the ambient temperature in the animal cargo space is 75 °F (23.9 °C) or higher. The ambient temperature within the animal cargo space shall not exceed 85 °F (29.5...

  1. Design and Analysis Tools for Supersonic Inlets

    NASA Technical Reports Server (NTRS)

    Slater, John W.; Folk, Thomas C.

    2009-01-01

    Computational tools are being developed for the design and analysis of supersonic inlets. The objective is to update existing tools and provide design and low-order aerodynamic analysis capability for advanced inlet concepts. The Inlet Tools effort includes aspects of creating an electronic database of inlet design information, a document describing inlet design and analysis methods, a geometry model for describing the shape of inlets, and computer tools that implement the geometry model and methods. The geometry model has a set of basic inlet shapes that include pitot, two-dimensional, axisymmetric, and stream-traced inlet shapes. The inlet model divides the inlet flow field into parts that facilitate the design and analysis methods. The inlet geometry model constructs the inlet surfaces through the generation and transformation of planar entities based on key inlet design factors. Future efforts will focus on developing the inlet geometry model, the inlet design and analysis methods, a Fortran 95 code to implement the model and methods. Other computational platforms, such as Java, will also be explored.

  2. Development of a vehicle emission inventory with high temporal-spatial resolution based on NRT traffic data and its impact on air pollution in Beijing - Part 1: Development and evaluation of vehicle emission inventory

    NASA Astrophysics Data System (ADS)

    Jing, Boyu; Wu, Lin; Mao, Hongjun; Gong, Sunning; He, Jianjun; Zou, Chao; Song, Guohua; Li, Xiaoyu; Wu, Zhong

    2016-03-01

    This paper presents a bottom-up methodology based on the local emission factors, complemented with the widely used emission factors of Computer Programme to Calculate Emissions from Road Transport (COPERT) model and near-real-time traffic data on road segments to develop a vehicle emission inventory with high temporal-spatial resolution (HTSVE) for the Beijing urban area. To simulate real-world vehicle emissions accurately, the road has been divided into segments according to the driving cycle (traffic speed) on this road segment. The results show that the vehicle emissions of NOx, CO, HC and PM were 10.54 × 104, 42.51 × 104 and 2.13 × 104 and 0.41 × 104 Mg respectively. The vehicle emissions and fuel consumption estimated by the model were compared with the China Vehicle Emission Control Annual Report and fuel sales thereafter. The grid-based emissions were also compared with the vehicular emission inventory developed by the macro-scale approach. This method indicates that the bottom-up approach better estimates the levels and spatial distribution of vehicle emissions than the macro-scale method, which relies on more information. Based on the results of this study, improved air quality simulation and the contribution of vehicle emissions to ambient pollutant concentration in Beijing have been investigated in a companion paper (He et al., 2016).

  3. Experimental Investigation of Project Orion Crew Exploration Vehicle Aeroheating: LaRC 20-Inch Mach 6 Air Tunnel Test 6931

    NASA Technical Reports Server (NTRS)

    Hollis, Brian R.

    2009-01-01

    An investigation of the aeroheating environment of the Project Orion Crew Entry Vehicle has been performed in the Langley Research Center 20-Inch Mach 6 Air Tunnel. Data were measured on a approx.3.5% scale model (0.1778-m/7-inch diameter) of the vehicle using coaxial thermocouples at free stream Reynolds numbers of 2.0 10(exp 6)/ft to 7.30 10(exp 6)/ft and computational predictions were generated for all test conditions. The primary goals of this test were to obtain convective heating data for use in assessing the accuracy of the computational technique and to validate test methodology and heating data from a test of the same wind tunnel model in the Arnold Engineering Development Center Tunnel 9. Secondary goals were to determine the extent of transitional/turbulent data which could be produced on a CEV model in this facility, either with or without boundary-layer trips, and to demonstrate continuous pitch-sweep operation in this tunnel for heat transfer testing.

  4. Novel adaptive neural control design for a constrained flexible air-breathing hypersonic vehicle based on actuator compensation

    NASA Astrophysics Data System (ADS)

    Bu, Xiangwei; Wu, Xiaoyan; He, Guangjun; Huang, Jiaqi

    2016-03-01

    This paper investigates the design of a novel adaptive neural controller for the longitudinal dynamics of a flexible air-breathing hypersonic vehicle with control input constraints. To reduce the complexity of controller design, the vehicle dynamics is decomposed into the velocity subsystem and the altitude subsystem, respectively. For each subsystem, only one neural network is utilized to approach the lumped unknown function. By employing a minimal-learning parameter method to estimate the norm of ideal weight vectors rather than their elements, there are only two adaptive parameters required for neural approximation. Thus, the computational burden is lower than the ones derived from neural back-stepping schemes. Specially, to deal with the control input constraints, additional systems are exploited to compensate the actuators. Lyapunov synthesis proves that all the closed-loop signals involved are uniformly ultimately bounded. Finally, simulation results show that the adopted compensation scheme can tackle actuator constraint effectively and moreover velocity and altitude can stably track their reference trajectories even when the physical limitations on control inputs are in effect.

  5. Prediction of thermal behaviors of an air-cooled lithium-ion battery system for hybrid electric vehicles

    NASA Astrophysics Data System (ADS)

    Choi, Yong Seok; Kang, Dal Mo

    2014-12-01

    Thermal management has been one of the major issues in developing a lithium-ion (Li-ion) hybrid electric vehicle (HEV) battery system since the Li-ion battery is vulnerable to excessive heat load under abnormal or severe operational conditions. In this work, in order to design a suitable thermal management system, a simple modeling methodology describing thermal behavior of an air-cooled Li-ion battery system was proposed from vehicle components designer's point of view. A proposed mathematical model was constructed based on the battery's electrical and mechanical properties. Also, validation test results for the Li-ion battery system were presented. A pulse current duty and an adjusted US06 current cycle for a two-mode HEV system were used to validate the accuracy of the model prediction. Results showed that the present model can give good estimations for simulating convective heat transfer cooling during battery operation. The developed thermal model is useful in structuring the flow system and determining the appropriate cooling capacity for a specified design prerequisite of the battery system.

  6. Micro air vehicle-motivated computational biomechanics in bio-flights: aerodynamics, flight dynamics and maneuvering stability

    NASA Astrophysics Data System (ADS)

    Liu, Hao; Nakata, Toshiyuki; Gao, Na; Maeda, Masateru; Aono, Hikaru; Shyy, Wei

    2010-12-01

    Aiming at developing an effective tool to unveil key mechanisms in bio-flight as well as to provide guidelines for bio-inspired micro air vehicles (MAVs) design, we propose a comprehensive computational framework, which integrates aerodynamics, flight dynamics, vehicle stability and maneuverability. This framework consists of (1) a Navier-Stokes unsteady aerodynamic model; (2) a linear finite element model for structural dynamics; (3) a fluid-structure interaction (FSI) model for coupled flexible wing aerodynamics aeroelasticity; (4) a free-flying rigid body dynamic (RBD) model utilizing the Newtonian-Euler equations of 6DoF motion; and (5) flight simulator accounting for realistic wing-body morphology, flapping-wing and body kinematics, and a coupling model accounting for the nonlinear 6DoF flight dynamics and stability of insect flapping flight. Results are presented based on hovering aerodynamics with rigid and flexible wings of hawkmoth and fruitfly. The present approach can support systematic analyses of bio- and bio-inspired flight.

  7. A Common Communications, Navigation and Surveillance Infrastructure for Accommodating Space Vehicles in the Next Generation Air Transportation System

    NASA Technical Reports Server (NTRS)

    VanSuetendael, RIchard; Hayes, Alan; Birr, Richard

    2008-01-01

    Suborbital space flight and space tourism are new potential markets that could significantly impact the National Airspace System (NAS). Numerous private companies are developing space flight capabilities to capture a piece of an emerging commercial space transportation market. These entrepreneurs share a common vision that sees commercial space flight as a profitable venture. Additionally, U.S. space exploration policy and national defense will impose significant additional demands on the NAS. Air traffic service providers must allow all users fair access to limited airspace, while ensuring that the highest levels of safety, security, and efficiency are maintained. The FAA's Next Generation Air Transportation System (NextGen) will need to accommodate spacecraft transitioning to and from space through the NAS. To accomplish this, space and air traffic operations will need to be seamlessly integrated under some common communications, navigation and surveillance (CNS) infrastructure. As part of NextGen, the FAA has been developing the Automatic Dependent Surveillance Broadcast (ADS-B) which utilizes the Global Positioning System (GPS) to track and separate aircraft. Another key component of NextGen, System-Wide Information Management/ Network Enabled Operations (SWIM/NEO), is an open architecture network that will provide NAS data to various customers, system tools and applications. NASA and DoD are currently developing a space-based range (SBR) concept that also utilizes GPS, communications satellites and other CNS assets. The future SBR will have very similar utility for space operations as ADS-B and SWIM has for air traffic. Perhaps the FAA, NASA, and DoD should consider developing a common space-based CNS infrastructure to support both aviation and space transportation operations. This paper suggests specific areas of research for developing a CNS infrastructure that can accommodate spacecraft and other new types of vehicles as an integrated part of NextGen.

  8. Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs)

    NASA Astrophysics Data System (ADS)

    Hatfield, M. C.; Webley, P.; Saiet, E., II

    2014-12-01

    Remote Sensing of Arctic Environmental Conditions and Critical Infrastructure using Infra-Red (IR) Cameras and Unmanned Air Vehicles (UAVs) Numerous scientific and logistical applications exist in Alaska and other arctic regions requiring analysis of expansive, remote areas in the near infrared (NIR) and thermal infrared (TIR) bands. These include characterization of wild land fire plumes and volcanic ejecta, detailed mapping of lava flows, and inspection of lengthy segments of critical infrastructure, such as the Alaska pipeline and railroad system. Obtaining timely, repeatable, calibrated measurements of these extensive features and infrastructure networks requires localized, taskable assets such as UAVs. The Alaska Center for Unmanned Aircraft Systems Integration (ACUASI) provides practical solutions to these problem sets by pairing various IR sensors with a combination of fixed-wing and multi-rotor air vehicles. Fixed-wing assets, such as the Insitu ScanEagle, offer long reach and extended duration capabilities to quickly access remote locations and provide enduring surveillance of the target of interest. Rotary-wing assets, such as the Aeryon Scout or the ACUASI-built Ptarmigan hexcopter, provide a precision capability for detailed horizontal mapping or vertical stratification of atmospheric phenomena. When included with other ground capabilities, we will show how they can assist in decision support and hazard assessment as well as giving those in emergency management a new ability to increase knowledge of the event at hand while reducing the risk to all involved. Here, in this presentation, we illustrate how UAV's can provide the ideal tool to map and analyze the hazardous events and critical infrastructure under extreme environmental conditions.

  9. Isokinetic air sampler

    DOEpatents

    Sehmel, George A.

