40 CFR 86.084-2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for... light-duty trucks, the engine speed with the transmission in neutral or with the clutch disengaged and...

40 CFR 86.084-2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for... light-duty trucks, the engine speed with the transmission in neutral or with the clutch disengaged and...

40 CFR 86.084-2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for... light-duty trucks, the engine speed with the transmission in neutral or with the clutch disengaged and...

40 CFR 86.084-2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for... light-duty trucks, the engine speed with the transmission in neutral or with the clutch disengaged and...

40 CFR 86.084-2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Provisions for Emission Regulations for 1977 and Later Model Year New Light-Duty Vehicles, Light-Duty Trucks and Heavy-Duty Engines, and for... light-duty trucks, the engine speed with the transmission in neutral or with the clutch disengaged and...

USSR Report, Engineering and Equipment

DTIC Science & Technology

1984-04-17

MEKHANIKA ZHIDKOSTI I GAZA, No 5, May 83). 17 Wave Drag of Elongated Astroid Bodies at Moderate Supersonic Flight Velocities (M, I. Follej...mechanical components of such a test stand include an electric drive motor with speed regulation, a Belt transmission, a worm gear for speed

The application of LQR synthesis techniques to the turboshaft engine control problem. [Linear Quadratic Regulator

NASA Technical Reports Server (NTRS)

Pfeil, W. H.; De Los Reyes, G.; Bobula, G. A.

1985-01-01

A power turbine governor was designed for a recent-technology turboshaft engine coupled to a modern, articulated rotor system using Linear Quadratic Regulator (LQR) and Kalman Filter (KF) techniques. A linear, state-space model of the engine and rotor system was derived for six engine power settings from flight idle to maximum continuous. An integrator was appended to the fuel flow input to reduce the steady-state governor error to zero. Feedback gains were calculated for the system states at each power setting using the LQR technique. The main rotor tip speed state is not measurable, so a Kalman Filter of the rotor was used to estimate this state. The crossover of the system was increased to 10 rad/s compared to 2 rad/sec for a current governor. Initial computer simulations with a nonlinear engine model indicate a significant decrease in power turbine speed variation with the LQR governor compared to a conventional governor.

A New Turbo-shaft Engine Control Law during Variable Rotor Speed Transient Process

NASA Astrophysics Data System (ADS)

Hua, Wei; Miao, Lizhen; Zhang, Haibo; Huang, Jinquan

2015-12-01

A closed-loop control law employing compressor guided vanes is firstly investigated to solve unacceptable fuel flow dynamic change in single fuel control for turbo-shaft engine here, especially for rotorcraft in variable rotor speed process. Based on an Augmented Linear Quadratic Regulator (ALQR) algorithm, a dual-input, single-output robust control scheme is proposed for a turbo-shaft engine, involving not only the closed loop adjustment of fuel flow but also that of compressor guided vanes. Furthermore, compared to single fuel control, some digital simulation cases using this new scheme about variable rotor speed have been implemented on the basis of an integrated system of helicopter and engine model. The results depict that the command tracking performance to the free turbine rotor speed can be asymptotically realized. Moreover, the fuel flow transient process has been significantly improved, and the fuel consumption has been dramatically cut down by more than 2% while keeping the helicopter level fight unchanged.

Aerodynamic design optimization of a fuel efficient high-performance, single-engine, business airplane

NASA Technical Reports Server (NTRS)

Holmes, B. J.

1980-01-01

A design study has been conducted to optimize a single-engine airplane for a high-performance cruise mission. The mission analyzed included a cruise speed of about 300 knots, a cruise range of about 1300 nautical miles, and a six-passenger payload (5340 N (1200 lb)). The purpose of the study is to investigate the combinations of wing design, engine, and operating altitude required for the mission. The results show that these mission performance characteristics can be achieved with fuel efficiencies competitive with present-day high-performance, single- and twin-engine, business airplanes. It is noted that relaxation of the present Federal Aviation Regulation, Part 23, stall-speed requirement for single-engine airplanes facilitates the optimization of the airplane for fuel efficiency.

77 FR 51724 - Airworthiness Directives; The Boeing Company

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-27

... ON Thrust Levers CLOSE Speed Brakes FLIGHT DETENT Target Speed MO/MMO'' Note 1 to paragraphs (j)(2... W. Palmer, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft... charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations...

49 CFR 571.124 - Standard No. 124; Accelerator control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and injuries resulting from engine overspeed caused by malfunctions in the accelerator control system. S3. Application. This standard applies to passenger cars, multi-purpose passenger vehicles, trucks... components, except the fuel metering device, that regulate engine speed in direct response to movement of the...

A study on emission characteristics of an EFI engine with ethanol blended gasoline fuels

NASA Astrophysics Data System (ADS)

He, Bang-Quan; Wang, Jian-Xin; Hao, Ji-Ming; Yan, Xiao-Guang; Xiao, Jian-Hua

The effect of ethanol blended gasoline fuels on emissions and catalyst conversion efficiencies was investigated in a spark ignition engine with an electronic fuel injection (EFI) system. The addition of ethanol to gasoline fuel enhances the octane number of the blended fuels and changes distillation temperature. Ethanol can decrease engine-out regulated emissions. The fuel containing 30% ethanol by volume can drastically reduce engine-out total hydrocarbon emissions (THC) at operating conditions and engine-out THC, CO and NO x emissions at idle speed, but unburned ethanol and acetaldehyde emissions increase. Pt/Rh based three-way catalysts are effective in reducing acetaldehyde emissions, but the conversion of unburned ethanol is low. Tailpipe emissions of THC, CO and NO x have close relation to engine-out emissions, catalyst conversion efficiency, engine's speed and load, air/fuel equivalence ratio. Moreover, the blended fuels can decrease brake specific energy consumption.

EFFECTS OF ENGINE SPEED AND ACCESSORY LOAD ON IDLING EMISSIONS FROM HEAVY-DUTY DIESEL TRUCK ENGINES

EPA Science Inventory

A nontrivial portion of heavy-duty vehicle emissions of nitrogen oxides (NOx) and particulate matter (PM) occurs during idling. Regulators and the environmental community are interested in curtailing truck idling emissions, but current emissions models do not characterize them ac...

Filter-based control of particulate matter from a lean gasoline direct injection engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parks, II, James E; Lewis Sr, Samuel Arthur; DeBusk, Melanie Moses

New regulations requiring increases in vehicle fuel economy are challenging automotive manufacturers to identify fuel-efficient engines for future vehicles. Lean gasoline direct injection (GDI) engines offer significant increases in fuel efficiency over the more common stoichiometric GDI engines already in the marketplace. However, particulate matter (PM) emissions from lean GDI engines, particularly during stratified combustion modes, are problematic for lean GDI technology to meet U.S. Environmental Protection Agency Tier 3 and other future emission regulations. As such, the control of lean GDI PM with wall-flow filters, referred to as gasoline particulate filter (GPF) technology, is of interest. Since lean GDImore » PM chemistry and morphology differ from diesel PM (where more filtration experience exists), the functionality of GPFs needs to be studied to determine the operating conditions suitable for efficient PM removal. In addition, lean GDI engine exhaust temperatures are generally higher than diesel engines which results in more continuous regeneration of the GPF and less presence of the soot cake layer common to diesel particulate filters. Since the soot layer improves filtration efficiency, this distinction is important to consider. Research on the emission control of PM from a lean GDI engine with a GPF was conducted on an engine dynamometer. PM, after dilution, was characterized with membrane filters, organic vs. elemental carbon characterization, and size distribution techniques at various steady state engine speed and load points. The engine was operated in three primary combustion modes: stoichiometric, lean homogeneous, and lean stratified. In addition, rich combustion was utilized to simulate PM from engine operation during active regeneration of lean NOx control technologies. High (>95%) PM filtration efficiencies were observed over a wide range of conditions; however, some PM was observed to slip through the GPF at high speed and load conditions. The PM characterization at various engine speeds and loads will help enable optimized GPF design and control to achieve more fuel efficient lean GDI vehicles with low PM emissions.« less

Closed loop engine control for regulating NOx emissions, using a two-dimensional fuel-air curve

DOEpatents

Bourn, Gary D.; Smith, Jack A.; Gingrich, Jess W.

2007-01-30

An engine control strategy that ensures that NOx emissions from the engine will be maintained at an acceptable level. The control strategy is based on a two-dimensional fuel-air curve, in which air manifold pressure (AMP) is a function of fuel header pressure and engine speed. The control strategy provides for closed loop NOx adjustment to a base AMP value derived from the fuel-air curve.

The application of LQR synthesis techniques to the turboshaft engine control problem

NASA Technical Reports Server (NTRS)

Pfeil, W. H.; De Los Reyes, G.; Bobula, G. A.

1984-01-01

A power turbine governor was designed for a recent-technology turboshaft engine coupled to a modern, articulated rotor system using Linear Quadratic Regulator (LQR) and Kalman Filter (KF) techniques. A linear, state-space model of the engine and rotor system was derived for six engine power settings from flight idle to maximum continuous. An integrator was appended to the fuel flow input to reduce the steady-state governor error to zero. Feedback gains were calculated for the system states at each power setting using the LQR technique. The main rotor tip speed state is not measurable, so a Kalman Filter of the rotor was used to estimate this state. The crossover of the system was increased to 10 rad/s compared to 2 rad/sec for a current governor. Initial computer simulations with a nonlinear engine model indicate a significant decrease in power turbine speed variation with the LQR governor compared to a conventional governor.

The effect of noise constraints on engine cycle optimization for long-haul transports

NASA Technical Reports Server (NTRS)

Antl, R. J.

1973-01-01

Optimum engine cycles were determined for noise levels of 10, 15, and 20 EPNdB below current FAA regulations, using 200-passenger trijet aircraft flying over ranges from 5555 to 10,200 km at cruise speeds of Mach 0.90 and 0.98. The tests showed that the noise constraints imposed compromises on the optimum cycle with resulting economic penalties. The economic penalties, however, could be effectively offset by applying advanced engine technologies.

The experimental studies of operating modes of a diesel-generator set at variable speed

NASA Astrophysics Data System (ADS)

Obukhov, S. G.; Plotnikov, I. A.; Surkov, M. A.; Sumarokova, L. P.

2017-02-01

A diesel generator set working at variable speed to save fuel is studied. The results of experimental studies of the operating modes of an autonomous diesel generator set are presented. Areas for regulating operating modes are determined. It is demonstrated that the transfer of the diesel generator set to variable speed of the diesel engine makes it possible to improve the energy efficiency of the autonomous generator source, as well as the environmental and ergonomic performance of the equipment as compared with general industrial analogues.

40 CFR 1037.801 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

.... Auxiliary emission control device means any element of design that senses temperature, motive speed, engine... any device, system, or element of design that controls or reduces the emissions of regulated... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF...

40 CFR 1037.801 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

.... Auxiliary emission control device means any element of design that senses temperature, motive speed, engine... any device, system, or element of design that controls or reduces the emissions of regulated... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF...

Experimental investigation of regulated and unregulated emissions from a diesel engine fueled with ultralow-sulfur diesel fuel blended with ethanol and dodecanol

NASA Astrophysics Data System (ADS)

Cheung, C. S.; Di, Yage; Huang, Zuohua

Experiments were conducted on a four-cylinder direct-injection diesel engine using ultralow-sulfur diesel as the main fuel, ethanol as the oxygenate additive and dodecanol as the solvent, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev min -1. Blended fuels containing 6.1%, 12.2%, 18.2% and 24.2% by volume of ethanol, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. The results indicate that with an increase in ethanol in the fuel, the brake specific fuel consumption becomes higher while there is little change in the brake thermal efficiency. Regarding the regulated emissions, HC and CO increase significantly at low engine load but might decrease at high engine load, NO x emission slightly decreases at low engine load but slightly increases at high engine load, while particulate mass decreases significantly at high engine load. For the unregulated gaseous emissions, unburned ethanol and acetaldehyde increase but formaldehyde, ethene, ethyne, 1,3-butadiene and BTX (benzene, toluene and xylene) in general decrease, especially at high engine load. A diesel oxidation catalyst (DOC) is found to reduce significantly most of the pollutants, including the air toxics.

Direct Final Rule for Heavy-Duty Highway Program: Revisions for Emergency Vehicles

EPA Pesticide Factsheets

Revises the heavy-duty diesel regulations to enable emergency vehicles to perform mission-critical life-saving work without risking that abnormal conditions of the emission control system could lead to decreased engine power, speed or torque.

Adaptation of a zero-dimensional cylinder pressure model for diesel engines using the crankshaft rotational speed

NASA Astrophysics Data System (ADS)

Weißenborn, E.; Bossmeyer, T.; Bertram, T.

2011-08-01

Tighter emission regulations are driving the development of advanced engine control strategies relying on feedback information from the combustion chamber. In this context, it is especially seeked for alternatives to expensive in-cylinder pressure sensors. The present study addresses these issues by pursuing a simulation-based approach. It focuses on the extension of an empirical, zero-dimensional cylinder pressure model using the engine speed signal in order to detect cylinder-wise variations in combustion. As a special feature, only information available from the standard sensor configuration are utilized. Within the study, different methods for the model-based reconstruction of the combustion pressure including nonlinear Kalman filtering are compared. As a result, the accuracy of the cylinder pressure model can be enhanced. At the same time, the inevitable limitations of the proposed methods are outlined.

Embodied linearity of speed control in Drosophila melanogaster.

PubMed

Medici, V; Fry, S N

2012-12-07

Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles.

Embodied linearity of speed control in Drosophila melanogaster

PubMed Central

Medici, V.; Fry, S. N.

2012-01-01

Fruitflies regulate flight speed by adjusting their body angle. To understand how low-level posture control serves an overall linear visual speed control strategy, we visually induced free-flight acceleration responses in a wind tunnel and measured the body kinematics using high-speed videography. Subsequently, we reverse engineered the transfer function mapping body pitch angle onto flight speed. A linear model is able to reproduce the behavioural data with good accuracy. Our results show that linearity in speed control is realized already at the level of body posture-mediated speed control and is therefore embodied at the level of the complex aerodynamic mechanisms of body and wings. Together with previous results, this study reveals the existence of a linear hierarchical control strategy, which can provide relevant control principles for biomimetic implementations, such as autonomous flying micro air vehicles. PMID:22933185

A Modular Aero-Propulsion System Simulation of a Large Commercial Aircraft Engine

NASA Technical Reports Server (NTRS)

DeCastro, Jonathan A.; Litt, Jonathan S.; Frederick, Dean K.

2008-01-01

A simulation of a commercial engine has been developed in a graphical environment to meet the increasing need across the controls and health management community for a common research and development platform. This paper describes the Commercial Modular Aero Propulsion System Simulation (C-MAPSS), which is representative of a 90,000-lb thrust class two spool, high bypass ratio commercial turbofan engine. A control law resembling the state-of-the-art on board modern aircraft engines is included, consisting of a fan-speed control loop supplemented by relevant engine limit protection regulator loops. The objective of this paper is to provide a top-down overview of the complete engine simulation package.

Internal combustion engine fuel controls. December 1970-December 1989 (Citations from the US Patent data base). Report for December 1970-December 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-01-01

This bibliography contains citations of selected patents concerning fuel control devices, and methods used to regulate speed and load in internal combustion engines. Techniques utilized to control air-fuel ratios by sensing pressure, temperature, and exhaust composition, and the employment of electronic and feedback devices are discussed. Methods used for engine protection and optimum fuel conservation are considered. (This updated bibliography contains 327 citations, 160 of which are new entries to the previous edition.)

Concept Development of a Mach 1.6 High-Speed Civil Transport

NASA Technical Reports Server (NTRS)

Shields, Elwood W.; Fenbert, James W.; Ozoroski, Lori P.; Geiselhart, Karl A.

1999-01-01

A high-speed civil transport configuration with a Mach number of 1.6 was developed as part of the NASA High-Speed Research Program to serve as a baseline for assessing advanced technologies required for an aircraft with a service entry date of 2005. This configuration offered more favorable solutions to environmental concerns than configurations with higher Mach numbers. The Mach 1.6 configuration was designed for a 6500 n.mi. mission with a 250-passenger payload. The baseline configuration has a wing area of 8732 square feet a takeoff gross weight of 591570 lb, and four 41000-lb advanced turbine bypass engines defined by NASA. These engines have axisymmetric mixer-ejector nozzles that are assumed to yield 20 dB of noise suppression during takeoff, which is assumed to satisfy, the FAR Stage III noise requirements. Any substantial reduction in this assumed level of suppression would require oversizing the engines to meet community noise regulations and would severly impact the gross weight of the aircraft at takeoff. These engines yield a ratio of takeoff thrust to weight of 0.277 and a takeoff wing loading of 67.8 lb/square feet that results in a rotation speed of 169 knots. The approach velocity of the sized configuration at the end of the mission is 131 knots. The baseline configuration was resized with an engine having a projected life of 9000 hr for hot rotating parts and 18000 hr for the rest of the engine, as required for commercial use on an aircraft with a service entry date of 2005. Results show an increase in vehicle takeoff gross weight of approximately 58700 lb. This report presents the details of the configuration development, mass properties, aerodynamic design, propulsion system and integration, mission performance, and sizing.

Watt steam governor stability

NASA Astrophysics Data System (ADS)

Denny, Mark

2002-05-01

The physics of the fly-ball governor, introduced to regulate the speed of steam engines, is here analysed anew. The original analysis is generalized to arbitrary governor geometry. The well-known stability criterion for the linearized system breaks down for large excursions from equilibrium; we show approximately how this criterion changes.

Quantum Error Correction: Optimal, Robust, or Adaptive? Or, Where is The Quantum Flyball Governor?

NASA Astrophysics Data System (ADS)

Kosut, Robert; Grace, Matthew

2012-02-01

In The Human Use of Human Beings: Cybernetics and Society (1950), Norbert Wiener introduces feedback control in this way: ``This control of a machine on the basis of its actual performance rather than its expected performance is known as feedback ... It is the function of control ... to produce a temporary and local reversal of the normal direction of entropy.'' The classic classroom example of feedback control is the all-mechanical flyball governor used by James Watt in the 18th century to regulate the speed of rotating steam engines. What is it that is so compelling about this apparatus? First, it is easy to understand how it regulates the speed of a rotating steam engine. Secondly, and perhaps more importantly, it is a part of the device itself. A naive observer would not distinguish this mechanical piece from all the rest. So it is natural to ask, where is the all-quantum device which is self regulating, ie, the Quantum Flyball Governor? Is the goal of quantum error correction (QEC) to design such a device? Devloping the computational and mathematical tools to design this device is the topic of this talk.

The design of a turboshaft speed governor using modern control techniques

NASA Technical Reports Server (NTRS)

Delosreyes, G.; Gouchoe, D. R.

1986-01-01

The objectives of this program were: to verify the model of off schedule compressor variable geometry in the T700 turboshaft engine nonlinear model; to evaluate the use of the pseudo-random binary noise (PRBN) technique for obtaining engine frequency response data; and to design a high performance power turbine speed governor using modern control methods. Reduction of T700 engine test data generated at NASA-Lewis indicated that the off schedule variable geometry effects were accurate as modeled. Analysis also showed that the PRBN technique combined with the maximum likelihood model identification method produced a Bode frequency response that was as accurate as the response obtained from standard sinewave testing methods. The frequency response verified the accuracy of linear models consisting of engine partial derivatives and used for design. A power turbine governor was designed using the Linear Quadratic Regulator (LQR) method of full state feedback control. A Kalman filter observer was used to estimate helicopter main rotor blade velocity. Compared to the baseline T700 power turbine speed governor, the LQR governor reduced droop up to 25 percent for a 490 shaft horsepower transient in 0.1 sec simulating a wind gust, and up to 85 percent for a 700 shaft horsepower transient in 0.5 sec simulating a large collective pitch angle transient.

Performance of Blowdown Turbine driven by Exhaust Gas of Nine-Cylinder Radial Engine

DTIC Science & Technology

1944-12-01

blade speed to mean jet speed FIQUBE 6.—Variation of mean turbine efficiency with ratio of blade speed to moan Jot speed. Engine speed, 2000 rpm; full...conventional turbo - supercharger axe used in series, the blowdown turbine may be geared to the engine . Aircraft engines are operated at high speed for...guide vanes in blowdown-turblno noule box. PERFORMANCE OF BLOWDOWN TURBINE DRIVEN BT EXHAUST GAS OF RADIAL ENGINE 245 (6) Diaphragm

Preliminary Performance Data on Westinghouse Electronic Power Regulator Operating on J34-WE-32 Turbojet Engine in Altitude Wind Tunnel

NASA Technical Reports Server (NTRS)

Ketchum, James R.; Blivas, Darnold; Pack, George J.

1950-01-01

The behavior of the Westinghouse electronic power regulator operating on a J34-WE-32 turbojet engine was investigated in the NACA Lewis altitude wind tunnel at the request of the Bureau of Aeronautics, Department of the Navy. The object of the program was to determine the, steady-state stability and transient characteristics of the engine under control at various altitudes and ram pressure ratios, without afterburning. Recordings of the response of the following parameters to step changes in power lever position throughout the available operating range of the engine were obtained; ram pressure ratio, compressor-discharge pressure, exhaust-nozzle area, engine speed, turbine-outlet temperature, fuel-valve position, jet thrust, air flow, turbine-discharge pressure, fuel flow, throttle position, and boost-pump pressure. Representative preliminary data showing the actual time response of these variables are presented. These data are presented in the form of reproductions of oscillographic traces.

Simultaneously firing two cylinders of an even firing camless engine

DOEpatents

Brennan, Daniel G

2014-03-11

A valve control system includes an engine speed control module that determines an engine speed and a desired engine stop position. A piston position module determines a desired stopping position of a first piston based on the desired engine stop position. A valve control module receives the desired stopping position, commands a set of valves to close at the desired stopping position if the engine speed is less than a predetermined shutdown threshold, and commands the set of valves to reduce the engine speed if the engine speed is greater than the predetermined shutdown threshold.

Emission reduction potential of using gas-to-liquid and dimethyl ether fuels on a turbocharged diesel engine.

PubMed

Xinling, Li; Zhen, Huang

2009-03-15

A study of engine performance characteristics and both of regulated (CO, HC, NO(x), and smoke) and unregulated (ultrafine particle number, mass concentrations and size distribution) emissions for a turbocharged diesel engine fueled with conventional diesel, gas-to-liquid (GTL) and dimethyl ether (DME) fuels respectively at different engine loads and speeds have been carried out. The results indicated that fuel components significantly affected the engine performance and regulated/unregulated emissions. GTL exhibited almost the same power and torque output as diesel, while improved fuel economy. GTL significantly reduced regulated emissions with average reductions of 21.2% in CO, 15.7% in HC, 15.6% in NO(x) and 22.1% in smoke in comparison to diesel, as well as average reductions in unregulated emissions of total ultrafine particle number (N(tot)) and mass (M(tot)) emissions by 85.3% and 43.9%. DME can significantly increase torque and power, compared with the original diesel engine, as well as significantly reduced regulated emissions of 40.1% in HC, 48.2% in NO(x) and smoke free throughout all the engine conditions. However, N(tot) for DME is close to that for diesel. The reason is that the accumulation mode particle number emissions for DME are very low due to the characteristics of oxygen content and no C-C bond, which promotes the processes of nucleation and condensation of the semi-volatile compounds in the exhaust gas, as a result, a lot of nucleation mode particles produce.

Automated manual transmission clutch controller

DOEpatents

Lawrie, Robert E.; Reed, Jr., Richard G.; Rausen, David J.

1999-11-30

A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

Automated manual transmission shift sequence controller

DOEpatents

Lawrie, Robert E.; Reed, Richard G.; Rausen, David J.

2000-02-01

A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both, an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

Automated manual transmission mode selection controller

DOEpatents

Lawrie, Robert E.

1999-11-09

A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

Automated manual transmission controller

DOEpatents

Lawrie, Robert E.; Reed, Jr., Richard G.; Bernier, David R.

1999-12-28

A powertrain system for a hybrid vehicle. The hybrid vehicle includes a heat engine, such as a diesel engine, and an electric machine, which operates as both an electric motor and an alternator, to power the vehicle. The hybrid vehicle also includes a manual-style transmission configured to operate as an automatic transmission from the perspective of the driver. The engine and the electric machine drive an input shaft which in turn drives an output shaft of the transmission. In addition to driving the transmission, the electric machine regulates the speed of the input shaft in order to synchronize the input shaft during either an upshift or downshift of the transmission by either decreasing or increasing the speed of the input shaft. When decreasing the speed of the input shaft, the electric motor functions as an alternator to produce electrical energy which may be stored by a storage device. Operation of the transmission is controlled by a transmission controller which receives input signals and generates output signals to control shift and clutch motors to effect smooth launch, upshift shifts, and downshifts of the transmission, so that the transmission functions substantially as an automatic transmission from the perspective of the driver, while internally substantially functioning as a manual transmission.

Engine lubrication circuit including two pumps

DOEpatents

Lane, William H.

2006-10-03

A lubrication pump coupled to the engine is sized such that the it can supply the engine with a predetermined flow volume as soon as the engine reaches a peak torque engine speed. In engines that operate predominately at speeds above the peak torque engine speed, the lubrication pump is often producing lubrication fluid in excess of the predetermined flow volume that is bypassed back to a lubrication fluid source. This arguably results in wasted power. In order to more efficiently lubricate an engine, a lubrication circuit includes a lubrication pump and a variable delivery pump. The lubrication pump is operably coupled to the engine, and the variable delivery pump is in communication with a pump output controller that is operable to vary a lubrication fluid output from the variable delivery pump as a function of at least one of engine speed and lubrication flow volume or system pressure. Thus, the lubrication pump can be sized to produce the predetermined flow volume at a speed range at which the engine predominately operates while the variable delivery pump can supplement lubrication fluid delivery from the lubrication pump at engine speeds below the predominant engine speed range.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alderfer, R.R.; Futa, P.W.

This patent describes a fuel system for an engine having a filter through which fuel from a pump passes to a regulator in response to an operator input. The regulator controls the flow of fuel presented to a combustion chamber in the engine, the regulator having a feedback apparatus to provide an operator with a signal indicative of the fuel supplied to the combustion chamber. It comprises: bypass means having a housing with a chamber therein, the chamber having an entrance port connected to the pump and an exit port connected to the regulator; piston means located in the chambermore » for separating the entrance port from the exit port, the piston having a face with a projection extending therefrom; stop means located in the chamber; resilient means located is the chamber for urging the piston means toward the stop means to prevent the flow of fuel from the pump through the housing to the regulator; and indicator means having a body retained in the housing with a first end which extends through the housing into the from a full-open position at which the closed circuit is fully opened to a full-closed position at which the closed circuit is fully blocked; ratio detecting means which detects the speed reduction ratio to find if the speed reduction ratio becomes substantially 1; and valve position detecting means which detects position of the direct clutch valve to find if the direct clutch valve is moved to a slight-open position at which the closed circuit is slightly opened.« less

A Sequential Shifting Algorithm for Variable Rotor Speed Control

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Edwards, Jason M.; DeCastro, Jonathan A.

2007-01-01

A proof of concept of a continuously variable rotor speed control methodology for rotorcraft is described. Variable rotor speed is desirable for several reasons including improved maneuverability, agility, and noise reduction. However, it has been difficult to implement because turboshaft engines are designed to operate within a narrow speed band, and a reliable drive train that can provide continuous power over a wide speed range does not exist. The new methodology proposed here is a sequential shifting control for twin-engine rotorcraft that coordinates the disengagement and engagement of the two turboshaft engines in such a way that the rotor speed may vary over a wide range, but the engines remain within their prescribed speed bands and provide continuous torque to the rotor; two multi-speed gearboxes facilitate the wide rotor speed variation. The shifting process begins when one engine slows down and disengages from the transmission by way of a standard freewheeling clutch mechanism; the other engine continues to apply torque to the rotor. Once one engine disengages, its gear shifts, the multi-speed gearbox output shaft speed resynchronizes and it re-engages. This process is then repeated with the other engine. By tailoring the sequential shifting, the rotor may perform large, rapid speed changes smoothly, as demonstrated in several examples. The emphasis of this effort is on the coordination and control aspects for proof of concept. The engines, rotor, and transmission are all simplified linear models, integrated to capture the basic dynamics of the problem.

40 CFR 1065.510 - Engine mapping.

Code of Federal Regulations, 2012 CFR

2012-07-01

... expected maximum power. Continue the warm-up until the engine coolant, block, or head absolute temperature... torque of zero on the engine's primary output shaft, and allow the engine to govern the speed. Measure... values. (ii) For engines without a low-speed governor, operate the engine at warm idle speed and zero...

40 CFR 1065.510 - Engine mapping.

Code of Federal Regulations, 2014 CFR

2014-07-01

... expected maximum power. Continue the warm-up until the engine coolant, block, or head absolute temperature... torque of zero on the engine's primary output shaft, and allow the engine to govern the speed. Measure... values. (ii) For engines without a low-speed governor, operate the engine at warm idle speed and zero...

40 CFR 1065.510 - Engine mapping.

Code of Federal Regulations, 2013 CFR

2013-07-01

... expected maximum power. Continue the warm-up until the engine coolant, block, or head absolute temperature... torque of zero on the engine's primary output shaft, and allow the engine to govern the speed. Measure... values. (ii) For engines without a low-speed governor, operate the engine at warm idle speed and zero...

Experimental investigation of regulated and unregulated emissions from a diesel engine fueled with Euro V diesel fuel and fumigation methanol

NASA Astrophysics Data System (ADS)

Zhang, Z. H.; Cheung, C. S.; Chan, T. L.; Yao, C. D.

2010-03-01

Experiments were conducted on a four-cylinder direct-injection diesel engine with part of the engine load taken up by fumigation methanol injected into the air intake of each cylinder to investigate the regulated and unregulated gaseous emissions and particulate emission of the engine under five engine loads at an engine speed of 1920 rev min -1. The fumigation methanol was injected to top up 10%, 20% and 30% of the engine load under different engine operating conditions. The experimental results show that at low engine loads, the brake thermal efficiency (BTE) decreases with increase in fumigation methanol; but at high engine loads, the BTE is not significantly affected by fumigation methanol. The fumigation methanol results in significant increase in hydrocarbon (HC), carbon monoxide (CO) and nitrogen dioxide (NO 2) emissions, but decrease in nitrogen oxides (NO x). For the unregulated gaseous emissions, unburned methanol, formaldehyde and BTX (benzene, toluene and xylene) emissions increase but ethyne, ethene and 1,3-butadiene emissions decrease. Particulate mass and number concentrations also decrease with increase in fumigation methanol. A diesel oxidation catalyst (DOC) is found to reduce significantly most of the pollutants, including the air toxics, when the exhaust gas temperature is sufficiently high.

Idling speed control system of an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyazaki, M.; Ishii, M.; Kako, H.

1986-09-16

This patent describes an idling speed control system of an internal combustion engine comprising: a valve device which controls the amount of intake air for the engine; an actuator which includes an electric motor for variably controlling the opening of the value device; rotation speed detector means for detecting the rotation speed of the engine; idling condition detector means for detecting the idling condition of the engine; feedback control means responsive to the detected output of the idling condition detector means for generating feedback control pulses to intermittently drive the electric motor so that the detected rotation speed of themore » engine under the idling condition may converge into a target idling rotation speed; and control means responsive to the output of detector means that detects an abnormally low rotation speed of the engine detected by the rotation speed detector means for generating control pulses that do not overlap the feedback control pulses to drive the electric motor in a predetermined direction.« less

Nonlinear engine model for idle speed control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Livshiz, M.; Sanvido, D.J.; Stiles, S.D.

1994-12-31

This paper describes a nonlinear model of an engine used for the design of idle speed control and prediction in a broad range of idle speeds and operational conditions. Idle speed control systems make use of both spark advance and the idle air actuator to control engine speed for improved response relative to variations in the target idle speed due to load disturbances. The control system at idle can be presented by a multiple input multiple output (MIMO) nonlinear model. Information of nonlinearities helps to improve performance of the system over the whole range of engine speeds. A proposed simplemore » nonlinear model of the engine at idle was applied for design of optimal controllers and predictors for improved steady state, load rejection and transition from and to idle. This paper describes vehicle results of engine speed prediction based on the described model.« less

Speed And Power Control Of An Engine By Modulation Of The Load Torque

DOEpatents

Ziph, Benjamin; Strodtman, Scott; Rose, Thomas K

1999-01-26

A system and method of speed and power control for an engine in which speed and power of the engine is controlled by modulation of the load torque. The load torque is manipulated in order to cause engine speed, and hence power to be changed. To accomplish such control, the load torque undergoes a temporary excursion in the opposite direction of the desired speed and power change. The engine and the driven equipment will accelerate or decelerate accordingly as the load torque is decreased or increased, relative to the essentially fixed or constant engine torque. As the engine accelerates or decelerates, its power increases or decreases in proportion.

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p... approved overspeed, a means to limit the maximum engine and propeller speed to not more than the maximum... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propeller speed and pitch limits. 23.33...

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2013 CFR

2013-01-01

... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p... approved overspeed, a means to limit the maximum engine and propeller speed to not more than the maximum... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propeller speed and pitch limits. 23.33...

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2012 CFR

2012-01-01

... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p... approved overspeed, a means to limit the maximum engine and propeller speed to not more than the maximum... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propeller speed and pitch limits. 23.33...

The effect of noise constraints on engine cycle optimization for long-haul transports

NASA Technical Reports Server (NTRS)

Antl, R. J.

1973-01-01

Results are presented of NASA studies to determine optimum engine cycles for noise levels of 10, 15, and 20 EPNdb below current FAA regulations. The study aircraft were 200-passenger trijets flying over ranges of 5,556 and 10,200 km at cruise speeds of Mach 0.90 to 0.98. The economic impact of reducing noise, the identification of needed advanced technology and the effect of these advances are presented. The studies showed that the noise constraints imposed compromises on the optimum cycle with resulting economic penalties. The application of advanced engine technologies, however, could effectively offset these economic penalties.

Rotordynamic Feasibility of a Conceptual Variable-Speed Power Turbine Propulsion System for Large Civil Tilt-Rotor Applications

NASA Technical Reports Server (NTRS)

Howard, Samuel

2012-01-01

A variable-speed power turbine concept is analyzed for rotordynamic feasibility in a Large Civil Tilt-Rotor (LCTR) class engine. Implementation of a variable-speed power turbine in a rotorcraft engine would enable high efficiency propulsion at the high forward velocities anticipated of large tilt-rotor vehicles. Therefore, rotordynamics is a critical issue for this engine concept. A preliminary feasibility study is presented herein to address this concern and identify if variable-speed is possible in a conceptual engine sized for the LCTR. The analysis considers critical speed placement in the operating speed envelope, stability analysis up to the maximum anticipated operating speed, and potential unbalance response amplitudes to determine that a variable-speed power turbine is likely to be challenging, but not impossible to achieve in a tilt-rotor propulsion engine.

49 CFR 571.104 - Standard No. 104; Windshield wiping and washing systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... difference between one-half of the shoulder room dimension and the steering wheel centerline-to-car... frequency or speed shall be at least 45 cycles per minute regardless of engine load and engine speed. S4.1.1.3Regardless of engine speed and engine load, the highest and one lower frequency or speed shall differ by at...

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

14 CFR 23.33 - Propeller speed and pitch limits.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propeller speed and pitch limits. 23.33... Propeller speed and pitch limits. (a) General. The propeller speed and pitch must be limited to values that... the all engine(s) operating climb speed specified in § 23.65, the propeller must limit the engine r.p...

49 CFR 571.104 - Standard No. 104; Windshield wiping and washing systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... outboard of the steering wheel centerline 0.15 times the difference between one-half of the shoulder room... frequency or speed shall be at least 45 cycles per minute regardless of engine load and engine speed. S4.1.1.3Regardless of engine speed and engine load, the highest and one lower frequency or speed shall differ by at...

Idle speed and fuel vapor recovery control system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orzel, D.V.

1993-06-01

A method for controlling idling speed of an engine via bypass throttle connected in parallel to a primary engine throttle and for controlling purge flow through a vapor recovery system into an air/fuel intake of the engine is described, comprising the steps of: positioning the bypass throttle to decrease any difference between a desired engine idle speed and actual engine idle speed; and decreasing the purge flow when said bypass throttle position is less than a preselected fraction of a maximum bypass throttle position.

40 CFR Appendix II to Part 1039 - Steady-State Duty Cycles

Code of Federal Regulations, 2011 CFR

2011-07-01

... Appendix II to Part 1039—Steady-State Duty Cycles (a) The following duty cycles apply for constant-speed engines: (1) The following duty cycle applies for discrete-mode testing: D2 mode number Engine speed...(seconds) Engine speed Torque(percent) 1, 2 1a Steady-state 53 Engine governed 100. 1b Transition 20 Engine...

The Effect of Rotor Cruise Tip Speed, Engine Technology and Engine/Drive System RPM on the NASA Large Civil Tiltrotor (LCTR2) Size and Performance

NASA Technical Reports Server (NTRS)

Robuck, Mark; Wilkerson, Joseph; Maciolek, Robert; Vonderwell, Dan

2012-01-01

A multi-year study was conducted under NASA NNA06BC41C Task Order 10 and NASA NNA09DA56C task orders 2, 4, and 5 to identify the most promising propulsion system concepts that enable rotor cruise tip speeds down to 54% of the hover tip speed for a civil tiltrotor aircraft. Combinations of engine RPM reduction and 2-speed drive systems were evaluated. Three levels of engine and the drive system advanced technology were assessed; 2015, 2025 and 2035. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified. Design variables included engine speed reduction, drive system speed reduction, technology, and rotor cruise propulsion efficiency. The NASA Large Civil Tiltrotor, LCTR, aircraft served as the base vehicle concept for this study and was resized for over thirty combinations of operating cruise RPM and technology level, quantifying LCTR2 Gross Weight, size, and mission fuel. Additional studies show design sensitivity to other mission ranges and design airspeeds, with corresponding relative estimated operational cost. The lightest vehicle gross weight solution consistently came from rotor cruise tip speeds between 422 fps and 500 fps. Nearly equivalent results were achieved with operating at reduced engine RPM with a single-speed drive system or with a two-speed drive system and 100% engine RPM. Projected performance for a 2025 engine technology provided improved fuel flow over a wide range of operating speeds relative to the 2015 technology, but increased engine weight nullified the improved fuel flow resulting in increased aircraft gross weights. The 2035 engine technology provided further fuel flow reduction and 25% lower engine weight, and the 2035 drive system technology provided a 12% reduction in drive system weight. In combination, the 2035 technologies reduced aircraft takeoff gross weight by 14% relative to the 2015 technologies.

Investigation of frequency-response characteristics of engine speed for a typical turbine-propeller engine

NASA Technical Reports Server (NTRS)

Taylor, Burt L , III; Oppenheimer, Frank L

1951-01-01

Experimental frequency-response characteristics of engine speed for a typical turbine-propeller engine are presented. These data were obtained by subjecting the engine to sinusoidal variations of fuel flow and propeller-blade-angle inputs. Correlation is made between these experimental data and analytical frequency-response characteristics obtained from a linear differential equation derived from steady-state torque-speed relations.

Piloted Simulation Study of a Dual Thrust-Cutback Procedure for Reducing High-Speed Civil Transport Takeoff Noise Levels

NASA Technical Reports Server (NTRS)

Riley, Donald R.; Glaab, Louis J.; Brandon, Jay M.; Person, Lee H., Jr.; Glaab, Patricia C.

1999-01-01

A piloted simulation study was performed for the purpose of indicating the noise reduction benefits and piloting performance that could occur for a typical 4-engine high-Speed Civil Transport (HSCT) configuration during takeoff when a dual thrust-cutback procedure was employed with throttle operation under direct computer control. Two thrust cutbacks were employed with the first cutback performed while the vehicle was accelerating on the run-way and the second cutback performed at a distance farther downrange. Added vehicle performance improvements included the incorporation of high-lift increments into the aerodynamic database of the vehicle and the use of limited engine oversizing. Four single-stream turbine bypass engines that had no noise suppression of any kind were used with this configuration. This approach permitted establishing the additional noise suppression level that was needed to meet Federal Air Regulation Part 36 Stage 3 noise levels for subsonic commercial jet aircraft. Noise level results were calculated with the jet mixing and shock noise modules of the Aircraft Noise Prediction Program (ANOPP).

A model predictive speed tracking control approach for autonomous ground vehicles

NASA Astrophysics Data System (ADS)

Zhu, Min; Chen, Huiyan; Xiong, Guangming

2017-03-01

This paper presents a novel speed tracking control approach based on a model predictive control (MPC) framework for autonomous ground vehicles. A switching algorithm without calibration is proposed to determine the drive or brake control. Combined with a simple inverse longitudinal vehicle model and adaptive regulation of MPC, this algorithm can make use of the engine brake torque for various driving conditions and avoid high frequency oscillations automatically. A simplified quadratic program (QP) solving algorithm is used to reduce the computational time, and the approach has been applied in a 16-bit microcontroller. The performance of the proposed approach is evaluated via simulations and vehicle tests, which were carried out in a range of speed-profile tracking tasks. With a well-designed system structure, high-precision speed control is achieved. The system can robustly model uncertainty and external disturbances, and yields a faster response with less overshoot than a PI controller.

Diesel engine torsional vibration control coupling with speed control system

NASA Astrophysics Data System (ADS)

Guo, Yibin; Li, Wanyou; Yu, Shuwen; Han, Xiao; Yuan, Yunbo; Wang, Zhipeng; Ma, Xiuzhen

2017-09-01

The coupling problems between shafting torsional vibration and speed control system of diesel engine are very common. Neglecting the coupling problems sometimes lead to serious oscillation and vibration during the operation of engines. For example, during the propulsion shafting operation of a diesel engine, the oscillation of engine speed and the severe vibration of gear box occur which cause the engine is unable to operate. To find the cause of the malfunctions, a simulation model coupling the speed control system with the torsional vibration of deformable shafting is proposed and investigated. In the coupling model, the shafting is simplified to be a deformable one which consists of several inertias and shaft sections and with characteristics of torsional vibration. The results of instantaneous rotation speed from this proposed model agree with the test results very well and are successful in reflecting the real oscillation state of the engine operation. Furthermore, using the proposed model, the speed control parameters can be tuned up to predict the diesel engine a stable and safe running. The results from the tests on the diesel engine with a set of tuned control parameters are consistent with the simulation results very well.

Spatial regulation of controlled bioactive factor delivery for bone tissue engineering

PubMed Central

Samorezov, Julia E.; Alsberg, Eben

2015-01-01

Limitations of current treatment options for critical size bone defects create a significant clinical need for tissue engineered bone strategies. This review describes how control over the spatiotemporal delivery of growth factors, nucleic acids, and drugs and small molecules may aid in recapitulating signals present in bone development and healing, regenerating interfaces of bone with other connective tissues, and enhancing vascularization of tissue engineered bone. State-of-the-art technologies used to create spatially controlled patterns of bioactive factors on the surfaces of materials, to build up 3D materials with patterns of signal presentation within their bulk, and to pattern bioactive factor delivery after scaffold fabrication are presented, highlighting their applications in bone tissue engineering. As these techniques improve in areas such as spatial resolution and speed of patterning, they will continue to grow in value as model systems for understanding cell responses to spatially regulated bioactive factor signal presentation in vitro, and as strategies to investigate the capacity of the defined spatial arrangement of these signals to drive bone regeneration in vivo. PMID:25445719

Multiroller traction drive speed reducer: Evaluation for automotive gas turbine engine

NASA Technical Reports Server (NTRS)

Rohn, D. A.; Anderson, N. E.; Loewenthal, S. H.

1982-01-01

Tests were conducted on a nominal 14:1 fixed-ratio Nasvytis multiroller traction drive retrofitted as the speed reducer in an automotive gas turbine engine. Power turbine speeds of 45,000 rpm and a drive output power of 102 kW (137 hp) were reached. The drive operated under both variable roller loading (proportional to torque) and fixed roller loading (automatic loading mechanism locked). The drive operated smoothly and efficiently as the engine speed reducer. Engine specific fuel consumption with the traction speed reducer was comparable to that with the original helical gearset.

Method and apparatus for rapid thrust increases in a turbofan engine

NASA Technical Reports Server (NTRS)

Cornett, J. E.; Corley, R. C.; Fraley, T. O.; Saunders, A. A., Jr. (Inventor)

1980-01-01

Upon a landing approach, the normal compressor stator schedule of a fan speed controlled turbofan engine is temporarily varied to substantially close the stators to thereby increase the fuel flow and compressor speed in order to maintain fan speed and thrust. This running of the compressor at an off-design speed substantially reduces the time required to subsequently advance the engine speed to the takeoff thrust level by advancing the throttle and opening the compressor stators.

Voltage directive drive with claw pole motor and control without rotor position indicator

NASA Astrophysics Data System (ADS)

Stroenisch, Volker Ewald

Design and testing of a voltage directive drive for synchronous variable speed claw pole motor and control without rotor position indicator is described. Economic analysis of the designed regulation is performed. Computations of stationary and dynamic behavior are given and experimental operational behavior is determined. The motors can be used for electric transportation vehicles, diesel motors, and electric railway engines.

Quiet Clean Short-haul Experimental Engine (QCSEE) main reduction gears test program

NASA Technical Reports Server (NTRS)

Misel, O. W.

1977-01-01

Sets of under the wing (UTW) engine reduction gears and sets of over the wing (OTW) engine reduction gears were fabricated for rig testing and subsequent installation in engines. The UTW engine reduction gears which have a ratio of 2.465:1 and a design rating of 9712 kW at 3157 rpm fan speed were operated at up to 105% speed at 60% torque and 100% speed at 125% torque. The OTW engine reduction gears which have a ratio of 2.062:1 and a design rating of 12,615 kW at 3861 rpm fan speed were operated at up to 95% speed at 50% torque and 80% speed at 109% torque. Satisfactory operation was demonstrated at powers up to 12,172 kW, mechanical efficiency up to 99.1% UTW, and a maximum gear pitch line velocity of 112 m/s (22,300 fpm) with a corresponding star gear spherical roller bearing DN of 850,00 OTW. Oil and star gear bearing temperatures, oil churning, heat rejection, and vibratory characteristics were acceptable for engine installation.

Experimental investigation on NOx and green house gas emissions from a marine auxiliary diesel engine using ultralow sulfur light fuel.

PubMed

Geng, Peng; Tan, Qinming; Zhang, Chunhui; Wei, Lijiang; He, Xianzhong; Cao, Erming; Jiang, Kai

2016-12-01

In recent years, marine auxiliary diesel engine has been widely used to produce electricity in the large ocean-going ship. One of the main technical challenges for ocean-going ship is to reduce pollutant emissions from marine auxiliary diesel engine and to meet the criteria of disposal on ships pollutants of IMO (International Maritime Organization). Different technical changes have been introduced in marine auxiliary diesel engine to apply clean fuels to reduce pollutant emissions. The ultralow sulfur light fuel will be applied in diesel engine for emission reductions in China. This study is aimed to investigate the impact of fuel (ultralow sulfur light fuel) on the combustion characteristic, NOx and green house gas emissions in a marine auxiliary diesel engine, under the 50%-90% engine speeds and the 25%-100% engine torques. The experimental results show that, in the marine auxiliary diesel engine, the cylinder pressure and peak heat release rate increase slightly with the increase of engine torques, while the ignition advances and combustion duration become longer. With the increases of the engine speed and torque, the fuel consumption decreases significantly, while the temperature of the exhaust manifold increases. The NOx emissions increase significantly with the increases of the engine speed and torque. The NO emission increases with the increases of the engine speed and torque, while the NO 2 emission decreases. Meanwhile, the ratio of NO 2 and NO is about 1:1 when the diesel engine operated in the low speed and load, while the ratio increases significantly with the increases of engine speed and torque, due to the increase of the cylinder temperature in the diffusive combustion mode. Moreover, the CO 2 emission increases with the increases of engine speed and torque by the use of ultralow sulfur light fuel. Copyright © 2016. Published by Elsevier B.V.

Changes in technical regulations and drivers' safety in top‐class motor sports

PubMed Central

Lippi, G; Salvagno, G L; Franchini, M; Guidi, G C

2007-01-01

Motor racing is a dangerous sport and an inherently risky activity. The organisers of top‐class motor sports championships, Formula One and MotoGP, have agreed on a set of regulations to reduce speed and improve safety over the last 10 years. These changes include limitations in weight, fuel and engine capacity. Nevertheless, there is evidence that most of the restrictions that have been introduced over the past 10 years have failed slow down vehicles, since the lap times have decreased almost linearly from 1995 to 2006 and drivers continue to die or to sustain serious injuries that keep them away from competition. Therefore, new and efficient measures should be adopted, such as lowering the cornering speed, having heavier and safer vehicles, having barriers surrounding the track to protect both spectators and competitors better, and having innovative clothing and protective devices to defend key anatomical structures while minimising the hindrance to the rider. PMID:17925386

14 CFR 23.49 - Stalling period.

Code of Federal Regulations, 2011 CFR

2011-01-01

... on the stalling speed, with engine(s) idling and throttle(s) closed; (3) The propeller(s) in the... which the airplane is controllable with— (1) For reciprocating engine-powered airplanes, the engine(s... more than 110 percent of the stalling speed; (2) For turbine engine-powered airplanes, the propulsive...

Design of Intelligent Hydraulic Excavator Control System Based on PID Method

NASA Astrophysics Data System (ADS)

Zhang, Jun; Jiao, Shengjie; Liao, Xiaoming; Yin, Penglong; Wang, Yulin; Si, Kuimao; Zhang, Yi; Gu, Hairong

Most of the domestic designed hydraulic excavators adopt the constant power design method and set 85%~90% of engine power as the hydraulic system adoption power, it causes high energy loss due to mismatching of power between the engine and the pump. While the variation of the rotational speed of engine could sense the power shift of the load, it provides a new method to adjust the power matching between engine and pump through engine speed. Based on negative flux hydraulic system, an intelligent hydraulic excavator control system was designed based on rotational speed sensing method to improve energy efficiency. The control system was consisted of engine control module, pump power adjusted module, engine idle module and system fault diagnosis module. Special PLC with CAN bus was used to acquired the sensors and adjusts the pump absorption power according to load variation. Four energy saving control strategies with constant power method were employed to improve the fuel utilization. Three power modes (H, S and L mode) were designed to meet different working status; Auto idle function was employed to save energy through two work status detected pressure switches, 1300rpm was setting as the idle speed according to the engine consumption fuel curve. Transient overload function was designed for deep digging within short time without spending extra fuel. An increasing PID method was employed to realize power matching between engine and pump, the rotational speed's variation was taken as the PID algorithm's input; the current of proportional valve of variable displacement pump was the PID's output. The result indicated that the auto idle could decrease fuel consumption by 33.33% compared to work in maximum speed of H mode, the PID control method could take full use of maximum engine power at each power mode and keep the engine speed at stable range. Application of rotational speed sensing method provides a reliable method to improve the excavator's energy efficiency and realize power match between pump and engine.

Low-Noise Potential of Advanced Fan Stage Stator Vane Designs Verified in NASA Lewis Wind Tunnel Test

NASA Technical Reports Server (NTRS)

Hughes, Christopher E.

1999-01-01

With the advent of new, more stringent noise regulations in the next century, aircraft engine manufacturers are investigating new technologies to make the current generation of aircraft engines as well as the next generation of advanced engines quieter without sacrificing operating performance. A current NASA initiative called the Advanced Subsonic Technology (AST) Program has set as a goal a 6-EPNdB (effective perceived noise) reduction in aircraft engine noise relative to 1992 technology levels by the year 2000. As part of this noise program, and in cooperation with the Allison Engine Company, an advanced, low-noise, high-bypass-ratio fan stage design and several advanced technology stator vane designs were recently tested in NASA Lewis Research Center's 9- by 15-Foot Low-Speed Wind Tunnel (an anechoic facility). The project was called the NASA/Allison Low Noise Fan.

40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes how to determine the maximum engine power, displacement, and power density of an engine for the...

40 CFR 1042.140 - Maximum engine power, displacement, power density, and maximum in-use engine speed.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false Maximum engine power, displacement... Maximum engine power, displacement, power density, and maximum in-use engine speed. This section describes how to determine the maximum engine power, displacement, and power density of an engine for the...

40 CFR 86.1380-2004 - Load response test.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) The test has 5 separate measurement segments, each identified by a specific engine speed. At each of the following speeds, beginning with the lowest torque point at that engine speed within the NTE.... Prior to the beginning of each measurement segment, the engine shall be warmed up at the supplemental...

40 CFR 86.1380-2004 - Load response test.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) The test has 5 separate measurement segments, each identified by a specific engine speed. At each of the following speeds, beginning with the lowest torque point at that engine speed within the NTE.... Prior to the beginning of each measurement segment, the engine shall be warmed up at the supplemental...

40 CFR 86.1380-2004 - Load response test.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) The test has 5 separate measurement segments, each identified by a specific engine speed. At each of the following speeds, beginning with the lowest torque point at that engine speed within the NTE.... Prior to the beginning of each measurement segment, the engine shall be warmed up at the supplemental...

40 CFR 86.1380-2004 - Load response test.

Code of Federal Regulations, 2010 CFR

2010-07-01

...) The test has 5 separate measurement segments, each identified by a specific engine speed. At each of the following speeds, beginning with the lowest torque point at that engine speed within the NTE.... Prior to the beginning of each measurement segment, the engine shall be warmed up at the supplemental...

40 CFR Appendix B to Subpart E of... - Tables

Code of Federal Regulations, 2010 CFR

2010-07-01

... Variable-Speed Engines Test segment Mode number Engine speed 1 Observed torque 2 (percent of max. observed...'s specifications. Idle speed is specified by the manufacturer. 2 Torque (non-idle): Throttle fully open for 100 percent points. Other non-idle points: ± 2 percent of engine maximum value. Torque (idle...

14 CFR 33.84 - Engine overtorque test.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.84 Engine overtorque test. (a) If approval of a maximum engine overtorque is sought for an engine incorporating a free power turbine... at least 21/2 minutes duration. (2) A power turbine rotational speed equal to the highest speed at...

14 CFR 33.84 - Engine overtorque test.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.84 Engine overtorque test. (a) If approval of a maximum engine overtorque is sought for an engine incorporating a free power turbine... at least 21/2 minutes duration. (2) A power turbine rotational speed equal to the highest speed at...

14 CFR 33.84 - Engine overtorque test.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: AIRCRAFT ENGINES Block Tests; Turbine Aircraft Engines § 33.84 Engine overtorque test. (a) If approval of a maximum engine overtorque is sought for an engine incorporating a free power turbine... at least 21/2 minutes duration. (2) A power turbine rotational speed equal to the highest speed at...

Compact high-speed MWIR spectrometer applied to monitor CO2 exhaust dynamics from a turbojet engine

NASA Astrophysics Data System (ADS)

Linares-Herrero, R.; Vergara, G.; Gutiérrez Álvarez, R.; Fernández Montojo, C.; Gómez, L. J.; Villamayor, V.; Baldasano Ramírez, A.; Montojo, M. T.; Archilla, V.; Jiménez, A.; Mercader, D.; González, A.; Entero, A.

2013-05-01

Dfgfdg Due to international environmental regulations, aircraft turbojet manufacturers are required to analyze the gases exhausted during engine operation (CO, CO2, NOx, particles, unburned hydrocarbons (aka UHC), among others).Standard procedures, which involve sampling the gases from the exhaust plume and the analysis of the emissions, are usually complex and expensive, making a real need for techniques that allow a more frequent and reliable emissions measurements, and a desire to move from the traditional gas sampling-based methods to real time and non-intrusive gas exhaust analysis, usually spectroscopic. It is expected that the development of more precise and faster optical methods will provide better solutions in terms of performance/cost ratio. In this work the analysis of high-speed infrared emission spectroscopy measurements of plume exhaust are presented. The data was collected during the test trials of commercial engines carried out at Turbojet Testing Center-INTA. The results demonstrate the reliability of the technique for studying and monitoring the dynamics of the exhausted CO2 by the observation of the infrared emission of hot gases. A compact (no moving parts), high-speed, uncooled MWIR spectrometer was used for the data collection. This device is capable to register more than 5000 spectra per second in the infrared band ranging between 3.0 and 4.6 microns. Each spectrum is comprised by 128 spectral subbands with aband width of 60 nm. The spectrometer operated in a passive stand-off mode and the results from the measurements provided information of both the dynamics and the concentration of the CO2 during engine operation.

Gas turbine engine fuel control

NASA Technical Reports Server (NTRS)

Gold, H. S. (Inventor)

1973-01-01

A variable orifice system is described that is responsive to compressor inlet pressure and temperature, compressor discharge pressure and rotational speed of a gas-turbine engine. It is incorporated into a hydraulic circuit that includes a zero gradient pump driven at a speed proportional to the speed of the engine. The resulting system provides control of fuel rate for starting, steady running, acceleration and deceleration under varying altitudes and flight speeds.

Effect of turbulence intensity on PM emission of heavy duty diesel trucks - Wind tunnel studies

NASA Astrophysics Data System (ADS)

Littera, D.; Cozzolini, A.; Besch, M.; Carder, D.; Gautam, M.

2017-08-01

Stringent emission regulations have forced drastic technological improvements in diesel aftertreatment systems, particularly in reducing Particulate Matter (PM) emissions. The formation and evolution of PM from modern engines are more sensitive to overall changes in the dilution process, such as rapidity of mixing, background PM present in the air. These technological advancements were made in controlled laboratory environments compliant with measurement standards (i.e. Code of Federal Regulation CFR in the USA) and are not fully representative of real-world emissions from these engines or vehicles. In light of this, a specifically designed and built wind tunnel by West Virginia University (WVU) is used for the study of the exhaust plume of a heavy-duty diesel vehicle, providing a better insight in the dilution process and the representative nanoparticles emissions in a real-world scenario. The subsonic environmental wind tunnel is capable of accommodating a full-sized heavy-duty truck and generating wind speeds in excess of 50mph. A three-dimensional gantry system allows spanning the test section and sample regions in the plume with accuracy of less than 5 mm. The gantry system is equipped with engine exhaust gas analyzers and PM sizing instruments. The investigation involves three different heavy-duty Class-8 diesel vehicles representative of three emission regulation standards, namely a US-EPA 2007 compliant, a US-EPA 2010 compliant, and a baseline vehicle without any aftertreatment technologies as a pre US-EPA 2007, respectively. The testing procedure includes three different vehicle speeds: idling, 20mph, and 35mph. The vehicles were tested on WVU's medium-duty chassis dynamometer, with the load applied to the truck reflecting the road load equation at the corresponding vehicle test speeds. Wind tunnel wind speed and vehicle speed were maintained in close proximity to one another during the entire test. Results show that the cross-sectional plume area increases with increase in distance away from tailpipe. Also indicating the cooling and dilution of the exhaust begins at close vicinity to the tailpipe. The rate of cooling and dilution are greatest in early stages of the dilution process for the areas with high turbulence intensity (TI), where strong mixing phenomena occurs, leading to the formation of a predominant nucleation mode. On the other hand, the core of the plume observes a slower cooling and dilution rate. This difference is reflected in the PM formation and evolution of these two distinct regions, as shown by the particle size distributions and number concentrations. Continuous mixing will tend to mellow those differences, but its ;final; result is related to the dilution history.

The effect of chine tires on nose gear water-spray characteristics of a twin engine airplane

NASA Technical Reports Server (NTRS)

Yager, T. J.; Stubbs, S. M.; Mccarty, J. L.

1975-01-01

An experimental investigation was performed to evaluate the effectiveness of nose gear chine tires in eliminating or minimizing the engine spray ingestion problem encountered on several occasions by the Merlin 4, a twin-engine propjet airplane. A study of the photographic and television coverage indicated that under similar test conditions the spray from the chine tires presented less of a potential engine spray ingestion problem than the conventional tires. Neither tire configuration appeared to pose any ingestion problem at aircraft speeds in excess of the hydroplaning speed for each tire, however, significant differences were noted in the spray patterns of the two sets of tires at sub-hydroplaning speeds. At sub-hydroplaning speeds, the conventional tires produced substantial spray above the wing which approached the general area of the engine air inlet at lower test speeds. The chine tires produced two distinct spray plumes at sub-hydroplaning speeds: one low-level plume which presented no apparent threat of ingestion, and one which at most test speeds was observed to be below the wing leading edge and thus displaced from the intakes on the engine nacelle.

Prechamber equipped laser ignition for improved performance in natural gas engines

DOE PAGES

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.; ...

2017-04-25

Lean-burn operation of stationary natural gas engines offers lower NO x emissions and improved efficiency. A proven pathway to extend lean-burn operation has been to use laser ignition instead of standard spark ignition. However, under lean conditions, flame speed reduces thereby offsetting any efficiency gains resulting from the higher ratio of specific heats, γ. The reduced flame speeds, in turn, can be compensated with the use of a prechamber to result in volumetric ignition, and thereby lead to faster combustion. In this study, the optimal geometry of PCLI was identified through several tests in a single-cylinder engine as a compromisemore » between autoignition, NO x and soot formation within the prechamber. Subsequently, tests were conducted in a single-cylinder natural gas engine comparing the performance of three ignition systems: standard electrical spark ignition (SI), single-point laser ignition (LI), and prechamber equipped laser ignition (PCLI). Out of the three, the performance of PCLI was far superior compared to the other two. Efficiency gain of 2.1% points could be achieved while complying with EPA regulation (BSNO x < 1.34 kW-hr) and the industry standard for ignition stability (COV_IMEP < 5%). Finally, test results and data analysis are presented identifying the combustion mechanisms leading to the improved performance.« less

Fuel Spray and Flame Formation in a Compression-Ignition Engine Employing Air Flow

NASA Technical Reports Server (NTRS)

Rothrock, A M; Waldron, C D

1937-01-01

The effects of air flow on fuel spray and flame formation in a high-speed compression-ignition engine have been investigated by means of the NACA combustion apparatus. The process was studied by examining high-speed motion pictures taken at the rate of 2,200 frames a second. The combustion chamber was of the flat-disk type used in previous experiments with this apparatus. The air flow was produced by a rectangular displacer mounted on top of the engine piston. Three fuel-injection nozzles were tested: a 0.020-inch single-orifice nozzle, a 6-orifice nozzle, and a slit nozzle. The air velocity within the combustion chamber was estimated to reach a value of 425 feet a second. The results show that in no case was the form of the fuel spray completely destroyed by the air jet although in some cases the direction of the spray was changed and the spray envelope was carried away by the moving air. The distribution of the fuel in the combustion chamber of a compression-ignition engine can be regulated to some extent by the design of the combustion chamber, by the design of the fuel-injection nozzle, and by the use of air flow.

Engine speed control apparatus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ishii, M.; Miyazaki, M.; Nakamura, N.

1986-11-04

This patent describes an engine speed control apparatus. The system comprises an actuator for adjusting an engine speed, a first unit for computing a desired engine speed, a second unit for detecting the actual engine speed, and a third unit for detecting the difference between the outputs of the first and second units. The system also includes a fourth unit for computing a control pulse width for the actuator in accordance with the output of the third unit, a fifth unit for generating a control signal, a sixth unit for driving the actuator in response to the output of themore » fifth unit, and a seventh unit for computing an optimal halt time to interrupt the driving of the actuator. The actuator is driven intermittently in conformity in the control pulse width and the halt time.« less

Design and analysis of a fuel-efficient single-engine, turboprop-powered, business airplane

NASA Technical Reports Server (NTRS)

Martin, G. L.; Everest, D. E., Jr.; Lovell, W. A.; Price, J. E.; Walkley, K. B.; Washburn, G. F.

1981-01-01

The speed, range, payload, and fuel efficiency of a general aviation airplane powered by one turboprop engine was determined and compared to a twin engine turboprop aircraft. An airplane configuration was developed which can carry six people for a noreserve range of 2,408 km at a cruise speed above 154 m/s, and a cruise altitude of about 9,144 m. The cruise speed is comparable to that of the fastest of the current twin turboprop powered airplanes. It is found that the airplane has a cruise specific range greater than all twin turboprop engine airplanes flying in its speed range and most twin piston engine airplanes flying at considerably slower cruise airspeeds.

Turbulent flame propagation and combustion in spark ignition engines

NASA Technical Reports Server (NTRS)

Beretta, G. P.; Rashidi, M.; Keck, J. C.

1983-01-01

Pressure measurements synchronized with high-speed motion-picture records of flame propagation have been made in a transparent-piston engine. The data show that the initial expansion speed of the flame front is close to that of a laminar flame. As the flame expands, its speed rapidly accelerates to a quasi-steady value comparable with that of the turbulent velocity fluctuations in the unburned gas. During the quasi-steady propagation phase, a significant fraction of the gas behind the visible front is unburned. Final burnout of the charge may be approximated by an exponential decay in time. The data have been analyzed in a model-independent way to obtain a set of empirical equations for calculating mass burning rates in spark-ignition engines. The burning equations contain three parameters: the laminar burning speed, a characteristic speed (uT), and a characteristic length (lT). The laminar burning speed is known from laboratory measurements. Tentative correlations relating uT and lT to engine geometry and operating variables have been derived from the engine data.

Coupling of kinesin ATP turnover to translocation and microtubule regulation: one engine, many machines.

PubMed

Friel, Claire T; Howard, Jonathon

2012-12-01

The cycle of ATP turnover is integral to the action of motor proteins. Here we discuss how variation in this cycle leads to variation of function observed amongst members of the kinesin superfamily of microtubule associated motor proteins. Variation in the ATP turnover cycle among superfamily members can tune the characteristic kinesin motor to one of the range of microtubule-based functions performed by kinesins. The speed at which ATP is hydrolysed affects the speed of translocation. The ratio of rate constants of ATP turnover in relation to association and dissociation from the microtubule influence the processivity of translocation. Variation in the rate-limiting step of the cycle can reverse the way in which the motor domain interacts with the microtubule producing non-motile kinesins. Because the ATP turnover cycle is not fully understood for the majority of kinesins, much work remains to show how the kinesin engine functions in such a wide variety of molecular machines.

Investigation of dynamic characteristics of a turbine-propeller engine

NASA Technical Reports Server (NTRS)

Oppenheimer, Frank L; Jacques, James R

1951-01-01

Time constants that characterize engine speed response of a turbine-propeller engine over the cruising speed range for various values of constant fuel flow and constant blade angle were obtained both from steady-state characteristics and from transient operation. Magnitude of speed response to changes in fuel flow and blade angle was investigated and is presented in the form of gain factors. Results indicate that at any given value of speed in the engine cruising speed range, time constants obtained both from steady-state characteristics and from transient operation agree satisfactorily for any given constant fuel flow, whereas time constants obtained from transient operation exceed time constants obtained from steady-state characteristics by approximately 14 percent for any given blade angle.

Performance and Operational Characteristics of a Python Turbine-propeller Engine at Simulated Altitude Conditions / Carl L. Meyer and Lavern A. Johnson

NASA Technical Reports Server (NTRS)

Meyer, Carl L; Johnson, Lavern A

1952-01-01

The performance and operational characteristics of a Python turbine-propeller engine were investigated at simulated altitude conditions in the NACA Lewis altitude wind tunnel. In the performance phase, data were obtained over a range of engine speeds and exhaust nozzle areas at altitudes from 10,000 to 40,000 feet at a single cowl-inlet ram pressure ratio; independent control of engine speed and fuel flow was used to obtain a range of powers at each engine speed. Engine performance data obtained at a given altitude could not be used to predict performance accurately at other altitudes by use of the standard air pressure and temperature generalizing factors. At a given engine speed and turbine-inlet total temperature, a greater portion of the total available energy was converted to propulsive power as the altitude increased.

Urban traffic pollution reduction for sedan cars using petrol engines by hydro-oxide gas inclusion.

PubMed

Al-Rousan, Ammar A; Alkheder, Sharaf; Musmar, Sa'ed A

2015-12-01

Petrol cars, in particular nonhybrid cars, contribute significantly to the pollution problem as compared with other types of cars. The originality of this article falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/hr). Results indicated that through using hydro-oxy gas, a noticeable reduction in pollution was recorded. Oxygen (O2) percentage has increased by about 2.5%, and nitric oxide (NO) level has been reduced by about 500 ppm. Carbon monoxide (CO) has decreased by about 2.2%, and also CO2 has decreased by 2.1%. It's worth mentioning that for hybrid system in cars at speeds between 10 and 50 km/hr, the emission percentage change is zero. However, hybrid cars are less abundant than petrol cars. The originality of this paper falls in the direction of using hydro-oxy gas to reduce pollution from petrol car engines. Experiments were performed in city areas at low real speeds, with constant engine speeds in the average of 2500 rpm and at variable velocity ratios (first speed was 10-20 km/hr, second speed was 20-35 km/hr, and third speed was 35-50 km/h).

A study experiment of auto idle application in the excavator engine performance

NASA Astrophysics Data System (ADS)

Purwanto, Wawan; Maksum, Hasan; Putra, Dwi Sudarno; Azmi, Meri; Wahyudi, Retno

2016-03-01

The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

A study experiment of auto idle application in the excavator engine performance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purwanto, Wawan, E-mail: wawan5527@gmail.com; Maksum, Hasan; Putra, Dwi Sudarno, E-mail: dwisudarnoputra@ft.unp.ac.id

2016-03-29

The purpose of this study was to analyze the effect of applying auto idle to excavator engine performance, such as machine unitization and fuel consumption in Excavator. Steps to be done are to modify the system JA 44 and 67 in Vehicle Electronic Control Unit (V-ECU). The modifications will be obtained from the pattern of the engine speed. If the excavator attachment is not operated, the engine speed will return to the idle speed automatically. From the experiment results the auto idle reduces fuel consumption in excavator engine.

Cost of lower NO x emissions: Increased CO 2 emissions from heavy-duty diesel engines

NASA Astrophysics Data System (ADS)

Krishnamurthy, Mohan; Carder, Daniel K.; Thompson, Gregory; Gautam, Mridul

This paper highlights the effect of emissions regulations on in-use emissions from heavy-duty vehicles powered by different model year engines. More importantly, fuel economy data for pre- and post-consent decree engines are compared. The objective of this study was to determine the changes in brake-specific emissions of NO x as a result of emission regulations, and to highlight the effect these have had on brake-specific CO 2 emission; hence, fuel consumption. For this study, in-use, on-road emission measurements were collected. Test vehicles were instrumented with a portable on-board tailpipe emissions measurement system, WVU's Mobile Emissions Measurement System, and were tested on specific routes, which included a mix of highway and city driving patterns, in order to collect engine operating conditions, vehicle speed, and in-use emission rates of CO 2 and NO x. Comparison of on-road in-use emissions data suggests NO x reductions as high as 80% and 45% compared to the US Federal Test Procedure and Not-to-Exceed standards for model year 1995-2002. However, the results indicate that the fuel consumption; hence, CO 2 emissions increased by approximately 10% over the same period, when the engines were operating in the Not-to-Exceed region.

Optimal trajectories for an aerospace plane. Part 1: Formulation, results, and analysis

NASA Technical Reports Server (NTRS)

Miele, Angelo; Lee, W. Y.; Wu, G. D.

1990-01-01

The optimization of the trajectories of an aerospace plane is discussed. This is a hypervelocity vehicle capable of achieving orbital speed, while taking off horizontally. The vehicle is propelled by four types of engines: turbojet engines for flight at subsonic speeds/low supersonic speeds; ramjet engines for flight at moderate supersonic speeds/low hypersonic speeds; scramjet engines for flight at hypersonic speeds; and rocket engines for flight at near-orbital speeds. A single-stage-to-orbit (SSTO) configuration is considered, and the transition from low supersonic speeds to orbital speeds is studied under the following assumptions: the turbojet portion of the trajectory has been completed; the aerospace plane is controlled via the angle of attack and the power setting; the aerodynamic model is the generic hypersonic aerodynamics model example (GHAME). Concerning the engine model, three options are considered: (EM1), a ramjet/scramjet combination in which the scramjet specific impulse tends to a nearly-constant value at large Mach numbers; (EM2), a ramjet/scramjet combination in which the scramjet specific impulse decreases monotonically at large Mach numbers; and (EM3), a ramjet/scramjet/rocket combination in which, owing to stagnation temperature limitations, the scramjet operates only at M approx. less than 15; at higher Mach numbers, the scramjet is shut off and the aerospace plane is driven only by the rocket engines. Under the above assumptions, four optimization problems are solved using the sequential gradient-restoration algorithm for optimal control problems: (P1) minimization of the weight of fuel consumed; (P2) minimization of the peak dynamic pressure; (P3) minimization of the peak heating rate; and (P4) minimization of the peak tangential acceleration.

Italian High-speed Airplane Engines

NASA Technical Reports Server (NTRS)

Bona, C F

1940-01-01

This paper presents an account of Italian high-speed engine designs. The tests were performed on the Fiat AS6 engine, and all components of that engine are discussed from cylinders to superchargers as well as the test set-up. The results of the bench tests are given along with the performance of the engines in various races.

40 CFR 1065.510 - Engine mapping.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the warm-up until the engine coolant, block, or head absolute temperature is within ± 2% of its mean... demand to minimum, use the dynamometer or other loading device to target a torque of zero on the engine's...-speed governor, operate the engine at warm idle speed and zero torque on the engine's primary output...

Speed limiter integrated fatigue analyzer (SLIFA) for speed and fatigue control on diesel engine truck and bus

NASA Astrophysics Data System (ADS)

Wahyudi, Haris; Pranoto, Hadi; Leman, A. M.; Sebayang, Darwin; Baba, I.

2017-09-01

Every second, the number of road traffic deaths is increased globally with millions more sustaining severe injuries and living with long-term adverse health consequences. Jakarta alone in year 2015 had recorded 556 people died due to road accidents, approximately reached 6.231 road accident cases. The identified major contributory factors of such unfortunate events are both driver fatigue and over speeding habit especially related to the driving of truck and bus. This paper presents the idea on how to control the electronic system from input fuel system of injection pump and the combustion chamber engine will control the valve solenoid in injection pump which can lock and fuel will stop for moment, and speed limit can be success, by using sensor heart rate we can input reduce speed limit when fatigue detection driver. Integration process this tool can be relevant when Speed Limiter Integrated Fatigue Analyser (SLIFA) trial in the diesel engine for truck and bus, the result of this research Speed Limiter Integrated Fatigue Analyser (SLIFA) able to control speed of diesel engine for truck and bus almost 30km/h, 60km/h, and until 70 km/h. The installation of the sensor heart rate as the input speed limit SLIFA would work when the driver is detected to be in the fatigue condition. We make Speed Limiter Integrated Fatigue Analyser (SLIFA) for control and monitoring system for diesel engine in truck and bus. Speed Limiter Integrated Fatigue Analyser (SLIFA) system can save the historical of the speed record, fatigue, rpm, and body temperature of the driver.

Experimental quiet engine program

NASA Technical Reports Server (NTRS)

Cornell, W. G.

1975-01-01

Full-scale low-tip-speed fans, a full-scale high-tip-speed fan, scale model versions of fans, and two full-scale high-bypass-ratio turbofan engines, were designed, fabricated, tested, and evaluated. Turbine noise suppression was investigated. Preliminary design studies of flight propulsion system concepts were used in application studies to determine acoustic-economic tradeoffs. Salient results are as follows: tradeoff evaluation of fan tip speed and blade loading; systematic data on source noise characteristics and suppression effectiveness; documentation of high- and low-fan-speed aerodynamic and acoustic technology; aerodynamic and acoustic evaluation of acoustic treatment configurations, casing tip bleed, serrated and variable pitch rotor blades, leaned outlet guide vanes, slotted tip casings, rotor blade shape modifications, and inlet noise suppression; systematic evaluation of aerodynamic and acoustic effects; flyover noise projections of engine test data; turbine noise suppression technology development; and tradeoff evaluation of preliminary design high-fan-speed and low-fan-speed flight engines.

Experimental investigation on regulated and unregulated emissions of a diesel engine fueled with ultra-low sulfur diesel fuel blended with biodiesel from waste cooking oil.

PubMed

Di, Yage; Cheung, C S; Huang, Zuohua

2009-01-01

Experiments were conducted on a 4-cylinder direct-injection diesel engine using ultra-low sulfur diesel, bi oesel and their blends, to investigate the regulated and unregulated emissions of the engine under five engine loads at an engine speed of 1800 rev/min. Blended fuels containing 19.6%, 39.4%, 59.4% and 79.6% by volume of biodiesel, corresponding to 2%, 4%, 6% and 8% by mass of oxygen in the blended fuel, were used. Biodiesel used in this study was converted from waste cooking oil. The following results are obtained with an increase of biodiesel in the fuel. The brake specific fuel consumption and the brake thermal efficiency increase. The HC and CO emissions decrease while NO(x) and NO(2) emissions increase. The smoke opacity and particulate mass concentrations reduce significantly at high engine load. In addition, for submicron particles, the geometry mean diameter of the particles becomes smaller while the total number concentration increases. For the unregulated gaseous emissions, generally, the emissions of formaldehyde, 1,3-butadiene, toluene, xylene decrease, however, acetaldehyde and benzene emissions increase. The results indicate that the combination of ultra-low sulfur diesel and biodiesel from waste cooking oil gives similar results to those in the literature using higher sulfur diesel fuels and biodiesel from other sources.

Circuit Regulates Speed Of dc Motor

NASA Technical Reports Server (NTRS)

Weaver, Charles; Padden, Robin; Brown, Floyd A., Jr.

1990-01-01

Driving circuit regulates speed of small dc permanent-magnet motor in tape recorder. Two nested feedback loops maintain speed within 1 percent of constant value. Inner loop provides coarse regulation, while outer loop removes most of variation in speed that remains in the presence of regulation by the inner loop. Compares speed of motor with commanded speed and adjusts current supplied to motor accordingly.

Sample-based engine noise synthesis using an enhanced pitch-synchronous overlap-and-add method.

PubMed

Jagla, Jan; Maillard, Julien; Martin, Nadine

2012-11-01

An algorithm for the real time synthesis of internal combustion engine noise is presented. Through the analysis of a recorded engine noise signal of continuously varying engine speed, a dataset of sound samples is extracted allowing the real time synthesis of the noise induced by arbitrary evolutions of engine speed. The sound samples are extracted from a recording spanning the entire engine speed range. Each sample is delimitated such as to contain the sound emitted during one cycle of the engine plus the necessary overlap to ensure smooth transitions during the synthesis. The proposed approach, an extension of the PSOLA method introduced for speech processing, takes advantage of the specific periodicity of engine noise signals to locate the extraction instants of the sound samples. During the synthesis stage, the sound samples corresponding to the target engine speed evolution are concatenated with an overlap and add algorithm. It is shown that this method produces high quality audio restitution with a low computational load. It is therefore well suited for real time applications.

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

DOE PAGES

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James; ...

2017-03-28

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

Effects of Fuel Laminar Flame Speed Compared to Engine Tumble Ratio, Ignition Energy, and Injection Strategy on Lean and EGR Dilute Spark Ignition Combustion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kolodziej, Christopher P.; Pamminger, Michael; Sevik, James

Previously we show that fuels with higher laminar flame speed also have increased tolerance to EGR dilution. In this work, the effects of fuel laminar flame speed on both lean and EGR dilute spark ignition combustion stability were examined. Fuels blends of pure components (iso-octane, n-heptane, toluene, ethanol, and methanol) were derived at two levels of laminar flame speed. Each fuel blend was tested in a single-cylinder spark-ignition engine under both lean-out and EGR dilution sweeps until the coefficient of variance of indicated mean effective pressure increased above thresholds of 3% and 5%. The relative importance of fuel laminar flamemore » speed to changes to engine design parameters (spark ignition energy, tumble ratio, and port vs. direct injection) was also assessed. Our results showed that fuel laminar flame speed can have as big an effect on lean or EGR dilute engine operation as engine design parameters, with the largest effects seen during EGR dilute operation and when changes were made to cylinder charge motion.« less

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2011 CFR

2011-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2014 CFR

2014-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

14 CFR Appendix E to Part 135 - Helicopter Flight Recorder Specifications

Code of Federal Regulations, 2012 CFR

2012-01-01

... Keying On-Off (Discrete) 1 0.25 sec Power in Each Engine: Free Power Turbine Speed and Engine Torque 0-130% (power Turbine Speed) Full range (Torque) ±2% 1 speed 1 torque (per engine) 0.2% 1 to 0.4% 1 Main... Controls (Collective, Longitudinal Cyclic, Lateral Cyclic, Pedal) 3 Full range ±3% 2 0.5% 1 Flight Control...

Waste heat recovery on multiple low-speed reciprocating engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhew, R.E.

1982-09-01

With rising fuel costs, energy conservation has taken on added significance. Installation of Waste Heat Recovery Units (WHRU) on gas turbines is one method used in the past to reduce gas plant fuel consumption. More recently, waste heat recovery on multiple reciprocating compressor engines has also been identified as having energy conservation potential. This paper reviews the development and implementation of a Waste Heat Recovery Unit (WHRU) for multiple low speed engines at the Katy Gas Plant. WHRU's for these engines should be differentiated from high speed engines and gas turbines in that low speed engines produce low frequency, highmore » amplitude pulsating exhaust. The design of a waste heat system must take this potentially destructive pulsation into account. At Katy, the pulsation forces were measured at high amplitude frequencies and then used to design structural stiffness into the various components of the WHRU to minimize vibration and improve system reliability.« less

Waste heat recovery on multiple low-speed reciprocating engines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mayhew, R.E.

1984-09-01

With rising fuel costs, energy conservation has taken on added significance. Installation of waste heat recovery units (WHRU's) on gas turbines is one method used in the past to reduce gas plant fuel consumption. More recently, waste heat recovery on multiple reciprocating compressor engines also has been identified as having energy conservation potential. This paper reviews the development and implementation of a WHRU for multiple low-speed engines at the Katy (TX) gas plant. WHRU's for these engines should be differentiated from high-speed engines and gas turbines in that low-speed engines produce low-frequency, high-amplitude pulsating exhaust. The design of a WHRUmore » system must take this potentially destructive pulsation into account. At Katy, the pulsation forces were measured at high-amplitude frequencies and then used to design a pulsation filter and structural stiffness into the various components of the WHRU to minimize vibration and improve system reliability.« less

Performance and component frontal areas of a hypothetical two-spool turbojet engine for three modes of operation

NASA Technical Reports Server (NTRS)

Dugan, James F , Jr

1955-01-01

Engine performance is better for constant outer-spool mechanical-speed operation than for constant inner-spool mechanical-speed operation over most of the flight range considered. Combustor and afterburner frontal areas are about the same for the two modes. Engine performance for a mode characterized by a constant outer-spool equivalent speed over part of the flight range and a constant outer-spool mechanical speed over the rest of the flight range is better that that for constant outer-spool mechanical speed operation. The former mode requires larger outer-spool centrifugal stresses and larger component frontal areas.

Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing

NASA Astrophysics Data System (ADS)

Lack, D. A.; Corbett, J. J.