    1979-01-01

    An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

  10. Design and performance of an atmospheric pressure inlet system for lithium ion attachment mass spectrometry.

    PubMed

    Selvin, P Christopher; Iwase, Keiichiro; Fujii, Toshihiro

    2002-05-01

    We designed a simple and efficient inlet system to act as an interface between samples at atmospheric pressure and the high vacuum inside a mass spectrometer. The newly designed stainless steel orifice leak sample inlet system is simple and rugged and fulfills all the basic requirements. With this inlet system coupled with a lithium ion attachment mass spectrometer, it is possible to detect any chemical species at atmospheric pressure, including radical intermediates, on a real-time basis. For illustrative purposes, the sampling efficiency of the inlet probe coupled with a lithium ion attachment mass spectrometer is discussed for laboratory air and polyethylene pyrolysis. PMID:12033306

  11. A preliminary design study of supersonic through-flow fan inlets

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1988-01-01

    From Mach 3.20 cruise propulsion systems, preliminary design studies for two supersonic through-flow fan primary inlets and a single core inlet were undertaken. Method of characteristics and one dimensional performance techniques were applied to assess the potential improvements supersonic through-flow fan technology has over more conventional systems. A fixed geometry supersonic through-flow fan primary inlet was found to have better performance than a conventional inlet design on the basis of total pressure recovery, air flow, aerodynamic drag and size and weight.

  12. A preliminary design study of supersonic through-flow fan inlets

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1988-01-01

    From Mach 3.20 cruise propulsion systems, preliminary design studies for two supersonic through-flow fan primary inlets and a single core inlet were undertaken. Method of characteristics and one-dimensional performance techniques were applied to assess the potential improvements supersonic through-flow fan technology has over more conventional systems. A fixed geometry supersonic through-flow fan primary inlet was found to have better performance than a conventional inlet design on the basis of total pressure recovery, air flow, aerodynamic drag and size and weight.

  13. Investigation of corner shock boundary layer interactions to understand inlet unstart

    NASA Astrophysics Data System (ADS)

    Funderburk, Morgan

    2015-11-01

    Inlet unstart is a detrimental phenomenon in dual-mode ramjet/scramjet engines that causes severe loss of thrust, large transient structural load, and potentially a loss of the aircraft. In order to analyze the effects that the corner shock boundary layer interaction (SBLI) has on initiating and perpetuating inlet unstart, a qualitative and quantitative investigation into mean and dynamic features of corner SBLI at various Mach numbers is made. Surface streakline visualization showed that the corner SBLI is highly three-dimensional with a dominant presence of corner separation vortex. Further, the peak r.m.s. pressure was located at the periphery of corner separation vortex, suggesting that the unsteady loading is caused by the corner vortex. Power spectral densities of wall-pressure fluctuations in the peak r.m.s. location were analyzed in order to characterize the dominant frequencies of oscillation of the flow structures and to unravel the dynamic interactions between them in order to expand the operating margin of future hypersonic air breathing vehicles.

  14. Visual Servoing of Quadrotor Micro-Air Vehicle Using Color-Based Tracking Algorithm

    NASA Astrophysics Data System (ADS)

    Azrad, Syaril; Kendoul, Farid; Nonami, Kenzo

    This paper describes a vision-based tracking system using an autonomous Quadrotor Unmanned Micro-Aerial Vehicle (MAV). The vision-based control system relies on color target detection and tracking algorithm using integral image, Kalman filters for relative pose estimation, and a nonlinear controller for the MAV stabilization and guidance. The vision algorithm relies on information from a single onboard camera. An arbitrary target can be selected in real-time from the ground control station, thereby outperforming template and learning-based approaches. Experimental results obtained from outdoor flight tests, showed that the vision-control system enabled the MAV to track and hover above the target as long as the battery is available. The target does not need to be pre-learned, or a template for detection. The results from image processing are sent to navigate a non-linear controller designed for the MAV by the researchers in our group.

  15. Design and development of an unconventional VTOL micro air vehicle: The Cyclocopter

    NASA Astrophysics Data System (ADS)

    Benedict, Moble; Chopra, Inderjit

    2012-06-01

    This paper discusses the systematic experimental and vehicle design/development studies conducted at the University of Maryland which culminated in the development of the first flying Cyclocopter in the history. Cyclocopter is a novel Vertical Take-Off and Landing (VTOL) aircraft, which utilizes cycloidalrotors (cyclorotors), a revolutionary horizontal axis propulsion concept, that has many advantages such as higher aerodynamic efficiency, maneuverability and high-speed forward flight capability when compared to a conventional helicopter rotor. The experimental studies included a detailed parametric study to understand the effect of rotor geometry and blade kinematics on cyclorotor hover performance. Based on the experimental results, higher blade pitch angles were found to improve thrust and increase the power loading (thrust per unit power) of the cyclorotor. Asymmetric pitching with higher pitch angle at the top than at the bottom produced better power loading. The chordwise optimum pitching axis location was observed to be around 25-35% of the blade chord. Because of the flow curvature effects, the cycloidal rotor performance was a strong function of the chord/radius ratio. The optimum chord/radius ratios were extremely high, around 0.5-0.8, depending on the blade pitching amplitude. A flow field investigation was also conducted using Particle Image Velocimetry (PIV) to unravel the physics behind thrust production of a cyclorotor. PIV studies indicated evidence of a stall delay as well as possible increases in lift on the blades from the presence of a leading edge vortex. The goal of all these studies was to understand and optimize the performance of a micro-scale cyclorotor so that it could be used in a flying vehicle. An optimized cyclorotor was used to develop a 200 gram cyclocopter capable of autonomous stable hover using an onboard feedback controller.

  16. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, Frederick W.; Kartsounes, George T.

    1980-01-01

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air pressure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  17. Air ejector augmented compressed air energy storage system

    DOEpatents

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  18. Low speed test of the aft inlet designed for a tandem fan V/STOL nacelle

    NASA Technical Reports Server (NTRS)

    Rhoades, W. W.; Ybarra, A. H.

    1980-01-01

    An approximately .25 scale model of a Tandem Fan nacelle designed for a Type A V/STOL aircraft configuration was tested in a 10-by-10 foot wind tunnel. A 12 inch, tip driven, turbofan simulator was used to provide the suction source for the aft fan inlet. The front fan inlet was faired over for this test entry. Model variables consisted of a long aft inlet cowl, a short aft inlet cowl, a shaft simulator, blow-in door passages and diffuser vortex generators. Inlet pressure recovery, distortion, inlet angle of attack separation limits were evaluated at tunnel velocities from 0 to 240 knots, angles of attack from -10 to 40 degrees and inlet flow rates representative of throat Mach numbers of 0.1 to 0.6. High inlet performance and stable operation was verified at all design forward speed and angle of attack conditions. The short aft inlet configuration provided exceptionally high pressure recovery except at the highest combination of angle of attack and forward speed. The flow quality at the fan face was somewhat degraded by the addition of blow-in door passages to the long aft inlet configuration due to the pressure disturbances generated by the flow entering the diffuser through the auxiliary air passages.

  19. Implementation of the Rauch-Tung-Striebel Smoother for Sensor Compatibility Correction of a Fixed-Wing Unmanned Air Vehicle

    PubMed Central

    Chan, Woei-Leong; Hsiao, Fei-Bin

    2011-01-01

    This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly. PMID:22163819

  20. Implementation of the Rauch-Tung-Striebel smoother for sensor compatibility correction of a fixed-wing unmanned air vehicle.

    PubMed

    Chan, Woei-Leong; Hsiao, Fei-Bin

    2011-01-01

    This paper presents a complete procedure for sensor compatibility correction of a fixed-wing Unmanned Air Vehicle (UAV). The sensors consist of a differential air pressure transducer for airspeed measurement, two airdata vanes installed on an airdata probe for angle of attack (AoA) and angle of sideslip (AoS) measurement, and an Attitude and Heading Reference System (AHRS) that provides attitude angles, angular rates, and acceleration. The procedure is mainly based on a two pass algorithm called the Rauch-Tung-Striebel (RTS) smoother, which consists of a forward pass Extended Kalman Filter (EKF) and a backward recursion smoother. On top of that, this paper proposes the implementation of the Wiener Type Filter prior to the RTS in order to avoid the complicated process noise covariance matrix estimation. Furthermore, an easy to implement airdata measurement noise variance estimation method is introduced. The method estimates the airdata and subsequently the noise variances using the ground speed and ascent rate provided by the Global Positioning System (GPS). It incorporates the idea of data regionality by assuming that some sort of statistical relation exists between nearby data points. Root mean square deviation (RMSD) is being employed to justify the sensor compatibility. The result shows that the presented procedure is easy to implement and it improves the UAV sensor data compatibility significantly. PMID:22163819

  1. Inlet Flow Valve Engine Analyses

    NASA Technical Reports Server (NTRS)

    Champagne, G. A.

    2004-01-01

    Pratt&Whitney, under Task Order 13 of the NASA Large Engine Technology (LET) Contract, conducted a study to determine the operating characteristics, performance and weights of Inlet Flow Valve (IFV) propulsion concepts for a Mach 2.4 High Speed Civil Transport (HSCT).

  2. Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009

    PubMed Central

    Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

    2014-01-01

    On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs) during 1995–2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NOx, and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995–2009 period despite an increase in total vehicle distance traveled. The CO and NOx emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NOx in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001– 2009. Although this trend coexists with the declining trends in on-road NOx, VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NOx in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NOx during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of the

  3. IPAC-Inlet Performance Analysis Code

    NASA Technical Reports Server (NTRS)

    Barnhart, Paul J.

    1997-01-01

    A series of analyses have been developed which permit the calculation of the performance of common inlet designs. The methods presented are useful for determining the inlet weight flows, total pressure recovery, and aerodynamic drag coefficients for given inlet geometric designs. Limited geometric input data is required to use this inlet performance prediction methodology. The analyses presented here may also be used to perform inlet preliminary design studies. The calculated inlet performance parameters may be used in subsequent engine cycle analyses or installed engine performance calculations for existing uninstalled engine data.

  4. Method for Determining Optimum Injector Inlet Geometry

    NASA Technical Reports Server (NTRS)

    Trinh, Huu P. (Inventor); Myers, W. Neill (Inventor)

    2015-01-01

    A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The method calculates the tangential inlet area for each throttleable stage. The method also uses correlation between the tangential inlet areas and delta pressure values to calculate the spring displacement and variable inlet geometry of a liquid rocket engine swirl injector.