2012-01-01

The International Maritime Organization (IMO) has moved to address the health and climate impact of the emissions from the combustion of low-quality residual fuels within the commercial shipping industry. Fuel sulfur content (FS) limits and an efficiency design index for future ships are examples of such IMO actions. The impacts of black carbon (BC) emissions from shipping are now under review by the IMO, with a particular focus on the potential impacts of future Arctic shipping. Recognizing that associating impacts with BC emissions requires both ambient and onboard observations, we provide recommendations for the measurement of BC. We also evaluate current insights regarding the effect of ship speed (engine load), fuel quality and exhaust gas scrubbing on BC emissions from ships. Observations demonstrate that BC emission factors (EFBC) increases 3 to 6 times at very low engine loads (<25% compared to EFBC at 85-100% load); absolute BC emissions (per nautical mile of travel) also increase up to 100% depending on engine load, even with reduced load fuel savings. If fleets were required to operate at lower maximum engine loads, presumably associated with reduced speeds, then engines could be re-tuned, which would reduce BC emissions. Ships operating in the Arctic are likely running at highly variable engine loads (25-100%) depending on ice conditions and ice breaking requirements. The ships operating at low load may be emitting up to 50% more BC than they would at their rated load. Such variable load conditions make it difficult to assess the likely emissions rate of BC. Current fuel sulfur regulations have the effect of reducing EFBC by an average of 30% and potentially up to 80% regardless of engine load; a removal rate similar to that of scrubbers. Uncertainties among current observations demonstrate there is a need for more information on (a) the impact of fuel quality on EFBC using robust measurement methods and (b) the efficacy of scrubbers for the removal of particulate matter by size and composition.

Black carbon from ships: a review of the effects of ship speed, fuel quality and exhaust gas scrubbing

NASA Astrophysics Data System (ADS)

Lack, D. A.; Corbett, J. J.

2012-05-01

The International Maritime Organization (IMO) has moved to address the health and climate impact of the emissions from the combustion of low-quality residual fuels within the commercial shipping industry. Fuel sulfur content (FS) limits and an efficiency design index for future ships are examples of such IMO actions. The impacts of black carbon (BC) emissions from shipping are now under review by the IMO, with a particular focus on the potential impacts of future Arctic shipping. Recognizing that associating impacts with BC emissions requires both ambient and onboard observations, we provide recommendations for the measurement of BC. We also evaluate current insights regarding the effect of ship speed (engine load), fuel quality and exhaust gas scrubbing on BC emissions from ships. Observations demonstrate that BC emission factors (EFBC) increases 3 to 6 times at very low engine loads (<25% compared to EFBC at 85-100% load); absolute BC emissions (per nautical mile of travel) also increase up to 100% depending on engine load, even with reduced load fuel savings. If fleets were required to operate at lower maximum engine loads, presumably associated with reduced speeds, then engines could be re-tuned, which would reduce BC emissions. Ships operating in the Arctic are likely running at highly variable engine loads (25-100%) depending on ice conditions and ice breaking requirements. The ships operating at low load may be emitting up to 50% more BC than they would at their rated load. Such variable load conditions make it difficult to assess the likely emissions rate of BC. Current fuel sulfur regulations have the effect of reducing EFBC by an average of 30% and potentially up to 80% regardless of engine load; a removal rate similar to that of scrubbers. Uncertainties among current observations demonstrate there is a need for more information on a) the impact of fuel quality on EFBC using robust measurement methods and b) the efficacy of scrubbers for the removal of particulate matter by size and composition.

Speed limits set lower than engineering recommendations : project summary report.

DOT National Transportation Integrated Search

2016-08-01

The Montana Department of Transportation (MDT) generally ensures that posted speed limits are set in accordance with engineering recommendations, which means that speed limits are typically set such that they are about equal to the observed 85th-perc...

Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine. 5; Combustion-Chamber Characterisitcs

NASA Technical Reports Server (NTRS)

Geisenheyner, Robert M.; Berdysz, Joseph J.

1948-01-01

An investigation to determine the performance and operational characteristics of an axial-flow gas turbine-propeller engine was conducted in the Cleveland altitude wind tunnel. As part of this investigation, the combustion-chamber performance was determined at pressure altitudes from 5000 to 35,000 feet, compressor-inlet ram-pressure ratios of 1.00 and 1.09, and engine speeds from 8000 to 13,000 rpm. Combustion-chamber performance is presented as a function of corrected engine speed and corrected horsepower. For the range of corrected engine speeds investigated, overall total-pressure-loss ratio, cycle efficiency, and the fractional loss in cycle efficiency resulting from pressure losses in the combustion chambers were unaffected by a change in altitude or compressor-inlet ram-pressure ratio. For the range of corrected horsepowers investigated, the total-pressure-loss ratio and the fractional loss in cycle efficiency resulting from pressure losses in the combustion chambers decreased with an increase in corrected horsepower at a constant corrected engine speed. The combustion efficiency remained constant for the range of corrected horsepowers investigated at all corrected engine speeds.

Design Study of Propulsion and Drive Systems for the Large Civil TiltRotor (LCTR2) Rotorcraft

NASA Technical Reports Server (NTRS)

Robuck, Mark; Wilkerson, Joseph; Zhang, Yiyi; Snyder, Christopher A.; Vonderwell, Daniel

2013-01-01

Boeing, Rolls Royce, and NASA have worked together to complete a parametric sizing study for NASA's Large Civil Tilt Rotor (LCTR2) concept 2nd iteration. Vehicle gross weight and fuel usage were evaluated as propulsion and drive system characteristics were varied to maximize the benefit of reduced rotor tip speed during cruise conditions. The study examined different combinations of engine and gearbox variability to achieve rotor cruise tip speed reductions down to 54% of the hover tip speed. Previous NASA studies identified that a 54% rotor speed reduction in cruise minimizes vehicle gross weight and fuel burn. The LCTR2 was the study baseline for initial sizing. This study included rotor tip speed ratios (cruise to hover) of 100%, 77% and 54% at different combinations of engine RPM and gearbox speed reductions, which were analyzed to achieve the lightest overall vehicle gross weight (GW) at the chosen rotor tip speed ratio. Different engine and gearbox technology levels are applied ranging from commercial off-the-shelf (COTS) engines and gearbox technology to entry-in-service (EIS) dates of 2025 and 2035 to assess the benefits of advanced technology on vehicle gross weight and fuel burn. Interim results were previously reported1. This technical paper extends that work and summarizes the final study results including additional engine and drive system study accomplishments. New vehicle sizing data is presented for engine performance at a single operating speed with a multispeed drive system. Modeling details for LCTR2 vehicle sizing and subject engine and drive sub-systems are presented as well. This study was conducted in support of NASA's Fundamental Aeronautics Program, Subsonic Rotary Wing Project.

Engineering studies in support of the development of high-speed track geometry specifications

DOT National Transportation Integrated Search

1997-03-01

The Federal Railroad Administration has been directing engineering studies to support the development of high speed track geometry standards. These standards are intended to cover train operating speeds from 110 mph to 200 mph. The studies conducted ...

Emission rates of regulated pollutants from on-road heavy-duty diesel vehicles

NASA Astrophysics Data System (ADS)

Shah, Sandip D.; Johnson, Kent C.; Wayne Miller, J.; Cocker, David R.

Emissions from heavy-duty diesel (HDD) vehicles are affected by many factors. Changes in engine technology, operating mode, fuel properties, vehicle speed and ambient conditions can have significant effects on emission rates of regulated species. This paper presents the results of on-road emissions testing of 11 HDD vehicles (model years 1996-2000) over the ARB Four Phase driving schedule and the urban dynamometer driving schedule (UDDS). Emission rates were found to be highly dependent on vehicle operating mode. Per mile NO x emission rates for vehicle operation at low speeds, in simulated congested traffic, were three times higher per mile emissions then while cruising on the freeway. Comparisons of NO x emission factors to EMFAC baseline emission factors were within 5-40% for vehicles of various model years tested over the UDDS. A comparison of NO x emission factors for a weighted average of the ARB four phase driving schedule yielded values within 17-57% of EMFAC values. Generally, particulate matter (PM) emission rates were lower than EMFAC values.

Study of alcohol fuel of butanol and ethanol effect on the compression ignition (CI) engine performance, combustion and emission characteristic

NASA Astrophysics Data System (ADS)

Aziz, M. A.; Yusop, A. F.; Mat Yasin, M. H.; Hamidi, M. A.; Alias, A.; Hussin, H.; Hamri, S.

2017-10-01

Diesel engine which is one of the larger contributors to total consumption for petroleum is an attractive power unit used widely in many fields. However, diesel engines are among the main contributors to air pollutions for the large amount of emissions, such as CO, CO2 and NOx lead to an adverse effect on human health. Many researches have been done to find alternative fuels that are clean and efficient. Biodiesel is preferred as an alternative source for diesel engine which produces lower emission of pollutants. This study has focused on the evaluation of diesel and alcohol-diesel fuel properties and also the performance, combustion and exhaust emission from diesel engine fuelled with diesel and alcohol. Butanol and ethanol is blend with diesel fuel at 1:9 ratio. There are three test fuel that is tested which Diesel (100% diesel), D90BU10 (10% Butanol and 90% diesel) and D90E10 (10% Ethanol and 90% diesel). The comparison between diesel and alcohol-diesel blend has been made in terms of fuel properties characterization, engine performance such as brake power (BP) and brake specific fuel consumption (BSFC) also the in cylinder maximum pressure characteristic. Thus, exhaust gas emission of CO, CO2, NOx and O2 emission also has been observed at constant load of 50% but in different operating engine speed (1100 rpm, 1400 rpm, 1700 rpm, 2000 rpm and 2300 rpm). The results show the addition of 10% of each butanol and ethanol to diesel fuel had decreased the fuel density about 0.3% to 0.5% compared to mineral diesel. In addition, viscosity and energy content are also decrease. The addition of 10% butanol had improved the fuel cetane number however the ethanol blends react differently. In term of engine performance, as the engine speed increased, BP output also increase respectively. Hence, the alcohol blends fuel generates lower BP compared to diesel, plus BSFC for all test fuel shows decreasing trend at low and medium speed, however increased gradually at higher engine speed. Thus, D90BU10 had higher BSFC compared to mineral diesel and D90E10. In general, the addition of alcohol blend in diesel fuel had increase the BSFC. In term of in cylinder pressure, as the engine speed is increased, the crank angle noted to move away from TDC for all test fuel. The maximum cylinder pressure increased at low and medium speed, but decrease in higher engine speed. The addition of 10% of butanol and ethanol in the mineral diesel decreased the maximum cylinder pressure. Meanwhile, O2 emission of D90E10 is higher compared to D90BU10 due to higher oxygen content found in ethanol. The CO2 emission of D90BU10 recorded higher compared to mineral diesel due to the high oxygen contents in the alcohol. CO emission of alcohol blend on the other hand had lower emission at higher engine speed compared to mineral diesel. As engine speed is increased, NOx emission of mineral diesel and D90E10 had decreased gradually. However, D90BU10 had increased of NOx emission at lower to medium engine speed, than gradually decreased at higher engine speed.

A real-time control system of gene expression using ligand-bound nucleic acid aptamer for metabolic engineering.

PubMed

Wang, Jing; Cui, Xun; Yang, Le; Zhang, Zhe; Lv, Liping; Wang, Haoyuan; Zhao, Zhenmin; Guan, Ningzi; Dong, Lichun; Chen, Rachel

2017-07-01

Artificial control of bio-functions through regulating gene expression is one of the most important and attractive technologies to build novel living systems that are useful in the areas of chemical synthesis, nanotechnology, pharmacology, cell biology. Here, we present a novel real-time control system of gene regulation that includes an enhancement element by introducing duplex DNA aptamers upstream promoter and a repression element by introducing a RNA aptamer upstream ribosome binding site. With the presence of ligands corresponding to the DNA aptamers, the expression of the target gene can be potentially enhanced at the transcriptional level by strengthening the recognition capability of RNAP to the recognition region and speeding up the separation efficiency of the unwinding region due to the induced DNA bubble around the thrombin-bound aptamers; while with the presence of RNA aptamer ligand, the gene expression can be repressed at the translational level by weakening the recognition capability of ribosome to RBS due to the shielding of RBS by the formed aptamer-ligand complex upstream RBS. The effectiveness and potential utility of the developed gene regulation system were demonstrated by regulating the expression of ecaA gene in the cell-free systems. The realistic metabolic engineering application of the system has also tested by regulating the expression of mgtC gene and thrombin cDNA in Escherichia coli JD1021 for controlling metabolic flux and improving thrombin production, verifying that the real-time control system of gene regulation is able to realize the dynamic regulation of gene expression with potential applications in bacterial physiology studies and metabolic engineering. Copyright © 2017. Published by Elsevier Inc.

Analysis of automobile engine cylinder pressure and rotation speed from engine body vibration signal

NASA Astrophysics Data System (ADS)

Wang, Yuhua; Cheng, Xiang; Tan, Haishu

2016-01-01

In order to improve the engine vibration signal process method for the engine cylinder pressure and engine revolution speed measurement instrument, the engine cylinder pressure varying with the engine working cycle process has been regarded as the main exciting force for the engine block forced vibration. The forced vibration caused by the engine cylinder pressure presents as a low frequency waveform which varies with the cylinder pressure synchronously and steadily in time domain and presents as low frequency high energy discrete humorous spectrum lines in frequency domain. The engine cylinder pressure and the rotation speed can been extract form the measured engine block vibration signal by low-pass filtering analysis in time domain or by FFT analysis in frequency domain, the low-pass filtering analysis in time domain is not only suitable for the engine in uniform revolution condition but also suitable for the engine in uneven revolution condition. That provides a practical and convenient way to design motor revolution rate and cylinder pressure measurement instrument.

Comparison of Communication Architectures and Network Topologies for Distributed Propulsion Controls (Preprint)

DTIC Science & Technology

2013-05-01

logic to perform control function computations and are connected to the full authority digital engine control ( FADEC ) via a high-speed data...Digital Engine Control ( FADEC ) via a high speed data communication bus. The short term distributed engine control configu- rations will be core...concen- trator; and high temperature electronics, high speed communication bus between the data concentrator and the control law processor master FADEC

Compression Ratio Adjuster

NASA Technical Reports Server (NTRS)

Akkerman, J. W.

1982-01-01

New mechanism alters compression ratio of internal-combustion engine according to load so that engine operates at top fuel efficiency. Ordinary gasoline, diesel and gas engines with their fixed compression ratios are inefficient at partial load and at low-speed full load. Mechanism ensures engines operate as efficiently under these conditions as they do at highload and high speed.

Mass spectral chemical fingerprints reveal the molecular dependence of exhaust particulate matters on engine speeds.

PubMed

Li, Yi; Zhang, Hua; Zhao, Zongshan; Tian, Yong; Liu, Kun; Jie, Feifan; Zhu, Liang; Chen, Huanwen

2018-05-01

Particulate matters (PMs) emitted by automobile exhaust contribute to a significant fraction of the global PMs. Extractive atmospheric pressure chemical ionization mass spectrometry (EAPCI-MS) was developed to explore the molecular dependence of PMs collected from exhaust gases produced at different vehicle engine speeds. The mass spectral fingerprints of the organic compounds embedded in differentially sized PMs (e.g., 0.22-0.45, 0.45-1.00, 1.00-2.00, 2.00-3.00, 3.00-5.00, and 5.00-10.00μm) generated at different engine speeds (e.g., 1000, 1500, 2000, 2500, and 3000r/min) were chemically profiled in the mass range of mass to charge ratio (m/z) 50-800. Organic compounds, including alcohols, aldehydes, and esters, were detected in all the PMs tested, with varied concentration levels for each individual PM sample. At relatively low engine speeds (≤1500r/min), the total amount of organic species embedded in PMs of 0.22-1.00μm was greater than in PMs of other sizes, while more organic species were found in PMs of 5.00-10.00μm at high engine speeds (≥3000r/min), indicating that the organic compounds distributed in different sizes of PMs strongly correlated with the engine speed. The experimental data showed that the EAPCI-MS technique enables molecular characterization of PMs in exhaust, revealing the chemical dependence of PMs on the engine speeds (i.e., the combustion conditions) of automobiles. Copyright © 2017. Published by Elsevier B.V.

Modeling Parasitic Energy Losses and the Impact of Advanced Tribological Concepts on Fuel Efficiency - Final CRADA Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenske, George

2016-11-28

Our primary task for this project was to perform FMEP calculations for a broad range of parameters including engine type [spark ignition (SI) or compression ignition (CI)], engine size, engine mode (speed and load), lubricant viscosity, asperity friction, surface finish, oil type (mineral or synthetic), and additive (friction modifier), as discussed previously [1–3]. The actual analysis was limited to a large diesel engine and it included both load and speed dependencies as well as lubricant viscosity and speed.

Cooling Characteristics of a 2-Row Radial Engine

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Rollin, Vern G

1937-01-01

This report presents the results of cooling tests conducted on a calibrated GR-1535 Pratt and Whitney Wasp, Jr. Engine installed in a Vought X04U-2 airplane. The tests were made in the NACA full-scale tunnel at air speeds from 70 to 120 miles per hour, at engine speeds from 1,500 to 2,600 r.p.m., and at manifold pressures from 19 to 33 inches of mercury absolute. A Smith controllable propeller was used to facilitate obtaining the different combinations of engine speed, power, and manifold pressure.

Design and vibration control of vehicle engine mount activated by MR fluid and piezoelectric actuator

NASA Astrophysics Data System (ADS)

Lee, D. Y.; Park, Y. K.; Choi, S. B.; Lee, H. G.

2009-07-01

An engine is one of the most dominant noise and vibration sources in vehicle systems. Therefore, in order to resolve noise and vibration problems due to engine, various types of engine mounts have been proposed. This work presents a new type of active engine mount system featuring a magneto-rheological (MR) fluid and a piezostack actuator. As a first step, six degrees-of freedom dynamic model of an in-line four-cylinder engine which has three points mounting system is derived by considering the dynamic behaviors of MR mount and piezostack mount. In the configuration of engine mount system, two MR mounts are installed for vibration control of roll mode motion whose energy is very high in low frequency range, while one piezostack mount is installed for vibration control of bounce and pitch mode motion whose energy is relatively high in high frequency range. As a second step, linear quadratic regulator (LQR) controller is synthesized to actively control the imposed vibration. In order to demonstrate the effectiveness of the proposed active engine mount, vibration control performances are evaluated under various engine operating speeds (wide frequency range).

Modeling of Engine Parameters for Condition-Based Maintenance of the MTU Series 2000 Diesel Engine

DTIC Science & Technology

2016-09-01

are suitable. To model the behavior of the engine, an autoregressive distributed lag (ARDL) time series model of engine speed and exhaust gas... time series model of engine speed and exhaust gas temperature is derived. The lag length for ARDL is determined by whitening of residuals using the...15 B. REGRESSION ANALYSIS ....................................................................15 1. Time Series Analysis

Analysis of unregulated emissions from an off-road diesel engine during realistic work operations

NASA Astrophysics Data System (ADS)

Lindgren, Magnus; Arrhenius, Karine; Larsson, Gunnar; Bäfver, Linda; Arvidsson, Hans; Wetterberg, Christian; Hansson, Per-Anders; Rosell, Lars

2011-09-01

Emissions from vehicle diesel engines constitute a considerable share of anthropogenic emissions of pollutants, including many non-regulated compounds such as aromatic hydrocarbons and alkenes. One way to reduce these emissions might be to use fuels with low concentrations of aromatic hydrocarbons, such as Fischer-Tropsch (F-T) diesels. Therefore this study compared Swedish Environmental Class 1 diesel (EC1) with the F-T diesel fuel Ecopar™ in terms of emissions under varied conditions (steady state, controlled transients and realistic work operations) in order to identify factors influencing emissions in actual operation. Using F-T diesel reduced emissions of aromatic hydrocarbons, but not alkenes. Emissions were equally dependent on work operation character (load, engine speed, occurrence of transients) for both fuels. There were indications that the emissions originated from unburnt fuel, rather than from combustion products.

Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

NASA Astrophysics Data System (ADS)

Izzuddin, Nur; Sunarsih, Priyanto, Agoes

2015-05-01

As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel's speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel's speed to obtain better characteristics and hence optimize the fuel saving rate.

Scramjet nozzle design and analysis as applied to a highly integrated hypersonic research airplane

NASA Technical Reports Server (NTRS)

Small, W. J.; Weidner, J. P.; Johnston, P. J.

1976-01-01

Engine-nozzle airframe integration at hypersonic speeds was conducted by using a high-speed research aircraft concept as a focus. Recently developed techniques for analysis of scramjet-nozzle exhaust flows provide a realistic analysis of complex forces resulting from the engine-nozzle airframe coupling. By properly integrating the engine-nozzle propulsive system with the airframe, efficient, controlled and stable flight results over a wide speed range.

Flame Acceleration and Transition to Detonation in High-Speed Turbulent Combustion

DTIC Science & Technology

2016-12-21

Turbulent Combustion 1. Introduction to the Challenge Problem The importance of high-speed t urbulent combustion of gas mixtures and sprays is dif...engines, gas turbines, various types of jet engines, and some rocket engines . On the other hand , preventing high-speed combustion is critical for...the safety of any human activities that involve handling of po- t entially explosive gases or volatile liquids . Thus, the development of more fuel

Tablet PCs in Engineering Mathematics Courses at the J.B. Speed School of Engineering

ERIC Educational Resources Information Center

Hieb, Jeffrey L.; Ralston, Patricia A. S.

2010-01-01

In fall 2007, J.B. Speed School of Engineering at the University of Louisville joined the ranks of universities requiring the purchase of Tablet PCs for all new entering students. This article presents a description of how the Department of Engineering Fundamentals incorporated Tablet PCs into their instruction, a review of the literature…

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine. V; Combustion-Chamber Characteristics

NASA Technical Reports Server (NTRS)

Gensenheyner, Robert M.; Berdysz, Joseph J.

1947-01-01

An investigation to determine the performance and operational characteristics of the TG-1OOA gas turbine-propeller engine was conducted in the Cleveland altitude wind tunnel. As part of this investigation, the combustion-chamber performance was determined at pressure altitudes from 5000 to 35,000 feet, compressor-inlet rm-pressure ratios of 1.00 and 1.09, and engine speeds from 8000 to 13,000 rpm. Combustion-chamber performance is presented as a function of corrected engine speed and.correcte& horsepower. For the range of corrected engine speeds investigated, over-all total-pressure-loss ratio, cycle efficiency, ana the frac%ional loss in cycle efficiency resulting from pressure losses in the combustion chambers were unaffected by a change in altitude or compressor-inlet ram-pressure ratio. The scatter of combustion- efficiency data tended to obscure any effect of altitude or ram-pressure ratio. For the range of corrected horse-powers investigated, the total-pressure-loss ratio an& the fractional loss in cycle efficiency resulting from pressure losses in the combustion chambers decreased with an increase in corrected horsepower at a constant corrected engine speed. The combustion efficiency remained constant for the range of corrected horse-powers investigated at all corrected engine speeds.

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

40 CFR 92.116 - Engine output measurement system calibrations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... calibration. (1) The engine flywheel torque and engine speed measurement transducers shall be calibrated with... performed with the dynamometer operating at a constant speed. The flywheel torque measurement device readout... practice requires that both devices have approximately equal useful ranges of torque measurement.) The...

Performance potential of an advanced technology Mach 3 turbojet engine installed on a conceptual high-speed civil transport

NASA Technical Reports Server (NTRS)

Morris, Shelby J., Jr.; Geiselhart, Karl A.; Coen, Peter G.

1989-01-01

The performance of an advanced technology conceptual turbojet optimized for a high-speed civil aircraft is presented. This information represents an estimate of performance of a Mach 3 Brayton (gas turbine) cycle engine optimized for minimum fuel burned at supersonic cruise. This conceptual engine had no noise or environmental constraints imposed upon it. The purpose of this data is to define an upper boundary on the propulsion performance for a conceptual commercial Mach 3 transport design. A comparison is presented demonstrating the impact of the technology proposed for this conceptual engine on the weight and other characteristics of a proposed high-speed civil transport. This comparison indicates that the advanced technology turbojet described could reduce the gross weight of a hypothetical Mach 3 high-speed civil transport design from about 714,000 pounds to about 545,000 pounds. The aircraft with the baseline engine and the aircraft with the advanced technology engine are described.

Dynamic Testing of the NASA Hypersonic Project Combined Cycle Engine Testbed for Mode Transition Experiments

NASA Technical Reports Server (NTRS)

2011-01-01

NASA is interested in developing technology that leads to more routine, safe, and affordable access to space. Access to space using airbreathing propulsion systems has potential to meet these objectives based on Airbreathing Access to Space (AAS) system studies. To this end, the NASA Fundamental Aeronautics Program (FAP) Hypersonic Project is conducting fundamental research on a Turbine Based Combined Cycle (TBCC) propulsion system. The TBCC being studied considers a dual flow-path inlet system. One flow-path includes variable geometry to regulate airflow to a turbine engine cycle. The turbine cycle provides propulsion from take-off to supersonic flight. The second flow-path supports a dual-mode scramjet (DMSJ) cycle which would be initiated at supersonic speed to further accelerate the vehicle to hypersonic speed. For a TBCC propulsion system to accelerate a vehicle from supersonic to hypersonic speed, a critical enabling technology is the ability to safely and effectively transition from the turbine to the DMSJ-referred to as mode transition. To experimentally test methods of mode transition, a Combined Cycle Engine (CCE) Large-scale Inlet testbed was designed with two flow paths-a low speed flow-path sized for a turbine cycle and a high speed flow-path designed for a DMSJ. This testbed system is identified as the CCE Large-Scale Inlet for Mode Transition studies (CCE-LIMX). The test plan for the CCE-LIMX in the NASA Glenn Research Center (GRC) 10- by 10-ft Supersonic Wind Tunnel (10x10 SWT) is segmented into multiple phases. The first phase is a matrix of inlet characterization (IC) tests to evaluate the inlet performance and establish the mode transition schedule. The second phase is a matrix of dynamic system identification (SysID) experiments designed to support closed-loop control development at mode transition schedule operating points for the CCE-LIMX. The third phase includes a direct demonstration of controlled mode transition using a closed loop control system developed with the data obtained from the first two phases. Plans for a fourth phase include mode transition experiments with a turbine engine. This paper, focusing on the first two phases of experiments, presents developed operational and analysis tools for streamlined testing and data reduction procedures.

Design and Test of Fan/Nacelle Models Quiet High-Speed Fan

NASA Technical Reports Server (NTRS)

Miller, Christopher J. (Technical Monitor); Weir, Donald

2003-01-01

The Quiet High-Speed Fan program is a cooperative effort between Honeywell Engines & Systems (formerly AlliedSignal Engines & Systems) and the NASA Glenn Research Center. Engines & Systems has designed an advanced high-speed fan that will be tested on the Ultra High Bypass Propulsion Simulator in the NASA Glenn 9 x 15 foot wind tunnel, currently scheduled for the second quarter of 2000. An Engines & Systems modern fan design will be used as a baseline. A nacelle model is provided that is characteristic of a typical, modern regional aircraft nacelle and meets all of the program test objectives.

Quiet Clean Short-haul Experimental Engine (QCSEE) main reduction gears detailed design report

NASA Technical Reports Server (NTRS)

Defeo, A.; Kulina, M.

1977-01-01

Lightweight turbine engines with geared slower speed fans are considered. The design of two similar but different gear ratio, minimum weight, epicyclic star configuration main reduction gears for the under the wing (UTW) and over the wing (OTW) engines is discussed. The UTW engine reduction gear has a ratio of 2.465:1 and a 100% power design rating of 9885 kW (13,256 hp) at 3143 rpm fan speed. The OTW engine reduction gear has a ratio of 2.062:1 and a 100% power design rating of 12813 kW (17183 hp) at 3861 rpm fan speed. Details of configuration, stresses, deflections, and lubrication are presented.

Combat aircraft noise

NASA Astrophysics Data System (ADS)

Sgarbozza, M.; Depitre, A.

1992-04-01

A discussion of the characteristics and the noise levels of combat aircraft and of a transport aircraft in taking off and landing are presented. Some methods of noise reduction are discussed, including the following: operational anti-noise procedures; and concepts of future engines (silent post-combustion and variable cycle). Some measurement results concerning the noise generated in flight at great speeds and low altitude will also be examined. Finally, the protection of the environment of French air bases against noise will be described and the possibilities of regulation examined.

Electric scooter pilot project

NASA Astrophysics Data System (ADS)

Slanina, Zdenek; Dedek, Jan; Golembiovsky, Matej

2016-09-01

This article describes the issue of electric scooter development for educational and demonstration purposes on the Technical University of Ostrava. Electric scooter is equipped with a brushless motor with permanent magnets and engine controller, measuring and monitoring system for speed regulation, energy flow control and both online and off-line data analysis, visualization system for real-time diagnostics and battery management with balancing modules system. Implemented device brings a wide area for the following scientific research. This article also includes some initial test results and electric vehicles experiences.

High Specific Stiffness Shafts and Advanced Bearing Coatings for Gas Turbine Engines Final Report CRADA No. TC-1089-95

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barbee, Troy; Chin, Herbert

At the time of the CRADA, the largest in-service gas-turbine aircraft engines strove for increased thrust and power density to meet the requirements for take-off thrust, given the increase in take-off gross weight (TOGW) associated with longer range transport requirements. The trend in modem turbo shaft engines was toward turbine shafts with higher and higher length-to-diameter ratios, which reduced the shaft critical speed. Using co nventional shaft materials, this lead to shafts that needed to operate near or above sensitive shaft bending critical speeds, therefore requiring multiple bearings and/ or multiple squeeze-film dampers to control the dynamic response. Using newmore » materials and d esign concepts this project demonstrated the use of new shaft materials which could provide increased shaft speed range above existing maximum engine speeds without encountering a critic al speed event and high vector deflections. This increased main shaft speed also resulted in decreased bearing life associated with lower heat dissipation and higher centrifugal forces. Thus, a limited effort was devoted to feasibility of higher performance bearing coatings to mitigate the speed effects.« less

Software and hardware complex for research and management of the separation process

NASA Astrophysics Data System (ADS)

Borisov, A. P.

2018-01-01

The article is devoted to the development of a program for studying the operation of an asynchronous electric drive using vector-algorithmic switching of windings, as well as the development of a hardware-software complex for controlling parameters and controlling the speed of rotation of an asynchronous electric drive for investigating the operation of a cyclone. To study the operation of an asynchronous electric drive, a method was used in which the average value of flux linkage is found and a method for vector-algorithmic calculation of the power and electromagnetic moment of an asynchronous electric drive feeding from a single-phase network is developed, with vector-algorithmic commutation, and software for calculating parameters. The software part of the complex allows to regulate the speed of rotation of the motor by vector-algorithmic switching of transistors or, using pulse-width modulation (PWM), set any engine speed. Also sensors are connected to the hardware-software complex at the inlet and outlet of the cyclone. The developed cyclone with an inserted complex allows to receive high efficiency of product separation at various entrance speeds. At an inlet air speed of 18 m / s, the cyclone’s maximum efficiency is achieved. For this, it is necessary to provide the rotational speed of an asynchronous electric drive with a frequency of 45 Hz.

Double-reed exhaust valve engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, Charles L.

An engine based on a reciprocating piston engine that extracts work from pressurized working fluid. The engine includes a double reed outlet valve for controlling the flow of low-pressure working fluid out of the engine. The double reed provides a stronger force resisting closure of the outlet valve than the force tending to open the outlet valve. The double reed valve enables engine operation at relatively higher torque and lower efficiency at low speed, with lower torque, but higher efficiency at high speed.

A Comparative Propulsion System Analysis for the High-Speed Civil Transport

NASA Technical Reports Server (NTRS)

Berton, Jeffrey J.; Haller, William J.; Senick, Paul F.; Jones, Scott M.; Seidel, Jonathan A.

2005-01-01

Six of the candidate propulsion systems for the High-Speed Civil Transport are the turbojet, turbine bypass engine, mixed flow turbofan, variable cycle engine, Flade engine, and the inverting flow valve engine. A comparison of these propulsion systems by NASA's Glenn Research Center, paralleling studies within the aircraft industry, is presented. This report describes the Glenn Aeropropulsion Analysis Office's contribution to the High-Speed Research Program's 1993 and 1994 propulsion system selections. A parametric investigation of each propulsion cycle's primary design variables is analytically performed. Performance, weight, and geometric data are calculated for each engine. The resulting engines are then evaluated on two airframer-derived supersonic commercial aircraft for a 5000 nautical mile, Mach 2.4 cruise design mission. The effects of takeoff noise, cruise emissions, and cycle design rules are examined.

75 FR 65399 - Petition for Waiver of Compliance

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-22

... determination that the engineering principles used in its design of its Continuous Speed Control Yard located at... states that the design elements of the Continuous Speed Control System meets American Railway Engineering... Section 2.4 of the AREMA Manual for Railway Engineering. UP also states that the design of Roseville yard...

49 CFR 213.305 - Designation of qualified individuals; general qualifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... college level engineering program, supplemented by special on the job training emphasizing the techniques... of high speed track provided by the employer or by a college level engineering program, supplemented... maintenance of high speed track provided by the employer or by a college level engineering program...

49 CFR 213.305 - Designation of qualified individuals; general qualifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... college level engineering program, supplemented by special on the job training emphasizing the techniques... of high speed track provided by the employer or by a college level engineering program, supplemented... maintenance of high speed track provided by the employer or by a college level engineering program...

49 CFR 213.305 - Designation of qualified individuals; general qualifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... college level engineering program, supplemented by special on the job training emphasizing the techniques... of high speed track provided by the employer or by a college level engineering program, supplemented... maintenance of high speed track provided by the employer or by a college level engineering program...

40 CFR Appendix III to Part 1042 - Not-to-Exceed Zones

Code of Federal Regulations, 2011 CFR

2011-07-01

... marine engines used with controllable-pitch propellers or with electrically coupled propellers, as... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Pt. 1042... (or at Maximum Test Torque for constant-speed engines). (2) Percent speed means the percentage of...

40 CFR Appendix III to Part 1042 - Not-to-Exceed Zones

Code of Federal Regulations, 2010 CFR

2010-07-01

... marine engines used with controllable-pitch propellers or with electrically coupled propellers, as... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Pt. 1042... (or at Maximum Test Torque for constant-speed engines). (2) Percent speed means the percentage of...

40 CFR Appendix III to Part 1042 - Not-to-Exceed Zones

Code of Federal Regulations, 2014 CFR

2014-07-01

... marine engines used with controllable-pitch propellers or with electrically coupled propellers, as... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Pt. 1042... (or at Maximum Test Torque for constant-speed engines). (2) Percent speed means the percentage of...

40 CFR Appendix III to Part 1042 - Not-to-Exceed Zones

Code of Federal Regulations, 2013 CFR

2013-07-01

... marine engines used with controllable-pitch propellers or with electrically coupled propellers, as... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Pt. 1042... (or at Maximum Test Torque for constant-speed engines). (2) Percent speed means the percentage of...

40 CFR Appendix III to Part 1042 - Not-to-Exceed Zones

Code of Federal Regulations, 2012 CFR

2012-07-01

... marine engines used with controllable-pitch propellers or with electrically coupled propellers, as... CONTROLS CONTROL OF EMISSIONS FROM NEW AND IN-USE MARINE COMPRESSION-IGNITION ENGINES AND VESSELS Pt. 1042... (or at Maximum Test Torque for constant-speed engines). (2) Percent speed means the percentage of...

14 CFR 23.149 - Minimum control speed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Minimum control speed. 23.149 Section 23... Maneuverability § 23.149 Minimum control speed. (a) VMC is the calibrated airspeed at which, when the critical engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine...

Vibration measurements of automobile catalyst

NASA Astrophysics Data System (ADS)

Aatola, Seppo

1994-09-01

Vibration of catalyst cell, which is inside the casing of the catalyst, is difficult to measure with usual measuring instrumentation. When catalyst is in use, there is hot exhaust gas flow though the catalyst cell and temperature of the cell is approximately +900 degree(s)C. Therefore non-contact Laser- Doppler-Vibrometer was used to measure vibration velocity of the catalyst cell. The laser beam was directed towards the cell through pipe which was put through and welded to the casing of the catalyst. The outer end of the pipe was screw down with a tempered class to prevent exhaust gas flow from the pipe. The inner end of the pipe was open and few millimeters away from the measuring point. Catalyst was attached to the engine with two ways, rigidly close to the engine and flexible under the engine. The engine was running in test bench under controlled conditions. Vibration measurements were carried out during constant running speeds of the engine. Vibration signals were captured and analyzed with FFT-analyzer. Vibration of catalyst cell was strongest at running speed of 5000 rpm, from 10 to 20 g (1 g equals 9.81 ms-2), when catalyst was attached rigidly close to the engine. At running speed of 3000 rpm, vibration of catalyst cell was from 2 to 3 g in most cases, when catalyst was attached either rigidly or flexible to the engine. It is estimated that in real life, i.e. when catalyst is attached to car with same engine, vibration of catalyst cell at running speed of 5000 rpm is somewhere between 1 and 10 g. At running speed of 3000 rpm, which may be more often used when driving car (car speed approximately 100 kmh-1), vibration of catalyst cell is probably few g's.

Carbonyl compound emissions from a heavy-duty diesel engine fueled with diesel fuel and ethanol-diesel blend.

PubMed

Song, Chonglin; Zhao, Zhuang; Lv, Gang; Song, Jinou; Liu, Lidong; Zhao, Ruifen

2010-05-01

This paper presents an investigation of the carbonyl emissions from a direct injection heavy-duty diesel engine fueled with pure diesel fuel (DF) and blended fuel containing 15% by volume of ethanol (E/DF). The tests have been conducted under steady-state operating conditions at 1200, 1800, 2600 rpm and idle speed. The experimental results show that acetaldehyde is the most predominant carbonyl, followed by formaldehyde, acrolein, acetone, propionaldehyde and crotonaldehyde, produced from both fuels. The emission factors of total carbonyls vary in the range 13.8-295.9 mg(kWh)(-1) for DF and 17.8-380.2mg(kWh)(-1) for E/DF, respectively. The introduction of ethanol into diesel fuel results in a decrease in acrolein emissions, while the other carbonyls show general increases: at low engine speed (1200 rpm), 0-55% for formaldehyde, 4-44% for acetaldehyde, 38-224% for acetone, and 5-52% for crotonaldehyde; at medium engine speed (1800 rpm), 106-413% for formaldehyde, 4-143% for acetaldehyde, 74-113% for acetone, 114-1216% for propionaldehyde, and 15-163% for crotonaldehyde; at high engine speed (2600 rpm), 36-431% for formaldehyde, 18-61% for acetaldehyde, 22-241% for acetone, and 6-61% for propionaldehyde. A gradual reduction in the brake specific emissions of each carbonyl compound from both fuels is observed with increase in engine load. Among three levels of engine speed employed, both DF and E/DF emit most CBC emissions at high engine speed. On the whole, the presence of ethanol in diesel fuel leads to an increase in aldehyde emissions. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

DOE Office of Scientific and Technical Information (OSTI.GOV)

Izzuddin, Nur; Sunarsih,; Priyanto, Agoes

As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the targetmore » vessel’s speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.« less

Flow and pressure regulation in the cardiovascular system. [engineering systems model

NASA Technical Reports Server (NTRS)

Iberall, A.

1974-01-01

Principles and descriptive fragments which may contribute to a model of the regulating chains in the cardiovascular system are presented. Attention is given to the strain sensitivity of blood vessels, the law of the autonomy of the heart beat oscillator, the law of the encapsulation of body fluids, the law of the conservation of protein, the law of minimum 'arterial' pressure, the design of the 'mammalian' kidney, questions of homeokinetic organization, and the development of self-regulatory chains. Details concerning the development program for the heart muscle are considered along with the speed of response of the breathing rate and the significance of the pulmonary vascular pressure-flow characteristics.

RNA search engines empower the bacterial intranet.

PubMed

Dendooven, Tom; Luisi, Ben F

2017-08-15

RNA acts not only as an information bearer in the biogenesis of proteins from genes, but also as a regulator that participates in the control of gene expression. In bacteria, small RNA molecules (sRNAs) play controlling roles in numerous processes and help to orchestrate complex regulatory networks. Such processes include cell growth and development, response to stress and metabolic change, transcription termination, cell-to-cell communication, and the launching of programmes for host invasion. All these processes require recognition of target messenger RNAs by the sRNAs. This review summarizes recent results that have provided insights into how bacterial sRNAs are recruited into effector ribonucleoprotein complexes that can seek out and act upon target transcripts. The results hint at how sRNAs and their protein partners act as pattern-matching search engines that efficaciously regulate gene expression, by performing with specificity and speed while avoiding off-target effects. The requirements for efficient searches of RNA patterns appear to be common to all domains of life. © 2017 The Author(s).

RNA search engines empower the bacterial intranet

PubMed Central

Dendooven, Tom

2017-01-01

RNA acts not only as an information bearer in the biogenesis of proteins from genes, but also as a regulator that participates in the control of gene expression. In bacteria, small RNA molecules (sRNAs) play controlling roles in numerous processes and help to orchestrate complex regulatory networks. Such processes include cell growth and development, response to stress and metabolic change, transcription termination, cell-to-cell communication, and the launching of programmes for host invasion. All these processes require recognition of target messenger RNAs by the sRNAs. This review summarizes recent results that have provided insights into how bacterial sRNAs are recruited into effector ribonucleoprotein complexes that can seek out and act upon target transcripts. The results hint at how sRNAs and their protein partners act as pattern-matching search engines that efficaciously regulate gene expression, by performing with specificity and speed while avoiding off-target effects. The requirements for efficient searches of RNA patterns appear to be common to all domains of life. PMID:28710287

CooLN2Car: An Experimental Car Which Uses Liquid Nitrogen as Its Fuel

NASA Astrophysics Data System (ADS)

Parker, M. E.; Plummer, M. C.; Ordonez, C. A.