  5. Analysis of an advanced ducted propeller subsonic inlet

    NASA Technical Reports Server (NTRS)

    Iek, Chanthy; Boldman, Donald R.; Ibrahim, Mounir

    1992-01-01

    A time marching Navier-Stokes code called PARC (PARC2D for 2-D/axisymmetric and PARC3D for 3-D flow simulations) was validated for an advanced ducted propeller (ADP) subsonic inlet. The code validation for an advanced ducted propeller (ADP) subsonic inlet. The code validation was implemented for a non-separated flow condition associated with the inlet operating at angles-of-attack of 0 and 25 degrees. The inlet test data were obtained in the 9 x 15 ft Low Speed Wind Tunnel at NASA Lewis Research Center as part of a cooperative study with Pratt and Whitney. The experimental study focused on the ADP inlet performance for take-off and approach conditions. The inlet was tested at a free stream Mach number of 0.2, at angles-of-attack between O and 35 degrees, and at a maximum propeller speed of 12,000 RPM which induced a corrected air flow rate of about 46 lb/sec based on standard day conditions. The computational grid and flow boundary conditions (BC) were based on the actual inlet geometry and the funnel flow conditions. At the propeller face, two types of BC's were applied: a mass flow BC and a fixed flow properties BC. The fixed flow properties BC was based on a combination of data obtained from the experiment and calculations using a potential flow code. Comparison of the computational results with the test data indicates that the PARC code with the propeller face fixed flow properties BC provided a better prediction of the inlet surface static pressures than the predictions when the mass flow BC was used. For an angle-of-attack of 0 degrees, the PARC2D code with the propeller face mass flow BC provided a good prediction of inlet static pressures except in the region of high pressure gradient. With the propeller face fixed flow properties BC, the PARC2D code provided a good prediction of the inlet static pressures. For an angle-of-attack of 25 degrees with the mass flow BC, the PARC3D code predicted statis pressures which deviated significantly from the test data

  6. F-15 inlet/engine test techniques and distortion methodologies studies. Volume 2: Time variant data quality analysis plots

    NASA Technical Reports Server (NTRS)

    Stevens, C. H.; Spong, E. D.; Hammock, M. S.

    1978-01-01

    Time variant data quality analysis plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle.

  7. Water cooling system for an air-breathing hypersonic test vehicle

    NASA Technical Reports Server (NTRS)

    Petley, Dennis H.; Dziedzic, William M.

    1993-01-01

    This study provides concepts for hypersonic experimental scramjet test vehicles which have low cost and low risk. Cryogenic hydrogen is used as the fuel and coolant. Secondary water cooling systems were designed. Three concepts are shown: an all hydrogen cooling system, a secondary open loop water cooled system, and a secondary closed loop water cooled system. The open loop concept uses high pressure helium (15,000 psi) to drive water through the cooling system while maintaining the pressure in the water tank. The water flows through the turbine side of the turbopump to pump hydrogen fuel. The water is then allowed to vent. In the closed loop concept high pressure, room temperature, compressed liquid water is circulated. In flight water pressure is limited to 6000 psi by venting some of the water. Water is circulated through cooling channels via an ejector which uses high pressure gas to drive a water jet. The cooling systems are presented along with finite difference steady-state and transient analysis results. The results from this study indicate that water used as a secondary coolant can be designed to increase experimental test time, produce minimum venting of fluid and reduce overall development cost.

  8. Inertial attitude control of a bat-like morphing-wing air vehicle.

    PubMed

    Colorado, J; Barrientos, A; Rossi, C; Parra, C

    2013-03-01

    This paper presents a novel bat-like unmanned aerial vehicle inspired by the morphing-wing mechanism of bats. The goal of this paper is twofold. Firstly, a modelling framework is introduced for analysing how the robot should manoeuvre by means of changing wing morphology. This allows the definition of requirements for achieving forward and turning flight according to the kinematics of the wing modulation. Secondly, an attitude controller named backstepping+DAF is proposed. Motivated by biological evidence about the influence of wing inertia on the production of body accelerations, the attitude control law incorporates wing inertia information to produce desired roll (ϕ) and pitch (θ) acceleration commands (desired angular acceleration function (DAF)). This novel control approach is aimed at incrementing net body forces (F(net)) that generate propulsion. Simulations and wind-tunnel experimental results have shown an increase of about 23% in net body force production during the wingbeat cycle when the wings are modulated using the DAF as a part of the backstepping control law. Results also confirm accurate attitude tracking in spite of high external disturbances generated by aerodynamic loads at airspeeds up to 5 ms⁻¹. PMID:23211685

  9. Verification and Tuning of an Adaptive Controller for an Unmanned Air Vehicle

    NASA Technical Reports Server (NTRS)

    Crespo, Luis G.; Matsutani, Megumi; Annaswamy, Anuradha M.

    2010-01-01

    This paper focuses on the analysis and tuning of a controller based on the Adaptive Control Technology for Safe Flight (ACTS) architecture. The ACTS architecture consists of a nominal, non-adaptive controller that provides satisfactory performance under nominal flying conditions, and an adaptive controller that provides robustness under off-nominal ones. A framework unifying control verification and gain tuning is used to make the controller s ability to satisfy the closed-loop requirements more robust to uncertainty. In this paper we tune the gains of both controllers using this approach. Some advantages and drawbacks of adaptation are identified by performing a global robustness assessment of both the adaptive controller and its non-adaptive counterpart. The analyses used to determine these characteristics are based on evaluating the degradation in closed-loop performance resulting from uncertainties having increasing levels of severity. The specific adverse conditions considered can be grouped into three categories: aerodynamic uncertainties, structural damage, and actuator failures. These failures include partial and total loss of control effectiveness, locked-in-place control surface deflections, and engine out conditions. The requirements considered are the peak structural loading, the ability of the controller to track pilot commands, the ability of the controller to keep the aircraft s state within the reliable flight envelope, and the handling/riding qualities of the aircraft. The nominal controller resulting from these tuning strategies was successfully validated using the NASA GTM Flight Test Vehicle.

  10. A multimodal micro air vehicle for autonomous flight in near-earth environments

    NASA Astrophysics Data System (ADS)

    Green, William Edward

    Reconnaissance, surveillance, and search-and-rescue missions in near-Earth environments such as caves, forests, and urban areas pose many new challenges to command and control (C2) teams. Of great significance is how to acquire situational awareness when access to the scene is blocked by enemy fire, rubble, or other occlusions. Small bird-sized aerial robots are expendable and can fly over obstacles and through small openings to assist in the acquisition and distribution of intelligence. However, limited flying space and densely populated obstacle fields requires a vehicle that is capable of hovering, but also maneuverable. A secondary flight mode was incorporated into a fixed-wing aircraft to preserve its maneuverability while adding the capability of hovering. An inertial measurement sensor and onboard flight control system were interfaced and used to transition the hybrid prototype from cruise to hover flight and sustain a hover autonomously. Furthermore, the hovering flight mode can be used to maneuver the aircraft through small openings such as doorways. An ultrasonic and infrared sensor suite was designed to follow exterior building walls until an ingress route was detected. Reactive control was then used to traverse the doorway and gather reconnaissance. Entering a dangerous environment to gather intelligence autonomously will provide an invaluable resource to any C2 team. The holistic approach of platform development, sensor suite design, and control serves as the philosophy of this work.

  11. Hypersonic Airbreathing Vehicles/Technologies

    NASA Technical Reports Server (NTRS)

    Hunt, James L.

    1996-01-01

    Hypersonic airbreathing horizontal takeoff and landing (HTOL) vehicles are highly integrated systems involving many advanced technologies. The design environment is variable rich, intricately networked, and sensitivity intensive; as such, it represents a tremendous challenge. Creating a viable design requires addressing three main elements: (1) an understanding of the 'figures of merit' and their relationship, (2) the development of sophisticated configuration discipline prediction methods and a synthesis procedure, and (3) the synergistic integration of advanced technologies across the discipline spectrum. This paper will focus on the vision for hypersonic airbreathing vehicles and the advanced technologies that forge the designs. Airbreathing hypersonics encompass endoatmospheric (airplanes...missiles are a part of the matrix but will not be included in this paper since they are an air force focus) and space access vehicles with speed from Mach 4 up to Mach 25 (orbital). These vehicles can be divided into two classes...cruisers and accelerators. The cruiser designs reflect high lift-to-drag whereas the accelerators reflect low drag per unit inlet capture; thus, the cross section of the accelerator attributes a much larger percentage to propulsion. One of the more design influencing items is fuel. The hydrogen fueled vehicles must be very volumetric efficient to contain the low density fuel and thus tend to be a bit bulgy (more conducive to lifting bodies or wing bodies) whereas with hydrocarbon fueled vehicles, the concern is loading because of the high density fuel; thus, they may tend to be more towards waveriders which are not usually very volumetric efficient. Hydrocarbon fuels (endothermic) are limited in their engine cooling capacity to below Mach 8.

  12. Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.

    PubMed

    Lee, Eon S; Zhu, Yifang

    2014-02-18

    Modern passenger vehicles are commonly equipped with cabin air filters but their filtration efficiency for ultrafine particle (UFP) is rather low. Although setting the vehicle ventilation system to recirculation (RC) mode can reduce in-cabin UFPs by ∼ 90%, passenger-exhaled carbon dioxide (CO2) can quickly accumulate inside the cabin. Using outdoor air (OA) mode instead can provide sufficient air exchange to prevent CO2 buildup, but in-cabin UFP concentrations would increase. To overcome this dilemma, we developed a simultaneous mitigation method for UFP and CO2 using high-efficiency cabin air (HECA) filtration in OA mode. Concentrations of UFP and other air pollutants were simultaneously monitored in and out of 12 different vehicles under 3 driving conditions: stationary, on local roadways, and on freeways. Under each experimental condition, data were collected with no filter, in-use original equipment manufacturer (OEM) filter, and two types of HECA filters. The HECA filters offered an average in-cabin UFP reduction of 93%, much higher than the OEM filters (∼ 50% on average). Throughout the measurements, the in-cabin CO2 concentration remained in the range of 620-930 ppm, significantly lower than the typical level of 2500-4000 ppm observed in the RC mode. PMID:24471775

  13. Experimental Investigation of Flow Control in a Compact Inlet Duct

    NASA Astrophysics Data System (ADS)

    Debronsky, Brian; Amitay, Michael

    2012-11-01

    Attractive to aircraft designers are compact inlets, which implement curved flow paths from the air intake of the engine to the compressor face. A compromise must be made between the compactness of the inlet and its aerodynamic performance. The aerodynamic purpose of inlets is to decelerate the oncoming flow before reaching the engine while minimizing total pressure loss, unsteadiness and distortion. Low length-to-diameter ratio inlets have a high degree of curvature, which inevitably causes flow separation and secondary flows. To address this issue, active flow control was implemented on a compact (L/D = 1.6) inlet to improve its performance metrics. The experiments were conducted at a Mach number of 0.44, where the actuation from an array of skewed and pitched jets produced streamwise vortices opposite to the secondary flow structures. The actuation resulted in an improved pressure recovery at the aerodynamic interface plane (AIP), where both the strength of the secondary structures and the flow unsteadiness were significantly reduced. Northrop Grumman Corporation.