1997-10-01

A ``cryogenic" heat engine which operates using the atmosphere as a heat source and a cryogenic medium as a heat sink has been incorporated as the power system for an automobile. A 1973 Volkswagen Beetle has been converted and uses liquid nitrogen as its ``fuel." A Dewar was mounted in the car and provides nitrogen under pressure to two heat exchangers connected in parallel which use atmospheric heat to heat the nitrogen. The heat exchangers deliver compressed nitrogen gas to a vane-type pneumatic motor mounted in place of the original gasoline engine. Pressure in the tank is maintained internally at 1.2 MPa and is reduced to 0.7 MPa before the motor by a pressure regulator. A throttle, composed of a butterfly valve, is mounted between the regulator and the motor and is connected to the driver's accelerator peddle. The vehicle has good acceleration, a maximum range of 15 miles, and a maximum speed of 25 mph. A demonstration with the vehicle is planned.

Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiuchi, T.; Sakurai, H.

1988-09-20

This patent describes an apparatus for controlling the solenoid current of a solenoid valve which controls suction air in an internal combustion engine. The apparatus consists of: (a) engine rotational speed detector means for detecting engine rotational speed; (b) aimed idle speed setting means for generating a signal corresponding to a predetermined idling speed; (c) first calculating means coupled to the engine rotational speed detector means and the aimed idle speed setting means for calculating a feedback control term (Ifb(n)) as a function of an integration term (Iai), a proportion term (Ip), and a differentiation term (Id); (d) first determiningmore » and storing means coupled to the first calculating means, for determining an integration term (Iai(n)) of the the feedback control term (Ifb(n)) and for determining a determined value (Ixref) in accordance therewith; (e) changeover means coupled to the first calculating means and the first determining and storing means for selecting the output of one of the first calculating means or the first determining and storing means; (f) first signal generating means coupled to the changeover means for generating a solenoid current control value (Icmd) as a function of the output of the changeover means.« less

Method and apparatus for controlling the solenoid current of a solenoid valve which controls the amount of suction of air in an internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kiuchi, T.; Yasuoka, A.

1988-09-13

This patent describes apparatus for controlling the solenoid current of a selenoid valve which controls the amount of suction air in an internal combustion engine, the apparatus comprising: (a) engine rotational speed detector means for detecting engine rotational speed; (b) aimed idle speed setting means for generating a signal corresponding to a predetermined idling speed; (c) first calculating means coupled to the engine rotational speed detector means and the aimed idle speed setting means for calculating a feedback control term Ifb(n) as a function of an integration term (Iai), a proportion term (Ip), and a differentiation term (Id); (d) firstmore » determining and storing means coupled to the first calculating means, for determining an integration term (Iai(n)) of the feedback control term (Ifb(n)) and for determining a determined value (Ixref) in accordance therewith; (e) changeover means coupled to the first calculating means and the first determining and storing means for selecting the output of one of the first calculating means or the first determining and storing means; (f) first signal generating means coupled to the changeover means for generating a solenoid current control value (Icmd) as a function of the output of the changeover.« less

Super Turbocharging the Direct Injection Diesel engine

NASA Astrophysics Data System (ADS)

Boretti, Albert

2018-03-01

The steady operation of a turbocharged diesel direct injection (TDI) engine featuring a variable speed ratio mechanism linking the turbocharger shaft to the crankshaft is modelled in the present study. Key parameters of the variable speed ratio mechanism are range of speed ratios, efficiency and inertia, in addition to the ability to control relative speed and flow of power. The device receives energy from, or delivers energy to, the crankshaft or the turbocharger. In addition to the pistons of the internal combustion engine (ICE), also the turbocharger thus contributes to the total mechanical power output of the engine. The energy supply from the crankshaft is mostly needed during sharp accelerations to avoid turbo-lag, and to boost torque at low speeds. At low speeds, the maximum torque is drastically improved, radically expanding the load range. Additionally, moving closer to the points of operation of a balanced turbocharger, it is also possible to improve both the efficiency η, defined as the ratio of the piston crankshaft power to the fuel flow power, and the total efficiency η*, defined as the ratio of piston crankshaft power augmented of the power from the turbocharger shaft to the fuel flow power, even if of a minimal extent. The energy supply to the crankshaft is possible mostly at high speeds and high loads, where otherwise the turbine could have been waste gated, and during decelerations. The use of the energy at the turbine otherwise waste gated translates in improvements of the total fuel conversion efficiency η* more than the efficiency η. Much smaller improvements are obtained for the maximum torque, yet again moving closer to the points of operation of a balanced turbocharger. Adopting a much larger turbocharger (target displacement x speed 30% larger than a conventional turbocharger), better torque outputs and fuel conversion efficiencies η* and η are possible at every speed vs. the engine with a smaller, balanced turbocharger. This result motivates further studies of the mechanism that may considerably benefit traditional powertrains based on diesel engines.

Aircraft dual-shaft jet engine with indirect action fuel flow controller

NASA Astrophysics Data System (ADS)

Tudosie, Alexandru-Nicolae

2017-06-01

The paper deals with an aircraft single-jet engine's control system, based on a fuel flow controller. Considering the engine as controlled object and its thrust the most important operation effect, from the multitude of engine's parameters only its rotational speed n is measurable and proportional to its thrust, so engine's speed has become the most important controlled parameter. Engine's control system is based on fuel injection Qi dosage, while the output is engine's speed n. Based on embedded system's main parts' mathematical models, the author has described the system by its block diagram with transfer functions; furthermore, some Simulink-Matlab simulations are performed, concerning embedded system quality (its output parameters time behavior) and, meanwhile, some conclusions concerning engine's parameters mutual influences are revealed. Quantitative determinations are based on author's previous research results and contributions, as well as on existing models (taken from technical literature). The method can be extended for any multi-spool engine, single- or twin-jet.

A Retro-Fit Control Architecture to Maintain Engine Performance With Usage

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Sowers, T. Shane; Garg, Sanjay

2007-01-01

An outer loop retrofit engine control architecture is presented which modifies fan speed command to obtain a desired thrust based on throttle position. This maintains the throttle-to-thrust relationship in the presence of engine degradation, which has the effect of changing the engine s thrust output for a given fan speed. Such an approach can minimize thrust asymmetry in multi-engine aircraft, and reduce pilot workload. The outer loop control is demonstrated under various levels of engine deterioration using a standard deterioration profile as well as an atypical profile. It is evaluated across various transients covering a wide operating range. The modified fan speed command still utilizes the standard engine control logic so all original life and operability limits remain in place. In all cases it is shown that with the outer loop thrust control in place, the deteriorated engine is able to match the thrust performance of a new engine up to the limits the controller will allow.

Feasibility study for convertible engine torque converter

NASA Technical Reports Server (NTRS)

1985-01-01

The feasibility study has shown that a dump/fill type torque converter has excellent potential for the convertible fan/shaft engine. The torque converter space requirement permits internal housing within the normal flow path of a turbofan engine at acceptable engine weight. The unit permits operating the engine in the turboshaft mode by decoupling the fan. To convert to turbofan mode, the torque converter overdrive capability bring the fan speed up to the power turbine speed to permit engagement of a mechanical lockup device when the shaft speed are synchronized. The conversion to turbofan mode can be made without drop of power turbine speed in less than 10 sec. Total thrust delivered to the aircraft by the proprotor, fan, and engine during tansient can be controlled to prevent loss of air speed or altitude. Heat rejection to the oil is low, and additional oil cooling capacity is not required. The turbofan engine aerodynamic design is basically uncompromised by convertibility and allows proper fan design for quiet and efficient cruise operation. Although the results of the feasibility study are exceedingly encouraging, it must be noted that they are based on extrapolation of limited existing data on torque converters. A component test program with three trial torque converter designs and concurrent computer modeling for fluid flow, stress, and dynamics, updated with test results from each unit, is recommended.

Experimental Comparison of Speed : Fuel-flow and Speed-area Controls on a Turbojet Engine for Small Step Disturbances

NASA Technical Reports Server (NTRS)

Wenzel, L M; Hart, C E; Craig, R T

1957-01-01

Optimum proportional-plus-integral control settings for speed - fuel-flow control, determined by minimization of integral criteria, correlated well with analytically predicted optimum settings. Engine response data are given for a range of control settings around the optimum. An inherent nonlinearity in the speed-area loop necessitated the use of nonlinear controls. Response data for two such nonlinear control schemes are presented.

Preliminary Assessment of Variable Speed Power Turbine Technology on Civil Tiltrotor Size and Performance

NASA Technical Reports Server (NTRS)

Snyder, Christopher A.; Acree, Cecil W., Jr.

2012-01-01

A Large Civil Tiltrotor (LCTR) conceptual design was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing capability. This paper performs a preliminary assessment of variable-speed power turbine technology on LCTR2 sizing, while maintaining the same, advanced technology engine core. Six concepts were studied; an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE) using a multi-speed (shifting) gearbox. There were five variable-speed power turbine (VSPT) engine concepts, comprising a matrix of either three or four turbine stages, and fixed or variable guide vanes; plus a minimum weight, twostage, fixed-geometry VSPT. The ACE is the lightest engine, but requires a multi-speed (shifting) gearbox to maximize its fuel efficiency, whereas the VSPT concepts use a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle gross and empty weight, propulsion system weight and mission fuel burn for the civil mission. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. Major study assumptions are presented and discussed. Impressive engine power-to-weight and fuel efficiency reduced vehicle sensitivity to propulsion system choice. The 10% weight penalty for multi-speed gearbox was more significant than most engine technology weight penalties to the vehicle design because drive system weight is more than two times engine weight. Based on study assumptions, fixed-geometry VSPT concept options performed better than their variable-geometry counterparts. Optimum design gross weights varied 1% or less and empty weights less than 2% among the concepts studied, while optimum fuel burns varied up to 5%. The outcome for some optimum configurations was so unexpected as to recommend a deeper look at the underlying technology assumptions.

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. I - Pressure and Temperature Distributions

NASA Technical Reports Server (NTRS)

Prince, William R.; Hawkins, W. Kent

1947-01-01

Pressures and temperatures throughout the X24C-4B turbojet engine are presented in both tabular and graphical forms to show the effect of altitude, flight Mach number, and engine speed on the internal operation of the engine. These data were obtained in the NACA Cleveland altitude wind tunnel at simulated altitudes from 5000 to 45,000 feet, simulated flight Mach numbers from 0.25 to 1.08, and engine speeds from 4000 to 12,500 rpm. Location and detail drawings of the instrumentation installed at seven survey stations in the engine are shown. Application of generalization factors to pressures and temperatures at each measuring station for the range of altitudes investigated showed that the data did not generalize above an altitude of 25,000 feet. Total-pressure distribution at the compressor outlet varied only with change in engine speed. At altitudes above 35,000 feet and engine speeds above 11,000 rpm, the peak temperature at the turbine-outlet annulus moved inward toward the root of the blade, which is undesirable from blade-stress considerations. The temperature levels at the turbine outlet and the exhaust-nozzle outlet were lowered as the Mach number was increased. The static-pressure measurements obtained at each stator stage of the compressor showed a pressure drop through the inlet guide vanes and the first-stage rotor at high engine speeds. The average values measured by the manufacturer's instrumentation werein close agreement with the average values obtained with NACA instrumentation.

Altitude Performance of Annular Combustor Type Turbojet Engine with JFC-2 Fuel /james W. Useller, James L. Harp, Jr. and Zelmar Barson

NASA Technical Reports Server (NTRS)

Useller, James W; Harp, James L JR; Barson, Zelmar

1952-01-01

An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or low-speed combustiion blow-out characteristics of the two fuels. Turbine-discharge radial temperature profiles were nearly the same at altitudes up to 35,000 feet.

A comparative evaluation on the emission characteristics of ceramic and metallic catalytic converter in internal combustion engine

NASA Astrophysics Data System (ADS)

Leman, A. M.; Jajuli, Afiqah; Rahman, Fakhrurrazi; Feriyanto, Dafit; Zakaria, Supaat

2017-09-01

Enforcement of a stricter regulation on exhaust emission by many countries has led to utilization of catalytic converter to reduce the harmful pollutant emission. Ceramic and metallic catalytic converters are the most common type of catalytic converter used. The purpose of this study is to evaluate the performance of the ceramic and metallic catalytic converter on its conversion efficiency using experimental measurement. Both catalysts were placed on a modified exhaust system equipped with a Mitshubishi 4G93 single cylinder petrol engine that was tested on an eddy current dynamometer under steady state conditions for several engine speeds. The experimental results show that the metallic catalytic converter reduced a higher percentage of CO up to 98.6% reduction emissions while ceramic catalytic converter had a better reduction efficiency of HC up to 85.4% and 87.2% reduction of NOx.

Friction of Compression-ignition Engines

NASA Technical Reports Server (NTRS)

Moore, Charles S; Collins, John H , Jr

1936-01-01

The cost in mean effective pressure of generating air flow in the combustion chambers of single-cylinder compression-ignition engines was determined for the prechamber and the displaced-piston types of combustion chamber. For each type a wide range of air-flow quantities, speeds, and boost pressures was investigated. Supplementary tests were made to determine the effect of lubricating-oil temperature, cooling-water temperature, and compression ratio on the friction mean effective pressure of the single-cylinder test engine. Friction curves are included for two 9-cylinder, radial, compression-ignition aircraft engines. The results indicate that generating the optimum forced air flow increased the motoring losses approximately 5 pounds per square inch mean effective pressure regardless of chamber type or engine speed. With a given type of chamber, the rate of increase in friction mean effective pressure with engine speed is independent of the air-flow speed. The effect of boost pressure on the friction cannot be predicted because the friction was decreased, unchanged, or increased depending on the combustion-chamber type and design details. High compression ratio accounts for approximately 5 pounds per square inch mean effective pressure of the friction of these single-cylinder compression-ignition engines. The single-cylinder test engines used in this investigation had a much higher friction mean effective pressure than conventional aircraft engines or than the 9-cylinder, radial, compression-ignition engines tested so that performance should be compared on an indicated basis.

40 CFR 91.305 - Dynamometer specifications and calibration accuracy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... specifications. (1) The dynamometer test stand and other instruments for measurement of engine speed and torque... accuracy. (1) The dynamometer test stand and other instruments for measurement of engine torque and speed...

40 CFR 91.305 - Dynamometer specifications and calibration accuracy.

Code of Federal Regulations, 2014 CFR

2014-07-01

... specifications. (1) The dynamometer test stand and other instruments for measurement of engine speed and torque... accuracy. (1) The dynamometer test stand and other instruments for measurement of engine torque and speed...

40 CFR 91.305 - Dynamometer specifications and calibration accuracy.

Code of Federal Regulations, 2013 CFR

2013-07-01

... specifications. (1) The dynamometer test stand and other instruments for measurement of engine speed and torque... accuracy. (1) The dynamometer test stand and other instruments for measurement of engine torque and speed...

40 CFR 91.305 - Dynamometer specifications and calibration accuracy.

Code of Federal Regulations, 2010 CFR

2010-07-01

... specifications. (1) The dynamometer test stand and other instruments for measurement of engine speed and torque... accuracy. (1) The dynamometer test stand and other instruments for measurement of engine torque and speed...

40 CFR 91.305 - Dynamometer specifications and calibration accuracy.

Code of Federal Regulations, 2012 CFR

2012-07-01

... specifications. (1) The dynamometer test stand and other instruments for measurement of engine speed and torque... accuracy. (1) The dynamometer test stand and other instruments for measurement of engine torque and speed...

40 CFR 1039.505 - How do I test engines using steady-state duty cycles, including ramped-modal testing?

Code of Federal Regulations, 2013 CFR

2013-07-01

.... You may extend the sampling time to improve measurement accuracy of PM emissions, using good..., you may omit speed, torque, and power points from the duty-cycle regression statistics if the... mapped. (2) For variable-speed engines without low-speed governors, you may omit torque and power points...

40 CFR 1039.505 - How do I test engines using steady-state duty cycles, including ramped-modal testing?

Code of Federal Regulations, 2012 CFR

2012-07-01

.... You may extend the sampling time to improve measurement accuracy of PM emissions, using good..., you may omit speed, torque, and power points from the duty-cycle regression statistics if the... mapped. (2) For variable-speed engines without low-speed governors, you may omit torque and power points...

AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT VI, MAINTAINING MECHANICAL GOVERNORS--DETROIT DIESEL ENGINES.

ERIC Educational Resources Information Center

Human Engineering Inst., Cleveland, OH.

THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF MECHANICAL GOVERNORS USED ON DIESEL ENGINES. TOPICS ARE (1) TYPES OF GOVERNORS AND ENGINE LOCATION, (2) GOVERNOR APPLICATIONS, (3) LIMITING SPEED MECHANICAL GOVERNOR, (4) VARIABLE SPEED MECHANICAL GOVERNOR, AND (5) CONSTANT SPEED…

Regulated and unregulated emissions from a diesel engine fueled with biodiesel and biodiesel blended with methanol

NASA Astrophysics Data System (ADS)

Cheung, C. S.; Zhu, Lei; Huang, Zhen

Experiments were carried out on a diesel engine operating on Euro V diesel fuel, pure biodiesel and biodiesel blended with methanol. The blended fuels contain 5%, 10% and 15% by volume of methanol. Experiments were conducted under five engine loads at a steady speed of 1800 rev min -1 to assess the performance and the emissions of the engine associated with the application of the different fuels. The results indicate an increase of brake specific fuel consumption and brake thermal efficiency when the diesel engine was operated with biodiesel and the blended fuels, compared with the diesel fuel. The blended fuels could lead to higher CO and HC emissions than biodiesel, higher CO emission but lower HC emission than the diesel fuel. There are simultaneous reductions of NO x and PM to a level below those of the diesel fuel. Regarding the unregulated emissions, compared with the diesel fuel, the blended fuels generate higher formaldehyde, acetaldehyde and unburned methanol emissions, lower 1,3-butadiene and benzene emissions, while the toluene and xylene emissions not significantly different.

An investigation of the performance of an electronic in-line pump system for diesel engines

NASA Astrophysics Data System (ADS)

Fan, Li-Yun; Zhu, Yuan-Xian; Long, Wu-Qiang; Ma, Xiu-Zhen; Xue, Ying-Ying

2008-12-01

WIT Electronic Fuel System Co., Ltd. has developed a new fuel injector, the Electronic In-line Pump (EIP) system, designed to meet China’s diesel engine emission and fuel economy regulations. It can be used on marine diesel engines and commercial vehicle engines through different EIP systems. A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization. The model was used to predict key injection characteristics under different operating conditions, such as injection pressure, injection rate, and injection duration. To validate these predictions, experimental tests were conducted under the conditions that were modeled. The results were quite encouraging and in agreement with model predictions. Additional experiments were conducted to study the injection characteristics of the EIP system. These results show that injection pressure and injection quantity are insensitive to injection timing variations, this is due to the design of the constant velocity cam profile. Finally, injection quantity and pressure vs. pulse width at different cam speeds are presented, an important injection characteristic for EIP system calibration.

High-Speed Tests of a Model Twin-Engine Low-Wing Transport Airplane

NASA Technical Reports Server (NTRS)

Becker, John V; LEONARD LLOYD H

1942-01-01

Report presents the results of force tests made of a 1/8-scale model of a twin-engine low-wing transport airplane in the NACA 8-foot high-speed tunnel to investigate compressibility and interference effects of speeds up to 450 miles per hour. In addition to tests of the standard arrangement of the model, tests were made with several modifications designed to reduce the drag and to increase the critical speed.

Real-Time Aircraft Engine-Life Monitoring

NASA Technical Reports Server (NTRS)

Klein, Richard

2014-01-01

This project developed an inservice life-monitoring system capable of predicting the remaining component and system life of aircraft engines. The embedded system provides real-time, inflight monitoring of the engine's thrust, exhaust gas temperature, efficiency, and the speed and time of operation. Based upon this data, the life-estimation algorithm calculates the remaining life of the engine components and uses this data to predict the remaining life of the engine. The calculations are based on the statistical life distribution of the engine components and their relationship to load, speed, temperature, and time.

Heat engine generator control system

DOEpatents

Rajashekara, K.; Gorti, B.V.; McMullen, S.R.; Raibert, R.J.

1998-05-12

An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power. 8 figs.

Heat engine generator control system

DOEpatents

Rajashekara, Kaushik; Gorti, Bhanuprasad Venkata; McMullen, Steven Robert; Raibert, Robert Joseph

1998-01-01

An electrical power generation system includes a heat engine having an output member operatively coupled to the rotor of a dynamoelectric machine. System output power is controlled by varying an electrical parameter of the dynamoelectric machine. A power request signal is related to an engine speed and the electrical parameter is varied in accordance with a speed control loop. Initially, the sense of change in the electrical parameter in response to a change in the power request signal is opposite that required to effectuate a steady state output power consistent with the power request signal. Thereafter, the electrical parameter is varied to converge the output member speed to the speed known to be associated with the desired electrical output power.

40 CFR 90.302 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to this subpart. Intermediate speed means the engine speed which is 85 percent of the rated speed. Natural gas means a fuel whose primary constituent is methane. Rated speed means the speed at which the...

40 CFR 90.302 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... apply to this subpart. Intermediate speed means the engine speed which is 85 percent of the rated speed. Natural gas means a fuel whose primary constituent is methane. Rated speed means the speed at which the...

An assessment of the real-world driving gaseous emissions from a Euro 6 light-duty diesel vehicle using a portable emissions measurement system (PEMS)

NASA Astrophysics Data System (ADS)

Luján, José M.; Bermúdez, Vicente; Dolz, Vicente; Monsalve-Serrano, Javier

2018-02-01

Recent investigations demonstrated that real-world emissions usually exceed the levels achieved in the laboratory based type approval processes. By means of on-board emissions measurements, it has been shown that nitrogen oxides emitted by diesel engines substantially exceed the limit imposed by the Euro 6 regulation. Thus, with the aim of complementing the worldwide harmonized light vehicles test cycle, the real driving emissions cycle will be introduced after 1 September 2017 to regulate the vehicle emissions in real-world driving situations. This paper presents on-board gaseous emissions measurements from a Euro 6 light-duty diesel vehicle in a real-world driving route using a portable emissions measurement system. The test route characteristics follow the requirements imposed by the RDE regulation. The analysis of the raw emissions results suggests that the greatest amount of nitrogen oxides and nitrogen dioxide are emitted during the urban section of the test route, confirming that lower speeds with more accelerations and decelerations lead to higher nitrogen oxides emissions levels than constant high speeds. Moreover, the comparison of the two calculation methods proposed by the real driving emissions regulation has revealed emissions rates differences ranging from 10% to 45% depending on the pollutant emission and the trip section considered (urban or total). Thus, the nitrogen oxides emissions conformity factor slightly varies from one method to the other.

System Noise Assessment of Blended-Wing-Body Aircraft With Open Rotor Propulsion

NASA Technical Reports Server (NTRS)

Guo, Yueping; Thomas, Russell H.

2015-01-01

An aircraft system noise study is presented for the Blended-Wing-Body (BWB) aircraft concept with three open rotor engines mounted on the upper surface of the airframe. It is shown that for such an aircraft, the cumulative Effective Perceived Noise Level (EPNL) is about 24 dB below the current aircraft noise regulations of Stage 4. While this makes the design acoustically viable in meeting the regulatory requirements, even with the consideration of more stringent noise regulations of a possible Stage 5 in the next decade or so, the design will likely meet stiff competitions from aircraft with turbofan engines. It is shown that the noise levels of the BWB design are held up by the inherently high noise levels of the open rotor engines and the limitation on the shielding benefit due to the practical design constraint on the engine location. Furthermore, it is shown that the BWB design has high levels of noise from the main landing gear, due to their exposure to high speed flow at the junction between the center body and outer wing. These are also the reasons why this baseline BWB design does not meet the NASA N+2 noise goal of 42 dB below Stage 4. To identify approaches that may further reduce noise, parametric studies are also presented, including variations in engine location, vertical tail and elevon variations, and airframe surface acoustic liner treatment effect. These have the potential to further reduce noise but they are only at the conceptual stage.

Compressibility Effects in Aeronautical Engineering

NASA Technical Reports Server (NTRS)

Stack, John

1941-01-01

Compressible-flow research, while a relatively new field in aeronautics, is very old, dating back almost to the development of the first firearm. Over the last hundred years, researches have been conducted in the ballistics field, but these results have been of practically no use in aeronautical engineering because the phenomena that have been studied have been the more or less steady supersonic condition of flow. Some work that has been done in connection with steam turbines, particularly nozzle studies, has been of value, In general, however, understanding of compressible-flow phenomena has been very incomplete and permitted no real basis for the solution of aeronautical engineering problems in which.the flow is likely to be unsteady because regions of both subsonic and supersonic speeds may occur. In the early phases of the development of the airplane, speeds were so low that the effects of compressibility could be justifiably ignored. During the last war and immediately after, however, propellers exhibited losses in efficiency as the tip speeds approached the speed of sound, and the first experiments of an aeronautical nature were therefore conducted with propellers. Results of these experiments indicated serious losses of efficiency, but aeronautical engineers were not seriously concerned at the time became it was generally possible. to design propellers with quite low tip. speeds. With the development of new engines having increased power and rotational speeds, however, the problems became of increasing importance.

Comprehensive Modeling and Analysis of Rotorcraft Variable Speed Propulsion System With Coupled Engine/Transmission/Rotor Dynamics

NASA Technical Reports Server (NTRS)

DeSmidt, Hans A.; Smith, Edward C.; Bill, Robert C.; Wang, Kon-Well

2013-01-01

This project develops comprehensive modeling and simulation tools for analysis of variable rotor speed helicopter propulsion system dynamics. The Comprehensive Variable-Speed Rotorcraft Propulsion Modeling (CVSRPM) tool developed in this research is used to investigate coupled rotor/engine/fuel control/gearbox/shaft/clutch/flight control system dynamic interactions for several variable rotor speed mission scenarios. In this investigation, a prototypical two-speed Dual-Clutch Transmission (DCT) is proposed and designed to achieve 50 percent rotor speed variation. The comprehensive modeling tool developed in this study is utilized to analyze the two-speed shift response of both a conventional single rotor helicopter and a tiltrotor drive system. In the tiltrotor system, both a Parallel Shift Control (PSC) strategy and a Sequential Shift Control (SSC) strategy for constant and variable forward speed mission profiles are analyzed. Under the PSC strategy, selecting clutch shift-rate results in a design tradeoff between transient engine surge margins and clutch frictional power dissipation. In the case of SSC, clutch power dissipation is drastically reduced in exchange for the necessity to disengage one engine at a time which requires a multi-DCT drive system topology. In addition to comprehensive simulations, several sections are dedicated to detailed analysis of driveline subsystem components under variable speed operation. In particular an aeroelastic simulation of a stiff in-plane rotor using nonlinear quasi-steady blade element theory was conducted to investigate variable speed rotor dynamics. It was found that 2/rev and 4/rev flap and lag vibrations were significant during resonance crossings with 4/rev lagwise loads being directly transferred into drive-system torque disturbances. To capture the clutch engagement dynamics, a nonlinear stick-slip clutch torque model is developed. Also, a transient gas-turbine engine model based on first principles mean-line compressor and turbine approximations is developed. Finally an analysis of high frequency gear dynamics including the effect of tooth mesh stiffness variation under variable speed operation is conducted including experimental validation. Through exploring the interactions between the various subsystems, this investigation provides important insights into the continuing development of variable-speed rotorcraft propulsion systems.

Influence of Alternative Engine Concepts on LCTR2 Sizing and Mission Profile

NASA Technical Reports Server (NTRS)

Acree, C. W., Jr.; Snyder, Christopher A.

2012-01-01

The Large Civil Tiltrotor (LCTR) was developed as part of the NASA Heavy Lift Rotorcraft Systems Investigation in order to establish a consistent basis for evaluating the benefits of advanced technology for large tiltrotors. The concept has since evolved into the second-generation LCTR2, designed to carry 90 passengers for 1,000 nm at 300 knots, with vertical takeoff and landing. This paper examines the impact of advanced propulsion system concepts on LCTR2 sizing. Two concepts were studied: an advanced, single-speed engine with a conventional power turbine layout (Advanced Conventional Engine, or ACE), and a variable-speed power turbine engine (VSPT). The ACE is the lighter engine, but requires a multi-speed (shifting) gearbox, whereas the VSPT uses a lighter, fixed-ratio gearbox. The NASA Design and Analysis of Rotorcraft (NDARC) design code was used to study the trades between rotor and engine efficiency and weight. Rotor performance was determined by Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II), and engine performance was estimated with the Numerical Propulsion System Simulation (NPSS). Design trades for the ACE vs. VSPT are presented in terms of vehicle weight empty for variations in mission altitude and range; the effect of different One Engine Inoperative (OEI) criteria are also examined. Because of its strong effect on gearbox weight and on both rotor and engine efficiency, rotor speed was chosen as the reference design variable for comparing design trades. The two propulsion concepts had nearly identical vehicle weights and mission fuel consumption, and their relative advantages varied little with cruise altitude, mission range, or OEI criteria; high cruise altitude and low cruise tip speed were beneficial for both concepts.

Supercruiser Arrow HS-8

NASA Technical Reports Server (NTRS)

Lord, Paul; Kao, Edward; Abobo, Joey B.; Collins, Todd A.; Ma, Leong; Murad, Adnan; Naran, Hitesh; Nguyen, Thuan P.; Nuon, Timithy I.; Thomas, Dimitri D.

1992-01-01

Technology in aeronautics has advanced dramatically since the last design of a production High Speed Civil Transport (HSCT) aircraft. Newly projected requirements call for a new High Speed Civil Transport aircraft with a range of approximately 550 nm and at least 275 passenger capacity. The aircraft must be affordable and marketable. The new HSCT must be able to sustain long-duration flights and to absorb the abuse of daily operation. The new aircraft must be safe and simple to fly and require a minimum amount of maintenance. This aircraft must meet FAA certification criteria of FAR Part 25 and environmental constraints. Several design configurations were examined and two designs were selected for further investigation. The first design employs the delta planform wings and conventional empennage layout. The other design uses a swing wing layout and conventional empennage. Other engineering challenges, including materials and propulsion are also discussed. At a cruise flight speed between Mach 2.2 and Mach 3.0, no current generation of materials can endure the thermal loading of supersonic flight and satisfy the stringent weight requirements. A new generation of lightweight composite materials must be developed for the HSCT. With the enforcement of stage 3 noise restrictions, these new engines must be able to propel the aircraft and satisfy the noise limit. The engine with the most promise is the variable cycle engine. At low subsonic speeds the engine operates like a turbofan engine, providing the most efficient performance. At higher speeds the variable cycle engine operates as a turbojet power plant. The two large engine manufacturers, General Electric and Pratt & Whitney in the United States, are combining forces to make the variable cycle engine a reality.

Speed limits set lower than engineering recommendations.

DOT National Transportation Integrated Search

2016-08-01

The purpose of this project is to provide the Montana Department of Transportation (MDT) with a better understanding of the : operational and safety impacts of setting posted speed limits below engineering recommended values. This practice has been :...

Flame Acceleration and Transition to Detonation in High Speed Turbulent Combustion

DTIC Science & Technology

2016-12-21

gas mixtures and sprays is dif- ficult to overestimate, as it is the main process in all internal-combustion engines used for propulsion and energy...generation. These include piston engines, gas turbines, various types of jet engines, and some rocket engines . On the other hand , preventing high...speed combustion is critical for the safety of any human activities that involve handling of po- t entially explosive gases or volatile liquids . Thus

33 CFR 401.28 - Speed limits.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not to...

33 CFR 401.28 - Speed limits.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Speed limits. 401.28 Section 401... TRANSPORTATION SEAWAY REGULATIONS AND RULES Regulations Seaway Navigation § 401.28 Speed limits. (a) The maximum speed over the bottom for a vessel of more than 12 m in overall length shall be regulated so as not to...

Non-intrusive speed sensor. [space shuttle main engine turbopumps

NASA Technical Reports Server (NTRS)

Maram, J.; Wyett, L.

1984-01-01

A computerized literature search was performed to identify candidate technologies for remote, non-intrusive speed sensing applications in Space Shuttle Main Engine (SSME) turbopumps. The three most promising technologies were subjected to experimental evaluation to quantify their performance characteristics under the harsh environmental requirements within the turbopumps. Although the infrared and microwave approaches demonstrated excellent cavitation immunity in laboratory tests, the variable-source magnetic speed sensor emerged as the most viable approach. Preliminary design of this speed sensor encountered no technical obstacles and resulted in viable and feasible speed nut, sensor housing, and sensor coil designs.

Engineering Data on Selected High Speed Passenger Trucks

DOT National Transportation Integrated Search

1978-07-01

The purpose of this project is to compile a list of high speed truck engineering parameters for characterization in dynamic performance modeling activities. Data tabulations are supplied for trucks from France, Germany, Italy, England, Japan, U.S.S.R...

A brief review on the recent advances in scramjet engine

NASA Astrophysics Data System (ADS)

Choubey, Gautam; Pandey, K. M.; Maji, Ambarish; Deshamukhya, Tuhin

2017-07-01

The scramjet engine is the most favourable air breathing propulsive system and suitable option for high-speed flight (Ma<4). Several scientists across the globe are continuously working on the advancement of the high-speed scramjet engine due to its implementation in the military missiles, low-cost access to space etc. The mixing phenomena associated with air and fuel is the salient feature for the effective combustion process and the fuel and air should be mixed adequately before entering into the combustor. But the key challenges associated with scramjet engine are the high speed of air inside the combustor and low residence time which actually deteriorate the combustion phenomena. That's why numerous computational, as well as experimental researches are being carried out by several researchers. The flow-field inside the scramjet engine is very complex. Hence an elaborated approach of the complicated combustion and mixing process inside the combustor is essential for the upgradation of the effective scramjet engine. This paper clearly signifies a brief review of the current development in scramjet engine.

Correction of Temperatures of Air-Cooled Engine Cylinders for Variation in Engine and Cooling Conditions

NASA Technical Reports Server (NTRS)

Schey, Oscar W; Pinkel, Benjamin; Ellerbrock, Herman H , Jr

1939-01-01

Factors are obtained from semiempirical equations for correcting engine-cylinder temperatures for variation in important engine and cooling conditions. The variation of engine temperatures with atmospheric temperature is treated in detail, and correction factors are obtained for various flight and test conditions, such as climb at constant indicated air speed, level flight, ground running, take-off, constant speed of cooling air, and constant mass flow of cooling air. Seven conventional air-cooled engine cylinders enclosed in jackets and cooled by a blower were tested to determine the effect of cooling-air temperature and carburetor-air temperature on cylinder temperatures. The cooling air temperature was varied from approximately 80 degrees F. to 230 degrees F. and the carburetor-air temperature from approximately 40 degrees F. to 160 degrees F. Tests were made over a large range of engine speeds, brake mean effective pressures, and pressure drops across the cylinder. The correction factors obtained experimentally are compared with those obtained from the semiempirical equations and a fair agreement is noted.

Dynamic control of a homogeneous charge compression ignition engine

DOEpatents

Duffy, Kevin P [Metamora, IL; Mehresh, Parag [Peoria, IL; Schuh, David [Peoria, IL; Kieser, Andrew J [Morton, IL; Hergart, Carl-Anders [Peoria, IL; Hardy, William L [Peoria, IL; Rodman, Anthony [Chillicothe, IL; Liechty, Michael P [Chillicothe, IL

2008-06-03

A homogenous charge compression ignition engine is operated by compressing a charge mixture of air, exhaust and fuel in a combustion chamber to an autoignition condition of the fuel. The engine may facilitate a transition from a first combination of speed and load to a second combination of speed and load by changing the charge mixture and compression ratio. This may be accomplished in a consecutive engine cycle by adjusting both a fuel injector control signal and a variable valve control signal away from a nominal variable valve control signal. Thereafter in one or more subsequent engine cycles, more sluggish adjustments are made to at least one of a geometric compression ratio control signal and an exhaust gas recirculation control signal to allow the variable valve control signal to be readjusted back toward its nominal variable valve control signal setting. By readjusting the variable valve control signal back toward its nominal setting, the engine will be ready for another transition to a new combination of engine speed and load.

Military Hybrid Vehicle Survey

DTIC Science & Technology

2011-08-03

III Composite 4.3% Integrated starter generator for engine shut down, regenerative braking and avoidance of inefficient engine operation [28]. FMTV...eliminating the inefficiencies associated with idling, vehicle braking and low engine speed part load efficiency, many improvements can be realized...literature. They can be divided into the following two categories : (1) Time dependent speed profiles, shown in Figure 4, usually defined by the federal

Wide speed range turboshaft study

NASA Technical Reports Server (NTRS)

Dangelo, Martin

1995-01-01

NASA-Lewis and NASA-Ames have sponsored a series of studies over the last few years to identify key high speed rotorcraft propulsion and airframe technologies. NASA concluded from these studies that for near term aircraft with cruise speeds up to 450 kt, tilting rotor rotorcraft concepts are the most economical and technologically viable. The propulsion issues critical to tilting rotor rotorcraft are: (1) high speed cruise propulsion system efficiency and (2) adequate power to hover safely with one engine inoperative. High speed cruise propeller efficiency can be dramatically improved by reducing rotor speed, yet high rotor speed is critical for good hover performance. With a conventional turboshaft, this wide range of power turbine operating speeds would result in poor engine performance at one or more of these critical operating conditions. This study identifies several wide speed range turboshaft concepts, and analyzes their potential to improve performance at the diverse cruise and hover operating conditions. Many unique concepts were examined, and the selected concepts are simple, low cost, relatively low risk, and entirely contained within the power turbine. These power turbine concepts contain unique, incidence tolerant airfoil designs that allow the engine to cruise efficiently at 51 percent of the hover rotor speed. Overall propulsion system efficiency in cruise is improved as much as 14 percent, with similar improvements in engine weight and cost. The study is composed of a propulsion requirement survey, a concept screening study, a preliminary definition and evaluation of selected concepts, and identification of key technologies and development needs. In addition, a civil transport tilting rotor rotorcraft mission analysis was performed to show the benefit of these concepts versus a conventional turboshaft. Other potential applications for this technology are discussed.

High-speed schlieren imaging of rocket exhaust plumes

NASA Astrophysics Data System (ADS)

Coultas-McKenney, Caralyn; Winter, Kyle; Hargather, Michael

2016-11-01

Experiments are conducted to examine the exhaust of a variety of rocket engines. The rocket engines are mounted in a schlieren system to allow high-speed imaging of the engine exhaust during startup, steady state, and shutdown. A variety of rocket engines are explored including a research-scale liquid rocket engine, consumer/amateur solid rocket motors, and water bottle rockets. Comparisons of the exhaust characteristics, thrust and cost for this range of rockets is presented. The variety of nozzle designs, target functions, and propellant type provides unique variations in the schlieren imaging.

Method and apparatus for selectively controlling the speed of an engine

DOEpatents

Davis, Roy Inge

2001-02-27

A control assembly 12 for use within a vehicle 10 having an engine 14 and which selectively controls the speed of the engine 14 in order to increase fuel efficiency and to effect relatively smooth starting and stopping of the engine. Particularly, in one embodiment, control assembly 12 cooperatively operates with a starter/alternator assembly 20 and is adapted for use with hybrid vehicles employing a start/stop powertrain assembly, wherein fuel efficiency is increased by selectively stopping engine operation when the vehicle has stopped.

Stratified charge rotary aircraft engine technology enablement program

NASA Technical Reports Server (NTRS)

Badgley, P. R.; Irion, C. E.; Myers, D. M.

1985-01-01

The multifuel stratified charge rotary engine is discussed. A single rotor, 0.7L/40 cu in displacement, research rig engine was tested. The research rig engine was designed for operation at high speeds and pressures, combustion chamber peak pressure providing margin for speed and load excursions above the design requirement for a high is advanced aircraft engine. It is indicated that the single rotor research rig engine is capable of meeting the established design requirements of 120 kW, 8,000 RPM, 1,379 KPA BMEP. The research rig engine, when fully developed, will be a valuable tool for investigating, advanced and highly advanced technology components, and provide an understanding of the stratified charge rotary engine combustion process.

Autonomous grain combine control system

DOEpatents

Hoskinson, Reed L.; Kenney, Kevin L.; Lucas, James R.; Prickel, Marvin A.

2013-06-25

A system for controlling a grain combine having a rotor/cylinder, a sieve, a fan, a concave, a feeder, a header, an engine, and a control system. The feeder of the grain combine is engaged and the header is lowered. A separator loss target, engine load target, and a sieve loss target are selected. Grain is harvested with the lowered header passing the grain through the engaged feeder. Separator loss, sieve loss, engine load and ground speed of the grain combine are continuously monitored during the harvesting. If the monitored separator loss exceeds the selected separator loss target, the speed of the rotor/cylinder, the concave setting, the engine load target, or a combination thereof is adjusted. If the monitored sieve loss exceeds the selected sieve loss target, the speed of the fan, the size of the sieve openings, or the engine load target is adjusted.

Design and Test of Fan/Nacelle Models Quiet High-Speed Fan Design

NASA Technical Reports Server (NTRS)

Miller, Christopher J. (Technical Monitor); Repp, Russ; Gentile, David; Hanson, David; Chunduru, Srinivas

2003-01-01

The primary objective of the Quiet High-Speed Fan (QHSF) program was to develop an advanced high-speed fan design that will achieve a 6 dB reduction in overall fan noise over a baseline configuration while maintaining similar performance. The program applies and validates acoustic, aerodynamic, aeroelastic, and mechanical design tools developed by NASA, US industry, and academia. The successful fan design will be used in an AlliedSignal Engines (AE) advanced regional engine to be marketed in the year 2000 and beyond. This technology is needed to maintain US industry leadership in the regional turbofan engine market.

Synchronizing Photography For High-Speed-Engine Research

NASA Technical Reports Server (NTRS)

Chun, K. S.

1989-01-01

Light flashes when shaft reaches predetermined angle. Synchronization system facilitates visualization of flow in high-speed internal-combustion engines. Designed for cinematography and holographic interferometry, system synchronizes camera and light source with predetermined rotational angle of engine shaft. 10-bit resolution of absolute optical shaft encoder adapted, and 2 to tenth power combinations of 10-bit binary data computed to corresponding angle values. Pre-computed angle values programmed into EPROM's (erasable programmable read-only memories) to use as angle lookup table. Resolves shaft angle to within 0.35 degree at rotational speeds up to 73,240 revolutions per minute.

Acoustical design economic trade off for transport aircraft

NASA Astrophysics Data System (ADS)

Benito, A.

The effects of ICAO fixed certification limits and local ordinances on acoustic emissions from jets on commercial transport aircraft and costs of operations are explored. The regulations effectively ban some aircraft from operation over populated areas, impose curfews on airports and, in conjunction with local civil aviation rules, levy extra taxes and quotas on noisier equipment. Jet engine manufacturers have attempted to increase the flow laminarity, decrease the exhaust speed and develop acoustic liners for selected duct areas. Retrofits are, however, not usually cost effective due to increased operational costs, e.g., fuel consumption can increase after engine modification because of increased weight. Finally, an attempt is made to assess, monetarily, the costs of noise pollution, wherein fines are levied for noisy aircraft and the money is spent insulating homes from noise.

The Effect of Connecting-passage Diameter on the Performance of a Compression-ignition Engine with a Precombustion Chamber

NASA Technical Reports Server (NTRS)

Moore, C S; Collins, J H

1932-01-01

Results of motoring tests are presented showing the effect of passage diameter on chamber and cylinder compression pressures, maximum pressure differences, and f.m.e.p. over a speed range from 300 to 1,750 r.p.m. Results of engine performance tests are presented which show the effect of passage diameter on m.e.p., explosion pressures, specific fuel consumption, and rates of pressure rise for a range of engine speeds from 500 to 1,500 r.p.m. The cylinder compression pressure, the maximum pressure difference, and the f.m.e.p. decreased rapidly as the passage diameter increased to 29/64 inch, whereas further increase in passage diameter effected only a slight change. The most suitable passage diameter for good engine performance and operating characteristics was 29/64 inch. Passage diameter became less critical with a decrease in engine speed. Therefore, the design should be based on maximum operating speed. Optimum performance and satisfactory combustion control could not be obtained by means of any single diameter of the connecting passage.

Emissions and Total Energy Consumption of a Multicylinder Piston Engine Running on Gasoline and a Hydrogen-gasoline Mixture

NASA Technical Reports Server (NTRS)

Cassidy, J. F.

1977-01-01

A multicylinder reciprocating engine was used to extend the efficient lean operating range of gasoline by adding hydrogen. Both bottled hydrogen and hydrogen produced by a research methanol steam reformer were used. These results were compared with results for all gasoline. A high-compression-ratio, displacement production engine was used. Apparent flame speed was used to describe the differences in emissions and performance. Therefore, engine emissions and performance, including apparent flame speed and energy lost to the cooling system and the exhaust gas, were measured over a range of equivalence ratios for each fuel. All emission levels decreased at the leaner conditions. Adding hydrogen significantly increased flame speed over all equivalence ratios.

High Speed Balancing Applied to the T700 Engine

NASA Technical Reports Server (NTRS)

Walton, J.; Lee, C.; Martin, M.

1989-01-01

The work performed under Contracts NAS3-23929 and NAS3-24633 is presented. MTI evaluated the feasibility of high-speed balancing for both the T700 power turbine rotor and the compressor rotor. Modifications were designed for the existing Corpus Christi Army Depot (CCAD) T53/T55 high-speed balancing system for balancing T700 power turbine rotors. Tests conducted under these contracts included a high-speed balancing evaluation for T700 power turbines in the Army/NASA drivetrain facility at MTI. The high-speed balancing tests demonstrated the reduction of vibration amplitudes at operating speed for both low-speed balanced and non-low-speed balanced T700 power turbines. In addition, vibration data from acceptance tests of T53, T55, and T700 engines were analyzed and a vibration diagnostic procedure developed.

Numerical Simulation of Tubular Pumping Systems with Different Regulation Methods

NASA Astrophysics Data System (ADS)

Zhu, Honggeng; Zhang, Rentian; Deng, Dongsheng; Feng, Xusong; Yao, Linbi

2010-06-01

Since the flow in tubular pumping systems is basically along axial direction and passes symmetrically through the impeller, most satisfying the basic hypotheses in the design of impeller and having higher pumping system efficiency in comparison with vertical pumping system, they are being widely applied to low-head pumping engineering. In a pumping station, the fluctuation of water levels in the sump and discharge pool is most common and at most time the pumping system runs under off-design conditions. Hence, the operation of pump has to be flexibly regulated to meet the needs of flow rates, and the selection of regulation method is as important as that of pump to reduce operation cost and achieve economic operation. In this paper, the three dimensional time-averaged Navier-Stokes equations are closed by RNG κ-ɛ turbulent model, and two tubular pumping systems with different regulation methods, equipped with the same pump model but with different designed system structures, are numerically simulated respectively to predict the pumping system performances and analyze the influence of regulation device and help designers make final decision in the selection of design schemes. The computed results indicate that the pumping system with blade-adjusting device needs longer suction box, and the increased hydraulic loss will lower the pumping system efficiency in the order of 1.5%. The pumping system with permanent magnet motor, by means of variable speed regulation, obtains higher system efficiency partly for shorter suction box and partly for different structure design. Nowadays, the varied speed regulation is realized by varied frequency device, the energy consumption of which is about 3˜4% of output power of the motor. Hence, when the efficiency of variable frequency device is considered, the total pumping system efficiency will probably be lower.

Demonstration, Testing and Qualification of a High Temperature, High Speed Magnetic Thrust Bearing

NASA Technical Reports Server (NTRS)

DeWitt, Kenneth

2005-01-01

The gas turbine industry has a continued interest in improving engine performance and reducing net operating and maintenance costs. These goals are being realized because of advancements in aeroelasticity, materials, and computational tools such as CFD and engine simulations. These advancements aid in increasing engine thrust-to-weight ratios, specific fuel consumption, pressure ratios, and overall reliability through higher speed, higher temperature, and more efficient engine operation. Currently, rolling element bearing and squeeze film dampers are used to support rotors in gas turbine engines. Present ball bearing configurations are limited in speed (<2 million DN) and temperature (<5OO F) and require both cooling air and an elaborate lubrication system. Also, ball bearings require extensive preventative maintenance in order to assure their safe operation. Since these bearings are at their operational limits, new technologies must be found in order to take advantage of other advances. Magnetic bearings are well suited to operate at extreme temperatures and higher rotational speeds and are a promising solution to the problems that conventional rolling element bearings present. Magnetic bearing technology is being developed worldwide and is considered an enabling technology for new engine designs. Using magnetic bearings, turbine and compressor spools can be radically redesigned to be significantly larger and stiffer with better damping and higher rotational speeds. These advances, a direct result of magnetic bearing technology, will allow significant increases in engine power and efficiency. Also, magnetic bearings allow for real-time, in-situ health monitoring of the system, lower maintenance costs and down time.

Multiroller Traction Drive Speed Reducer. Evaluation for Automotive Gas Turbine Engine

DTIC Science & Technology

1982-06-01

Speed is deLermined by a magnetic pickup on a toothed wheel . Gas turbine engine instrumunelLtiouu i -designed 1f0r measurement of specific fuel...buffer seal and the fluid--film bearing measured a maximum total runout of 0.038 mm (0.0015 in.) at low speed. At higher speeds, above 8000 rpm, the...maximum was 0.025 mm (0.001 in.) except near 10 000 rpm, where the oscilloscope indicated an excursion of 0.045 mm (0.0018 in.). This runout was within

78 FR 65161 - Airworthiness Directives; Agusta S.p.A. (Type Certificate Currently Held by AgustaWestland S.p.A...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain... alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third...

Aircraft thrust control

NASA Technical Reports Server (NTRS)

Walker, Neil (Inventor); Day, Stanley G. (Inventor); Collopy, Paul D. (Inventor); Bennett, George W. (Inventor)

1988-01-01

An integrated control system for coaxial counterrotating aircraft propulsors driven by a common gas turbine engine. The system establishes an engine pressure ratio by control of fuel flow and uses the established pressure ratio to set propulsor speed. Propulsor speed is set by adjustment of blade pitch.

High-speed noncontacting instrumentation for jet engine testing

NASA Astrophysics Data System (ADS)

Scotto, M. J.; Eismeier, M. E.

1980-03-01

This paper discusses high-speed, noncontacting instrumentation systems for measuring the operating characteristics of jet engines. The discussion includes optical pyrometers for measuring blade surface temperatures, capacitance clearanceometers for measuring blade tip clearance and vibration, and optoelectronic systems for measuring blade flex and torsion. In addition, engine characteristics that mandate the use of such unique instrumentation are pointed out as well as the shortcomings of conventional noncontacting devices. Experimental data taken during engine testing are presented and recommendations for future development discussed.

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine. 3; Pressure and Temperature Distributions

NASA Technical Reports Server (NTRS)

Geisenheyner, Robert M.; Berdysz, Joseph J.

1947-01-01

An altitude-wind-tunnel investigation of a TG-100A gas turbine-propeller engine was performed. Pressure and temperature data were obtained at altitudes from 5000 to 35000 feet, compressor inlet ram-pressure ratios from 1.00 to 1.17, and engine speeds from 800 to 13000 rpm. The effect of engine speed, shaft horsepower, and compressor-inlet ram-pressure ratio on pressure and temperature distribution at each measuring station are presented graphically.

The Fundamental Principles of High-speed Semi-diesel Engines. Part I: a General Discussion of the Subject of Fuel Injection in Diesel Engines and Detailed Descriptions of Many Types of Injection Nozzles

NASA Technical Reports Server (NTRS)

Buchner,

1926-01-01

Three questions relating to the technical progress in the utilization of heavy oils are discussed. The first question considers solid injection in high-speed automobile engines, the second concerns the development of the hot-bulb engine, and the third question relates to the need for a more thorough investigation of the processes on which the formatation of combustible, rapidly-burning mixtures depend.

An airline study of advanced technology requirements for advanced high speed commercial transport engines. 1: Engine design study assessment

NASA Technical Reports Server (NTRS)

Sallee, G. P.

1973-01-01

The advanced technology requirements for an advanced high speed commercial tranport engine are presented. The results of the phase 1 study effort cover the following areas: (1) statement of an airline's major objectives for future transport engines, (2) airline's method of evaluating engine proposals, (3) description of an optimum engine for a long range subsonic commercial transport including installation and critical design features, (4) discussion of engine performance problems and experience with performance degradation, (5) trends in engine and pod prices with increasing technology and objectives for the future, (6) discussion of the research objectives for composites, reversers, advanced components, engine control systems, and devices to reduce the impact of engine stall, and (7) discussion of the airline objectives for noise and pollution reduction.

Speed Variance and Its Influence on Accidents.

ERIC Educational Resources Information Center

Garber, Nicholas J.; Gadirau, Ravi

A study was conducted to investigate the traffic engineering factors that influence speed variance and to determine to what extent speed variance affects accident rates. Detailed analyses were carried out to relate speed variance with posted speed limit, design speeds, and other traffic variables. The major factor identified was the difference…

Simulated Altitude Performance of Combustor of Westinghouse 19XB-1 Jet-Propulsion Engine

NASA Technical Reports Server (NTRS)

Childs, J. Howard; McCafferty, Richard J.

1948-01-01

A 19XB-1 combustor was operated under conditions simulating zero-ram operation of the 19XB-1 turbojet engine at various altitudes and engine speeds. The combustion efficiencies and the altitude operational limits were determined; data were also obtained on the character of the combustion, the pressure drop through the combustor, and the combustor-outlet temperature and velocity profiles. At altitudes about 10,000 feet below the operational limits, the flames were yellow and steady and the temperature rise through the combustor increased with fuel-air ratio throughout the range of fuel-air ratios investigated. At altitudes near the operational limits, the flames were blue and flickering and the combustor was sluggish in its response to changes in fuel flow. At these high altitudes, the temperature rise through the combustor increased very slowly as the fuel flow was increased and attained a maximum at a fuel-air ratio much leaner than the over-all stoichiometric; further increases in fuel flow resulted in decreased values of combustor temperature rise and increased resonance until a rich-limit blow-out occurred. The approximate operational ceiling of the engine as determined by the combustor, using AN-F-28, Amendment-3, fuel, was 30,400 feet at a simulated engine speed of 7500 rpm and increased as the engine speed was increased. At an engine speed of 16,000 rpm, the operational ceiling was approximately 48,000 feet. Throughout the range of simulated altitudes and engine speeds investigated, the combustion efficiency increased with increasing engine speed and with decreasing altitude. The combustion efficiency varied from over 99 percent at operating conditions simulating high engine speed and low altitude operation to less than 50 percent at conditions simulating operation at altitudes near the operational limits. The isothermal total pressure drop through the combustor was 1.82 times as great as the inlet dynamic pressure. As expected from theoretical considerations, a straight-line correlation was obtained when the ratio of the combustor total pressure drop to the combustor-inlet dynamic pressure was plotted as a function of the ratio of the combustor-inlet air density to the combustor-outlet gas density. The combustor-outlet temperature profiles were, in general, more uniform for runs in which the temperature rise was low and the combustion efficiency was high. Inspection of the combustor basket after 36 hours of operation showed very little deterioration and no appreciable carbon deposits.

Analysis of Experimental Sea-level Transient Data and Analog Method of Obtaining Altitude Response for Turbine-propeller Engine with Relay-type Speed Control

NASA Technical Reports Server (NTRS)

Vasu, George; Pack, George J

1951-01-01

Correlation has been established between transient engine and control data obtained experimentally and data obtained by simulating the engine and control with an analog computer. This correlation was established at sea-level conditions for a turbine-propeller engine with a relay-type speed control. The behavior of the controlled engine at altitudes of 20,000 and 35,000 feet was determined with an analog computer using the altitude pressure and temperature generalization factors to calculate the new engine constants for these altitudes. Because the engine response varies considerably at altitude some type of compensation appears desirable and four methods of compensation are discussed.

An experimental study of gaseous exhaust emissions of diesel engine using blend of natural fatty acid methyl ester

NASA Astrophysics Data System (ADS)

Sudrajad, Agung; Ali, Ismail; Samo, Khalid; Faturachman, Danny

2012-09-01

Vegetable oil form in Natural Fatty Acid Methyl Ester (FAME) has their own advantages: first of all they are available everywhere in the world. Secondly, they are renewable as the vegetables which produce oil seeds can be planted year after year. Thirdly, they are friendly with our environment, as they seldom contain sulphur element in them. This makes vegetable fuel studies become current among the various popular investigations. This study is attempt to optimization of using blend FAME on diesel engine by experimental laboratory. The investigation experimental project is comparison between using blend FAME and base diesel fuel. The engine experiment is conducted with YANMAR TF120M single cylinder four stroke diesel engine set-up at variable engine speed with constant load. The data have been taken at each point of engine speed during the stabilized engine-operating regime. Measurement of emissions parameters at difference engine speed conditions have generally indicated lower in emission NOx, but slightly higher on CO2 emission. The result also shown that the blends FAME are good in fuel consumption and potentially good substitute fuels for diesel engine

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades

NASA Astrophysics Data System (ADS)

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

Aircraft engine-mounted camera system for long wavelength infrared imaging of in-service thermal barrier coated turbine blades.

PubMed

Markham, James; Cosgrove, Joseph; Scire, James; Haldeman, Charles; Agoos, Ian

2014-12-01

This paper announces the implementation of a long wavelength infrared camera to obtain high-speed thermal images of an aircraft engine's in-service thermal barrier coated turbine blades. Long wavelength thermal images were captured of first-stage blades. The achieved temporal and spatial resolutions allowed for the identification of cooling-hole locations. The software and synchronization components of the system allowed for the selection of any blade on the turbine wheel, with tuning capability to image from leading edge to trailing edge. Its first application delivered calibrated thermal images as a function of turbine rotational speed at both steady state conditions and during engine transients. In advance of presenting these data for the purpose of understanding engine operation, this paper focuses on the components of the system, verification of high-speed synchronized operation, and the integration of the system with the commercial jet engine test bed.

The Charging Process in a High-speed, Single-cylinder, Four-stroke Engine

NASA Technical Reports Server (NTRS)

Reynolds, Blake; Schecter, Harry; Taylor, E S

1939-01-01

Experimental measurements and theoretical calculations were made on an aircraft-type, single cylinder engine, in order to determine the physical nature of the inlet process, especially at high piston speeds. The engine was run at speeds from 1,500 to 2,600 r.p.m. (mean piston speeds of 1,370 to 2,380 feet per minute). Measurements were made of the cylinder pressure during the inlet stroke and of the power output and volumetric efficiency. Measurements were also made, with the engine not running, to determine the resistance and mass of air in the inlet valve port at various crank angles. Results of analysis indicate that mass has an appreciable effect, but friction plays the major part in restricting flow. The observed fact that the volumetric efficiency is considerably less than 100 percent is attributed to thermal effects. An estimate was made of the magnitude of these effects in the present case, and their general nature is discussed.

Investigation of acceleration characteristics of a single-spool turbojet engine

NASA Technical Reports Server (NTRS)

Oppenheimer, Frank L; Pack, George J

1953-01-01

Operation of a single-spool turbojet engine with constant exhaust-nozzle area was investigated at one flight condition. Data were obtained by subjecting the engine to approximate-step changes in fuel flow, and the information necessary to show the relations of acceleration to the sensed engine variables was obtained. These data show that maximum acceleration occurred prior to stall and surge. In the low end of the engine-speed range the margin was appreciable; in the high-speed end the margin was smaller but had not been completely defined by these data. Data involving acceleration as a function of speed, fuel flow, turbine-discharge temperature, compressor-discharge pressure, and thrust have been presented and an effort has been made to show how a basic control system could be improved by addition of an override in which the acceleration characteristic is used not only to prevent the engine from entering the surge region but also to obtain acceleration along the maximum acceleration line during throttle bursts.

Real-time analysis system for gas turbine ground test acoustic measurements.

PubMed

Johnston, Robert T

2003-10-01

This paper provides an overview of a data system upgrade to the Pratt and Whitney facility designed for making acoustic measurements on aircraft gas turbine engines. A data system upgrade was undertaken because the return-on-investment was determined to be extremely high. That is, the savings on the first test series recovered the cost of the hardware. The commercial system selected for this application utilizes 48 input channels, which allows either 1/3 octave and/or narrow-band analyses to be preformed real-time. A high-speed disk drive allows raw data from all 48 channels to be stored simultaneously while the analyses are being preformed. Results of tests to ensure compliance of the new system with regulations and with existing systems are presented. Test times were reduced from 5 h to 1 h of engine run time per engine configuration by the introduction of this new system. Conservative cost reduction estimates for future acoustic testing are 75% on items related to engine run time and 50% on items related to the overall length of the test.

Fluctuating pressures on fan blades of a turbofan engine: Static and wind-tunnel investigations

NASA Technical Reports Server (NTRS)

Schoenster, J. A.

1982-01-01

To investigate the fan noise generated from turbofan engines, miniature pressure transducers were used to measure the fluctuating pressure on the fan blades of a JT15D engine. Tests were conducted with the engine operating on an outdoor test stand and in a wind tunnel. It was found that a potential flow interaction between the fan blades and six, large support struts in the bypass duct is a dominant noise source in the JT15D engine. Effects of varying fan speed and the forward speed on the blade pressure are also presented.

Allison V–1710 Engine on a Dynamotor Stand in the Engine Research Building

NASA Image and Video Library

1943-03-21

The first research assignment specifically created for the National Advisory Committee for Aeronautics’ (NACA) new Aircraft Engine Research Laboratory was the integration of a supercharger into the Allison V–1710 engine. The military was relying on the liquid-cooled V–1710 to power several types of World War II fighter aircraft and wanted to improve the engine's speed and altitude performance. Superchargers forced additional airflow into the combustion chamber, which increased the engine’s performance resulting in greater altitudes and speeds. They also generated excess heat that affected the engine cylinders, oil, and fuel. In 1943 the military tasked the new Aircraft Engine Research Laboratory to integrate the supercharger, improve the cooling system, and remedy associated engine knock. Three Allison engines were provided to the laboratory’s research divisions. One group was tasked with improving the supercharger performance, another analyzed the effect of the increased heat on knock in the fuel, one was responsible for improving the cooling system, and another would install the new components on the engine with minimal drag penalties. The modified engines were installed on this 2000-horsepower dynamotor stand in a test cell within the Engine Research Building. The researchers could run the engine at different temperatures, fuel-air ratios, and speeds. When the modifications were complete, the improved V–1710 was flight tested on a P–63A Kingcobra loaned to the NACA for this project.

Prediction of in-use emissions of heavy-duty diesel vehicles from engine testing.

PubMed

Yanowitz, Janet; Graboski, Michael S; McCormick, Robert L

2002-01-15

A model of a heavy-duty vehicle driveline with automatic transmission has been developed for estimating engine speed and load from vehicle speed. The model has been validated using emissions tests conducted on three diesel vehicles on a chassis dynamometer and then on the engines removed from the vehicles tested on an engine dynamometer. Nitrogen oxide (NOx) emissions were proportional to work done by the engine. For two of the engines, the NOx/horsepower(HP) ratio was the same on the engine and on the chassis dynamometer tests. For the third engine NOx/HP was significantly higher from the chassis test, possibly due to the use of dual engine maps. The engine certification test generated consistently less particulate matter emissions on a gram per brake horsepower-hour basis than the Heavy Duty Transient and Central Business District chassis cycles. A good linear correlation (r2 = 0.97 and 0.91) was found between rates of HP increase integrated over the test cycle and PM emissions for both the chassis and the engine tests for two of the vehicles. The model also shows how small changes in vehicle speeds can lead to a doubling of load on the engine. Additionally, the model showed that it is impossible to drive a vehicle cycle equivalent to the heavy-duty engine federal test procedure on these vehicles.

Detecting the crankshaft torsional vibration of diesel engines for combustion related diagnosis

NASA Astrophysics Data System (ADS)

Charles, P.; Sinha, Jyoti K.; Gu, F.; Lidstone, L.; Ball, A. D.

2009-04-01

Early fault detection and diagnosis for medium-speed diesel engines is important to ensure reliable operation throughout the course of their service. This work presents an investigation of the diesel engine combustion related fault detection capability of crankshaft torsional vibration. The encoder signal, often used for shaft speed measurement, has been used to construct the instantaneous angular speed (IAS) waveform, which actually represents the signature of the torsional vibration. Earlier studies have shown that the IAS signal and its fast Fourier transform (FFT) analysis are effective for monitoring engines with less than eight cylinders. The applicability to medium-speed engines, however, is strongly contested due to the high number of cylinders and large moment of inertia. Therefore the effectiveness of the FFT-based approach has further been enhanced by improving the signal processing to determine the IAS signal and subsequently tested on a 16-cylinder engine. In addition, a novel method of presentation, based on the polar coordinate system of the IAS signal, has also been introduced; to improve the discrimination features of the faults compared to the FFT-based approach of the IAS signal. The paper discusses two typical experimental studies on 16- and 20-cylinder engines, with and without faults, and the diagnosis results by the proposed polar presentation method. The results were also compared with the earlier FFT-based method of the IAS signal.

A Demonstration of a Retrofit Architecture for Intelligent Control and Diagnostics of a Turbofan Engine

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Turso, James A.; Shah, Neerav; Sowers, T. Shane; Owen, A. Karl

2005-01-01

A retrofit architecture for intelligent turbofan engine control and diagnostics that changes the fan speed command to maintain thrust is proposed and its demonstration in a piloted flight simulator is described. The objective of the implementation is to increase the level of autonomy of the propulsion system, thereby reducing pilot workload in the presence of anomalies and engine degradation due to wear. The main functions of the architecture are to diagnose the cause of changes in the engine s operation, warning the pilot if necessary, and to adjust the outer loop control reference signal in response to the changes. This requires that the retrofit control architecture contain the capability to determine the changed relationship between fan speed and thrust, and the intelligence to recognize the cause of the change in order to correct it or warn the pilot. The proposed retrofit architecture is able to determine the fan speed setting through recognition of the degradation level of the engine, and it is able to identify specific faults and warn the pilot. In the flight simulator it was demonstrated that when degradation is introduced into an engine with standard fan speed control, the pilot needs to take corrective action to maintain heading. Utilizing the intelligent retrofit control architecture, the engine thrust is automatically adjusted to its expected value, eliminating yaw without pilot intervention.

Systems Engineering Methodology for Fuel Efficiency and its Application to the TARDEC Fuel Efficient Demonstrator (FED) Program

DTIC Science & Technology

2010-08-19

highlight the benefits of regenerative braking . Parameters within the drive cycle may include vehicle speed, elevation/grade changes, road surface...assist to downsize the engine due to infinite maximum speed requirements • Drive cycle less suited to regenerative braking improvement compared to...will be cycle dependent. A high speed drive cycle may for example drive a focus on aerodynamic improvements, while high frequency of braking will

Dynamics of the inlet system of a four-stroke engine

NASA Technical Reports Server (NTRS)

Boden, R H; Schecter, Harry

1944-01-01

Tests were run on a single-cylinder and a multicylinder four-stroke engine in order to determine the effect of the dynamics of the inlet system upon indicated mean effective pressure. Tests on the single-cylinder engine were made at various speeds, inlet valve timings, and inlet pipe lengths. These tests indicated that the indicated mean effective pressure could be raised considerably at any one speed by the use of a suitably long inlet pipe. Tests at other speeds with this length of pipe showed higher indicated mean effective pressure than with a very short pipe, although not so high as could be obtained with the pipe length adjusted for each speed. A general relation was discovered between optimum time of inlet valve closing and pipe length; namely, that longer pipes require later inlet valve closing in order to be fully effective. Tests were also made on three cylinders connected to a single pipe. With this arrangement, increased volumetric efficiency at low speed was obtainable by using a long pipe, but only with a sacrifice of volumetric efficiency at high speed. Volumetric efficiency at high speed was progressively lower as the pipe length was increased.

Performance of a Small Internal Combustion Engine Using N-Heptane and Iso-Octane

DTIC Science & Technology

2010-03-01

evaluate the ON effects on a FUJI BF34-EI, small 4-stroke spark ignition engine as preliminary steps to using a military grade JP-8 jet turbine fuel ...K) Pcrit (MPa) HHV (kJ/kg) LHV (kJ/kg) n-Heptane C7H16 100.20 371.60 537.70 2.62 48,456 44,926 i-Octane C8H18 114.22 398.40 567.50 2.40 48,275 44,791...meter the fuel . The carburetor is equipped with both a high speed and low speed fuel jet . It is unknown what engine speed it switches from one to

Model-based diagnosis of large diesel engines based on angular speed variations of the crankshaft

NASA Astrophysics Data System (ADS)

Desbazeille, M.; Randall, R. B.; Guillet, F.; El Badaoui, M.; Hoisnard, C.

2010-07-01

This work aims at monitoring large diesel engines by analyzing the crankshaft angular speed variations. It focuses on a powerful 20-cylinder diesel engine with crankshaft natural frequencies within the operating speed range. First, the angular speed variations are modeled at the crankshaft free end. This includes modeling both the crankshaft dynamical behavior and the excitation torques. As the engine is very large, the first crankshaft torsional modes are in the low frequency range. A model with the assumption of a flexible crankshaft is required. The excitation torques depend on the in-cylinder pressure curve. The latter is modeled with a phenomenological model. Mechanical and combustion parameters of the model are optimized with the help of actual data. Then, an automated diagnosis based on an artificially intelligent system is proposed. Neural networks are used for pattern recognition of the angular speed waveforms in normal and faulty conditions. Reference patterns required in the training phase are computed with the model, calibrated using a small number of actual measurements. Promising results are obtained. An experimental fuel leakage fault is successfully diagnosed, including detection and localization of the faulty cylinder, as well as the approximation of the fault severity.

Performance and Durability Assessment of Two Emission Control Technologies Installed on a Legacy High-Speed Marine Diesel Engine

DTIC Science & Technology

2015-11-05

program investigated cost- effective technologies to reduce emissions from legacy marine engines. High-speed, high-population engine models in both...respectively) were driven by health effects and environmental impacts. The U.S. Navy assessed its contribution to the domestic marine emission inventory...greatest potential. A laboratory developmental assessment was followed by a shipboard evaluation. Effective technology concepts applied to high

High load operation in a homogeneous charge compression ignition engine

DOEpatents

Duffy, Kevin P [Metamora, IL; Kieser, Andrew J [Morton, IL; Liechty, Michael P [Chillicothe, IL; Hardy, William L [Peoria, IL; Rodman, Anthony [Chillicothe, IL; Hergart, Carl-Anders [Peoria, IL

2008-12-23

A homogeneous charge compression ignition engine is set up by first identifying combinations of compression ratio and exhaust gas percentages for each speed and load across the engines operating range. These identified ratios and exhaust gas percentages can then be converted into geometric compression ratio controller settings and exhaust gas recirculation rate controller settings that are mapped against speed and load, and made available to the electronic

Acoustic and Emission Characteristics of Small, High-Speed Internal Combustion Engines

DOT National Transportation Integrated Search

1981-07-01

The intent of this study is to obtain information on small high-speed engines so that their effect on the urban environment may be assessed, and if necessary, programs devised to reduce the noise and other emissions from vehicles using these highly d...

14 CFR 27.1521 - Powerplant limitations.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions... rotational speed shown under the rotor speed requirements in § 27.1509(c); and (3) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions for which certification is...

14 CFR 27.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

...) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions... rotational speed shown under the rotor speed requirements in § 27.1509(c); and (3) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions for which certification is...

14 CFR 27.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions... rotational speed shown under the rotor speed requirements in § 27.1509(c); and (3) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions for which certification is...

14 CFR 27.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

...) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions... rotational speed shown under the rotor speed requirements in § 27.1509(c); and (3) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions for which certification is...

14 CFR 27.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

...) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions... rotational speed shown under the rotor speed requirements in § 27.1509(c); and (3) The gas temperature limits for turbine engines over the range of operating and atmospheric conditions for which certification is...

14 CFR 23.1563 - Airspeed placards.

Code of Federal Regulations, 2014 CFR

2014-01-01

... multiengine-powered airplanes of more than 6,000 pounds maximum weight, and turbine engine-powered airplanes, the maximum value of the minimum control speed, VMC (one-engine-inoperative) determined under § 23.149... control and the airspeed indicator has features such as low speed awareness that provide ample warning...

14 CFR 23.1563 - Airspeed placards.

Code of Federal Regulations, 2013 CFR

2013-01-01

... multiengine-powered airplanes of more than 6,000 pounds maximum weight, and turbine engine-powered airplanes, the maximum value of the minimum control speed, VMC (one-engine-inoperative) determined under § 23.149... control and the airspeed indicator has features such as low speed awareness that provide ample warning...

Regulated and unregulated emissions from a diesel engine fueled with diesel fuel blended with diethyl adipate

NASA Astrophysics Data System (ADS)

Zhu, Ruijun; Cheung, C. S.; Huang, Zuohua; Wang, Xibin

2011-04-01

Experiments were carried out on a four-cylinder direct-injection diesel engine operating on Euro V diesel fuel blended with diethyl adipate (DEA). The blended fuels contain 8.1%, 16.4%, 25% and 33.8% by volume fraction of DEA, corresponding to 3%, 6%, 9% and 12% by mass of oxygen in the blends. The engine performance and exhaust gas emissions of the different fuels were investigated at five engine loads at a steady speed of 1800 rev/min. The results indicated an increase of brake specific fuel consumption and brake thermal efficiency when the engine was fueled with the blended fuels. In comparison with diesel fuel, the blended fuels resulted in an increase in hydrocarbon (HC) and carbon monoxide (CO), but a decrease in particulate mass concentrations. The nitrogen oxides (NO x) emission experienced a slight variation among the test fuels. In regard to the unregulated gaseous emissions, formaldehyde and acetaldehyde increased, while 1,3-butadiene, ethene, ethyne, propylene and BTX (benzene, toluene and xylene) in general decreased. A diesel oxidation catalyst (DOC) was found to reduce significantly most of the investigated unregulated pollutants when the exhaust gas temperature was sufficiently high.

Method of controlling a variable geometry type turbocharger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirabayashi, Y.

1988-08-23

This patent describes a method of controlling the supercharging pressure of a variable geometry type turbocharger having a bypass, comprising the following steps which are carried out successively: receiving signals from an engine speed sensor and from an engine knocking sensor; receiving a signal from a throttle valve sensor; judging whether or not an engine is being accelerated, and proceeding to step below if the engine is being accelerated and to step below if the engine is not being accelerated, i.e., if the engine is in a constant speed operation; determining a first correction value and proceeding to step below;more » judging whether or not the engine is knocking, and proceeding to step (d) if knocking is occurring and to step (f) below if no knocking is occurring; determining a second correction value and proceeding to step; receiving signals from the engine speed sensor and from an airflow meter which measures the quantity of airflow to be supplied to the engine; calculating an airflow rate per engine revolution; determining a duty valve according to the calculated airflow rate; transmitting the corrected duty value to control means for controlling the geometry of the variable geometry type turbocharger and the opening of bypass of the turbocharger, thereby controlling the supercharging pressure of the turbocharger.« less

Drive cycle simulation of high efficiency combustions on fuel economy and exhaust properties in light-duty vehicles

DOE PAGES

Gao, Zhiming; Curran, Scott J.; Parks, James E.; ...

2015-04-06

We present fuel economy and engine-out emissions for light-duty (LD) conventional and hybrid vehicles powered by conventional and high-efficiency combustion engines. Engine technologies include port fuel-injected (PFI), direct gasoline injection (GDI), reactivity controlled compression ignition (RCCI) and conventional diesel combustion (CDC). In the case of RCCI, the engine utilized CDC combustion at speed/load points not feasible with RCCI. The results, without emissions considered, show that the best fuel economies can be achieved with CDC/RCCI, with CDC/RCCI, CDC-only, and lean GDI all surpassing PFI fuel economy significantly. In all cases, hybridization significantly improved fuel economy. The engine-out hydrocarbon (HC), carbon monoxidemore » (CO), nitrogen oxides (NOx), and particulate matter (PM) emissions varied remarkably with combustion mode. The simulated engine-out CO and HC emissions from RCCI are significantly higher than CDC, but RCCI makes less NOx and PM emissions. Hybridization can improve lean GDI and RCCI cases by increasing time percentage for these more fuel efficient modes. Moreover, hybridization can dramatically decreases the lean GDI and RCCI engine out emissions. Importantly, lean GDI and RCCI combustion modes decrease exhaust temperatures, especially for RCCI, which limits aftertreatment performance to control tailpipe emissions. Overall, the combination of engine and hybrid drivetrain selected greatly affects the emissions challenges required to meet emission regulations.« less

78 FR 66252 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-05

... actions are intended to alert pilots to avoid certain engine speeds during steady- state operations...%. The proposed requirements were intended to alert pilots to avoid certain engine speeds during steady... the RFMs, advising pilots of the change, and installing a decal as described in Bell Alert Service...

14 CFR 23.1563 - Airspeed placards.

Code of Federal Regulations, 2012 CFR

2012-01-01

... than 6,000 pounds maximum weight, and turbine engine-powered airplanes, the maximum value of the minimum control speed, VMC (one-engine-inoperative) determined under § 23.149(b). [Amdt. 23-7, 34 FR 13097... lighted area such as the landing gear control and the airspeed indicator has features such as low speed...

Experimental Determination of Linear Dynamics of Two-Spool Turbojet Engines

NASA Technical Reports Server (NTRS)

Novik, David; Heppler, Herbert

1954-01-01

Transfer functions descriptive of the response of most engine variables were determined from transient data that were obtained from approximate step inputs in fuel flow and in exhaust-nozzle area. The speed responses of both spools to fuel flow and to turbine-inlet temperature appeared as identical first-order lags. Response to exhaust-nozzle area was characterized by a first-order lag response of the outer-spool speed, accompanied by virtually no change in inner-spool speed.

Cryogenic gear technology for an orbital transfer vehicle engine and tester design

NASA Technical Reports Server (NTRS)

Calandra, M.; Duncan, G.

1986-01-01

Technology available for gears used in advanced Orbital Transfer Vehicle rocket engines and the design of a cryogenic adapted tester used for evaluating advanced gears are presented. The only high-speed, unlubricated gears currently in cryogenic service are used in the RL10 rocket engine turbomachinery. Advanced rocket engine gear systems experience operational load conditions and rotational speed that are beyond current experience levels. The work under this task consisted of a technology assessment and requirements definition followed by design of a self-contained portable cryogenic adapted gear test rig system.

ISG hybrid powertrain: a rule-based driver model incorporating look-ahead information

NASA Astrophysics Data System (ADS)

Shen, Shuiwen; Zhang, Junzhi; Chen, Xiaojiang; Zhong, Qing-Chang; Thornton, Roger

2010-03-01

According to European regulations, if the amount of regenerative braking is determined by the travel of the brake pedal, more stringent standards must be applied, otherwise it may adversely affect the existing vehicle safety system. The use of engine or vehicle speed to derive regenerative braking is one way to avoid strict design standards, but this introduces discontinuity in powertrain torque when the driver releases the acceleration pedal or applies the brake pedal. This is shown to cause oscillations in the pedal input and powertrain torque when a conventional driver model is adopted. Look-ahead information, together with other predicted vehicle states, are adopted to control the vehicle speed, in particular, during deceleration, and to improve the driver model so that oscillations can be avoided. The improved driver model makes analysis and validation of the control strategy for an integrated starter generator (ISG) hybrid powertrain possible.

The Waukesha Turbocharger Control Module: A tool for improved engine efficiency and response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zurlo, J.R.; Reinbold, E.O.; Mueller, J.

1996-12-31

The Waukesha Turbocharger Control Module allows optimum control of turbochargers on lean burn gaseous fueled engines. The Turbocharger Control Module is user programmed to provide either maximum engine efficiency or best engine response to load changes. In addition, the Turbocharger Control Module prevents undesirable turbocharger surge. The Turbocharger Control Module consists of an electronic control box, engine speed, intake manifold pressure, ambient temperature sensors, and electric actuators driving compressor bypass and wastegate valves. The Turbocharger Control Module expands the steady state operational environment of the Waukesha AT27GL natural gas engine from sea level to 1,525 m altitude with one turbochargermore » match and improves the engine speed turn down by 80 RPM. Finally, the Turbocharger Control Module improves engine response to load changes.« less

Minimum data requirement for neural networks based on power spectral density analysis.

PubMed

Deng, Jiamei; Maass, Bastian; Stobart, Richard

2012-04-01

One of the most critical challenges ahead for diesel engines is to identify new techniques for fuel economy improvement without compromising emissions regulations. One technique is the precise control of air/fuel ratio, which requires the measurement of instantaneous fuel consumption. Measurement accuracy and repeatability for fuel rate is the key to successfully controlling the air/fuel ratio and real-time measurement of fuel consumption. The volumetric and gravimetric measurement principles are well-known methods for measurement of fuel consumption in internal combustion engines. However, the fuel flow rate measured by these methods is not suitable for either real-time control or real-time measurement purposes because of the intermittent nature of the measurements. This paper describes a technique that can be used to find the minimum data [consisting of data from just 2.5% of the non-road transient cycle (NRTC)] to solve the problem concerning discontinuous data of fuel flow rate measured using an AVL 733S fuel meter for a medium or heavy-duty diesel engine using neural networks. Only torque and speed are used as the input parameters for the fuel flow rate prediction. Power density analysis is used to find the minimum amount of the data. The results show that the nonlinear autoregressive model with exogenous inputs could predict the particulate matter successfully with R(2) above 0.96 using 2.5% NRTC data with only torque and speed as inputs.

49 CFR 229.117 - Speed indicators.

Code of Federal Regulations, 2012 CFR

2012-10-01

... locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is— (1) Accurate within ±3 miles per hour of actual speed at speeds of 10 to 30 miles per hour and accurate within ±5 miles per hour at speeds above 30 miles per hour; and (2) Clearly readable from the engineer's...

49 CFR 229.117 - Speed indicators.

Code of Federal Regulations, 2013 CFR

2013-10-01

... locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is— (1) Accurate within ±3 miles per hour of actual speed at speeds of 10 to 30 miles per hour and accurate within ±5 miles per hour at speeds above 30 miles per hour; and (2) Clearly readable from the engineer's...

49 CFR 229.117 - Speed indicators.

Code of Federal Regulations, 2014 CFR

2014-10-01

... locomotive at speeds in excess of 20 miles per hour shall be equipped with a speed indicator which is— (1) Accurate within ±3 miles per hour of actual speed at speeds of 10 to 30 miles per hour and accurate within ±5 miles per hour at speeds above 30 miles per hour; and (2) Clearly readable from the engineer's...

An airline study of advanced technology requirements for advanced high speed commercial transport engines. 2: Engine preliminary design assessment

NASA Technical Reports Server (NTRS)

Sallee, G. P.

1973-01-01

The advanced technology requirements for an advanced high speed commercial transport engine are presented. The results of the phase 2 study effort cover the following areas: (1) general review of preliminary engine designs suggested for a future aircraft, (2) presentation of a long range view of airline propulsion system objectives and the research programs in noise, pollution, and design which must be undertaken to achieve the goals presented, (3) review of the impact of propulsion system unreliability and unscheduled maintenance on cost of operation, (4) discussion of the reliability and maintainability requirements and guarantees for future engines.