  14. Air toxics exposure from vehicle emissions at a U.S. border crossing: Buffalo Peace Bridge Study.

    PubMed

    Spengler, John; Lwebuga-Mukasa, Jamson; Vallarino, Jose; Melly, Steve; Chillrud, Steve; Baker, Joel; Minegishi, Taeko

    2011-07-01

    is upwind of the plaza with dominant winds, were used to characterize contaminants in regional air masses. On-site meteorologic measurements and hourly truck and car counts were used to assess the role of traffic on UFP counts and pPAH concentrations. The array of parallel and perpendicular residential streets adjacent to the plaza provided a grid on which to plot the spatial patterns of UFP counts and pPAH concentrations to determine the extent to which traffic emissions from the Peace Bridge plaza might extend into the neighboring community. For lake-wind conditions (southwest to northwest) 12-hour integrated daytime samples showed clear evidence that vehicle-related emissions at the Peace Bridge plaza were responsible for elevated downwind concentrations of PM2.5, EC, and benzene, toluene, ethylbenzene, and xylenes (BTEX), as well as 1,3-butadiene and styrene. The chlorinated VOCs and aldehydes were not differentially higher at the downwind site. Several metals (aluminum, calcium, iron, copper, and antimony) were two times higher at the site adjacent to the plaza as they were at the upwind GLC site on lake-wind sampling days. Other metals (beryllium, sodium, magnesium, potassium, titanium, manganese, cobalt, strontium, tin, cesium, and lanthanum) showed significant increases downwind as well. Sulfur, arsenic, selenium, and a few other elements appeared to be markers for regional transport as their upwind and downwind concentrations were correlated, with ratios near unity. Using positive matrix factorization (PMF), we identified the sources for PAHs at the three fixed sampling sites as regional, diesel, general vehicle, and asphalt volatilization. Diesel exhaust at the Peace Bridge plaza accounted for approximately 30% of the PAHs. The NPAH sources were identified as nitrate (NO3) radical reactions, diesel, and mixed sources. Diesel exhaust at the Peace Bridge plaza accounted for 18% of the NPAHs. Further evidence for the impact of the Peace Bridge plaza on local

  15. Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.

    PubMed

    Zhang, G Q; Yu, S C M

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the "ventilation" in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  16. Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle

    PubMed Central

    Zhang, G. Q.; Yu, S. C. M.

    2014-01-01

    Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

  17. Assessment of Charging Infrastructure for Plug-in Electric Vehicles at Naval Air Station Whidbey Island: Task 3

    SciTech Connect

    Schey, Steve; Francfort, Jim

    2015-07-01

    Several U.S. Department of Defense base studies have been conducted to identify potential U.S. Department of Defense transportation systems that are strong candidates for introduction or expansion of plug-in electric vehicles (PEVs). Task 1 consisted of a survey of the non-tactical fleet of vehicles at NASWI to begin the review of vehicle mission assignments and types of vehicles in service. Task 2 selected vehicles for further monitoring and involved identifying daily operational characteristics of these select vehicles. Data logging of vehicle movements was initiated in order to characterize the vehicle’s mission. The Task 3 Vehicle Utilization report provided the results of the data analysis and observations related to the replacement of current vehicles with PEVs. This report provides an assessment of charging infrastructure required to support the suggested PEV replacements.

  18. Design, fabrication, and characterization of multifunctional wings to harvest solar energy in flapping wing air vehicles

    NASA Astrophysics Data System (ADS)

    Perez-Rosado, Ariel; Gehlhar, Rachel D.; Nolen, Savannah; Gupta, Satyandra K.; Bruck, Hugh A.

    2015-06-01

    Currently, flapping wing unmanned aerial vehicles (a.k.a., ornithopters or robotic birds) sustain very short duration flight due to limited on-board energy storage capacity. Therefore, energy harvesting elements, such as flexible solar cells, need to be used as materials in critical components, such as wing structures, to increase operational performance. In this paper, we describe a layered fabrication method that was developed for realizing multifunctional composite wings for a unique robotic bird we developed, known as Robo Raven, by creating compliant wing structure from flexible solar cells. The deformed wing shape and aerodynamic lift/thrust loads were characterized throughout the flapping cycle to understand wing mechanics. A multifunctional performance analysis was developed to understand how integration of solar cells into the wings influences flight performance under two different operating conditions: (1) directly powering wings to increase operation time, and (2) recharging batteries to eliminate need for external charging sources. The experimental data is then used in the analysis to identify a performance index for assessing benefits of multifunctional compliant wing structures. The resulting platform, Robo Raven III, was the first demonstration of a robotic bird that flew using energy harvested from solar cells. We developed three different versions of the wing design to validate the multifunctional performance analysis. It was also determined that residual thrust correlated to shear deformation of the wing induced by torsional twist, while biaxial strain related to change in aerodynamic shape correlated to lift. It was also found that shear deformation of the solar cells induced changes in power output directly correlating to thrust generation associated with torsional deformation. Thus, it was determined that multifunctional solar cell wings may be capable of three functions: (1) lightweight and flexible structure to generate aerodynamic forces, (2

  19. LPV H-infinity Control for the Longitudinal Dynamics of a Flexible Air-Breathing Hypersonic Vehicle

    NASA Astrophysics Data System (ADS)

    Hughes, Hunter Douglas

    This dissertation establishes the method needed to synthesize and simulate an Hinfinity Linear Parameter-Varying (LPV) controller for a flexible air-breathing hypersonic vehicle model. A study was conducted to gain the understanding of the elastic effects on the open loop system. It was determined that three modes of vibration would be suitable for the hypersonic vehicle model. It was also discovered from the open loop study that there is strong coupling in the hypersonic vehicle states, especially between the angle of attack, pitch rate, pitch attitude, and the exible modes of the vehicle. This dissertation outlines the procedure for synthesizing a full state feedback Hinfinity LPV controller for the hypersonic vehicle. The full state feedback study looked at both velocity and altitude tracking for the exible vehicle. A parametric study was conducted on each of these controllers to see the effects of changing the number of gridding points in the parameter space and changing the parameter variation rate limits in the system on the robust performance of the controller. As a result of the parametric study, a 7 x 7 grid ranging from Mach 7 to Mach 9 in velocity and from 70,000 feet to 90,000 feet in altitude, and a parameter variation rate limit of [.5 200]T was used for both the velocity tracking and altitude tracking cases. The resulting Hinfinity robust performances were gamma = 2.2224 for the velocity tracking case and = 1:7582 for the altitude tracking case. A linear analysis was then conducted on five different selected trim points from the Hinfinity LPV controller. This was conducted for the velocity tracking and altitude tracking cases. The results of linear analysis show that there is a slight difference in the response of the Hinfinity LPV controller and the fixed point H infinity controller. For the tracking task, the Hinfinity controller responds more quickly, and has a lower Hinfinity performance value. Next, the H infinity LPV controller was simulated

  20. An approach to optimum subsonic inlet design

    NASA Technical Reports Server (NTRS)

    Luidens, R. W.; Stockman, N. O.; Diedrich, J. H.

    1978-01-01

    Inlet operating requirements are compared with estimated inlet separation characteristics to identify the most critical inlet operating condition. This critical condition is taken to be the design point and is defined by the values of inlet mass flow, free-stream velocity and inlet angle of attack. Optimum flow distributions on the inlet surface were determined to be a high, flat top Mach number distribution on the inlet lip to turn the flow quickly into the inlet and a flat bottom skin-friction distribution on the diffuser wall to diffuse the flow rapidly and efficiently to the velocity required at the fan face. These optimum distributions are then modified to achieve other desirable flow characteristics. Example applications are given.

  1. An approach to optimum subsonic inlet design

    NASA Technical Reports Server (NTRS)

    Luidens, R. W.; Stockman, N. O.; Diedrich, J. H.

    1979-01-01

    The approach consists of comparing inlet operating requirements with estimated inlet separation characteristics to identify the most critical inlet operating condition. This critical condition is taken to be the design point and is defined by the values of inlet mass flow, free stream velocity, and inlet angle of attack. Optimum flow distributions on the inlet surface are determined to be a high, flat top Mach number distribution on the inlet lip to turn the flow quickly into the inlet and a low, flat bottom skin friction distribution on the diffuser wall to diffuse the flow rapidly and efficiently to the velocity required at the fan face. These optimum distributions are then modified to achieve other desirable flow characteristics. Example applications are given. Extension of the method is suggested.

  2. Effect of piano-key shape inlet on critical submergence at a vertical pipe intake

    NASA Astrophysics Data System (ADS)

    Shemshi, R.; Kabiri-Samani, A.

    2012-11-01

    Intake vortices are the result of angular momentum conservation at the flow constriction, where angular velocity increases with a decrease in the cross sectional area. The common solution for avoiding air-entrainment and swirl is to provide sufficient submergence to the intake. If the required approach flow conditions can not be met to avoid swirl and air entrainment, other approaches for preventing vortices at water intakes are considered. There are several means of avoiding air-entrainment, where the most cost-effective option is often determined by a physical model study. Among the most economical and common measures of reducing the effect of air-entrainment and swirl strength, is the optimized shape of inlet for instance by installing a Piano-Key inlet over the pipe intake. If Piano-Key inlet is used, then, its' optimum geometry should be studied experimentally. Since there is not any realized guidance for the use of Piano-Key inlets in pipe intakes, hence, a comprehensive set of model experiments have been carried out using Piano-Key inlets with different dimensions, with respect to the vertical pipe intakes, and four different pipe diameters of (D=) 75, 100, 125 and 150 mm. Results showed that by employing a Piano-Key inlet over the vertical pipe intake, the critical submergence reduces significantly. Fianally, according to the results, the effect of Piano-Key inlet geometry on critical submergence were evaluated in the form of realized relationships which would be of practical interest for design engineers.

  3. Space Shuttle Main Engine Start with Off-Nominal Propellant Inlet Pressures

    NASA Technical Reports Server (NTRS)

    Bradley, Michael

    1997-01-01

    This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal propellant inlet conditions during the Reusable Launch Vehicle (RLV) evaluation tests. The nominal inlet condition range is: 103 to 111 psia and 170.5 to 178 deg. R for the oxidizer and 43 to 47 psia and 37 to 40 deg. R for the fuel. The SSME start was successfully demonstrated with engine inlet pressures of 50 psia liquid oxygen (LOX) with subcooled LOX at 160 deg R and 38 psia fuel at 38 deg. R. Four tests were used to incrementally modify the start sequence to demonstrate the final goal.

  4. Meeting Review: Airborne Aerosol Inlet Workshop

    NASA Technical Reports Server (NTRS)

    Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

    1991-01-01

    Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

  5. High resolution modeling of the effects of alternative fuels use on urban air quality: introduction of natural gas vehicles in Barcelona and Madrid Greater Areas (Spain).

    PubMed

    Gonçalves, María; Jiménez-Guerrero, Pedro; Baldasano, José M

    2009-01-01

    The mitigation of the effects of on-road traffic emissions on urban air pollution is currently an environmental challenge. Air quality modeling has become a powerful tool to design environment-related strategies. A wide range of options is being proposed; such as the introduction of natural gas vehicles (NGV), biofuels or hydrogen vehicles. The impacts on air quality of introducing specific NGV fleets in Barcelona and Madrid (Spain) are assessed by means of the WRF-ARW/HERMES/CMAQ modeling system with high spatial-temporal resolution (1 km(2), 1 h). Seven emissions scenarios are defined taking into account the year 2004 vehicle fleet composition of the study areas and groups of vehicles susceptible of change under a realistic perspective. O(3) average concentration rises up to 1.3% in Barcelona and up to 2.5% in Madrid when introducing the emissions scenarios, due to the NO(x) reduction in VOC-controlled areas. Nevertheless, NO(2), PM10 and SO(2) average concentrations decrease, up to 6.1%, 1.5% and 6.6% in Barcelona and up to 20.6%, 8.7% and 14.9% in Madrid, respectively. Concerning SO(2) and PM10 reductions the most effective single scenario is the introduction of 50% of NGV instead of the oldest commercial vehicles; it also reduces NO(2) concentrations in Barcelona, however in Madrid lower levels are attained when substituting 10% of the private cars. This work introduces the WRF-ARW/HERMES/CMAQ modeling system as a useful management tool and proves that the air quality improvement plans must be designed considering the local characteristics. PMID:19022477

  6. Collaboration for Land, Air, Sea, and Space Vehicles: Developing the Common Ground in Vehicle Dynamics, System Identification, Control, and Handling Qualities

    NASA Astrophysics Data System (ADS)

    2002-11-01

    This technical report is the culmination of the SCI-053 Task Group - Vehicle Dynamics, System Identification, Control and Handling Qualities. It summarizes the discussions of tank, truck, aircraft, helicopter, ship, submarine and satellite experts held over a three-year period. It addresses the various technical areas identified in the name of the task group, exploring the similarities and differences between the vehicle types and identifying areas where collaboration between experts would be the most valuable. Twenty-three specific technical issues are identified as initial areas with high potential for valuable collaboration. Overall, the report provides the vehicle expert of one environment a sufficient background on the other vehicle environments, so that meaningful discussions towards these technical collaborations can be initiated.

  7. Generic Hypersonic Inlet Module Analysis

    NASA Technical Reports Server (NTRS)

    Cockrell, Chares E., Jr.; Huebner, Lawrence D.

    2004-01-01

    A computational study associated with an internal inlet drag analysis was performed for a generic hypersonic inlet module. The purpose of this study was to determine the feasibility of computing the internal drag force for a generic scramjet engine module using computational methods. The computational study consisted of obtaining two-dimensional (2D) and three-dimensional (3D) computational fluid dynamics (CFD) solutions using the Euler and parabolized Navier-Stokes (PNS) equations. The solution accuracy was assessed by comparisons with experimental pitot pressure data. The CFD analysis indicates that the 3D PNS solutions show the best agreement with experimental pitot pressure data. The internal inlet drag analysis consisted of obtaining drag force predictions based on experimental data and 3D CFD solutions. A comparative assessment of each of the drag prediction methods is made and the sensitivity of CFD drag values to computational procedures is documented. The analysis indicates that the CFD drag predictions are highly sensitive to the computational procedure used.

  8. Wind tunnel experiments on flow separation control of an Unmanned Air Vehicle by nanosecond discharge plasma aerodynamic actuation

    NASA Astrophysics Data System (ADS)

    Kang, Chen; Hua, Liang

    2016-02-01

    Plasma flow control (PFC) is a new kind of active flow control technology, which can improve the aerodynamic performances of aircrafts remarkably. The flow separation control of an unmanned air vehicle (UAV) by nanosecond discharge plasma aerodynamic actuation (NDPAA) is investigated experimentally in this paper. Experimental results show that the applied voltages for both the nanosecond discharge and the millisecond discharge are nearly the same, but the current for nanosecond discharge (30 A) is much bigger than that for millisecond discharge (0.1 A). The flow field induced by the NDPAA is similar to a shock wave upward, and has a maximal velocity of less than 0.5 m/s. Fast heating effect for nanosecond discharge induces shock waves in the quiescent air. The lasting time of the shock waves is about 80 μs and its spread velocity is nearly 380 m/s. By using the NDPAA, the flow separation on the suction side of the UAV can be totally suppressed and the critical stall angle of attack increases from 20° to 27° with a maximal lift coefficient increment of 11.24%. The flow separation can be suppressed when the discharge voltage is larger than the threshold value, and the optimum operation frequency for the NDPAA is the one which makes the Strouhal number equal one. The NDPAA is more effective than the millisecond discharge plasma aerodynamic actuation (MDPAA) in boundary layer flow control. The main mechanism for nanosecond discharge is shock effect. Shock effect is more effective in flow control than momentum effect in high speed flow control. Project supported by the National Natural Science Foundation of China (Grant Nos. 61503302, 51207169, and 51276197), the China Postdoctoral Science Foundation (Grant No. 2014M562446), and the Natural Science Foundation of Shaanxi Province, China (Grant No. 2015JM1001).

  9. Optimal control of a supersonic inlet to minimize frequency of inlet unstart

    NASA Technical Reports Server (NTRS)

    Lehtinen, B.; Zeller, J. R.; Geyser, L. C.

    1978-01-01

    A preliminary investigation into the use of modern control theory for the design of controls for a supersonic inlet is described. In particular, the task of controlling a mixed-compression supersonic inlet is formulated as a linear optimal stochastic control and estimation problem. An inlet can exhibit an undesirable instability due to excessive inlet normal shock motion. For the optimal control formulation of the inlet problem, a non quadratic performance index, which is equal to the expected frequency of inlet unstarts, is used. This physically meaningful performance index is minimized for a range of inlet disturbance and measurement noise covariances.

  10. SIG: Multiple Views on Safety-Critical Automation: Aircraft, Autonomous Vehicles, Air Traffic Management and Satellite Ground Segments Perspectives

    NASA Technical Reports Server (NTRS)

    Feary, Michael; Palanque, Philippe; Martinie, Célia; Tscheligi, Manfred

    2016-01-01

    This SIG focuses on the engineering of automation in interactive critical systems. Automation has already been studied in a number of (sub-) disciplines and application fields: design, human factors, psychology, (software) engineering, aviation, health care, games. One distinguishing feature of the area we are focusing on is that in the field of interactive critical systems properties such as reliability, dependability, fault tolerance are as important as usability, user experience or overall acceptance issues. The SIG targets at two problem areas: first the engineering of the user interaction with (partly-) autonomous systems: how to design, build and assess autonomous behavior, especially in cases where there is a need to represent on the user interface both autonomous and interactive objects. An example of such integration is the representation of an unmanned aerial vehicle (UAV) (where no direct interaction is possible), together with aircrafts (that have to be instructed by an air traffic controller to avoid the UAV). Second the design and engineering of user interaction in general for autonomous objects/systems (for example a cruise control in a car or an autopilot in an aircraft). The goal of the SIG is to raise interest in the CHI community on the general aspects of automation and to identify a community of researchers and practitioners interested in those increasingly prominent issues of interfaces towards (semi)-autonomous systems. The expected audience should be interested in addressing the issues of integration of mainly unconnected research domains to formulate a new joint research agenda.

  11. Ethanol and air quality: influence of fuel ethanol content on emissions and fuel economy of flexible fuel vehicles.

    PubMed

    Hubbard, Carolyn P; Anderson, James E; Wallington, Timothy J

    2014-01-01

    Engine-out and tailpipe emissions of NOx, CO, nonmethane hydrocarbons (NMHC), nonmethane organic gases (NMOG), total hydrocarbons (THC), methane, ethene, acetaldehyde, formaldehyde, ethanol, N2O, and NH3 from a 2006 model year Mercury Grand Marquis flexible fuel vehicle (FFV) operating on E0, E10, E20, E30, E40, E55, and E80 on a chassis dynamometer are reported. With increasing ethanol content in the fuel, the tailpipe emissions of ethanol, acetaldehyde, formaldehyde, methane, and ammonia increased; NOx and NMHC decreased; while CO, ethene, and N2O emissions were not discernibly affected. NMOG and THC emissions displayed a pronounced minimum with midlevel (E20-E40) ethanol blends; 25-35% lower than for E0 or E80. Emissions of NOx decreased by approximately 50% as the ethanol content increased from E0 to E30-E40, with no further decrease seen with E55 or E80. We demonstrate that emission trends from FFVs are explained by fuel chemistry and engine calibration effects. Fuel chemistry effects are fundamental in nature; the same trend of increased ethanol, acetaldehyde, formaldehyde, and CH4 emissions and decreased NMHC and benzene emissions are expected for all FFVs. Engine calibration effects are manufacturer and model specific; emission trends for NOx, THC, and NMOG will not be the same for all FFVs. Implications for air quality are discussed. PMID:24328061

  12. Dynamic output feedback control of a flexible air-breathing hypersonic vehicle via T-S fuzzy approach

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoxiang; Wu, Ligang; Hu, Changhua; Wang, Zhaoqiang; Gao, Huijun

    2014-08-01

    By utilising Takagi-Sugeno (T-S) fuzzy set approach, this paper addresses the robust H∞ dynamic output feedback control for the non-linear longitudinal model of flexible air-breathing hypersonic vehicles (FAHVs). The flight control of FAHVs is highly challenging due to the unique dynamic characteristics, and the intricate couplings between the engine and fight dynamics and external disturbance. Because of the dynamics' enormous complexity, currently, only the longitudinal dynamics models of FAHVs have been used for controller design. In this work, T-S fuzzy modelling technique is utilised to approach the non-linear dynamics of FAHVs, then a fuzzy model is developed for the output tracking problem of FAHVs. The fuzzy model contains parameter uncertainties and disturbance, which can approach the non-linear dynamics of FAHVs more exactly. The flexible models of FAHVs are difficult to measure because of the complex dynamics and the strong couplings, thus a full-order dynamic output feedback controller is designed for the fuzzy model. A robust H∞ controller is designed for the obtained closed-loop system. By utilising the Lyapunov functional approach, sufficient solvability conditions for such controllers are established in terms of linear matrix inequalities. Finally, the effectiveness of the proposed T-S fuzzy dynamic output feedback control method is demonstrated by numerical simulations.

  13. Effects on Air Pollution and Regional Climate of Producing and Using Hydrogen in Fuel Cells in all U.S. OnroadVehicles

    NASA Astrophysics Data System (ADS)

    Jacobson, M. Z.; Colella, W. G.; Golden, D. M.