Parametric tests of a traction drive retrofitted to an automotive gas turbine

NASA Technical Reports Server (NTRS)

Rohn, D. A.; Lowenthal, S. H.; Anderson, N. E.

1980-01-01

The results of a test program to retrofit a high performance fixed ratio Nasvytis Multiroller Traction Drive in place of a helical gear set to a gas turbine engine are presented. Parametric tests up to a maximum engine power turbine speed of 45,500 rpm and to a power level of 11 kW were conducted. Comparisons were made to similar drives that were parametrically tested on a back-to-back test stand. The drive showed good compatibility with the gas turbine engine. Specific fuel consumption of the engine with the traction drive speed reducer installed was comparable to the original helical gearset equipped engine.

Compressed air production with waste heat utilization in industry

NASA Astrophysics Data System (ADS)

Nolting, E.

1984-06-01

The centralized power-heat coupling (PHC) technique using block heating power stations, is presented. Compressed air production in PHC technique with internal combustion engine drive achieves a high degree of primary energy utilization. Cost savings of 50% are reached compared to conventional production. The simultaneous utilization of compressed air and heat is especially interesting. A speed regulated drive via an internal combustion motor gives a further saving of 10% to 20% compared to intermittent operation. The high fuel utilization efficiency ( 80%) leads to a pay off after two years for operation times of 3000 hr.

The Effects of Engine Speed and Mixture Temperature on the Knocking Characteristics of Several Fuels

NASA Technical Reports Server (NTRS)

Lee, Dana W

1940-01-01

Six 100-octane and two 87-octane aviation engine fuels were tested in a modified C.F.R. variable-compression engine at 1,500, 2,000 and 2,500 rpm. The mixture temperature was raised from 50 to 300 F in approximately 50 degree steps and, at each temperature, the compression ratio was adjusted to give incipient knock as shown by a cathode ray indicator. The results are presented in tabular form. The results are analyzed on the assumption that the conditions which determine whether a given fuel will knock are the maximum values of density and temperature reached by the burning gases. A maximum permissible density factor, proportional to the maximum density of the burning gases just prior to incipient knock, and the temperature of the burning gases at that time were computed for each of the test conditions. Values of the density factors were plotted against the corresponding end-gas temperatures for the three engine speeds and also against engine speed for several and end-gas temperatures. The maximum permissible density factor varied only slightly with engine speed but decreased rapidly with an increase in the end-gas temperature. The effect of changing the mixture temperature was different for fuels of different types. The results emphasize the desirability of determining the anti knock values of fuels over a wide range of engine and intake-air conditions rather that at a single set of conditions.

Engineering Design Handbook. Helicopter Engineering. Part Two. Detail Design

DTIC Science & Technology

1976-01-01

rates are sp-ed for a given amount of power available, involved in both symmetrical and turning maneu- Normally•, the high - speed performance problem...safe mnain rotor specls. cessive oiling should be avoided. Good estimations of The power losses of a typical high - speed twin- gear windage losses F...rotor gearbox and consise.d of two hy- gearbox is pitting or spa,:,iig of the gears and draulic pumps and a high - speed generator. bearinbs (par. 4-2.1

New research assessing the effect of engine operating conditions on regulated emissions of a 4-stroke motorcycle by test bench measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iodice, Paolo, E-mail: paolo.iodice@unina.it; Senatore, Adolfo

In the latest years the effect of powered two-wheelers on air polluting emissions is generally noteworthy all over the world, notwithstanding advances in internal combustion engines allowed to reduce considerably both fuel consumption and exhaust emissions of SI engines. Nowadays, in fact, these vehicles represent common means of quotidian moving, serving to meet daily urban transport necessities with a significant environmental impact on air quality. Besides, the emissive behavior of the two-wheelers measured under fixed legislative driving standards (and not on the local driving conditions) might not be sufficiently representative of real world motorcycle riding. The purpose of this investigationmore » is a deeper research on emissive levels of in-use motorcycles equipped with last generation SI engines under real world driving behavior. In order to analyze the effect of vehicle instantaneous speed and acceleration on emissive behavior, instantaneous emissions of CO, HC and NO{sub X} were measured in the exhaust of a four-stroke motorcycle, equipped with a three-way catalyst and belonging to the Euro-3 legislative category. Experimental tests were executed on a chassis dynamometer bench in the laboratories of the National Research Council (Italy), during the Type Approval test cycle, at constant speed and under real-world driving cycles. This analytical-experimental investigation was executed with a methodology that improves vehicles emission assessment in comparison with the modeling approaches that are based on fixed legislative driving standards. The statistical processing results so obtained are very useful also in order to improve the database of emission models commonly used for estimating emissions from road transport sector, then they can be used to evaluate the environmental impact of last generation medium-size motorcycles under real driving behaviors.« less

78 FR 65206 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... engine speeds during steady- state operations. These actions are intended to alert pilots to avoid... intended to alert pilots to avoid certain engine speeds during steady- state operations, prevent failure of... decal as described in Bell Alert Service Bulletin (ASB) No. 430-05-34, dated June 10, 2005 (ASB 430-05...

78 FR 65200 - Airworthiness Directives; Bell Helicopter Textron Canada Limited (Bell) Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-31

... vibrations at certain engine speeds during steady- state operations. These actions are intended to alert... proposed requirements were intended to alert pilots to avoid certain engine speeds during steady-state... the change, and installing a decal as described in Bell Alert Service Bulletin (ASB) No. 407-05-67...

Stratified charge rotary engine - Internal flow studies at the MSU engine research laboratory

NASA Technical Reports Server (NTRS)

Hamady, F.; Kosterman, J.; Chouinard, E.; Somerton, C.; Schock, H.; Chun, K.; Hicks, Y.

1989-01-01

High-speed visualization and laser Doppler velocimetry (LDV) systems consisting of a 40-watt copper vapor laser, mirrors, cylindrical lenses, a high speed camera, a synchronization timing system, and a particle generator were developed for the study of the fuel spray-air mixing flow characteristics within the combustion chamber of a motored rotary engine. The laser beam is focused down to a sheet approximately 1 mm thick, passing through the combustion chamber and illuminates smoke particles entrained in the intake air. The light scattered off the particles is recorded by a high speed rotating prism camera. Movies are made showing the air flow within the combustion chamber. The results of a movie showing the development of a high-speed (100 Hz) high-pressure (68.94 MPa, 10,000 psi) fuel jet are also discussed. The visualization system is synchronized so that a pulse generated by the camera triggers the laser's thyratron.

Design of a high-speed digital processing element for parallel simulation

NASA Technical Reports Server (NTRS)

Milner, E. J.; Cwynar, D. S.

1983-01-01

A prototype of a custom designed computer to be used as a processing element in a multiprocessor based jet engine simulator is described. The purpose of the custom design was to give the computer the speed and versatility required to simulate a jet engine in real time. Real time simulations are needed for closed loop testing of digital electronic engine controls. The prototype computer has a microcycle time of 133 nanoseconds. This speed was achieved by: prefetching the next instruction while the current one is executing, transporting data using high speed data busses, and using state of the art components such as a very large scale integration (VLSI) multiplier. Included are discussions of processing element requirements, design philosophy, the architecture of the custom designed processing element, the comprehensive instruction set, the diagnostic support software, and the development status of the custom design.

Preliminary Data on the Effects of Inlet Pressure Distortions on the J57-P-1 Turbojet Engine

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Lubick, Robert J.; Einstein, Thomas H.

1954-01-01

An investigation to determine the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine with various inlet air-flow distortions was conducted in the altitude wind tunnel at the NACA Lewis laboratory. Along with a uniform inlet total-pressure distribution, one circumferential and three radial pressure distortions were investigated. Data were obtained over a complete range of compressor speeds both with and without intercompressor air bleed at a flight Mach number of 0.8 and at altitudes of 35,000 and 50,000 feet. Total-pressure distortions of the magnitudes investigated had very little effect on the steady-state operating line for either the outer or inner compressor. The small radial distortions investigated also had engine over that obtained with the uniform inlet pressure distribution. The circumferential distortion, however, raised the minimum speed at which the engine could operate without encountering surge when the intercompressor bleeds were closed. This increase in minimum speed resulted in a substantial reduction in the operable speed range accompanied by a reduction in the altitude operating limit.

Foil Bearing Starting Considerations and Requirements for Rotorcraft Engine Applications

NASA Technical Reports Server (NTRS)

Radil, Kevin C.; DellaCorte, Christopher

2009-01-01

Foil gas bearings under development for rotorcraft-sized, hot core engine applications have been susceptible to damage from the slow acceleration and rates typically encountered during the pre-ignition stage in conventional engines. Recent laboratory failures have been assumed to be directly linked to operating foil bearings below their lift-off speed while following conventional startup procedures for the engines. In each instance, the continuous sliding contact between the foils and shaft was believed to thermally overload the bearing and cause the engines to fail. These failures highlight the need to characterize required acceleration rates and minimum operating speeds for these applications. In this report, startup experiments were conducted with a large, rotorcraft engine sized foil bearing under moderate load and acceleration rates to identify the proper start procedures needed to avoid bearing failure. The results showed that a bearing under a 39.4 kPa static load can withstand a modest acceleration rate of 500 rpm/s and excessive loitering below the bearing lift-off speed provided an adequate solid lubricant is present.

Acoustic characteristics of a large-scale wind tunnel model of an upper-surface blown flap transport having two engines

NASA Technical Reports Server (NTRS)

Falarski, M. D.; Aoyagi, K.; Koenig, D. G.

1973-01-01

The upper-surface blown (USB) flap as a powered-lift concept has evolved because of the potential acoustic shielding provided when turbofan engines are installed on a wing upper surface. The results from a wind tunnel investigation of a large-scale USB model powered by two JT15D-1 turbofan engines are-presented. The effects of coanda flap extent and deflection, forward speed, and exhaust nozzle configuration were investigated. To determine the wing shielding the acoustics of a single engine nacelle removed from the model were also measured. Effective shielding occurred in the aft underwing quadrant. In the forward quadrant the shielding of the high frequency noise was counteracted by an increase in the lower frequency wing-exhaust interaction noise. The fuselage provided shielding of the opposite engine noise such that the difference between single and double engine operation was 1.5 PNdB under the wing. The effects of coanda flap deflection and extent, angle of attack, and forward speed were small. Forward speed reduced the perceived noise level (PNL) by reducing the wing-exhaust interaction noise.

Multivariate statistical analysis strategy for multiple misfire detection in internal combustion engines

NASA Astrophysics Data System (ADS)

Hu, Chongqing; Li, Aihua; Zhao, Xingyang

2011-02-01

This paper proposes a multivariate statistical analysis approach to processing the instantaneous engine speed signal for the purpose of locating multiple misfire events in internal combustion engines. The state of each cylinder is described with a characteristic vector extracted from the instantaneous engine speed signal following a three-step procedure. These characteristic vectors are considered as the values of various procedure parameters of an engine cycle. Therefore, determination of occurrence of misfire events and identification of misfiring cylinders can be accomplished by a principal component analysis (PCA) based pattern recognition methodology. The proposed algorithm can be implemented easily in practice because the threshold can be defined adaptively without the information of operating conditions. Besides, the effect of torsional vibration on the engine speed waveform is interpreted as the presence of super powerful cylinder, which is also isolated by the algorithm. The misfiring cylinder and the super powerful cylinder are often adjacent in the firing sequence, thus missing detections and false alarms can be avoided effectively by checking the relationship between the cylinders.

Some Effects of Injection Advance Angle, Engine-Jacket Temperature, and Speed on Combustion in a Compression-Ignition Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Waldron, C D

1936-01-01

An optical indicator and a high-speed motion-picture camera capable of operating at the rate of 2,000 frames per second were used to record simultaneously the pressure development and the flame formation in the combustion chamber of the NACA combustion apparatus. Tests were made at engine speeds of 570 and 1,500 r.p.m. The engine-jacket temperature was varied from 100 degrees to 300 degrees F. And the injection advance angle from 13 degrees after top center to 120 degrees before top center. The results show that the course of the combustion is largely controlled by the temperature and pressure of the air in the chamber from the time the fuel is injected until the time at which combustion starts and by the ignition lag. The conclusion is presented that in a compression-ignition engine with a quiescent combustion chamber the ignition lag should be the longest that can be used without excessive rates of pressure rise; any further shortening of the ignition lag decreased the effective combustion of the engine.

High-Speed, High-Temperature Finger Seal Test Evaluated

NASA Technical Reports Server (NTRS)

Proctor, Margaret P.

2003-01-01

A finger seal, designed and fabricated by Honeywell Engines, Systems and Services, was tested at the NASA Glenn Research Center at surface speeds up to 1200 ft/s, air temperatures up to 1200 F, and pressures across the seal of 75 psid. These are the first test results obtained with NASA s new High-Temperature, High-Speed Turbine Seal Test Rig (see the photograph). The finger seal is an innovative design recently patented by AlliedSignal Engines, which has demonstrated considerably lower leakage than commonly used labyrinth seals and is considerably cheaper than brush seals. The cost to produce finger seals is estimated to be about half of the cost to produce brush seals. Replacing labyrinth seals with fingers seals at locations that have high-pressure drops in gas turbine engines, typically main engine and thrust seals, can reduce air leakage at each location by 50 percent or more. This directly results in a 0.7- to 1.4-percent reduction in specific fuel consumption and a 0.35- to 0.7-percent reduction in direct operating costs . Because the finger seal is a contacting seal, this testing was conducted to address concerns about its heat generation and life capability at the higher speeds and temperatures required for advanced engines. The test results showed that the seal leakage and wear performance are acceptable for advanced engines.

F1 style MGU-H applied to the turbocharger of a gasoline hybrid electric passenger car

NASA Astrophysics Data System (ADS)

Boretti, Albert

2017-12-01

We consider a turbocharged gasoline direct injection (DI) engine featuring a motor-generator-unit (MGU-H) fitted on the turbocharger shaft. The MGU-H receives or delivers energy to the same energy storage (ES) of the hybrid power unit that comprises a motor-generator unit on the driveline (MGU-K) in addition to the internal combustion engine (ICE). The energy supply from the ES is mostly needed during sharp accelerations to avoid turbo-lag, and to boost torque at low speeds. At low speeds, it also improves the ratio of engine crankshaft power to fuel flow power, as well as the ratio of engine crankshaft plus turbocharger shaft power to fuel flow power. The energy supply to the ES is possible at high speeds and loads, where otherwise the turbine could have been waste gated, and during decelerations. This improves the ratio of engine crankshaft plus turbocharger shaft power to fuel flow power.

Driving Skills of Young Adults with Developmental Coordination Disorder: Regulating Speed and Coping with Distraction

ERIC Educational Resources Information Center

de Oliveira, Rita F.; Wann, John P.

2011-01-01

In two experiments, we used an automatic car simulator to examine the steering control, speed regulation and response to hazards of young adults with developmental coordination disorder (DCD) and limited driving experience. In Experiment 1 participants either used the accelerator pedal to regulate their speed, or used the brake pedal when they…

Performance of a 13-Stage Development Compressor for the J40-WE-24 Engine at Equivalent Speeds from 30 to 112 Percent of Design

NASA Technical Reports Server (NTRS)

Hatch, James E.; Lucas, James G.; Finger, Harold B.

1953-01-01

The performance of a 13-stage development comressor for the J40-WE-24 engine has been determined at equivalent speeds from 30 to 112 percent of design. The design total-pressure ratio of 6.0 and the design weight flow of 164 pounds per second were not attained, An analysis was conducted to determine the reasons for the poor performance at the design and over-design speed. The analysis indicated that most of the difficulty could be attributed to the fact that the first stage was overcompromised to favor part-speed performance,

Performance of J33 turbojet engine with shaft-power extraction III : turbine performance

NASA Technical Reports Server (NTRS)

Huppert, M C; Nettles, J C

1949-01-01

The performance of the turbine component of a J33 turbojet engine was determined over a range of turbine speeds from 8000 to 11,500 rpm.Turbine-inlet temperature was varied from the minimum required to drive the compressor to a maximum of approximately 2000 degrees R at each of several intermediate turbine speeds. Data are presented that show the horsepower developed by the turbine per pound of gas flow. The relation between turbine-inlet stagnation pressure, turbine-outlet stagnation pressure, and turbine-outlet static pressure was established. The turbine-weight-flow parameter varied from 39.2 to 43.6. The maximum turbine efficiency measured was 0.86 at a pressure ratio of 3.5 and a ratio of blade speed to theoretical nozzle velocity of 0.39. A generalized performance map of the turbine-horsepower parameter plotted against the turbine-speed parameter indicated that the best turbine efficiency is obtained when the turbine power is 10 percent greater than the compressor horsepower. The variation of efficiency with the ratio of blade speed to nozzle velocity indicated that the turbine operates at a speed above that for maximum efficiency when the engine is operated normally with the 19-inch-diameter jet nozzle.

Examination of Wave Speed in Rotating Detonation Engines Using Simplified Computational Fluid Dynamics

NASA Technical Reports Server (NTRS)

Paxson, Daniel E.

2018-01-01

A simplified, two-dimensional, computational fluid dynamic (CFD) simulation, with a reactive Euler solver is used to examine possible causes for the low detonation wave propagation speeds that are consistently observed in air breathing rotating detonation engine (RDE) experiments. Intense, small-scale turbulence is proposed as the primary mechanism. While the solver cannot model this turbulence, it can be used to examine the most likely, and profound effect of turbulence. That is a substantial enlargement of the reaction zone, or equivalently, an effective reduction in the chemical reaction rate. It is demonstrated that in the unique flowfield of the RDE, a reduction in reaction rate leads to a reduction in the detonation speed. A subsequent test of reduced reaction rate in a purely one-dimensional pulsed detonation engine (PDE) flowfield yields no reduction in wave speed. The reasons for this are explained. The impact of reduced wave speed on RDE performance is then examined, and found to be minimal. Two other potential mechanisms are briefly examined. These are heat transfer, and reactive mixture non-uniformity. In the context of the simulation used for this study, both mechanisms are shown to have negligible effect on either wave speed or performance.

Aerodynamic Design of a Dual-Flow Mach 7 Hypersonic Inlet System for a Turbine-Based Combined-Cycle Hypersonic Propulsion System

NASA Technical Reports Server (NTRS)

Sanders, Bobby W.; Weir, Lois J.

2008-01-01

A new hypersonic inlet for a turbine-based combined-cycle (TBCC) engine has been designed. This split-flow inlet is designed to provide flow to an over-under propulsion system with turbofan and dual-mode scramjet engines for flight from takeoff to Mach 7. It utilizes a variable-geometry ramp, high-speed cowl lip rotation, and a rotating low-speed cowl that serves as a splitter to divide the flow between the low-speed turbofan and the high-speed scramjet and to isolate the turbofan at high Mach numbers. The low-speed inlet was designed for Mach 4, the maximum mode transition Mach number. Integration of the Mach 4 inlet into the Mach 7 inlet imposed significant constraints on the low-speed inlet design, including a large amount of internal compression. The inlet design was used to develop mechanical designs for two inlet mode transition test models: small-scale (IMX) and large-scale (LIMX) research models. The large-scale model is designed to facilitate multi-phase testing including inlet mode transition and inlet performance assessment, controls development, and integrated systems testing with turbofan and scramjet engines.

Performance of a Laser Ignited Multicylinder Lean Burn Natural Gas Engine

DOE PAGES

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.; ...

2017-06-06

Market demands for lower fueling costs and higher specific powers in stationary natural gas engines has engine designs trending towards higher in-cylinder pressures and leaner combustion operation. However, Ignition remains as the main limiting factor in achieving further performance improvements in these engines. Addressing this concern, while incorporating various recent advances in optics and laser technologies, laser igniters were designed and developed through numerous iterations. Final designs incorporated water-cooled, passively Q-switched, Nd:YAG micro-lasers that were optimized for stable operation under harsh engine conditions. Subsequently, the micro-lasers were installed in the individual cylinders of a lean-burn, 350 kW, inline 6-cylinder, open-chamber,more » spark ignited engine and tests were conducted. To the best of our knowledge, this is the world’s first demonstration of a laser ignited multi-cylinder natural gas engine. The engine was operated at high-load (298 kW) and rated speed (1800 rpm) conditions. Ignition timing sweeps and excess-air ratio (λ) sweeps were performed while keeping the NOx emissions below the USEPA regulated value (BSNOx < 1.34 g/kW-hr), and while maintaining ignition stability at industry acceptable values (COV_IMEP <5 %). Through such engine tests, the relative merits of (i) standard electrical ignition system, and (ii) laser ignition system were determined. In conclusion, a rigorous combustion data analysis was performed and the main reasons leading to improved performance in the case of laser ignition were identified.« less

Performance of a Laser Ignited Multicylinder Lean Burn Natural Gas Engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Almansour, Bader; Vasu, Subith; Gupta, Sreenath B.

Market demands for lower fueling costs and higher specific powers in stationary natural gas engines has engine designs trending towards higher in-cylinder pressures and leaner combustion operation. However, Ignition remains as the main limiting factor in achieving further performance improvements in these engines. Addressing this concern, while incorporating various recent advances in optics and laser technologies, laser igniters were designed and developed through numerous iterations. Final designs incorporated water-cooled, passively Q-switched, Nd:YAG micro-lasers that were optimized for stable operation under harsh engine conditions. Subsequently, the micro-lasers were installed in the individual cylinders of a lean-burn, 350 kW, inline 6-cylinder, open-chamber,more » spark ignited engine and tests were conducted. To the best of our knowledge, this is the world’s first demonstration of a laser ignited multi-cylinder natural gas engine. The engine was operated at high-load (298 kW) and rated speed (1800 rpm) conditions. Ignition timing sweeps and excess-air ratio (λ) sweeps were performed while keeping the NOx emissions below the USEPA regulated value (BSNOx < 1.34 g/kW-hr), and while maintaining ignition stability at industry acceptable values (COV_IMEP <5 %). Through such engine tests, the relative merits of (i) standard electrical ignition system, and (ii) laser ignition system were determined. In conclusion, a rigorous combustion data analysis was performed and the main reasons leading to improved performance in the case of laser ignition were identified.« less

Summary of state speed laws

DOT National Transportation Integrated Search

2006-04-01

This summary reports only the status of State statutes or regulations that are concerned with either speed limit or speed-related violations. Local laws are not reported. Unless otherwise indicated, the status of the State laws or regulations reporte...

Summary of state speed laws

DOT National Transportation Integrated Search

2007-08-01

This summary reports only the status of State statutes or regulations that are concerned with either speed limit or speed-related violations. Local laws are not reported. Unless otherwise indicated, the status of the State laws or regulations reporte...

Time Resolved Digital PIV Measurements of Flow Field Cyclic Variation in an Optical IC Engine

NASA Astrophysics Data System (ADS)

Jarvis, S.; Justham, T.; Clarke, A.; Garner, C. P.; Hargrave, G. K.; Halliwell, N. A.

2006-07-01

Time resolved digital particle image velocimetry (DPIV) experimental data is presented for the in-cylinder flow field development of a motored four stroke spark ignition (SI) optical internal combustion (IC) engine. A high speed DPIV system was employed to quantify the velocity field development during the intake and compression stroke at an engine speed of 1500 rpm. The results map the spatial and temporal development of the in-cylinder flow field structure allowing comparison between traditional ensemble average and cycle average flow field structures. Conclusions are drawn with respect to engine flow field cyclic variations.

Fluid flow and fuel-air mixing in a motored two-dimensional Wankel rotary engine

NASA Technical Reports Server (NTRS)

Shih, T. I.-P.; Nguyen, H. L.; Stegeman, J.

1986-01-01

The implicit-factored method of Beam and Warming was employed to obtain numerical solutions to the conservation equations of mass, species, momentum, and energy to study the unsteady, multidimensional flow and mixing of fuel and air inside the combustion chambers of a two-dimensional Wankel rotary engine under motored conditions. The effects of the following engine design and operating parameters on fluid flow and fuel-air mixing during the intake and compression cycles were studied: engine speed, angle of gaseous fuel injection during compression cycle, and speed of the fuel leaving fuel injector.

Fluid flow and fuel-air mixing in a motored two-dimensional Wankel rotary engine

NASA Astrophysics Data System (ADS)

Shih, T. I.-P.; Nguyen, H. L.; Stegeman, J.

1986-06-01

The implicit-factored method of Beam and Warming was employed to obtain numerical solutions to the conservation equations of mass, species, momentum, and energy to study the unsteady, multidimensional flow and mixing of fuel and air inside the combustion chambers of a two-dimensional Wankel rotary engine under motored conditions. The effects of the following engine design and operating parameters on fluid flow and fuel-air mixing during the intake and compression cycles were studied: engine speed, angle of gaseous fuel injection during compression cycle, and speed of the fuel leaving fuel injector.

Aerodynamic and acoustic behavior of a YF-12 inlet at static conditions

NASA Technical Reports Server (NTRS)

Bangert, L. H.; Feltz, E. P.; Godby, L. A.; Miller, L. D.

1981-01-01

An aeroacoustic test program to determine the cause of YF-12 inlet noise suppression was performed with a YF-12 aircraft at ground static conditions. Data obtained over a wide range of engine speeds and inlet configurations are reported. Acoustic measurements were made in the far field and aerodynamic and acoustic measurements were made inside the inlet. The J-58 test engine was removed from the aircraft and tested separately with a bellmouth inlet. The far field noise level was significantly lower for the YF-12 inlet than for the bellmouth inlet at engine speeds above 5500 rpm. There was no evidence that noise suppression was caused by flow choking. Multiple pure tones were reduced and the spectral peak near the blade passing frequency disappeared in the region of the spike support struts at engine speeds between 6000 and 6600 rpm.

[Particulate distribution characteristics of Chinese phrase V diesel engine based on butanol-diesel blends].

PubMed

Lou, Di-Ming; Xu, Ning; Fan, Wen-Jia; Zhang, Tao

2014-02-01

With a common rail diesel engine without any modification and the engine exhaust particle number and particle size analyzer EEPS, this study used the air-fuel ratio to investigate the particulate number concentration, mass concentration and number distribution characteristics of a diesel engine fueled with butanol-diesel blends (Bu10, Bu15, Bu20, Bu30 and Bu40) and petroleum diesel. The results show: for all test fuels, the particle number distributions turn to be unimodal. With the increasing of butanol, numbers of nucleation mode particles and small accumulation mode particle decrease. At low speed and low load conditions, the number of large accumulation mode particle increases slightly, but under higher speed and load conditions, the number does not increase. When the fuels contain butanol, the total particle number concentration and mass concentration in all conditions decrease and that is more obvious at high speed load.

Backup control airstart performance on a digital electronic engine control-equipped F100-engine

NASA Technical Reports Server (NTRS)

Johnson, J. B.

1984-01-01

The air start capability of a backup control (BUC) was tested for a digital electronic engine control (DEEC) equipped F100 engine, which was installed in an F-15 aircraft. Two air start schedules were tested. Using the group 1 start schedule, based on a 40 sec timer, an air speed of 300 knots was required to ensure successful 40 and 25% BUC mode spooldown airstarts. If core rotor speed (N2) was less than 40% a stall would occur when the start bleed closed, 40 sec after initiation of the air start. All jet fuel starter (JFS) assisted air starts were successful with the group 1 start schedule. For the group 2 schedule, the time between pressurization and start bleed closure ranged between 50 sec and 72 sec. Idle rps was lower than the desired 65% for air starts at higher altitudes and lower air speeds.

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds... Model means all commercial aircraft turbine engines which are of the same general series, displacement...

Study and Sub-System Optimization of Propulsion and Drive Systems for the Large Civil TiltRotor (LCTR2) Rotorcraft

NASA Technical Reports Server (NTRS)

Robuck, Mark; Wilkerson, Joseph; Snyder, Christopher A.; Zhang, Yiyi; Maciolek, Bob

2013-01-01

In a series of study tasks conducted as a part of NASA's Fundamental Aeronautics Program, Rotary Wing Project, Boeing and Rolls-Royce explored propulsion, drive, and rotor system options for the NASA Large Civil Tilt Rotor (LCTR2) concept vehicle. The original objective of this study was to identify engine and drive system configurations to reduce rotor tip speed during cruise conditions and quantify the associated benefits. Previous NASA studies concluded that reducing rotor speed (from 650 fps hover tip speed) during cruise would reduce vehicle gross weight and fuel burn. Initially, rotor cruise speed ratios of 54% of the hover tip speed were of most interest during operation at cruise air speed of 310 ktas. Interim results were previously reported1 for cruise tip speed ratios of 100%, 77%, and 54% of the hover tip speed using engine and/or gearbox features to achieve the reduction. Technology levels from commercial off-the-shelf (COTS), through entry-in-service (EIS) dates of 2025 and 2035 were considered to assess the benefits of advanced technology on vehicle gross weight and fuel burn. This technical paper presents the final study results in terms of vehicle sizing and fuel burn as well as Operational and Support (O&S) costs. New vehicle sizing at rotor tip speed reduced to 65% of hover is presented for engine performance with an EIS 2035 fixed geometry variable speed power turbine. LCTR2 is also evaluated for missions range cases of 400, 600, 800, 1000, and 1200 nautical miles and cruise air speeds of 310, 350 and 375 ktas.

An experimental and modeling study investigating the ignition delay in a military diesel engine running hexadecane (cetane) fuel

DOE PAGES

Cowart, Jim S.; Fischer, Warren P.; Hamilton, Leonard J.; ...

2013-02-01

In an effort aimed at predicting the combustion behavior of a new fuel in a conventional diesel engine, cetane (n-hexadecane) fuel was used in a military engine across the entire speed–load operating range. The ignition delay was characterized for this fuel at each operating condition. A chemical ignition delay was also predicted across the speed–load range using a detailed chemical kinetic mechanism with a constant pressure reactor model. At each operating condition, the measured in-cylinder pressure and predicted temperature at the start of injection were applied to the detailed n-hexadecane kinetic mechanism, and the chemical ignition delay was predicted withoutmore » any kinetic mechanism calibration. The modeling results show that fuel–air parcels developed from the diesel spray with an equivalence ratio of 4 are the first to ignite. The chemical ignition delay results also showed decreasing igntion delays with increasing engine load and speed, just as the experimental data revealed. At lower engine speeds and loads, the kinetic modeling results show the characteristic two-stage negative temperature coefficient behavior of hydrocarbon fuels. However, at high engine speeds and loads, the reactions do not display negative temperature coefficient behavior, as the reactions proceed directly into high-temperature pathways due to higher temperatures and pressure at injection. A moderate difference between the total and chemical ignition delays was then characterized as a phyical delay period that scales inversely with engine speed. This physical delay time is representative of the diesel spray development time and is seen to become a minority fraction of the total igntion delay at higher engine speeds. In addition, the approach used in this study suggests that the ignition delay and thus start of combustion may be predicted with reasonable accuracy using kinetic modeling to determine the chemical igntion delay. Then, in conjunction with the physical delay time (experimental or modeling based), a new fuel’s acceptability in a conventional engine could be assessed by determining that the total ignition delay is not too short or too long.« less

Emulation study on system characteristic of high pressure common-rail fuel injection system for marine medium-speed diesel engine

NASA Astrophysics Data System (ADS)

Wang, Qinpeng; Yang, Jianguo; Xin, Dong; He, Yuhai; Yu, Yonghua

2018-05-01

In this paper, based on the characteristic analyzing of the mechanical fuel injection system for the marine medium-speed diesel engine, a sectional high-pressure common rail fuel injection system is designed, rated condition rail pressure of which is 160MPa. The system simulation model is built and the performance of the high pressure common rail fuel injection system is analyzed, research results provide the technical foundation for the system engineering development.

Research on Correlation between Vehicle Cycle and Engine Cycle in Heavy-duty commercial vehicle

NASA Astrophysics Data System (ADS)

lin, Chen; Zhong, Wang; Shuai, Liu

2017-12-01

In order to study the correlation between vehicle cycle and engine cycle in heavy commercial vehicles, the conversion model of vehicle cycle to engine cycle is constructed based on the vehicle power system theory and shift strategy, which considers the verification on diesel truck. The results show that the model has high rationality and reliability in engine operation. In the acceleration process of high speed, the difference of model gear selection leads to the actual deviation. Compared with the drum test, the engine speed distribution obtained by the model deviates to right, which fits to the lower grade. The grade selection has high influence on the model.

Investigation of Water-spray Cooling of Turbine Blades in a Turbojet Engine

NASA Technical Reports Server (NTRS)

Freche, John C; Stelpflug, William J

1953-01-01

An analytical and experimental investigation was made with a J33-A-9 engine to determine the effectiveness of spray cooling as a means of increasing thrust by permitting engine operation at inlet-gas temperatures and speeds above rated. With the assumption of adequate spray cooling at a coolant-to-gas flow ratio of 3 percent, calculations for the sea-level static condition indicated a thrust may be achieved by engine operation at an inlet-gas temperature of 2000 degrees F and an overspeed of 10 percent. Of the water-injection configurations investigated experimentally, those located in the inner ring of the stator diaphragm provided the best cooling at rated engine speed.

SOAC - State-of-the-Art Car Engineering Tests at Department of Transportation High Speed Ground Test Center : Volume 7. Post-Repair Tests.

DOT National Transportation Integrated Search

1976-11-01

This document presents the test results from the State-of-the-Art Post-Repair Engineering Test Program conducted at the DOT High-Speed Ground Test Center, Pueblo, Colorado, from March 18th to 29th, 1974. The SOAC has been developed under UMTA's Urban...

Power of a Finite Speed Carnot Engine

ERIC Educational Resources Information Center

Agrawal, D. C.; Menon, V. J.

2009-01-01

A model of an endoreversible Carnot engine is considered where the piston moves with a constant speed "u." Expressions for the cycle time [tau] for the four branches, as well as output power, P[subscript W], are derived and the optimized root for maximum power is obtained in closed form. Our results are discussed in terms of the isothermal…

A Finite Speed Curzon-Ahlborn Engine

ERIC Educational Resources Information Center

Agrawal, D. C.

2009-01-01

Curzon and Ahlborn achieved finite power output by introducing the concept of finite rate of heat transfer in a Carnot engine. The finite power can also be achieved through a finite speed of the piston on the four branches of the Carnot cycle. The present paper combines these two approaches to study the behaviour of output power in terms of…

40 CFR Appendix II to Part 1039 - Steady-State Duty Cycles

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Steady-State Duty Cycles II Appendix... Appendix II to Part 1039—Steady-State Duty Cycles (a) The following duty cycles apply for constant-speed engines: (1) The following duty cycle applies for discrete-mode testing: D2 mode number Engine speed...

System simulation of direct-current speed regulation based on Simulink

NASA Astrophysics Data System (ADS)

Yang, Meiying

2018-06-01

Many production machines require the smooth adjustment of speed in a certain range In the process of modern industrial production, and require good steady-state and dynamic performance. Direct-current speed regulation system with wide speed regulation range, small relative speed variation, good stability, large overload capacity, can bear the frequent impact load, can realize stepless rapid starting-braking and inversion of frequency and other good dynamic performances, can meet the different kinds of special operation requirements in production process of automation system. The direct-current power drive system is almost always used in the field of drive technology of high performance for a long time.

14 CFR 23.73 - Reference landing approach speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Reference landing approach speed. 23.73... Reference landing approach speed. (a) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of 6,000 pounds or less maximum weight, the reference landing approach speed, VREF, must...

40 CFR 205.54-1 - Low speed sound emission test procedures.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 25 2011-07-01 2011-07-01 false Low speed sound emission test....54-1 Low speed sound emission test procedures. (a) Instrumentation. The following instrumentation... checked annually to verify that its output has not changed. (3) An engine-speed tachometer which is...

14 CFR 23.73 - Reference landing approach speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Reference landing approach speed. 23.73... Reference landing approach speed. (a) For normal, utility, and acrobatic category reciprocating engine-powered airplanes of 6,000 pounds or less maximum weight, the reference landing approach speed, VREF, must...

Feedback control of a Darrieus wind turbine and optimization of the produced energy

NASA Astrophysics Data System (ADS)

Maurin, T.; Henry, B.; Devos, F.; de Saint Louvent, B.; Gosselin, J.

1984-03-01

A microprocessor-driven control system, applied to the feedback control of a Darrieus wind turbine is presented. The use of a dc machine as a generator to recover the energy and as a motor to start the engine, allows simplified power electronics. The architecture of the control unit is built to ensure four different functions: starting, optimization of the recoverable energy, regulation of the speed, and braking. An experimental study of the system in a wind tunnel allowed optimization of the coefficients of the proportional and integral (pi) control algorithm. The electrical energy recovery was found to be much more efficient using the feedback system than without the control unit. This system allows a better characterization of the wind turbine and a regulation adapted to the wind statistics observed in one given geographical location.

14 CFR 33.63 - Vibration.

Code of Federal Regulations, 2011 CFR

2011-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.63 Vibration. Each engine... range of rotational speeds and power/thrust, without inducing excessive stress in any engine part...

14 CFR 33.63 - Vibration.

Code of Federal Regulations, 2010 CFR

2010-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.63 Vibration. Each engine... range of rotational speeds and power/thrust, without inducing excessive stress in any engine part...

Application of several variable-valve-timing concepts to an LHR engine

NASA Technical Reports Server (NTRS)

Morel, T.; Keribar, R.; Sawlivala, M.; Hakim, N.

1987-01-01

The paper discusses advantages provided by electronically controlled hydraulically activated valves (ECVs) when applied to low heat rejection (LHR) engines. The ECV concept provides additional engine control flexibility by allowing for a variable valve timing as a function of speed and load, or for a given transient condition. The results of a study carried out to assess the benefits that this flexibility can offer to an LHR engine indicated that, when judged on the benefits to BSFC, volumetric efficiency, and peak firing pressure, ECVs would provide only modest benefits in comparison to conventional valve profiles. It is noted, however, that once installed on the engine, the ECVs would permit a whole range of certain more sophisticated variable valve timing strategies not otherwise possible, such as high compression cranking, engine braking, cylinder cutouts, and volumetric efficiency timing with engine speed.

Conversion and control of an all-terrain vehicle for use as an autonomous mobile robot

NASA Astrophysics Data System (ADS)

Jacob, John S.; Gunderson, Robert W.; Fullmer, R. R.

1998-08-01

A systematic approach to ground vehicle automation is presented, combining low-level controls, trajectory generation and closed-loop path correction in an integrated system. Development of cooperative robotics for precision agriculture at Utah State University required the automation of a full-scale motorized vehicle. The Triton Predator 8- wheeled skid-steering all-terrain vehicle was selected for the project based on its ability to maneuver precisely and the simplicity of controlling the hydrostatic drivetrain. Low-level control was achieved by fitting an actuator on the engine throttle, actuators for the left and right drive controls, encoders on the left and right drive shafts to measure wheel speeds, and a signal pick-off on the alternator for measuring engine speed. Closed loop control maintains a desired engine speed and tracks left and right wheel speeds commands. A trajectory generator produces the wheel speed commands needed to steer the vehicle through a predetermined set of map coordinates. A planar trajectory through the points is computed by fitting a 2D cubic spline over each path segment while enforcing initial and final orientation constraints at segment endpoints. Acceleration and velocity profiles are computed for each trajectory segment, with the velocity over each segment dependent on turning radius. Left and right wheel speed setpoints are obtained by combining velocity and path curvature for each low-level timestep. The path correction algorithm uses GPS position and compass orientation information to adjust the wheel speed setpoints according to the 'crosstrack' and 'downtrack' errors and heading error. Nonlinear models of the engine and the skid-steering vehicle/ground interaction were developed for testing the integrated system in simulation. These test lead to several key design improvements which assisted final implementation on the vehicle.

Aerodynamic characteristics of a six-jet V/STOL configuration with four swing-out lift jets in the transition speed range

NASA Technical Reports Server (NTRS)

Carter, A. W.

1970-01-01

A wind-tunnel investigation has been made of the longitudinal aerodynamic characteristics and jet-interference effects of a model of a jet V/STOL variable-sweep fighter airplane that employs four direct-lift engines which swing out from the fuselage and two lift-cruise engines located in the rear part of the fuselage. Data were obtained with two wing areas for various forward speeds and power conditions in the transition speed range. The data are presented without analysis or discussion.

Towards a better understanding of helicopter external noise

NASA Astrophysics Data System (ADS)

Damongeot, A.; Dambra, F.; Masure, B.

The problem of helicopter external noise generation is studied taking into consideration simultaneously the multiple noise sources: rotor rotational-, rotor broadband -, and engine noise. The main data are obtained during flight tests of the rather quiet AS 332 Super Puma. The flight procedures settled by ICAO for noise regulations are used: horizontal flyover at 90 percent of the maximum speed, approach at minimum power velocity, take-off at best rate of climb. Noise source levels are assessed through narrow band analysis of ground microphone recordings, ground measurements of engine noise and theoretical means. With the perceived noise level unit used throughout the study, relative magnitude of noise sources is shown to be different from that obtained with linear noise unit. A parametric study of the influence of some helicopter parameters on external noise has shown that thickness-tapered, chord-tapered, and swept-back blade tips are good means to reduce the overall noise level in flyover and approach.

46 CFR 121.620 - Propulsion engine control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

46 CFR 121.620 - Propulsion engine control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

46 CFR 121.620 - Propulsion engine control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

46 CFR 121.620 - Propulsion engine control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

40 CFR 89.410 - Engine test cycle.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., except constant speed engines, engines rated under 19 kW, and propulsion marine diesel engines. (2) The 5... this subpart shall be used for propulsion marine diesel engines. (5) Notwithstanding the provisions of... rated under 19 kW; or (B) Propulsion marine diesel engines, provided the propulsion marine diesel...

46 CFR 121.620 - Propulsion engine control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hessell, Steven M.; Morris, Robert L.; McGrogan, Sean W.

A powertrain including an engine and torque machines is configured to transfer torque through a multi-mode transmission to an output member. A method for controlling the powertrain includes employing a closed-loop speed control system to control torque commands for the torque machines in response to a desired input speed. Upon approaching a power limit of a power storage device transferring power to the torque machines, power limited torque commands are determined for the torque machines in response to the power limit and the closed-loop speed control system is employed to determine an engine torque command in response to the desiredmore » input speed and the power limited torque commands for the torque machines.« less

Evaluation of an Outer Loop Retrofit Architecture for Intelligent Turbofan Engine Thrust Control

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Sowers, T. Shane

2006-01-01

The thrust control capability of a retrofit architecture for intelligent turbofan engine control and diagnostics is evaluated. The focus of the study is on the portion of the hierarchical architecture that performs thrust estimation and outer loop thrust control. The inner loop controls fan speed so the outer loop automatically adjusts the engine's fan speed command to maintain thrust at the desired level, based on pilot input, even as the engine deteriorates with use. The thrust estimation accuracy is assessed under nominal and deteriorated conditions at multiple operating points, and the closed loop thrust control performance is studied, all in a complex real-time nonlinear turbofan engine simulation test bed. The estimation capability, thrust response, and robustness to uncertainty in the form of engine degradation are evaluated.

Adaptive Gas Turbine Engine Control for Deterioration Compensation Due to Aging

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Parker, Khary I.; Chatterjee, Santanu

2003-01-01

This paper presents an ad hoc adaptive, multivariable controller tuning rule that compensates for a thrust response variation in an engine whose performance has been degraded though use and wear. The upset appears when a large throttle transient is performed such that the engine controller switches from low-speed to high-speed mode. A relationship was observed between the level of engine degradation and the overshoot in engine temperature ratio, which was determined to cause the thrust response variation. This relationship was used to adapt the controller. The method is shown to work very well up to the operability limits of the engine. Additionally, since the level of degradation can be estimated from sensor data, it would be feasible to implement the adaptive control algorithm on-line.

Genetically modified organisms: an analysis of the regulatory framework currently employed within the European Union.

PubMed

Gent, R N

1999-09-01

Genetic engineering technology is starting to bring many commercial products to the market. These genetically modified organisms (GMOs) and their derived products are subject to topical debate as to their benefits and risks. The strengths and weaknesses of the regulatory framework that controls their development and application is central to the question of whether this technology poses significant risk to the public health during this critical phase of its evolution. A critical review was carried out of the legal framework regulating the contained use, deliberate release and some aspects of consumer protection relevant to the control of GMOs in Europe and the United Kingdom. The current legal framework is failing to provide a speed of adaptation commensurate with the development of the science of genetic engineering; failing to properly respond to democratic control; failing to resolve significant conflict between the protection of free markets and protection of public health and the environment; and failing to implement obligations on biodiversity. The present legal framework must be replaced. Current European Union proposals for new standards of regulation are welcome, but provide only for further incremental change, and do not address some significant fundamental flaws in our current laws.

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

14 CFR 34.1 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... series, displacement, and design characteristics and are approved under the same type certificate... engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

Ultrafine particle emission characteristics of diesel engine by on-board and test bench measurement.

PubMed

Huang, Cheng; Lou, Diming; Hu, Zhiyuan; Tan, Piqiang; Yao, Di; Hu, Wei; Li, Peng; Ren, Jin; Chen, Changhong

2012-01-01

This study investigated the emission characteristics of ultrafine particles based on test bench and on-board measurements. The bench test results showed the ultrafine particle number concentration of the diesel engine to be in the range of (0.56-8.35) x 10(8) cm(-3). The on-board measurement results illustrated that the ultrafine particles were strongly correlated with changes in real-world driving cycles. The particle number concentration was down to 2.0 x 10(6) cm(-3) and 2.7 x 10(7) cm(-3) under decelerating and idling operations and as high as 5.0 x 10(8) cm(-3) under accelerating operation. It was also indicated that the particle number measured by the two methods increased with the growth of engine load at each engine speed in both cases. The particle number presented a "U" shaped distribution with changing speed at high engine load conditions, which implies that the particle number will reach its lowest level at medium engine speeds. The particle sizes of both measurements showed single mode distributions. The peak of particle size was located at about 50-80 nm in the accumulation mode particle range. Nucleation mode particles will significantly increase at low engine load operations like idling and decelerating caused by the high concentration of unburned organic compounds.

Continued Investigation of Leakage and Power Loss Test Results for Competing Turbine Engine Seals

NASA Technical Reports Server (NTRS)

Delgado, Irebert R.; Proctor, Margaret P.

2006-01-01

Secondary seal leakage in jet engine applications results in power losses to the engine cycle. Likewise, seal power loss in jet engines not only result in efficiency loss but also increase the heat input into the engine resulting in reduced component lives. Experimental work on labyrinth and annular seals was performed at NASA Glenn Research Center to quantify seal leakage and power loss at various temperatures, seal pressure differentials, and surface speeds. Data from annular and labyrinth seals are compared with previous brush and finger seal test results. Data are also compared to literature. Annular and labyrinth seal leakage rates are 2 to 3 times greater than brush and finger seal rates. Seal leakage decreases with increasing speed but increases with increasing test temperature due to thermal expansion mismatch. Also seal power loss increases with surface speed, seal pressure differential, mass flow rate, and radial clearance. Annular and labyrinth seal power losses were higher than those of brush or finger seal data. The brush seal power loss was 15 to 30 percent lower than annular and labyrinth seal power loss.

Control logic for exhaust gas driven turbocharger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adeff, G.A.

1991-12-31

This patent describes a method of controlling an exhaust gas driven turbocharger supplying charge air for an internal combustion engine powering vehicle, the turbocharger being adjustable from a normal mode to a power mode in which the charge air available to the engine during vehicle acceleration is increased over that available when the turbocharger is in the normal mode, the vehicle including engine power control means switchable by the vehicle operator from a normal mode to a power mode so that the vehicle operator may selectively elect either the normal mode or the power mode, comprising the steps of measuringmore » the speed of the vehicle, permitting the vehicle operator to elect either the power mode or the normal mode for a subsequent vehicle acceleration, and then adjusting the turbocharger to the power mode when the speed of the vehicle is less than a predetermined reference speed and the vehicle operator has elected to power mode to increase the charge air available to the engine and thereby increasing engine power on a subsequent acceleration of the vehicle.« less

Preliminary Results of an Altitude-Wind-Tunnel Investigation of an Axial-Flow Gas Turbine-Propeller Engine. 4; Compressor and Turbine Performance Characteristics

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Saari, Martin J.

1948-01-01

As part of an investigation of the performance and operational characteristics of the axial-flow gas turbine-propeller engine, conducted in the Cleveland altitude wind tunnel, the performance characteristics of the compressor and the turbine were obtained. The data presented were obtained at a compressor-inlet ram-pressure ratio of 1.00 for altitudes from 5000 to 35,000 feet, engine speeds from 8000 to 13,000 rpm, and turbine-inlet temperatures from 1400 to 2100 R. The highest compressor pressure ratio obtained was 6.15 at a corrected air flow of 23.7 pounds per second and a corrected turbine-inlet temperature of 2475 R. Peak adiabatic compressor efficiencies of about 77 percent were obtained near the value of corrected air flow corresponding to a corrected engine speed of 13,000 rpm. This maximum efficiency may be somewhat low, however, because of dirt accumulations on the compressor blades. A maximum adiabatic turbine efficiency of 81.5 percent was obtained at rated engine speed for all altitudes and turbine-inlet temperatures investigated.

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine. 4; Compressor and Turbine Performance Characteristics

NASA Technical Reports Server (NTRS)

Wallner, Lewis E.; Saari, Martin J.

1947-01-01

As part of an investigation of the performance and operational characteristics of the TG-100A gas turbine-propeller engine, conducted in the Cleveland altitude wind tunnel, the performance characteristics of the compressor and the turbine were obtained. The data presented were obtained at a compressor-inlet ram-pressure ratio of 1.00 for altitudes from 5000 to 35,000 feet, engine speeds from 8000 to 13,000 rpm, and turbine-inlet temperatures from 1400 to 2100R. The highest compressor pressure ratio was 6.15 at a corrected air flow of 23.7 pounds per second and a corrected turbine-inlet temperature of 2475R. Peak adiabatic compressor efficiencies of about 77 percent were obtained near the value of corrected air flow corresponding to a corrected engine speed of 13,000 rpm. This maximum efficiency may be somewhat low, however, because of dirt accumulations on the compressor blades. A maximum adiabatic turbine efficiency of 81.5 percent was obtained at rated engine speed for all altitudes and turbine-inlet temperatures investigated.

Improved methods for fan sound field determination

NASA Technical Reports Server (NTRS)

Cicon, D. E.; Sofrin, T. G.; Mathews, D. C.

1981-01-01

Several methods for determining acoustic mode structure in aircraft turbofan engines using wall microphone data were studied. A method for reducing data was devised and implemented which makes the definition of discrete coherent sound fields measured in the presence of engine speed fluctuation more accurate. For the analytical methods, algorithms were developed to define the dominant circumferential modes from full and partial circumferential arrays of microphones. Axial arrays were explored to define mode structure as a function of cutoff ratio, and the use of data taken at several constant speeds was also evaluated in an attempt to reduce instrumentation requirements. Sensitivities of the various methods to microphone density, array size and measurement error were evaluated and results of these studies showed these new methods to be impractical. The data reduction method used to reduce the effects of engine speed variation consisted of an electronic circuit which windowed the data so that signal enhancement could occur only when the speed was within a narrow range.

14 CFR 23.49 - Stalling period.

Code of Federal Regulations, 2010 CFR

2010-01-01

... which the airplane is controllable with— (1) For reciprocating engine-powered airplanes, the engine(s... more than 110 percent of the stalling speed; (2) For turbine engine-powered airplanes, the propulsive..., VSOand VS1at maximum weight must not exceed 61 knots for— (1) Single-engine airplanes; and (2...

Quiet engine program flight engine design study

NASA Technical Reports Server (NTRS)

Klapproth, J. F.; Neitzel, R. E.; Seeley, C. T.

1974-01-01

The results are presented of a preliminary flight engine design study based on the Quiet Engine Program high-bypass, low-noise turbofan engines. Engine configurations, weight, noise characteristics, and performance over a range of flight conditions typical of a subsonic transport aircraft were considered. High and low tip speed engines in various acoustically treated nacelle configurations were included.

Effect of cooled EGR on performance and exhaust gas emissions in EFI spark ignition engine fueled by gasoline and wet methanol blends

NASA Astrophysics Data System (ADS)

Rohadi, Heru; Syaiful, Bae, Myung-Whan

2016-06-01

Fuel needs, especially the transport sector is still dominated by fossil fuels which are non-renewable. However, oil reserves are very limited. Furthermore, the hazardous components produced by internal combustion engine forces many researchers to consider with alternative fuel which is environmental friendly and renewable sources. Therefore, this study intends to investigate the impact of cooled EGR on the performance and exhaust gas emissions in the gasoline engine fueled by gasoline and wet methanol blends. The percentage of wet methanol blended with gasoline is in the range of 5 to 15% in a volume base. The experiment was performed at the variation of engine speeds from 2500 to 4000 rpm with 500 intervals. The re-circulated exhaust gasses into combustion chamber was 5%. The experiment was performed at the constant engine speed. The results show that the use of cooled EGR with wet methanol of 10% increases the brake torque up to 21.3%. The brake thermal efficiency increases approximately 39.6% using cooled EGR in the case of the engine fueled by 15% wet methanol. Brake specific fuel consumption for the engine using EGR fueled by 10% wet methanol decreases up to 23% at the engine speed of 2500 rpm. The reduction of CO, O2 and HC emissions was found, while CO2 increases.

Ignition study of a petrol/CNG single cylinder engine

NASA Astrophysics Data System (ADS)

Khan, N.; Saleem, Z.; Mirza, A. A.

2005-11-01

Benefits of laser ignition over the electrical ignition system for Compressed Natural Gas (CNG) engines have fuelled automobile industry and led to an extensive research on basic characteristics to switch over to the emerging technologies. This study was undertaken to determine the electrical and physical characteristics of the electric spark ignition of single cylinder petrol/CNG engine to determine minimum ignition requirements and timeline of ignition events to use in subsequent laser ignition study. This communication briefly reviews the ongoing research activities and reports the results of this experimental study. The premixed petrol and CNG mixtures were tested for variation of current and voltage characteristics of the spark with speed of engine. The current magnitude of discharge circuit was found to vary linearly over a wide range of speed but the stroke to stroke fire time was found to vary nonlinearly. The DC voltage profiles were observed to fluctuate randomly during ignition process and staying constant in rest of the combustion cycle. Fire to fire peaks of current amplitudes fluctuated up to 10% of the peak values at constant speed but increased almost linearly with increase in speed. Technical barriers of laser ignition related to threshold minimum ignition energy, inter-pulse durations and firing sequence are discussed. Present findings provide a basic initiative and background information for designing suitable timeline algorithms for laser ignited leaner direct injected CNG engines.

40 CFR 87.1 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR... turboprop engines. Class TF means all turbofan or turbojet aircraft engines or aircraft engines designed for... turbine engines employed for propulsion of aircraft designed to operate at supersonic flight speeds...

NREL: News - Prototype Low-Emissions Natural Gas Engine Saves Fuel

Science.gov Websites

/heavy_vehicle/natgas_pub.html#engine for a copy of the full NREL report, "Development of a Throttleless engines. In testing, the prototype engine operated over the full speed and load range, delivering 250

Biocatalysis in the Pharmaceutical Industry: The Need for Speed

PubMed Central

2017-01-01

The use of biocatalysis in the pharmaceutical industry continues to expand as a result of increased access to enzymes and the ability to engineer those enzymes to meet the demands of industrial processes. However, we are still just scratching the surface of potential biocatalytic applications. The time pressures present in pharmaceutical process development are incompatible with the long lead times required for engineering a suitable biocatalyst. Dramatic increases in the speed of protein engineering are needed to deliver on the ever increasing opportunities for industrial biocatalytic processes. PMID:28523096

Biocatalysis in the Pharmaceutical Industry: The Need for Speed.

PubMed

Truppo, Matthew D

2017-05-11

The use of biocatalysis in the pharmaceutical industry continues to expand as a result of increased access to enzymes and the ability to engineer those enzymes to meet the demands of industrial processes. However, we are still just scratching the surface of potential biocatalytic applications. The time pressures present in pharmaceutical process development are incompatible with the long lead times required for engineering a suitable biocatalyst. Dramatic increases in the speed of protein engineering are needed to deliver on the ever increasing opportunities for industrial biocatalytic processes.

Performance of a High-Speed Compression-Ignition Engine Using Multiple Orifice Fuel Injection Nozzles

NASA Technical Reports Server (NTRS)

Spanogle, J A; Foster, H H

1930-01-01

This report presents test results obtained at the Langley Memorial Aeronautical Laboratory of the National Advisory Committee for Aeronautics during an investigation to determine the relative performance of a single-cylinder, high-speed, compression-ignition engine when using fuel injection valve nozzles with different numbers, sizes, and directions of round orifices. A spring-loaded, automatic injection valve was used, centrally located at the top of a vertical disk-type combustion chamber formed between horizontally opposed inlet and exhaust valves of a 5 inch by 7 inch engine.

Preliminary Results of Altitude-Wind-Tunnel Investigation of X24C-4B Turbojet Engine. IV - Performance of Modified Compressor. Part 4; Performance of Modified Compressor

NASA Technical Reports Server (NTRS)

Thorman, H. Carl; Dupree, David T.

1947-01-01

The performance of the 11-stage axial-flow compressor, modified to improve the compressor-outlet velocity, in a revised X24C-4B turbojet engine is presented and compared with the performance of the compressor in the original engine. Performance data were obtained from an investigation of the revised engine in the MACA Cleveland altitude wind tunnel. Compressor performance data were obtained for engine operation with four exhaust nozzles of different outlet area at simulated altitudes from 15,OOO to 45,000 feet, simulated flight Mach numbers from 0.24 to 1.07, and engine speeds from 4000 to 12,500 rpm. The data cover a range of corrected engine speeds from 4100 to 13,500 rpm, which correspond to compressor Mach numbers from 0.30 to 1.00.

An investigation of crankshaft oscillations for cylinder health diagnostics

NASA Astrophysics Data System (ADS)

Geveci, Mert; Osburn, Andrew W.; Franchek, Matthew A.

2005-09-01

The vibrational characteristics of an internal combustion engine crankshaft are investigated from a cylinder health diagnostics point of view. Experimental results from a six-cylinder industrial diesel engine are presented to demonstrate the effects of cylinder imbalance on the individual harmonic components of the engine speed signal. A crank-angle domain numerical model of the crankshaft dynamics for a six-cylinder industrial diesel engine is also adopted to establish the effects of continuous low-power production in individual cylinders of a multi-cylinder engine. Outline of a diagnostics algorithm that makes use of the properties of crankshaft vibration behaviour is provided. In particular, crank-angle domain notch filters are employed to extact the harmonic components of engine speed. The outlined method can be implemented for individual cylinder health diagnostics across a family of multi-cylinder engines and can be formulated to handle changes in crankshaft characteristics due to replacement of mechanical components and/or wear.

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

46 CFR 184.620 - Propulsion engine control systems.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

40 CFR 1051.140 - What is my vehicle's maximum engine power and displacement?

Code of Federal Regulations, 2012 CFR

2012-07-01

... power and displacement? 1051.140 Section 1051.140 Protection of Environment ENVIRONMENTAL PROTECTION... displacement? This section describes how to quantify your vehicle's maximum engine power and displacement for... available engine torque with engine speed. (b) An engine configuration's displacement is the intended swept...

40 CFR 1051.140 - What is my vehicle's maximum engine power and displacement?

Code of Federal Regulations, 2013 CFR

2013-07-01

... power and displacement? 1051.140 Section 1051.140 Protection of Environment ENVIRONMENTAL PROTECTION... displacement? This section describes how to quantify your vehicle's maximum engine power and displacement for... available engine torque with engine speed. (b) An engine configuration's displacement is the intended swept...

40 CFR 1051.140 - What is my vehicle's maximum engine power and displacement?

Code of Federal Regulations, 2010 CFR

2010-07-01

... power and displacement? 1051.140 Section 1051.140 Protection of Environment ENVIRONMENTAL PROTECTION... displacement? This section describes how to quantify your vehicle's maximum engine power and displacement for... available engine torque with engine speed. (b) An engine configuration's displacement is the intended swept...

40 CFR 1051.140 - What is my vehicle's maximum engine power and displacement?

Code of Federal Regulations, 2014 CFR

2014-07-01

... power and displacement? 1051.140 Section 1051.140 Protection of Environment ENVIRONMENTAL PROTECTION... displacement? This section describes how to quantify your vehicle's maximum engine power and displacement for... available engine torque with engine speed. (b) An engine configuration's displacement is the intended swept...

40 CFR 1051.140 - What is my vehicle's maximum engine power and displacement?

Code of Federal Regulations, 2011 CFR

2011-07-01

... power and displacement? 1051.140 Section 1051.140 Protection of Environment ENVIRONMENTAL PROTECTION... displacement? This section describes how to quantify your vehicle's maximum engine power and displacement for... available engine torque with engine speed. (b) An engine configuration's displacement is the intended swept...

40 CFR 91.410 - Engine test cycle.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Engine test cycle. 91.410 Section 91...) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.410 Engine... in dynamometer operation tests of marine engines. (b) During each non-idle mode the specified speed...

Spark ignition timing control system for internal combustion engine with feature of suppression of jerking during engine acceleration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tomisawa, N.

1989-07-04

This patent describes a spark ignition timing control system for an internal combustion engine, it comprises: sensor means monitoring preselected parameters for producing a sensor signal; first means for deriving a spark ignition timing on the basis of data contained in the sensor signal; second means for detecting an engine acceleration demand for producing an accelerating condition indicative signal; and third means, responsive to the accelerating condition indicative signal, for modifying the spark ignition timing derived by the first means after expiration of a first predetermined period of time of occurence of the accelerating condition indicative signal, in such amore » manner that the spark ignition timing is advanced and retarded for suppressing cycle-to-cycle fluctuation of engine speed and for smoothly increasing engine speed.« less

Mod II engine performance

NASA Technical Reports Server (NTRS)

Richey, Albert E.; Huang, Shyan-Cherng

1987-01-01

The testing of a prototype of an automotive Stirling engine, the Mod II, is discussed. The Mod II is a one-piece cast block with a V-4 single-crankshaft configuration and an annular regenerator/cooler design. The initial testing of Mod II concentrated on the basic engine, with auxiliaries driven by power sources external to the engine. The performance of the engine was tested at 720 C set temperature and 820 C tube temperature. At 720 C, it is observed that the power deficiency is speed dependent and linear, with a weak pressure dependency, and at 820 C, the power deficiency is speed and pressure dependent. The effects of buoyancy and nozzle spray pattern on the heater temperature spread are investigated. The characterization of the oil pump and the operating cycle and temperature spread tests are proposed for further evaluation of the engine.

Instantaneous flywheel torque of IC engine grey-box identification

NASA Astrophysics Data System (ADS)

Milašinović, A.; Knežević, D.; Milovanović, Z.; Škundrić, J.

2018-01-01

In this paper a mathematical model developed for the identification of excitation torque acting on the IC engine flywheel is presented. The excitation torque gained through internal combustion of the fuel in the IC engine is transmitted from the flywheel to the transmission. The torque is not constant but variable and is a function of the crank angle. The verification of the mathematical model was done on a 4-cylinder 4-stroke diesel engine for which the in-cylinder pressure was measured in one cylinder and the instantaneous angular speed of the crankshaft at its free end. The research was conducted on a hydraulic engine brake. Inertial forces of all rotational parts, from flywheel to the turbine wheel of the engine brake, are acting on the flywheel due to the nonuniform motion of the flywheel. It is known from the theory of turbomachinery that the torque on the hydraulic brake is a quadratic function of angular speed. Due to that and the variable angular speed of the turbine wheel of the engine brake, the torque during one engine cycle is also variable. The motivation for this research was the idea (intention) to determine the instantaneous torque acting on the flywheel as a function of the crank angle with a mathematical model without any measuring and based on this to determine the quality of work of specific cylinders of the multi-cylinder engine. The crankshaft was considered elastic and also its torsional vibrations were taken into account.

Background and principles of throttles-only flight control

NASA Technical Reports Server (NTRS)

Burcham, Frank W., Jr.

1995-01-01

There have been many cases in which the crew of a multi-engine airplane had to use engine thrust for emergency flight control. Such a procedure is very difficult, because the propulsive control forces are small, the engine response is slow, and airplane dynamics such as the phugoid and dutch roll are difficult to damp with thrust. In general, thrust increases are used to climb, thrust decreases to descend, and differential thrust is used to turn. Average speed is not significantly affected by changes in throttle setting. Pitch control is achieved because of pitching moments due to speed changes, from thrust offset, and from the vertical component of thrust. Roll control is achieved by using differential thrust to develop yaw, which, through the normal dihedral effect, causes a roll. Control power in pitch and roll tends to increase as speed decreases. Although speed is not controlled by the throttles, configuration changes are often available (lowering gear, flaps, moving center-of-gravity) to change the speed. The airplane basic stability is also a significant factor. Fuel slosh and gyroscopic moments are small influences on throttles-only control. The background and principles of throttles-only flight control are described.

AIRCRAFT REACTOR CONTROL SYSTEM APPLICABLE TO TURBOJET AND TURBOPROP POWER PLANTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gorker, G.E.

1955-07-19

Control systems proposed for direct cycle nuclear powered aircraft commonly involve control of engine speed, nuclear energy input, and chcmical energy input. A system in which these parameters are controlled by controlling the total energy input, the ratio of nuclear and chemical energy input, and the engine speed is proposed. The system is equally applicable to turbojet or turboprop applications. (auth)

Dynamic similitude in internal-combustion engines

NASA Technical Reports Server (NTRS)

Lutz, O

1941-01-01

In this report it will be seen that the piston speed - as, moreover, any other speed, such as bearing velocity - must be independent of the quantity dimensions and must be a representative quantity similar to the high speed and the specific weight per horsepower.

Scramjet integration on hypersonic research airplane concepts

NASA Technical Reports Server (NTRS)

Weidner, J. P.; Small, W. J.; Penland, J. A.

1976-01-01

Several rocket-boosted research airplane concepts were evaluated with a research scramjet engine to determine their potential to provide research on critical aspects of airframe-integrated hypersonic systems. Extensive calculations to determine the force and moment contributions of the scramjet inlet, combustor, nozzle, and airframe were conducted to evaluate the overall performance of the combined engine/airframe system at hypersonic speeds. Results of both wind-tunnel tests and analysis indicate that it is possible to develop a research airplane configuration that will cruise at hypersonic speed on scramjet power alone, and will also have acceptable low-speed aerodynamic characteristics for landing.

The History and Promise of Combined Cycle Engines for Access to Space Applications

NASA Technical Reports Server (NTRS)

Clark, Casie

2010-01-01

For the summer of 2010, I have been working in the Aerodynamics and Propulsion Branch at NASA Dryden Flight Research Center studying combined-cycle engines, a high speed propulsion concept. Combined cycle engines integrate multiple propulsion systems into a single engine capable of running in multiple modes. These different modes allow the engine to be extremely versatile and efficient in varied flight conditions. The two most common types of combined cycle engines are Rocket-Based Combined Cycle (RBCC) and Turbine Based Combined Cycle (TBCC). The RBCC essentially combines a rocket and ramjet engine, while the TBCC integrates a turbojet and ramjet1. These two engines are able to switch between different propulsion modes to achieve maximum performance. Extensive conceptual and ground test studies of RBCC engines have been undertaken; however, an RBCC engine has never, to my knowledge, been demonstrated in flight. RBCC engines are of particular interest because they could potentially power a reusable launch vehicle (RLV) into space. The TBCC has been flight tested and shown to be effective at reaching supersonic speeds, most notably in the SR-71 Blackbird2.

14 CFR 25.175 - Demonstration of static longitudinal stability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... at which the airplane— (1) Is trimmed, with— (i) Wing flaps retracted; (ii) Landing gear retracted... climb for turbine engines; and (2) Is trimmed at the speed for best rate-of-climb except that the speed... stable slope at all speeds within a range which is the greater of 15 percent of the trim speed plus the...

40 CFR 85.2214 - Two speed idle test-EPA 81.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 18 2011-07-01 2011-07-01 false Two speed idle test-EPA 81. 85.2214... Tests § 85.2214 Two speed idle test—EPA 81. (a)(1) General calendar year applicability. The test... exhaust pipes originate from a common point. (4) The engine speed is increased to 2500 ±300 rpm, with...

40 CFR 85.2214 - Two speed idle test-EPA 81.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 18 2010-07-01 2010-07-01 false Two speed idle test-EPA 81. 85.2214... Tests § 85.2214 Two speed idle test—EPA 81. (a)(1) General calendar year applicability. The test... exhaust pipes originate from a common point. (4) The engine speed is increased to 2500 ±300 rpm, with...

Engine Power Turbine and Propulsion Pod Arrangement Study

NASA Technical Reports Server (NTRS)

Robuck, Mark; Zhang, Yiyi

2014-01-01

A study has been conducted for NASA Glenn Research Center under contract NNC10BA05B, Task NNC11TA80T to identify beneficial arrangements of the turboshaft engine, transmissions and related systems within the propulsion pod nacelle of NASA's Large Civil Tilt-Rotor 2nd iteration (LCTR2) vehicle. Propulsion pod layouts were used to investigate potential advantages, disadvantages, as well as constraints of various arrangements assuming front or aft shafted engines. Results from previous NASA LCTR2 propulsion system studies and tasks performed by Boeing under NASA contracts are used as the basis for this study. This configuration consists of two Fixed Geometry Variable Speed Power Turbine Engines and related drive and rotor systems (per nacelle) arranged in tilting nacelles near the wing tip. Entry-into-service (EIS) 2035 technology is assumed for both the engine and drive systems. The variable speed rotor system changes from 100 percent speed for hover to 54 percent speed for cruise by the means of a two speed gearbox concept developed under previous NASA contracts. Propulsion and drive system configurations that resulted in minimum vehicle gross weight were identified in previous work and used here. Results reported in this study illustrate that a forward shafted engine has a slight weight benefit over an aft shafted engine for the LCTR2 vehicle. Although the aft shafted engines provide a more controlled and centered CG (between hover and cruise), the length of the long rotor shaft and complicated engine exhaust arrangement outweighed the potential benefits. A Multi-Disciplinary Analysis and Optimization (MDAO) approach for transmission sizing was also explored for this study. This tool offers quick analysis of gear loads, bearing lives, efficiencies, etc., through use of commercially available RomaxDESIGNER software. The goal was to create quick methods to explore various concept models. The output results from RomaxDESIGNER have been successfully linked to Boeing spreadsheets that generate gear tooth geometry in Catia 3D environment. Another initial goal was to link information from RomaxDESIGNER (such as hp, rpm, gear ratio) to populate Boeing's parametric weight spreadsheet and create an automated method to estimate drive system weight. This was only partially achieved due to the variety of weight models, number of manual inputs, and qualitative assessments required. A simplified weight spreadsheet was used with data inputs from RomaxDESIGNER along with manual inputs to perform rough weight calculations.

An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

NASA Technical Reports Server (NTRS)

Bruckner, Robert J.

2010-01-01

Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

A second-generation high speed civil transport: Stingray

NASA Technical Reports Server (NTRS)

Engdahl, Sean; Lopes, Kevin; Ngan, Angelen; Perrin, Joseph; Phipps, Marcus; Westman, Blake; Yeo, Urn

1992-01-01

The Stingray is the second-generation High Speed Civil Transport (HSCT) designed for the 21st Century. This aircraft is designed to be economically viable and environmentally sound transportation competitive in markets currently dominated by subsonic aircraft such as the Boeing 747 and upcoming McDonnell Douglas MD-12. With the Stringray coming into service in 2005, a ticket price of 21 percent over current subsonic airlines will cover operational costs with a 10 percent return on investment. The cost per aircraft will be $202 million with the Direct Operating Cost equal to $0.072 per mile per seat. This aircraft has been designed to be a realistic aircraft that can be built within the next ten to fifteen years. There was only one main technological improvement factor used in the design, that being for the engine specific fuel consumption. The Stingray, therefore, does not rely on technology that does not exist. The Stingray will be powered by four mixed flow turbofans that meet both nitrous oxide emissions and FAR 36 Stage 3 noise regulations. It will carry 250 passengers a distance of 5200 nautical miles at a speed of Mach 2.4. The shape of the Stingray, while optimized for supersonic flight, is compatible with all current airline facilities in airports around the world. As the demand for economical, high-speed flight increases, the Stingray will be ready and able to meet those demands.

The comparative performance of Roots type aircraft engine superchargers as affected by change in impeller speed and displacement

NASA Technical Reports Server (NTRS)

Ware, Marsden; Wilson, Ernest E

1929-01-01

This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements. According to simple theory, when assuming no losses, the air weight handled and the power required for a given pressure difference are directly proportional to the speed and the displacement. These simple relations are altered considerably by the losses. When comparing the performance of different sizes of machines whose impeller speeds are so related that the same service requirements are met, it is found that the individual effects of speed and displacement are canceled to a large extent, and the only considerable difference is the difference in the power losses which decrease with increase in the displacement and the accompanying decrease in speed. This difference is small in relation to the net power of the engine supercharger unit, so that a supercharger with short impellers may be used in those applications where the space available is very limited with any considerable sacrifice in performance.

Prediction of far-field wind turbine noise propagation with parabolic equation.

PubMed

Lee, Seongkyu; Lee, Dongjai; Honhoff, Saskia

2016-08-01

Sound propagation of wind farms is typically simulated by the use of engineering tools that are neglecting some atmospheric conditions and terrain effects. Wind and temperature profiles, however, can affect the propagation of sound and thus the perceived sound in the far field. A better understanding and application of those effects would allow a more optimized farm operation towards meeting noise regulations and optimizing energy yield. This paper presents the parabolic equation (PE) model development for accurate wind turbine noise propagation. The model is validated against analytic solutions for a uniform sound speed profile, benchmark problems for nonuniform sound speed profiles, and field sound test data for real environmental acoustics. It is shown that PE provides good agreement with the measured data, except upwind propagation cases in which turbulence scattering is important. Finally, the PE model uses computational fluid dynamics results as input to accurately predict sound propagation for complex flows such as wake flows. It is demonstrated that wake flows significantly modify the sound propagation characteristics.

Dual motor drive vehicle speed synchronization and coordination control strategy

NASA Astrophysics Data System (ADS)

Huang, Hao; Tu, Qunzhang; Jiang, Chenming; Ma, Limin; Li, Pei; Zhang, Hongxing

2018-04-01

Multi-motor driven systems are more and more widely used in the field of electric engineering vehicles, as a result of the road conditions and the variable load of engineering vehicles, makes multi-motors synchronization coordinated control system as a key point of the development of the electric vehicle drive system. This paper based on electrical machinery transmission speed in the process of engineering vehicles headed for coordinated control problem, summarized control strategies at home and abroad in recent years, made analysis and comparison of the characteristics, finally discussed the trend of development of the multi-motor coordination control, provided a reference for synchronized control system research of electric drive engineering vehicles.

An airline study of advanced technology requirements for advanced high speed commercial engines. 3: Propulsion system requirements

NASA Technical Reports Server (NTRS)

Sallee, G. P.

1973-01-01

The advanced technology requirements for an advanced high speed commercial transport engine are presented. The results of the phase 3 effort cover the requirements and objectives for future aircraft propulsion systems. These requirements reflect the results of the Task 1 and 2 efforts and serve as a baseline for future evaluations, specification development efforts, contract/purchase agreements, and operational plans for future subsonic commercial engines. This report is divided into five major sections: (1) management objectives for commercial propulsion systems, (2) performance requirements for commercial transport propulsion systems, (3) design criteria for future transport engines, (4) design requirements for powerplant packages, and (5) testing.

Effect of design over-all compressor pressure ratio division on acceleration characteristics of three hypothetical two-spool turbojet engines

NASA Technical Reports Server (NTRS)

Filippi, Richard E; Dugan, James F , Jr

1956-01-01

The engines, each with a compressor overall total-pressure ratio of 12 and a design inner-turbine-inlet temperature of 2500 degrees R, were investigated at static sea-level conditions to determine the effect on transient performance of varying the desitn pressure ratio divisions 2-6, 3-4, and 4-3 between the outer and inner compressors. The transient considered was an acceleration from 40 to 100 percent design thrust. When the outer compressor of each engine reached design speed, the inner compressors were overspeeding, the maximum being only 1.7 over design mechanical speed. Acceleration times for the three engines were equal.

Hierarchical representation and machine learning from faulty jet engine behavioral examples to detect real time abnormal conditions

NASA Technical Reports Server (NTRS)

Gupta, U. K.; Ali, M.

1988-01-01

The theoretical basis and operation of LEBEX, a machine-learning system for jet-engine performance monitoring, are described. The behavior of the engine is modeled in terms of four parameters (the rotational speeds of the high- and low-speed sections and the exhaust and combustion temperatures), and parameter variations indicating malfunction are transformed into structural representations involving instances and events. LEBEX extracts descriptors from a set of training data on normal and faulty engines, represents them hierarchically in a knowledge base, and uses them to diagnose and predict faults on a real-time basis. Diagrams of the system architecture and printouts of typical results are shown.

40 CFR 90.502 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF..., emission control system, governed speed, fuel system, engine calibration, and other parameters as... engines selected from the population of an engine family for emission testing. ...

40 CFR 90.502 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF..., emission control system, governed speed, fuel system, engine calibration, and other parameters as... engines selected from the population of an engine family for emission testing. ...

40 CFR 90.502 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF..., emission control system, governed speed, fuel system, engine calibration, and other parameters as... engines selected from the population of an engine family for emission testing. ...

40 CFR 90.502 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF..., emission control system, governed speed, fuel system, engine calibration, and other parameters as... engines selected from the population of an engine family for emission testing. ...

Research of rotating machinery vibration parameters - Shaft speed relationship

NASA Astrophysics Data System (ADS)

Kostyukov, V. N.; Kostyukov, A. V.; Zaytsev, A. V.; Teterin, A. O.

2017-08-01

The paper considers the relationship between the parameters of the vibration arising in rotating machinery during operation and the shaft speed. The goal of this paper is to determine the dependence of the vibration parameters on the shaft speed for solving applied engineering problems. To properly evaluate the technical condition of bearing assemblies, we should take into account the pattern of the rotating machinery vibration parameters-shaft speed relationship, which will allow creating new diagnostic features, the totality of which will ensure an increased reliability of diagnosis. We took the check for a correlation between the factor and resultative feature parameters as the correlation analysis method. A high pair linear correlation between the diagnostic features (acceleration, velocity, displacement) and the shaft speed was determined on the basis of the check for correlation between the vibration parameters and the shaft speed, and also the linear correlation coefficients can be used to solve the applied engineering problems of diagnosing the bearing assemblies of the rotating machinery.

Low-speed wind-tunnel investigation of a large scale advanced arrow-wing supersonic transport configuration with engines mounted above wing for upper-surface blowing

NASA Technical Reports Server (NTRS)

Shivers, J. P.; Mclemore, H. C.; Coe, P. L., Jr.

1976-01-01

Tests have been conducted in a full scale tunnel to determine the low speed aerodynamic characteristics of a large scale advanced arrow wing supersonic transport configuration with engines mounted above the wing for upper surface blowing. Tests were made over an angle of attack range of -10 deg to 32 deg, sideslip angles of + or - 5 deg, and a Reynolds number range of 3,530,000 to 7,330,000. Configuration variables included trailing edge flap deflection, engine jet nozzle angle, engine thrust coefficient, engine out operation, and asymmetrical trailing edge boundary layer control for providing roll trim. Downwash measurements at the tail were obtained for different thrust coefficients, tail heights, and at two fuselage stations.

Effect of water injection and off scheduling of variable inlet guide vanes, gas generator speed and power turbine nozzle angle on the performance of an automotive gas turbine engine

NASA Technical Reports Server (NTRS)

Warren, E. L.

1980-01-01

The Chrysler/ERDA baseline automotive gas turbine engine was used to experimentally determine the power augmentation and emissions reductions achieved by the effect of variable compressor and power engine geometry, water injection downstream of the compressor, and increases in gas generator speed. Results were dependent on the mode of variable geometry utilization. Over 20 percent increase in power was accompanied by over 5 percent reduction in SFC. A fuel economy improvement of at least 6 percent was estimated for a vehicle with a 75 kW (100 hp) engine which could be augmented to 89 kW (120 hp) relative to an 89 Kw (120 hp) unaugmented engine.

Prediction of the production of nitrogen oxide (NOx) in turbojet engines

NASA Astrophysics Data System (ADS)

Tsague, Louis; Tsogo, Joseph; Tatietse, Thomas Tamo

Gaseous nitrogen oxides (NO+NO2=NOx) are known as atmospheric trace constituent. These gases remain a big concern despite the advances in low NOx emission technology because they play a critical role in regulating the oxidization capacity of the atmosphere according to Crutzen [1995. My life with O 3, NO x and other YZO x S; Nobel Lecture; Chemistry 1995; pp 195; December 8, 1995] . Aircraft emissions of nitrogen oxides ( NOx) are regulated by the International Civil Aviation Organization. The prediction of NOx emission in turbojet engines by combining combustion operational data produced information showing correlation between the analytical and empirical results. There is close similarity between the calculated emission index and experimental data. The correlation shows improved accuracy when the 2124 experimental data from 11 gas turbine engines are evaluated than a previous semi empirical correlation approach proposed by Pearce et al. [1993. The prediction of thermal NOx in gas turbine exhausts. Eleventh International Symposium on Air Breathing Engines, Tokyo, 1993, pp. 6-9]. The new method we propose predict the production of NOx with far more improved accuracy than previous methods. Since a turbojet engine works in an atmosphere where temperature, pressure and humidity change frequently, a correction factor is developed with standard atmospheric laws and some correlations taken from scientific literature [Swartwelder, M., 2000. Aerospace engineering 410 Term Project performance analysis, November 17, 2000, pp. 2-5; Reed, J.A. Java Gas Turbine Simulator Documentation. pp. 4-5]. The new correction factor is validated with experimental observations from 19 turbojet engines cruising at altitudes of 9 and 13 km given in the ICAO repertory [Middleton, D., 1992. Appendix K (FAA/SETA). Section 1: Boeing Method Two Indices, 1992, pp. 2-3]. This correction factor will enable the prediction of cruise NOx emissions of turbojet engines at cruising speeds. The ICAO database [Goehlich, R.A., 2000. Investigation into the applicability of pollutant emission models for computer aided preliminary aircraft design, Book number 175654, 4.2.2000, pp. 57-79] can now be completed using the approach we propose to complete the whole mission flight NOx emissions.

Supercharged two-cycle engines employing novel single element reciprocating shuttle inlet valve mechanisms and with a variable compression ratio

NASA Technical Reports Server (NTRS)

Wiesen, Bernard (Inventor)

2008-01-01

This invention relates to novel reciprocating shuttle inlet valves, effective with every type of two-cycle engine, from small high-speed single cylinder model engines, to large low-speed multiple cylinder engines, employing spark or compression ignition. Also permitting the elimination of out-of-phase piston arrangements to control scavenging and supercharging of opposed-piston engines. The reciprocating shuttle inlet valve (32) and its operating mechanism (34) is constructed as a single and simple uncomplicated member, in combination with the lost-motion abutments, (46) and (48), formed in a piston skirt, obviating the need for any complex mechanisms or auxiliary drives, unaffected by heat, friction, wear or inertial forces. The reciprocating shuttle inlet valve retains the simplicity and advantages of two-cycle engines, while permitting an increase in volumetric efficiency and performance, thereby increasing the range of usefulness of two-cycle engines into many areas that are now dominated by the four-cycle engine.