    2004-12-01

    The purpose of this study was to examine the potential effects on U.S. air pollution and regional climate of switching the current U.S. fleet of onroad motor vehicles to hydrogen fuel-cell vehicles, where hydrogen was produced by (1) steam-reforming of methane, (2) wind energy, or (3) coal gasification. An additional scenario in which the U.S. fleet was switched to gasoline-electric hybrid vehicles was also examined. The model used was GATOR-GCMOM, a global-through-urban-scale nested and parallelized gas, aerosol, transport, radiation, general-circulation, mesoscale, and ocean model. U.S. emission data for the baseline case were obtained from the U.S. National Emission Inventory, which considers 370,000 stack and fugitive sources, 250,000 area sources, and 1700 categories of onroad and nonroad vehicular sources (including motorcycles, passenger vehicles, trucks, recreational vehicles, construction vehicles, farm vehicles, industrial vehicles, etc.). Emission inventories for each of the three hydrogen scenarios were prepared following a process chain analysis that accounted for energy inputs and pollution outputs during all stages of hydrogen and fossil-fuel production, distribution, storage, and end-use. Emitted pollutants accounted for included CO, CO2, H2, H2O, CH4, speciated ROGs, NOx, NH3, SOx, and speciated particulate matter. Results from the first scenario suggest that switching vehicles in the U.S. to hydrogen produced by steam-reforming of methane may reduce emission of NOx, reactive hydrocarbons, CO, CO2, BC, NO3-, and NH4+, but increase CH4, H2, and SO2 (slightly).The switch may also decrease O3 over most of the U.S. but short-term near-surfaces increases may occur over low-vegetated cities (e.g., in Los Angeles and along the Boston-Washington corridor) due to loss of NOx that otherwise titrates O3. The switch is also estimated to decrease PAN, HCHO, and several other pollutants formed in the atmosphere. Isoprene may increase since fewer oxidants (OH, O3

  14. Inlet Jet Interaction in Horizontal Pipe Flow

    NASA Astrophysics Data System (ADS)

    Jha, Pranab; Smith, Chuck; Metcalfe, Ralph

    2012-11-01

    Laminar incompressible flow (Re < 1000) inside a horizontal channel with multiple cross-flow inlets was studied numerically. First, two cross-flow inlets were used to observe the flow interference phenomenon between the inlets. This concept was extended to axisymmetric pipe flow with five cross-flow inlets. Three basic flow regimes - trickle flow, partially blocked flow and fully blocked flow - were identified with respect to the blocking of upstream inlets by the downstream ones. The effects of inlet pressure and different inlet sizes on the flow regimes under steady state condition were studied. A hydrostatic model of fluid reservoirs draining into the channel was constructed using a linear function for pressure at the inlet boundaries to study the dynamic behavior of the inlets. Three different time scales related to the depletion of the reservoirs were identified. The dynamic behavior of two cross-flow inlets was observed with the initial conditions corresponding to the three flow regimes. Similar study was carried out for a five-inlet case and the dynamic behavior of individual reservoirs was observed. The change of flow regimes in the system over time with reservoir draining was evident and the different time-scales involved were identified. Supported in Part by Apache Corporation.

  15. Scramjet including integrated inlet and combustor

    SciTech Connect

    Kutschenreuter, P.H. Jr.; Blanton, J.C.

    1992-02-04

    This patent describes a scramjet engine. It comprises: a first surface including an aft facing step; a cowl including: a leading edge and a trailing edge; an upper surface and a lower surface extending between the leading edge and the trailing edge; the cowl upper surface being spaced from and generally parallel to the first surface to define an integrated inlet-combustor therebetween having an inlet for receiving and channeling into the inlet-combustor supersonic inlet airflow; means for injecting fuel into the inlet-combustor at the step for mixing with the supersonic inlet airflow for generating supersonic combustion gases; and further including a spaced pari of sidewalls extending between the first surface to the cowl upper surface and wherein the integrated inlet-combustor is generally rectangular and defined by the sidewall pair, the first surface and the cowl upper surface.

  16. Ultra-lean combustion at high inlet temperatures

    NASA Technical Reports Server (NTRS)

    Anderson, D. N.

    1981-01-01

    Combustion at inlet-air temperatures of 1100 to 1250 K was studied for application to advanced automotive gas turbine engines. Combustion was initiated by the hot environment, and therefore no external ignition source was used. Combustion was stabilized without a flameholder. The tests were performed in a 12-cm-diameter test section at a pressure of 250,000 Pa, with reference velocities of 32 to 60 m/s and at maximum combustion temperatures of 1350 to 1850 K. Number 2 diesel fuel was injected by means of a multiple-source fuel injector. Unburned hydrocarbon emissions were negligible for all test conditions. Nitrogen oxide emissions were less than 1.9 g NO2/kg fuel for combustion temperatures below 1680 K. Carbon monoxide emissions were less than 16 g CO/kg fuel for combustion temperatures greater than 1600 K, inlet-air temperatures higher than 1150 K, and residence times greater than 4.3 ms.

  17. Federal certification test results for 1992 model year. Control of air pollution from new motor vehicles and new motor vehicle engines

    SciTech Connect

    Not Available

    1992-01-01

    Each manufacturer of a passenger car, (light-duty-vehicle), light-duty truck, motorcycle, heavy-duty gasoline engine, and heavy-duty diesel engine is required to demonstrate compliance with the applicable exhaust emission standard. This report contains all of the individual tests that were required by the certification-procedures found in Title 40 of the Code of Federal Regulations in Part 86. These data were submitted to the Environmental Protection Agency's Certification Division at the National Vehicle and Fuel Emissions Laboratory.

  18. Life-cycle assessment of greenhouse gas and air emissions of electric vehicles: A comparison between China and the U.S.

    NASA Astrophysics Data System (ADS)

    Huo, Hong; Cai, Hao; Zhang, Qiang; Liu, Fei; He, Kebin

    2015-05-01

    We evaluated the fuel-cycle emissions of greenhouse gases (GHGs) and air pollutants (NOx, SO2, PM10, and PM2.5) of electric vehicles (EVs) in China and the United States (U.S.), two of the largest potential markets for EVs in the world. Six of the most economically developed and populated regions in China and the U.S. were selected. The results showed that EV fuel-cycle emissions depend substantially on the carbon intensity and cleanness of the electricity mix, and vary significantly across the regions studied. In those regions with a low share of coal-based electricity (e.g., California), EVs can reduce GHG and air pollutant emissions (except for PM) significantly compared with conventional vehicles. However, in the Chinese regions and selected U.S. Midwestern states where coal dominates in the generation mix, EVs can reduce GHG emissions but increase the total and urban emissions of air pollutants. In 2025, EVs will offer greater reductions in GHG and air pollutant emissions because emissions from power plants will be better controlled; EVs in the Chinese regions examined, however, may still increase SO2 and PM emissions. Reductions of 60-85% in GHGs and air pollutants could be achieved were EVs charged with 80% renewable electricity or the electricity generated from the best available technologies of coal-fired power plants, which are futuristic power generation scenarios.

  19. Evaluation of on-road vehicle CO and NOx National Emission Inventories using an urban-scale source-oriented air quality model

    NASA Astrophysics Data System (ADS)

    Kota, Sri Harsha; Zhang, Hongliang; Chen, Gang; Schade, Gunnar W.; Ying, Qi

    2014-03-01

    The MOBILE6.2 model was replaced by the Motor Vehicle Emission Simulator (MOVES) in 2012 as an official tool recommended by the United States Environmental Protection Agency (US EPA) to predict vehicular pollutant emission factors. In this study, on-road vehicle emission inventories of CO and NOx for Southeast Texas generated by MOVES and MOBILE6.2 in two versions of the 2005 National Emission Inventory (NEI) were studied by comparing predicted CO and NOx using the EPA's Community Multiscale Air Quality (CMAQ) Model incorporated with a source-oriented gas phase chemical mechanism with measurements made at six urban and industrial sites in Southeast Texas. The source tracing technique allows direct determination of contributions of on-road vehicles to overall CO and NOx concentrations and identification of ambient concentration measurements which are mostly impacted by vehicle emissions. By grouping the fractional bias (FB) values of the hourly predictions based on vehicle contributions to total CO or NOx concentrations, clear trends in the FB were observed, indicating systematic biases in the emission inventory for these species. Data points dominated by vehicle emissions suggest that surface CO concentrations due to vehicle exhaust are significantly over-estimated by a factor of 2 using either MOVES or MOBILE6.2. NOx concentrations are overestimated by approximately 20-35% and 70% by using the MOBILE6.2 and MOVES emissions, respectively. Emission scaling runs show that a domain-wide reduction of MOBILE6.2 CO emissions by 60% and NOx emissions by 15-25% leads to better model performance of exhaust CO and NOx concentrations in the current study.

  20. Numerical analyses of passive and active flow control over a micro air vehicle with an optimized airfoil

    NASA Astrophysics Data System (ADS)

    Gada, Komal Kantilal

    Numerical investigations of an optimized thin airfoil with a passive and an active flow control device (riblets and rotary cylinder) have been performed. The objectives of the thesis were to investigate the tip vortices reduction using riblets and decrease in flow separation, using a rotary cylinder for improved lift-to-drag ratio. The investigations has application potentials in improving performances of Micro Air Vehicles (MAVs). The airfoil has a chord length of 19.66 cm and a span of 25 cm. with the free stream mean velocity was set at 20 m/s. The Reynolds number was calculated as 3 x 10 4. Investigations with base model of the airfoil have shown flow separation at approximately 85% chord length at an angle of attack of 17 degrees. For investigation using passive flow control device, i.e. riblets, investigations were performed for different radial sizes but at a fixed location. It was found that with 1 mm radial size riblet, the tip vortices were reduced by approximately 95%, as compared to the baseline model. Although negligible lift-to-drag improvement was seen, a faster dissipation rate in turbulent kinetic energy was observed. Furthermore, investigations were carried out using the active flow control device. The rotary cylinder with a 0.51 cm in diameter was placed slightly downstream of the location of flow separation, i.e. at x/c = 0.848. Investigations were performed at different cylinder's rotations, corresponding to different tangential velocities of being higher than, equal to and less than the free stream mean velocity. Results have shown approximately 10% improvement in lift to drag ratio when the tangential velocity is near the free stream mean velocity. Further investigation may include usage of the riblets and the rotary cylinder combined, to increase the stability as well as the lift-to-drag ratio of the MAVs.

  1. Trends in on-road vehicle emissions and ambient air quality in Atlanta, Georgia, USA, from the late 1990s through 2009.

    PubMed

    Vijayaraghavan, Krish; DenBleyker, Allison; Ma, Lan; Lindhjem, Chris; Yarwood, Greg

    2014-07-01

    On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NO(x)), and volatile organic compounds (VOCs) during 1995-2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NO(x), and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995-2009 period despite an increase in total vehicle distance traveled. The CO and NO(x) emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NO(x) in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001-2009. Although this trend coexists with the declining trends in on-road NO(x), VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors. Implications: Large reductions in on-road vehicle emissions of CO and NO(x) in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NO(x) during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of

  2. Validation of Inlet and Exhaust Boundary Conditions for a Cartesian Method

    NASA Technical Reports Server (NTRS)

    Pandya, Shishir A.; Murman, Scott M.; Aftosmis, Michael J.

    2004-01-01

    Inlets and exhaust nozzles are often omitted in aerodynamic simulations of aircraft due to the complexities involved in the modeling of engine details and flow physics. However, the omission is often improper since inlet or plume flows may have a substantial effect on vehicle aerodynamics. A method for modeling the effect of inlets and exhaust plumes using boundary conditions within an inviscid Cartesian flow solver is presented. This approach couples with both CAD systems and legacy geometry to provide an automated tool suitable for parameter studies. The method is validated using two and three-dimensional test problems which are compared with both theoretical and experimental results. The numerical results demonstrate excellent agreement with theory and available data, even for extremely strong jets and very sensitive inlets.

  3. Forebody and Inlet Design for the HIFiRE 2 Flight Test

    NASA Technical Reports Server (NTRS)

    Ferlemann, Paul G.

    2008-01-01

    A forebody and inlet have been designed for the HIFiRE 2 scramjet flight test. The test will explore the operating, performance, and stability characteristics of a simple hydrocarbon-fueled scramjet combustor as it transitions from dual-mode to scramjet-mode operation and during supersonic combustion at Mach 8+ flight conditions. Requirements for the compression system were derived from inlet starting and combustor inflow requirements as well as physical size constraints. The design process is described. A planar, fixed geometry, mixed compression concept was used to produce laterally uniform flow at the inlet entrance and a conservative amount of internal contraction with respect to inlet starting. A grid sensitivity study was performed so that important flow physics caused by three-dimensional shock boundary layer interactions could be captured with confidence. Results from low Mach number operability studies, nominal trajectory cases, and high dynamic pressure heat load cases are discussed. The forebody and inlet solutions provide information for on-going combustor calculations, mass capture across the trajectory for fuel system design, and surface heating rates for thermal/structural analysis. The design has a one freestream Mach number margin for inlet starting, exceeds the high Mach number combustor entrance pressure requirement, produces high quality flow at the inlet exit for all Mach numbers and vehicle attitudes in the design space, and fits inside the booster shroud.

  4. An Experimental Parametric Study of Geometric, Reynolds Number, and Ratio of Specific Heats Effects in Three-Dimensional Sidewall Compression Scramjet Inlets at Mach 6

    NASA Technical Reports Server (NTRS)

    Holland, Scott D.; Murphy, Kelly J.

    1993-01-01

    Since mission profiles for airbreathing hypersonic vehicles such as the National Aero-Space Plane include single-stage-to-orbit requirements, real gas effects may become important with respect to engine performance. The effects of the decrease in the ratio of specific heats have been investigated in generic three-dimensional sidewall compression scramjet inlets with leading-edge sweep angles of 30 and 70 degrees. The effects of a decrease in ratio of specific heats were seen by comparing data from two facilities in two test gases: in the Langley Mach 6 CF4 Tunnel in tetrafluoromethane (where gamma=1.22) and in the Langley 15-Inch Mach 6 Air Tunnel in perfect gas air (where gamma=1.4). In addition to the simulated real gas effects, the parametric effects of cowl position, contraction ratio, leading-edge sweep, and Reynolds number were investigated in the 15-Inch Mach 6 Air Tunnel. The models were instrumented with a total of 45 static pressure orifices distributed on the sidewalls and baseplate. Surface streamline patterns were examined via oil flow, and schlieren videos were made of the external flow field. The results of these tests have significant implications to ground based testing of inlets in facilities which do not operate at flight enthalpies.

  5. Radial inlet guide vanes for a combustor

    SciTech Connect

    Zuo, Baifang; Simons, Derrick; York, William; Ziminsky, Willy S

    2013-02-12

    A combustor may include an interior flow path therethrough, a number of fuel nozzles in communication with the interior flow path, and an inlet guide vane system positioned about the interior flow path to create a swirled flow therein. The inlet guide vane system may include a number of windows positioned circumferentially around the fuel nozzles. The inlet guide vane system may also include a number of inlet guide vanes positioned circumferentially around the fuel nozzles and adjacent to the windows to create a swirled flow within the interior flow path.

  6. Planar Inlet Design and Analysis Process (PINDAP)

    NASA Technical Reports Server (NTRS)

    Slater, John W.; Gruber, Christopher R.

    2005-01-01

    The Planar Inlet Design and Analysis Process (PINDAP) is a collection of software tools that allow the efficient aerodynamic design and analysis of planar (two-dimensional and axisymmetric) inlets. The aerodynamic analysis is performed using the Wind-US computational fluid dynamics (CFD) program. A major element in PINDAP is a Fortran 90 code named PINDAP that can establish the parametric design of the inlet and efficiently model the geometry and generate the grid for CFD analysis with design changes to those parameters. The use of PINDAP is demonstrated for subsonic, supersonic, and hypersonic inlets.

  7. Afterburner performance of film-vaporizing V-gutters for inlet temperatures up to 1255 K

    NASA Technical Reports Server (NTRS)

    Branstetter, J. R.; Reck, G. M.

    1973-01-01

    Combustion tests of five variations of an integral, spray-bar - flameholder combination were conducted in a 0.49-m-diameter duct. Emphasis was on low levels of augmentation. Fuel impinged on guide plates, mixed with a controlled amount of inlet air, vaporized, and was guided into the V-gutter wake. Combustor length was 0.92 m. Good performance was demonstrated at fuel-air ratios less than 0.025 for inlet temperatures of 920 to 1255 K. Maximum combustion efficiency occured in the vicinity of fuel-air ratios of 0.02 and was 92 to 100 percent, depending on the inlet temperature. Lean blowout fuel-air ratios were in the vicinity of 0.005. Improvements in rich-limit blowout resulted from enlarging the guide-flow passageway areas. Other means of extending the operating range are suggested. A simplified afterburner concept for application to advanced engines is described.

  8. Aero-Thermo-Structural Analysis of Inlet for Rocket Based Combined Cycle Engines

    NASA Technical Reports Server (NTRS)

    Shivakumar, K. N.; Challa, Preeti; Sree, Dave; Reddy, Dhanireddy R. (Technical Monitor)

    2000-01-01

    NASA has been developing advanced space transportation concepts and technologies to make access to space less costly. One such concept is the reusable vehicles with short turn-around times. The NASA Glenn Research Center's concept vehicle is the Trailblazer powered by a rocket-based combined cycle (RBCC) engine. Inlet is one of the most important components of the RBCC engine. This paper presents fluid flow, thermal, and structural analysis of the inlet for Mach 6 free stream velocity for fully supersonic and supercritical with backpressure conditions. The results concluded that the fully supersonic condition was the most severe case and the largest stresses occur in the ceramic matrix composite layer of the inlet cowl. The maximum tensile and the compressive stresses were at least 3.8 and 3.4, respectively, times less than the associated material strength.

  9. FLOW FIELDS IN SUPERSONIC INLETS

    NASA Technical Reports Server (NTRS)

    Sorenson, R. L.

    1994-01-01

    This computer program is designed to calculate the flow fields in two-dimensional and three-dimensional axisymmetric supersonic inlets. The method of characteristics is used to compute arrays of points in the flow field. At each point the total pressure, local Mach number, local flow angle, and static pressure are calculated. This program can be used to design and analyze supersonic inlets by determining the surface compression rates and throat flow properties. The program employs the method of characteristics for a perfect gas. The basic equation used in the program is the compatibility equation which relates the change in stream angle to the change in entropy and the change in velocity. In order to facilitate the computation, the flow field behind the bow shock wave is broken into regions bounded by shock waves. In each region successive rays are computed from a surface to a shock wave until the shock wave intersects a surface or falls outside the cowl lip. As soon as the intersection occurs a new region is started and the previous region continued only in the area in which it is needed, thus eliminating unnecessary calculations. The maximum number of regions possible in the program is ten, which allows for the simultaneous calculations of up to nine shock waves. Input to this program consists of surface contours, free-stream Mach number, and various calculation control parameters. Output consists of printed and/or plotted results. For plotted results an SC-4020 or similar plotting device is required. This program is written in FORTRAN IV to be executed in the batch mode and has been implemented on a CDC 7600 with a central memory requirement of approximately 27k (octal) of 60 bit words.

  10. Low flight speed acoustic results for a supersonic inlet with auxiliary inlet doors

    NASA Technical Reports Server (NTRS)

    Woodward, R. P.; Glaser, F. W.; Lucas, J. G.

    1982-01-01

    A model supersonic inlet with auxiliary inlet doors and bounday layer bleeds was acoustically tested in simulated low speed flight up to Mach 0.2 in the NASA Lewis 9x15 Anechoic Wind Tunnel and statically in the NASA Lewis Anechoic Chamber. A JT8D refan model was used as the noise source. Data were also taken for a CTOL inlet and for an annular inlet with simulated centerbody support struts. Inlet operation with open auxiliary doors increased the blade passage tone by about 10 dB relative to the closed door configuration although noise radiation was primarily through the main inlet rather than the doors. Numerous strong spikes in the noise spectra were associated with the bleed system, and were strongly affected by the centerbody location. The supersonic inlet appeared to suppress multiple pure tone (MPT) generation at the fan source. Inlet length and the presence of support struts were shown not to cause this MPT suppression.

  11. Remote Operated Vehicle geophysical surveys on land (underground), air and submarine archaeology: General peculiarities of processing and interpretation

    NASA Astrophysics Data System (ADS)

    Eppelbaum, Lev

    2016-04-01

    The last Remote Operation Vehicles (ROV) generation - small and maneuvering vehicles with different geophysical sensors - can fly at levels of a few meters (and even tens of centimeters) over the earth's surface, to move on the earth's surface and in the inaccessible underground areas and to explore in underwater investigations (e.g., Mindel and Bingham, 2001; Rowlands and Sarris, 2006; Wilson et al., 2006; Rigaud, 2007; Eppelbaum, 2008; Patterson and Brescia, 2008; Sarris, 2008; Wang et al., 2009; Wu and Tian, 2010; Stall, 2011; Tezkan et al., 2011; Winn et al., 2012; El-Nahhas, 2013; Hadjimitsis et al., 2013; Hajiyev and Vural, 2013; Hugenholtz et al., 2013; Petzke et al., 2013; Pourier et al., 2013; Casana et al., 2014; Silverberg and Bieber, 2014). Such geophysical investigations should have an extremely low exploitation cost and can observe surface practically inaccessible archaeological sites (swampy areas, dense vegetation, rugged relief, over the areas of world recognized religious and cultural artifacts (Eppelbaum, 2010), etc.). Finally, measurements of geophysical fields at different observation levels could provide a new unique geological-geophysical information (Eppelbaum and Mishne, 2011). Let's consider ROV airborne magnetic measurements as example. The modern magnetometric equipment enables to carry out magnetic measurements with a frequency of 50 times per second (and more) that taking into account the low ROV flight speed provides a necessary density of observations. For instance, frequency of observation of 50 times per second by ROV velocity of 40 km/hour gives density of observation about 0.2 m. It is obvious that the calculated step between observation points is more than sufficient one. Such observations will allow not only reduce the influence of some small artificial sources of noise, but also to obtain some additional data necessary for quantitative analysis (some interpretation methodologies need to have observations at two levels; upward

  12. Clean Cities ozone air quality attainment and maintenance strategies that employ alternative fuel vehicles, with special emphasis on natural gas and propane

    SciTech Connect

    Santini, D.J.; Saricks, C.L.

    1998-08-04

    Air quality administrators across the nation are coming under greater pressure to find new strategies for further reducing automotive generated non-methane hydrocarbon (NMHC) and nitrogen oxide (NOx) emissions. The US Environmental Protection Agency (EPA) has established stringent emission reduction requirements for ozone non-attainment areas that have driven the vehicle industry to engineer vehicles meeting dramatically tightened standards. This paper describes an interim method for including alternative-fueled vehicles (AFVs) in the mix of strategies to achieve local and regional improvements in ozone air quality. This method could be used until EPA can develop the Mobile series of emissions estimation models to include AFVs and until such time that detailed work on AFV emissions totals by air quality planners and emissions inventory builders is warranted. The paper first describes the challenges confronting almost every effort to include AFVs in targeted emissions reduction programs, but points out that within these challenges resides an opportunity. Next, it discusses some basic relationships in the formation of ambient ozone from precursor emissions. It then describes several of the salient provisions of EPA`s new voluntary emissions initiative, which is called the Voluntary Mobile Source Emissions Reduction Program (VMEP). Recent emissions test data comparing gaseous-fuel light-duty AFVs with their gasoline-fueled counterparts is examined to estimate percent emissions reductions achievable with CNG and LPG vehicles. Examples of calculated MOBILE5b emission rates that would be used for summer ozone season planning purposes by an individual Air Quality Control Region (AQCR) are provided. A method is suggested for employing these data to compute appropriate voluntary emission reduction credits where such (lighter) AFVs would be acquired. It also points out, but does not quantify, the substantial reduction credits potentially achievable by substituting gaseous

  13. Ethical and economic issues in the use of zero-emission vehicles as a component of an air-pollution mitigation strategy.

    PubMed

    Duvall, Tim; Englander, Fred; Englander, Valerie; Hodson, Thomas J; Marpet, Mark

    2002-10-01

    The air pollution generated by motor vehicles and by static sources is, in certain geographic areas, a very serious problem, a problem that exists because of a failure of the marketplace. To address this marketplace failure, the State of California has mandated that by 2003, 10% of the Light-Duty Vehicle Fleet (LDV) be composed of Zero-Emission Vehicles (ZEVs). However, the policy-making process that was utilized to generate the ZEV mandate was problematic and the resulting ZEV mandate is economically unsound. Moreover, an ethical analysis, based primarily upon the work of John Rawls, suggests that implementation of the California ZEV mandate is--in spite of the wide latitude that ought to be given to policy decision makers--unethical. A more ethical and economically efficient approach to the pollution caused by marketplace failure is one that relies on market incentives and thereby achieves the desired improvement in air quality by appealing both to the self-interest of motorists and to those businesses that are directly or indirectly involved with the automobile industry. Such an approach would take better advantage of the creative forces of the market and improvements in technology over time and avoid the infringements on individual liberty and fairness embodied in the ZEV mandate. PMID:12501725

  14. Wave and Wind Effects on Inlet Circulation

    NASA Astrophysics Data System (ADS)

    Raubenheimer, B.; Wargula, A.; Orescanin, M. M.; Hopkins, J.; Elgar, S.

    2014-12-01

    Observations and numerical simulations of the water circulation and morphological change in two separate, well-mixed inlets will be compared with each other. Tides, winds, waves, and currents were measured from May 1 to 28, 2012 in and near New River Inlet, NC. Offshore significant wave heights were 0 to 3 m, and wind speeds ranged from 0 to 16 m/s. The long, narrow inlet is about 1000 m wide where it opens onto the ebb shoal, narrows to 100 m wide about 1000 m inland, and connects to the Intracoastal Waterway (which connects to additional ocean inlets about 12 and 36 km north and south, respectively) about 3000 m inland. Tides in the inlet are progressive and inlet flows are in phase with water depths. Measurements also were collected during the summers of 2011-2014, including during Hurricanes Irene and Sandy (offshore significant wave heights > 5 m and winds > 15 m/s), in Katama Bay, MA, which connects to Vineyard Sound via Edgartown Channel and to the Atlantic Ocean via Katama Inlet. During this period, Katama Inlet migrated east about 1000 m, narrowed from 400 to 100 m wide, changed depth from 7 to 2 m, and lengthened from 200 to 1000 m. Tidal flows in Katama Inlet are forced by sea level gradients resulting from the 3-hr phase lag between tides in Vineyard Sound and the Atlantic Ocean. Analyses of the momentum balances suggest that waves drive flows into the mouths of the inlets during storms. The timing of the storms relative to ebb and flood, and wind effects, may affect the discharge and sediment transport through the inlet. Winds and waves also drive alongshore flows on the ebb shoals. Lateral flows at bends in New River Inlet, which may be important to the along-inlet transfer of momentum and to mixing, are affected by winds. The importance of connections to additional inlets in multi-inlet systems will be discussed. Funded by ONR, ASD(R&E), NSF, Sea Grant, and NDSEG.

  15. The change of the inlet geometry of a centrifugal compressor stage and its influence on the compressor performance

    NASA Astrophysics Data System (ADS)

    Wang, Leilei; Yang, Ce; Zhao, Ben; Lao, Dazhong; Ma, Chaochen; Li, Du

    2013-06-01

    The impact on the compressor performance is important for designing the inlet pipe of the centrifugal compressor of a vehicle turbocharger with different inlet pipes. First, an experiment was performed to determine the compressor performance from three cases: a straight inlet pipe, a long bent inlet pipe and a short bent inlet pipe. Next, dynamic sensors were installed in key positions to collect the sign of the unsteady pressure of the centrifugal compressor. Combined with the results of numerical simulations, the total pressure distortion in the pipes, the pressure distributions on the blades and the pressure variability in the diffuser are studied in detail. The results can be summarized as follows: a bent pipe results in an inlet distortion to the compressor, which leads to performance degradation, and the effect is more apparent as the mass flow rate increases. The distortion induced by the bent inlet is not only influenced by the distance between the outlet of the bent section and the leading edge of the impeller but also by the impeller rotation. The flow fields in the centrifugal impeller and the diffuser are influenced by a coupling effect produced by the upstream inlet distortion and the downstream blocking effect from the volute tongue. If the inlet geometry is changed, the distributions and the fluctuation intensities of the static pressure on the main blade surface of the centrifugal impeller and in the diffuser are changed accordingly.

  16. External-Compression Supersonic Inlet Design Code

    NASA Technical Reports Server (NTRS)

    Slater, John W.

    2011-01-01

    A computer code named SUPIN has been developed to perform aerodynamic design and analysis of external-compression, supersonic inlets. The baseline set of inlets include axisymmetric pitot, two-dimensional single-duct, axisymmetric outward-turning, and two-dimensional bifurcated-duct inlets. The aerodynamic methods are based on low-fidelity analytical and numerical procedures. The geometric methods are based on planar geometry elements. SUPIN has three modes of operation: 1) generate the inlet geometry from a explicit set of geometry information, 2) size and design the inlet geometry and analyze the aerodynamic performance, and 3) compute the aerodynamic performance of a specified inlet geometry. The aerodynamic performance quantities includes inlet flow rates, total pressure recovery, and drag. The geometry output from SUPIN includes inlet dimensions, cross-sectional areas, coordinates of planar profiles, and surface grids suitable for input to grid generators for analysis by computational fluid dynamics (CFD) methods. The input data file for SUPIN and the output file from SUPIN are text (ASCII) files. The surface grid files are output as formatted Plot3D or stereolithography (STL) files. SUPIN executes in batch mode and is available as a Microsoft Windows executable and Fortran95 source code with a makefile for Linux.

  17. TiAl Scramjet Inlet Flap Subelement Designed and Fabricated

    NASA Technical Reports Server (NTRS)

    Draper, Susan L.

    2004-01-01

    Next-generation launch vehicles are being designed with turbine-based combined cycle (TBCC) propulsion systems having very aggressive thrust/weight targets and long lives. Achievement of these goals requires advanced materials in a wide spectrum of components. TiAl has been identified as a potential backstructure material for maintainable composite panel heat exchangers (HEX) in the inlet, combustor, and nozzle section of a TBCC propulsion system. Weight reduction is the primary objective of this technology. Design tradeoff studies have assessed that a TiAl structure, utilizing a high-strength, hightemperature TiAl alloy called Gamma MET PX,1 reduce weight by 41 to 48 percent in comparison to the baseline Inconel 718 configuration for the TBCC propulsion system inlet, combustor, and nozzle. A collaborative effort between the NASA Glenn Research Center, Pratt & Whitney, Engineering Evaluation & Design, PLANSEE AG (Austria), and the Austrian Space Agency was undertaken to design, manufacture, and validate a Gamma-MET PX TiAl structure for scramjet applications. The TiAl inlet flap was designed with segmented flaps to improve manufacturability, to better control thermal distortion and thermal stresses, and to allow for maintainable HEX segments. The design philosophy was to avoid excessively complicated shapes, to minimize the number of stress concentrations, to keep the part sizes reasonable to match processing capabilities, and to avoid risky processes such as welding. The conceptual design used a standard HEX approach with a double-pass coolant concept for centrally located manifolds. The flowpath side was actively cooled, and an insulation package was placed on the external side to save weight. The inlet flap was analyzed structurally, and local high-stress regions were addressed with local reinforcements.

  18. Experimental study on the inlet fogging system using two-fluid nozzles

    NASA Astrophysics Data System (ADS)

    Suryan, Abhilash; Kim, Dong Sun; Kim, Heuy Dong

    2010-04-01

    Large-capacity compressors in industrial plants and the compressors in gas turbine engines consume a considerable amount of power. The compression work is a strong function of the ambient air temperature. This increase in compression work presents a significant problem to utilities, generators and power producers when electric demands are high during the hot months. In many petrochemical process industries and gas turbine engines, the increase in compression work curtails plant output, demanding more electric power to drive the system. One way to counter this problem is to directly cool the inlet air. Inlet fogging is a popular means of cooling the inlet air to air compressors. In the present study, experiments have been performed to investigate the suitability of two-fluid nozzle for inlet fogging. Compressed air is used as the driving working gas for two-fluid nozzle and water at ambient conditions is dragged into the high-speed air jet, thus enabling the entrained water to be atomized in a very short distance from the exit of the two-fluid nozzle. The air supply pressure is varied between 2.0 and 5.0 bar and the water flow rate entrained is measured. The flow visualization and temperature and relative humidity measurements are carried out to specify the fogging characteristics of the two-fluid nozzle.

  19. F-15 inlet/engine test techniques and distortion methodologies studies. Volume 5: Effect of filter cutoff frequency on turbulence plots

    NASA Technical Reports Server (NTRS)

    Stevens, C. H.; Spong, E. D.; Hammock, M. S.

    1978-01-01

    The effect of filter cutoff frequency on turbulence plots were used to determine if peak distortion data taken from a subscale inlet model can be used to predict peak distortion levels for a full scale flight test vehicle.

  20. Aerodynamic analysis of VTOL inlets and definition of a short, blowing-lip inlet

    NASA Technical Reports Server (NTRS)

    Syberg, J.; Jones, A. L.

    1982-01-01

    The results indicated that, without boundary layer control, either a very long inlet or an inlet with a very high contraction ratio lip will be required to meet the stringent design requirements. It is shown that active boundary layer control is an effective means of preventing separation and that a significant reduction in inlet size can be achieved by removing only a small amount of bleed in the throat region of the inlet. A short, blowing-lip model was designed and fabricated. This model features an adjustable, blowing slot located near the hilite on the windward side of the inlet.