46 CFR 31.30-1 - Marine engineering regulations and material specifications-TB/ALL.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 1 2012-10-01 2012-10-01 false Marine engineering regulations and material... INSPECTION AND CERTIFICATION Marine Engineering § 31.30-1 Marine engineering regulations and material..., of subchapter F (Marine Engineering) of this chapter, whenever applicable, except as such regulations...

46 CFR 31.30-1 - Marine engineering regulations and material specifications-TB/ALL.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 1 2011-10-01 2011-10-01 false Marine engineering regulations and material... INSPECTION AND CERTIFICATION Marine Engineering § 31.30-1 Marine engineering regulations and material..., of subchapter F (Marine Engineering) of this chapter, whenever applicable, except as such regulations...

46 CFR 31.30-1 - Marine engineering regulations and material specifications-TB/ALL.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 1 2014-10-01 2014-10-01 false Marine engineering regulations and material... INSPECTION AND CERTIFICATION Marine Engineering § 31.30-1 Marine engineering regulations and material..., of subchapter F (Marine Engineering) of this chapter, whenever applicable, except as such regulations...

46 CFR 31.30-1 - Marine engineering regulations and material specifications-TB/ALL.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 1 2010-10-01 2010-10-01 false Marine engineering regulations and material... INSPECTION AND CERTIFICATION Marine Engineering § 31.30-1 Marine engineering regulations and material..., of subchapter F (Marine Engineering) of this chapter, whenever applicable, except as such regulations...

46 CFR 31.30-1 - Marine engineering regulations and material specifications-TB/ALL.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 1 2013-10-01 2013-10-01 false Marine engineering regulations and material... INSPECTION AND CERTIFICATION Marine Engineering § 31.30-1 Marine engineering regulations and material..., of subchapter F (Marine Engineering) of this chapter, whenever applicable, except as such regulations...

Unshrouded Centrifugal Turbopump Impeller Design Methodology

NASA Technical Reports Server (NTRS)

Prueger, George H.; Williams, Morgan; Chen, Wei-Chung; Paris, John; Williams, Robert; Stewart, Eric

2001-01-01

Turbopump weight continues to be a dominant parameter in the trade space for reduction of engine weight. Space Shuttle Main Engine weight distribution indicates that the turbomachinery make up approximately 30% of the total engine weight. Weight reduction can be achieved through the reduction of envelope of the turbopump. Reduction in envelope relates to an increase in turbopump speed and an increase in impeller head coefficient. Speed can be increased until suction performance limits are achieved on the pump or due to alternate constraints the turbine or bearings limit speed. Once the speed of the turbopump is set the impeller tip speed sets the minimum head coefficient of the machine. To reduce impeller diameter the head coefficient must be increased. A significant limitation with increasing head coefficient is that the slope of the head-flow characteristic is affected and this can limit engine throttling range. Unshrouded impellers offer a design option for increased turbopump speed without increasing the impeller head coefficient. However, there are several issues with regard to using an unshrouded impeller: there is a pump performance penalty due to the front open face recirculation flow, there is a potential pump axial thrust problem from the unbalanced front open face and the back shroud face, and since test data is very limited for this configuration, there is uncertainty in the magnitude and phase of the rotordynamic forces due to the front impeller passage. The purpose of the paper is to discuss the design of an unshrouded impeller and to examine the hydrodynamic performance, axial thrust, and rotordynamic performance. The design methodology will also be discussed. This work will help provide some guidelines for unshrouded impeller design.

78 FR 22811 - Special Local Regulations; Mayaguez Grand Prix, Mayaguez Bay; Mayaguez, PR

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-17

..., a high speed boat race. The event is scheduled to take place on Sunday, June 9, 2013. Approximately 30 high- speed power boats will be participating in the races. The special local regulation is... area, where all persons and vessels, except those persons and vessels participating in the high-speed...

The 7.5K lbf thrust engine preliminary design for Orbit Transfer Vehicle

NASA Technical Reports Server (NTRS)

Hayden, Warren R.; Sabiers, Ralph; Schneider, Judy

1994-01-01

This document summarizes the preliminary design of the Aerojet version of the Orbit Transfer Vehicle main engine. The concept of a 7500 lbf thrust LO2/GH2 engine using the dual expander cycle for optimum efficiency is validated through power balance and thermal calculations. The engine is capable of 10:1 throttling from a nominal 2000 psia to a 200 psia chamber pressure. Reservations are detailed on the feasibility of a tank head start, but the design incorporates low speed turbopumps to mitigate the problem. The mechanically separate high speed turbopumps use hydrostatic bearings to meet engine life requirements, and operate at sub-critical speed for better throttling ability. All components were successfully packaged in the restricted envelope set by the clearances for the extendible/retractable nozzle. Gimbal design uses an innovative primary and engine out gimbal system to meet the +/- 20 deg gimbal requirement. The hydrogen regenerator and LOX/GH2 heat exchanger uses the Aerojet platelet structures approach for a highly compact component design. The extendible/retractable nozzle assembly uses an electric motor driven jack-screw design and a one segment carbon-carbon or silicide coated columbium nozzle with an area ratio, when extended, of 1430:1. A reliability analysis and risk assessment concludes the report.

The difference engine: a model of diversity in speeded cognition.

PubMed

Myerson, Joel; Hale, Sandra; Zheng, Yingye; Jenkins, Lisa; Widaman, Keith F

2003-06-01

A theory of diversity in speeded cognition, the difference engine, is proposed, in which information processing is represented as a series of generic computational steps. Some individuals tend to perform all of these computations relatively quickly and other individuals tend to perform them all relatively slowly, reflecting the existence of a general cognitive speed factor, but the time required for response selection and execution is assumed to be independent of cognitive speed. The difference engine correctly predicts the positively accelerated form of the relation between diversity of performance, as measured by the standard deviation for the group, and task difficulty, as indexed by the mean response time (RT) for the group. In addition, the difference engine correctly predicts approximately linear relations between the RTs of any individual and average performance for the group, with the regression lines for fast individuals having slopes less than 1.0 (and positive intercepts) and the regression lines for slow individuals having slopes greater than 1.0 (and negative intercepts). Similar predictions are made for comparisons of slow, average, and fast subgroups, regardless of whether those subgroups are formed on the basis of differences in ability, age, or health status. These predictions are consistent with evidence from studies of healthy young and older adults as well as from studies of depressed and age-matched control groups.

78 FR 6202 - Airworthiness Directives; the Boeing Company

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-30

... Descent (If INITIATE Required). Passenger Oxygen Switch.... ON Thrust Levers CLOSE Speed Brakes FLIGHT... Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind... regard. Request To Correct AFM Reference to Target Speed Delta Airlines (DAL) asked that the target speed...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

40 CFR 91.502 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF... described on the basis of gross power, emission control system, governed speed, injector size, engine... engines selected from the population of an engine family for emission testing. ...

The Use of Steady and Unsteady Detonation Waves for Propulsion Systems

NASA Technical Reports Server (NTRS)

Adelman, Henry G.; Menees, Gene P.; Cambier, Jean-Luc; Bowles, Jeffrey V.; Cavolowsky, John A. (Technical Monitor)

1995-01-01

Detonation wave enhanced supersonic combustors such as the Oblique Detonation Wave Engine (ODWE) are attractive propulsion concepts for hypersonic flight. These engines utilize detonation waves to enhance fuel-air mixing and combustion. The benefits of wave combustion systems include shorter and lighter engines which require less cooling and generate lower internal drag. These features allow air-breathing operation at higher Mach numbers than the diffusive burning scramjet delaying the need for rocket engine augmentation. A comprehensive vehicle synthesis code has predicted the aerodynamic characteristics and structural size and weight of a typical single-stage-to-orbit vehicle using an ODWE. Other studies have focused on the use of unsteady or pulsed detonation waves. For low speed applications, pulsed detonation engines (PDE) have advantages in low weight and higher efficiency than turbojets. At hypersonic speeds, the pulsed detonations can be used in conjunction with a scramjet type engine to enhance mixing and provide thrust augmentation.

The effect of preignition on cylinder temperatures, pressures, power output, and piston failures

NASA Technical Reports Server (NTRS)

Corrington, Lester C; Fisher, William F

1947-01-01

An investigation was conducted using a cylinder of a V-type liquid-cooled engine to observe the behavior of the cylinder when operated under preignition conditions. Data were recorded that showed cylinder-head temperatures, time of ignition, engine speed, power output, and change in maximum cylinder pressure as a function of time as the engine entered preignition and was allowed to operate under preignition conditions for a short time. The effects of the following variables on the engine behavior during preignition were investigated: fuel-air ratio, power level, aromatic content of fuel, engine speed, mixture temperature, and preignition source. The power levels at which preignition would cause complete piston failure for the selected engine operating conditions and the types of failure encountered when using various values of clearance between the piston and cylinder barrel were determined. The fuels used had performance numbers high enough to preclude any possibility of knock throughout the test program.

Calculations of the Performance of a Compression-Ignition Engine-Compressor Turbine Combination I : Performance of a Highly Supercharged Compression-Ignition Engine

NASA Technical Reports Server (NTRS)

Sanders, J. C.; Mendelson, Alexander

1945-01-01

Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm. Exhaust pressures and temperatures were determined from an analysis of indicator cards. The analysis showed that, at rich mixtures with the exhaust back pressure equal to the inlet-air pressure, there is excess energy available for driving a turbine over that required for supercharging. The presence of this excess energy indicates that a highly supercharged compression-ignition engine might be desirable as a compressor and combustion chamber for a turbine.

Effects of injection pressure and injection timing to exhaust gas opacity for a conventional indirect diesel engine

NASA Astrophysics Data System (ADS)

Budiman, Agus; Majid, Akmal Irfan; Pambayun, Nirmala Adhi Yoga; Yuswono, Lilik Chaerul; Sukoco

2016-06-01

In relation to pollution control and environmental friendliness, the quality of exhaust gas from diesel engine needs to be considered. The influences of injection pressure and timing to exhaust gas opacity were investigated. A series of experiments were conducted in a one-cylinder conventional diesel engine with a naturally aspirated system and indirect injection. The default specification of injection pressure was 120 kg/cm2. To investigate the injection pressure, the engine speed was retained on 1000 rpm with pressure variations from 80 to 215 kg/cm2. On the other hand, the various injection timing (8, 10, 12, 16 degrees before TDC point and exact 18 degrees before TDC point) were used to determine their effects to exhaust gas opacity. In this case, the engine speed was varied from 1000 to 2400 rpm. The injector tester was used to measure injection pressure whereas the exhaust gas opacity was determined by the smoke meter. Those data were also statistically analyzed by product moment correlation. As the results, the injection pressure of diesel engine had a non-significant positive correlation to the exhaust gas opacity with r = 0.113 and p > 5 %. Injection pressure should be adjusted to the specification listed on the diesel engine as if it was too high or too low will lead to the higher opacity. Moreover, there was a significant positive correlation between injection timing and the exhaust gas opacity in all engine speeds.

40 CFR 94.105 - Duty cycles.

Code of Federal Regulations, 2014 CFR

2014-07-01

...) General cycle. Propulsion engines that are used with (or intended to be used with) fixed-pitch propellers, propeller-law auxiliary engines, and any other engines for which the other duty cycles of this section do... value. (c) Variable-pitch and electrically coupled propellers. (1) Constant-speed propulsion engines...

40 CFR 94.105 - Duty cycles.

Code of Federal Regulations, 2013 CFR

2013-07-01

...) General cycle. Propulsion engines that are used with (or intended to be used with) fixed-pitch propellers, propeller-law auxiliary engines, and any other engines for which the other duty cycles of this section do... value. (c) Variable-pitch and electrically coupled propellers. (1) Constant-speed propulsion engines...

40 CFR 94.105 - Duty cycles.

Code of Federal Regulations, 2012 CFR

2012-07-01

...) General cycle. Propulsion engines that are used with (or intended to be used with) fixed-pitch propellers, propeller-law auxiliary engines, and any other engines for which the other duty cycles of this section do... value. (c) Variable-pitch and electrically coupled propellers. (1) Constant-speed propulsion engines...

40 CFR 94.105 - Duty cycles.

Code of Federal Regulations, 2011 CFR

2011-07-01

...) General cycle. Propulsion engines that are used with (or intended to be used with) fixed-pitch propellers, propeller-law auxiliary engines, and any other engines for which the other duty cycles of this section do... value. (c) Variable-pitch and electrically coupled propellers. (1) Constant-speed propulsion engines...

Test data report, low speed wind tunnel tests of a full scale lift/cruise-fan inlet, with engine, at high angles of attack

NASA Technical Reports Server (NTRS)

Shain, W. M.

1978-01-01

A low speed wind tunnel test of a fixed lip inlet with engine, was performed. The inlet was close coupled to a Hamilton Standard 1.4 meter, variable pitch fan driven by a lycoming T55-L-11A engine. Tests were conducted with various combinations of inlet angle of attack freestream velocities, and fan airflows. Data were recorded to define the inlet airflow separation boundaries, performance characteristics, and fan blade stresses. The test model, installation, instrumentation, test, data reduction and final data are described.

Study of occupational stress among railway engine pilots

PubMed Central

Kumar, Devesh; Singh, Jai Vir; Kharwar, Poonam S.

2011-01-01

Background: Traffic volume and speed is going to be increased in Indian Railways successively, leading to higher stress in staff connected with train operations. The jobs of railway engine pilots come under the category of high-strain jobs, necessitating a need to conduct multicentric study to unfold the factors associated with occupational stress and organizational strategies. Materials and Methods: Present study covered 185 railway engine pilots and office clerks working in various railway zones by incidental method. Occupational Stress Index (OSI) test developed by Srivastva and Singh, questionnaire of specific stressors constructed by authors and laboratory test battery for psychological screening of high-speed train pilots were used as tools. Results: Means of OSI and all the 12 occupational stressors of railway engine pilots were found significantly higher to that of office clerks. Means of OSI and occupational stressors of goods train pilots were significantly higher in comparison to high-speed train pilots and passenger train pilots. Study revealed positive correlation of speed perception and complex reaction time tests and negative correlation of other constituent tests of laboratory test battery to OSI test. Highest subgroup of stressor observedwas role overload followed by role conflict. Conclusions: These findings provide a prima facie evidence of higher occupational stress among railway engine pilots because of identified specific stressors prevalent in their job and explore the possible intervention strategies for its reduction. Significant correlation is noticed between OSI and laboratory test results, indicating its relevant utility in preliminary psychological screening. PMID:21808497

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2013 CFR

2013-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2012 CFR

2012-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2011 CFR

2011-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2014 CFR

2014-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

34 CFR 637.3 - What regulations apply to the Minority Science and Engineering Improvement Program?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Engineering Improvement Program? 637.3 Section 637.3 Education Regulations of the Offices of the Department of... ENGINEERING IMPROVEMENT PROGRAM General § 637.3 What regulations apply to the Minority Science and Engineering Improvement Program? The following regulations apply to the Minority Science and Engineering Improvement...

Free-piston Stirling hydraulic engine and drive system for automobiles

NASA Technical Reports Server (NTRS)

Beremand, D. G.; Slaby, J. G.; Nussle, R. C.; Miao, D.

1982-01-01

The calculated fuel economy for an automotive free piston Stirling hydraulic engine and drive system using a pneumatic accumulator with the fuel economy of both a conventional 1980 spark ignition engine in an X body class vehicle and the estimated fuel economy of a 1984 spark ignition vehicle system are compared. The results show that the free piston Stirling hydraulic system with a two speed transmission has a combined fuel economy nearly twice that of the 1980 spark ignition engine - 21.5 versus 10.9 km/liter (50.7 versus 25.6 mpg) under comparable conditions. The fuel economy improvement over the 1984 spark ignition engine was 81 percent. The fuel economy sensitivity of the Stirling hydraulic system to system weight, number of transmission shifts, accumulator pressure ratio and maximum pressure, auxiliary power requirements, braking energy recovery, and varying vehicle performance requirements are considered. An important finding is that a multispeed transmission is not required. The penalty for a single speed versus a two speed transmission is about a 12 percent drop in combined fuel economy to 19.0 km/liter (44.7 mpg). This is still a 60 percent improvement in combined fuel economy over the projected 1984 spark ignition vehicle.

Effect of air-entry angle on performance of a 2-stroke-cycle compression-ignition engine

NASA Technical Reports Server (NTRS)

Earle, Sherod L; Dutee, Francis J

1937-01-01

An investigation was made to determine the effect of variations in the horizontal and vertical air-entry angles on the performance characteristics of a single-cylinder 2-stroke-cycle compression-ignition test engine. Performance data were obtained over a wide range of engine speed, scavenging pressure, fuel quantity, and injection advance angle with the optimum guide vanes. Friction and blower-power curves are included for calculating the indicated and net performances. The optimum horizontal air-entry angle was found to be 60 degrees from the radial and the optimum vertical angle to be zero, under which conditions a maximum power output of 77 gross brake horsepower for a specific fuel consumption of 0.52 pound per brake horsepower-hour was obtained at 1,800 r.p.m. and 16-1/2 inches of Hg scavenging pressure. The corresponding specific output was 0.65 gross brake horsepower per cubic inch of piston displacement. Tests revealed that the optimum scavenging pressure increased linearly with engine speed. The brake mean effective pressure increased uniformly with air quantity per cycle for any given vane angle and was independent of engine speed and scavenging pressure.

Flutter parametric studies of cantilevered twin-engine transport type wing with and without winglet. Volume 2: Transonic and density effect investigations

NASA Technical Reports Server (NTRS)

Bhatia, K. G.; Nagaraja, K. S.

1984-01-01

Flutter characteristics of a cantilevered high aspect ratio wing with winglet were investigated. The configuration represented a current technology, twin engine airplane. Compressibility effects through transonic Mach numbers and a wide range of mass-density ratios were evaluated on a low speed and high speed model. Four flutter mechanisms were obtained from test, and analysis from various combinations of configuration parameters. It is shown that the coupling between wing tip vertical and chordwise motions have significant effect under some conditions. It is concluded that for the flutter model configurations studied, the winglet related flutter is amenable to the conventional flutter analysis techniques. The low speed model flutter and the high-speed model flutter results are described.

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... standards apply as specified in 40 CFR part 94 for engines originally manufactured in model years 2004...

40 CFR 1042.104 - Exhaust emission standards for Category 3 engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for other testing. (2) NOX standards apply based on the engine's model year and maximum in-use engine... Engines (g/kW-hr) Emission standards Model year Maximum in-use engine speed Less than130 RPM 130-2000RPM a... Tier 1 NOX standards apply as specified in 40 CFR part 94 for engines originally manufactured in model...

High speed turboprop aeroacoustic study (counterrotation). Volume 2: Computer programs

NASA Technical Reports Server (NTRS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-01-01

The isolated counterrotating high speed turboprop noise prediction program developed and funded by GE Aircraft Engines was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in the NASA-Lewis 8 x 6 and 9 x 15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counter rotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attack was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combined into a single prediction program. The results were compared with data taken during the flight test of the B727/UDF (trademark) engine demonstrator aircraft.

High speed turboprop aeroacoustic study (counterrotation). Volume 2: Computer programs

NASA Astrophysics Data System (ADS)

Whitfield, C. E.; Mani, R.; Gliebe, P. R.

1990-07-01

The isolated counterrotating high speed turboprop noise prediction program developed and funded by GE Aircraft Engines was compared with model data taken in the GE Aircraft Engines Cell 41 anechoic facility, the Boeing Transonic Wind Tunnel, and in the NASA-Lewis 8 x 6 and 9 x 15 wind tunnels. The predictions show good agreement with measured data under both low and high speed simulated flight conditions. The installation effect model developed for single rotation, high speed turboprops was extended to include counter rotation. The additional effect of mounting a pylon upstream of the forward rotor was included in the flow field modeling. A nontraditional mechanism concerning the acoustic radiation from a propeller at angle of attack was investigated. Predictions made using this approach show results that are in much closer agreement with measurement over a range of operating conditions than those obtained via traditional fluctuating force methods. The isolated rotors and installation effects models were combined into a single prediction program. The results were compared with data taken during the flight test of the B727/UDF (trademark) engine demonstrator aircraft.

A Flight Examination of Operating Problems of V/STOL Aircraft in STOL-Type Landing and Approach

NASA Technical Reports Server (NTRS)

Innis, Robert C.; Quigley, Hervey C.

1961-01-01

A flight investigation has been conducted using a large twin-engine cargo aircraft to isolate the problems associated with operating propeller-driven aircraft in the STOL speed range where appreciable engine power is used to augment aerodynamic lift. The problems considered would also be representative of those of a large overloaded VTOL aircraft operating in an STOL manner with comparable thrust-to-weight ratios. The study showed that operation at low approach speeds was compromised by the necessity of maintaining high thrust to generate high lift and yet achieving the low lift-drag ratios needed for steep descents. The useable range of airspeed and flight path angle was limited by the pilot's demand for a positive climb margin at the approach speed, a suitable stall margin, and a control and/or performance margin for one engine inoperative. The optimum approach angle over an obstacle was found to be a compromise between obtaining the shortest air distance and the lowest touchdown velocity. In order to realize the greatest low-speed potential from STOL designs, the stability and control characteristics must be satisfactory.

30 CFR 7.82 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Definitions. 7.82 Section 7.82 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF... shall be 75 percent of rated speed. Low idle speed. The minimum no load speed as specified by the engine...

30 CFR 7.82 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Definitions. 7.82 Section 7.82 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF... shall be 75 percent of rated speed. Low idle speed. The minimum no load speed as specified by the engine...

30 CFR 7.82 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Definitions. 7.82 Section 7.82 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF... shall be 75 percent of rated speed. Low idle speed. The minimum no load speed as specified by the engine...

30 CFR 7.82 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Definitions. 7.82 Section 7.82 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR TESTING, EVALUATION, AND APPROVAL OF... shall be 75 percent of rated speed. Low idle speed. The minimum no load speed as specified by the engine...

14 CFR 23.233 - Directional stability and control.

Code of Federal Regulations, 2012 CFR

2012-01-01

... landings at normal landing speed, without using brakes or engine power to maintain a straight path until the speed has decreased to at least 50 percent of the speed at touchdown. (c) The airplane must have... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground...

14 CFR 23.233 - Directional stability and control.

Code of Federal Regulations, 2010 CFR

2010-01-01

... landings at normal landing speed, without using brakes or engine power to maintain a straight path until the speed has decreased to at least 50 percent of the speed at touchdown. (c) The airplane must have... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground...

14 CFR 23.233 - Directional stability and control.

Code of Federal Regulations, 2014 CFR

2014-01-01

... landings at normal landing speed, without using brakes or engine power to maintain a straight path until the speed has decreased to at least 50 percent of the speed at touchdown. (c) The airplane must have... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground...

14 CFR 23.233 - Directional stability and control.

Code of Federal Regulations, 2013 CFR

2013-01-01

... landings at normal landing speed, without using brakes or engine power to maintain a straight path until the speed has decreased to at least 50 percent of the speed at touchdown. (c) The airplane must have... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground...

14 CFR 23.233 - Directional stability and control.

Code of Federal Regulations, 2011 CFR

2011-01-01

... landings at normal landing speed, without using brakes or engine power to maintain a straight path until the speed has decreased to at least 50 percent of the speed at touchdown. (c) The airplane must have... AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground...

The Effects of a Highly Cambered Low-Drag Wing and of Auxiliary Flaps on the High-Speed Aerodynamic Characteristics of a Twin-Engine Pursuit Airplane Model

NASA Technical Reports Server (NTRS)

Ganzer, Victor M

1944-01-01

Results are presented for tests of two wings, an NACA 230-series wing and a highly-cambered NACA 66-series wing on a twin-engine pursuit airplane. Auxiliary control flaps were tested in combinations with each wing. Data showing comparison of high-speed aerodynamic characteristics of the model when equipped with each wing, the effect of the auxiliary control flaps on aerodynamic characteristics, and elevator effectiveness for the model with the 66-series wing are presented. High-speed aerodynamic characteristics of the model were improved with the 66-series wing.

40 CFR 94.203 - Application for certification.

Code of Federal Regulations, 2013 CFR

2013-07-01

... in § 94.210 to accurately reflect the manufacturer's production. (d) Each application shall include... temperature or engine speed); (iii) Each auxiliary emission control device (AECD); and (iv) All fuel system components to be installed on any production or test engine(s). (3) A description of the test engine. (4...

40 CFR 94.203 - Application for certification.

Code of Federal Regulations, 2011 CFR

2011-07-01

... in § 94.210 to accurately reflect the manufacturer's production. (d) Each application shall include... temperature or engine speed); (iii) Each auxiliary emission control device (AECD); and (iv) All fuel system components to be installed on any production or test engine(s). (3) A description of the test engine. (4...

40 CFR 1042.505 - Testing engines using discrete-mode or ramped-modal duty cycles.

Code of Federal Regulations, 2013 CFR

2013-07-01

... used with) controllable-pitch propellers or with electrically coupled propellers, unless these engines... engines that are used with (or intended to be used with) controllable-pitch propellers or with electrically coupled propellers. Use this duty cycle also for variable-speed propulsion marine engines that are...

14 CFR 23.149 - Minimum control speed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... extended; and (5) All propeller controls in the position recommended for approach with all engines... engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine... not more than 5 degrees. The method used to simulate critical engine failure must represent the most...

40 CFR 1042.505 - Testing engines using discrete-mode or ramped-modal duty cycles.

Code of Federal Regulations, 2011 CFR

2011-07-01

... used with) controllable-pitch propellers or with electrically coupled propellers, unless these engines... engines that are used with (or intended to be used with) controllable-pitch propellers or with electrically coupled propellers. Use this duty cycle also for variable-speed propulsion marine engines that are...

14 CFR 23.149 - Minimum control speed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... extended; and (5) All propeller controls in the position recommended for approach with all engines... engine is suddenly made inoperative, it is possible to maintain control of the airplane with that engine... not more than 5 degrees. The method used to simulate critical engine failure must represent the most...

40 CFR 1042.505 - Testing engines using discrete-mode or ramped-modal duty cycles.

Code of Federal Regulations, 2012 CFR

2012-07-01

... used with) controllable-pitch propellers or with electrically coupled propellers, unless these engines... engines that are used with (or intended to be used with) controllable-pitch propellers or with electrically coupled propellers. Use this duty cycle also for variable-speed propulsion marine engines that are...

40 CFR 91.404 - Test procedure overview.

Code of Federal Regulations, 2014 CFR

2014-07-01

... conducted on an engine dynamometer or equivalent load and speed measurement device. The exhaust gases... with an exponential relationship between torque and speed which span the typical operating range of...

The convertible engine: A dual-mode propulsion system

NASA Technical Reports Server (NTRS)

Mcardle, Jack G.

1988-01-01

A variable inlet guide vane (VIGV) convertible engine that could be used to power future high-speed rotorcraft was tested on an outdoor stand. The engine ran stably and smoothly in the turbofan, turboshaft, and dual (combined fan and shaft) power modes. In the turbofan mode with the VIGV open, fuel consumption was comparable to that of a conventional turbofan engine. In the turboshaft mode with the VIGV closed, fuel consumption was higher than that of present turboshaft engines because power was wasted in churning fan-tip air flow. In dynamic performance tests with a specially built digital engine control and using a waterbrake dynamometer for shaft load, the engine responded effectively to large steps in thrust command and shaft torque. Previous mission analyses of a conceptual X-wing rotorcraft capable of 400-knot cruise speed were revised to account for more fan-tip churning power loss that was originally estimated. The calculations confirm that using convertible engines rather than separate life and cruise engines would result in a smaller, lighter craft with lower fuel use and direct operating cost.

Outdoor test stand performance of a convertible engine with variable inlet guide vanes for advanced rotorcraft propulsion

NASA Technical Reports Server (NTRS)

Mcardle, Jack G.

1986-01-01

A variable inlet guide van (VIGV) type convertible engine that could be used to power future high-speed rotorcraft was tested on an outdoor stand. The engine ran stably and smoothly in the turbofan, turboshaft, and dual (combined fan and shaft) power modes. In the turbofan mode with the VIGV open fuel consumption was comparable to that of a conventional turbofan engine. In the turboshaft mode with the VIGV closed fuel consumption was higher than that of present turboshaft engines because power was wasted in churning fan-tip airflow. In dynamic performance tests with a specially built digital engine control and using a waterbrake dynamometer for shaft load, the engine responded effectively to large steps in thrust command and shaft torque. Previous mission analyses of a conceptual X-wing rotorcraft capable of 400-knot cruise speed were revised to account for more fan-tip churning power loss than was originally estimated. The new calculations confirm that using convertible engines rather than separate lift and cruise engines would result in a smaller, lighter craft with lower fuel use and direct operating cost.

Codon usage regulates protein structure and function by affecting translation elongation speed in Drosophila cells.

PubMed

Zhao, Fangzhou; Yu, Chien-Hung; Liu, Yi

2017-08-21

Codon usage biases are found in all eukaryotic and prokaryotic genomes and have been proposed to regulate different aspects of translation process. Codon optimality has been shown to regulate translation elongation speed in fungal systems, but its effect on translation elongation speed in animal systems is not clear. In this study, we used a Drosophila cell-free translation system to directly compare the velocity of mRNA translation elongation. Our results demonstrate that optimal synonymous codons speed up translation elongation while non-optimal codons slow down translation. In addition, codon usage regulates ribosome movement and stalling on mRNA during translation. Finally, we show that codon usage affects protein structure and function in vitro and in Drosophila cells. Together, these results suggest that the effect of codon usage on translation elongation speed is a conserved mechanism from fungi to animals that can affect protein folding in eukaryotic organisms. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Development of the Junkers-diesel Aircraft Engine

NASA Technical Reports Server (NTRS)

Gasterstadt,

1930-01-01

The working process of the Junkers engine has resulted from a series of attempts to attain high performance and to control the necessarily rapid and complete combustion at extremely high speeds. The two main problems of Diesel engines in aircraft are addressed; namely, incomplete combustion and the greater weight of Diesel engine parts compared to gasoline engines.

NACA D-558-2 Test Force w/P2B-1S & F-86

NASA Technical Reports Server (NTRS)

1952-01-01

These people and this equipment supported the flight of the NACA D-558-2 Skyrocket at the High-Speed Flight Station at South Base, Edwards AFB. Note the two Sabre chase planes, the P2B-1S launch aircraft, and the profusion of ground support equipment, including communications, tracking, maintenance, and rescue vehicles. Research pilot A. Scott Crossfield stands in front of the Skyrocket. Three D-558-2 'Skyrockets' were built by Douglas Aircraft, Inc. for NACA and the Navy. The mission of the D-558-2 program was to investigate the flight characteristics of a swept-wing aircraft at high supersonic speeds. Particular attention was given to the problem of 'pitch-up,' a phenomenon often encountered with swept-wing configured aircraft. The D-558-2 was a single-place, 35-degree swept-wing aircraft measuring 42 feet in length. It was 12 feet, 8 inches in height and had a wingspan of 25 feet. Fully fueled it weighed from about 10,572 pounds to 15,787 pounds depending on configuration. The first of the three D-558-IIs had a Westinghouse J34-40 jet engine and took off under its own power. The second was equipped with a turbojet engine replaced in 1950 with a Reaction Motors Inc. LR8-RM-6 rocket engine. This aircraft was modified so it could be air-launched from a P2B-1S (Navy designation for the B-29) carrier aircraft. The third Skyrocket had the jet engine and the rocket engine but was also modified so it could be air-launched. The jet engine was for takeoff and climbing to altitude and the four-chambered rocket engine was for reaching supersonic speeds. The rocket engine was rated at 6,000 pounds of thrust. The D-558-2 was first flown on Feb. 4, 1948, by John Martin, a Douglas test pilot. A NACA pilot, Scott Crossfield, became the first person to fly faster than twice the speed of sound when he piloted the D-558-II to its maximum speed of 1,291 miles per hour on Nov. 20, 1953. Its peak altitude, 83,235 feet, a record in its day, was reached with USMC Lt. Col. Marion Carl behind the controls.

Efficiency versus speed in quantum heat engines: Rigorous constraint from Lieb-Robinson bound

NASA Astrophysics Data System (ADS)

Shiraishi, Naoto; Tajima, Hiroyasu

2017-08-01

A long-standing open problem whether a heat engine with finite power achieves the Carnot efficiency is investgated. We rigorously prove a general trade-off inequality on thermodynamic efficiency and time interval of a cyclic process with quantum heat engines. In a first step, employing the Lieb-Robinson bound we establish an inequality on the change in a local observable caused by an operation far from support of the local observable. This inequality provides a rigorous characterization of the following intuitive picture that most of the energy emitted from the engine to the cold bath remains near the engine when the cyclic process is finished. Using this description, we prove an upper bound on efficiency with the aid of quantum information geometry. Our result generally excludes the possibility of a process with finite speed at the Carnot efficiency in quantum heat engines. In particular, the obtained constraint covers engines evolving with non-Markovian dynamics, which almost all previous studies on this topic fail to address.

Efficiency versus speed in quantum heat engines: Rigorous constraint from Lieb-Robinson bound.

PubMed

Shiraishi, Naoto; Tajima, Hiroyasu

2017-08-01

A long-standing open problem whether a heat engine with finite power achieves the Carnot efficiency is investgated. We rigorously prove a general trade-off inequality on thermodynamic efficiency and time interval of a cyclic process with quantum heat engines. In a first step, employing the Lieb-Robinson bound we establish an inequality on the change in a local observable caused by an operation far from support of the local observable. This inequality provides a rigorous characterization of the following intuitive picture that most of the energy emitted from the engine to the cold bath remains near the engine when the cyclic process is finished. Using this description, we prove an upper bound on efficiency with the aid of quantum information geometry. Our result generally excludes the possibility of a process with finite speed at the Carnot efficiency in quantum heat engines. In particular, the obtained constraint covers engines evolving with non-Markovian dynamics, which almost all previous studies on this topic fail to address.

Nonintrusive performance measurement of a gas turbine engine in real time

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeSilva, Upul P.; Claussen, Heiko

Performance of a gas turbine engine is monitored by computing a mass flow rate through the engine. Acoustic time-of-flight measurements are taken between acoustic transmitters and receivers in the flow path of the engine. The measurements are processed to determine average speeds of sound and gas flow velocities along those lines-of-sound. A volumetric flow rate in the flow path is computed using the gas flow velocities together with a representation of the flow path geometry. A gas density in the flow path is computed using the speeds of sound and a measured static pressure. The mass flow rate is calculatedmore » from the gas density and the volumetric flow rate.« less

A hybrid disturbance rejection control solution for variable valve timing system of gasoline engines.

PubMed

Xie, Hui; Song, Kang; He, Yu

2014-07-01

A novel solution for electro-hydraulic variable valve timing (VVT) system of gasoline engines is proposed, based on the concept of active disturbance rejection control (ADRC). Disturbances, such as oil pressure and engine speed variations, are all estimated and mitigated in real-time. A feed-forward controller was added to enhance the performance of the system based on a simple and static first principle model, forming a hybrid disturbance rejection control (HDRC) strategy. HDRC was validated by experimentation and compared with an existing manually tuned proportional-integral (PI) controller. The results show that HDRC provided a faster response and better tolerance of engine speed and oil pressure variations. © 2013 ISA Published by ISA All rights reserved.

Experimental analysis of IMEP in a rotary combustion engine

NASA Technical Reports Server (NTRS)

Schock, H. J.; Rice, W. J.; Meng, P. R.

1981-01-01

A real time indicated mean effective pressure measurement system is described which is used to judge proposed improvements in cycle efficiency of a rotary combustion engine. This is the first self-contained instrument that is capable of making real time measurements of IMEP in a rotary engine. Previous methods used require data recording and later processing using a digital computer. The unique features of this instrumentation include its ability to measure IMEP on a cycle by cycle, real time basis and the elimination of the need to differentiate volume function in real time. Measurements at two engine speeds (2000 and 3000 rpm) and a full range of loads are presented, although the instrument was designed to operate to speeds of 9000 rpm.

Cross-Correlations and Structures of Aero-Engine Gas Path System Based on DCCA Coefficient and Rooted Tree

NASA Astrophysics Data System (ADS)

Dong, Keqiang; Fan, Jie; Gao, You

2015-12-01

Identifying the mutual interaction is a crucial problem that facilitates the understanding of emerging structures in complex system. We here focus on aero-engine dynamic as an example of complex system. By applying the detrended cross-correlation analysis (DCCA) coefficient method to aero-engine gas path system, we find that the low-spool rotor speed (N1) and high-spool rotor speed (N2) fluctuation series exhibit cross-correlation characteristic. Further, we employ detrended cross-correlation coefficient matrix and rooted tree to investigate the mutual interactions of other gas path variables. The results can infer that the exhaust gas temperature (EGT), N1, N2, fuel flow (WF) and engine pressure ratio (EPR) are main gas path parameters.

Optimization design and performance analysis of a miniature stirling engine

NASA Astrophysics Data System (ADS)

You, Zhanping; Yang, Bo; Pan, Lisheng; Hao, Changsheng

2017-10-01

Under given operation conditions, a stirling engine of 2 kW is designed which takes hydrogen as working medium. Through establishment of adiabatic model, the ways are achieved about performance improving. The ways are raising the temperature of hot terminal, lowering the temperature of cold end, increasing the average cycle pressure, speeding up the speed, phase angle being 90°, stroke volume ratio approximating to 1 and increasing the performance of regenerator.

Pulse Detonation Engines for High Speed Flight

NASA Technical Reports Server (NTRS)

Povinelli, Louis A.

2002-01-01

Revolutionary concepts in propulsion are required in order to achieve high-speed cruise capability in the atmosphere and for low cost reliable systems for earth to orbit missions. One of the advanced concepts under study is the air-breathing pulse detonation engine. Additional work remains in order to establish the role and performance of a PDE in flight applications, either as a stand-alone device or as part of a combined cycle system. In this paper, we shall offer a few remarks on some of these remaining issues, i.e., combined cycle systems, nozzles and exhaust systems and thrust per unit frontal area limitations. Currently, an intensive experimental and numerical effort is underway in order to quantify the propulsion performance characteristics of this device. In this paper, we shall highlight our recent efforts to elucidate the propulsion potential of pulse detonation engines and their possible application to high-speed or hypersonic systems.

40 CFR 91.404 - Test procedure overview.

Code of Federal Regulations, 2013 CFR

2013-07-01

... to be conducted on an engine dynamometer or equivalent load and speed measurement device. The exhaust... four power modes with an exponential relationship between torque and speed which span the typical...

40 CFR 91.404 - Test procedure overview.

Code of Federal Regulations, 2012 CFR

2012-07-01

... to be conducted on an engine dynamometer or equivalent load and speed measurement device. The exhaust... four power modes with an exponential relationship between torque and speed which span the typical...

78 FR 13286 - Sharing Certain Business Information Regarding the Introduction of Genetically Engineered...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-27

... Information Regarding the Introduction of Genetically Engineered Organisms With State and Tribal Government... proposing to amend our regulations regarding genetically engineered organisms regulated by the United States...). The regulations refer to such genetically engineered (GE) organisms and products as ``regulated...

PIV investigation of the flow induced by a passive surge control method in a radial compressor

NASA Astrophysics Data System (ADS)

Guillou, Erwann; Gancedo, Matthieu; Gutmark, Ephraim; Mohamed, Ashraf

2012-09-01

Due to recent emission regulations, the use of turbochargers for force induction of internal combustion engines has increased. Actually, the trend in diesel engines is to downsize the engine by use of turbochargers that operate at higher pressure ratios. Unfortunately, increasing the impeller rotational speed of turbocharger radial compressors tends to reduce their range of operation, which is limited at low mass flow rate by the occurrence of surge. In order to extend the operability of turbochargers, compressor housings can be equipped with a passive surge control device such as a "ported shroud." This specific casing treatment has been demonstrated to enhance the surge margin with minor negative impact on the compressor efficiency. However, the actual working mechanisms of the system remain not well understood. Hence, in order to optimize the design of the ported shroud, it is crucial to identify the dynamic flow changes induced by the implementation of the device to control instabilities. From the full dynamic survey of the compressor performance characteristics obtained with and without ported shroud, specific points of operation were selected to carry out planar flow visualization. At normal working, both standard and stereoscopic particle imaging velocimetry (PIV) measurements were performed to evaluate instantaneous and mean velocity flow fields at the inlet of the compressor. At incipient and full surge, phase-locked PIV measurements were added. As a result, satisfying characterization of the compressor instabilities was provided at different operational speeds. Combining transient pressure data and PIV measurements, the time evolution of the complex flow patterns occurring at surge was reconstructed and a better insight into the bypass mechanism was achieved.

Possible improvements in gasoline engines

NASA Technical Reports Server (NTRS)

Ziembinski, S

1923-01-01

High-compression engines are investigated with the three main objects being elimination of vibration, increase of maximum efficiency, and conservation of this efficiency at the highest possible speeds.

Development of Diesel Diagnostics for U.S. Coast Guard Cutters

DOT National Transportation Integrated Search

1981-07-01

This program involved an investigation of techniques to perform engine fuel diagnosis on the large medium-speed diesel engines used as main propulsion power plants in medium- and high-endurance Coast Guard cutters. Two engine diagnostic parameters we...

Feedback Control of Rotor Overspeed

NASA Technical Reports Server (NTRS)

Churchill, G. B.

1984-01-01

Feedback system for automatically governing helicopter rotor speed promises to lessen pilot's workload, enhance maneuverability, and protect airframe. With suitable modifications, concept applied to control speed of electrical generators, automotive engines and other machinery.

NACA Aircraft on Lakebed - D-558-2, X-1B, and X-1E

NASA Technical Reports Server (NTRS)

1955-01-01

Early NACA research aircraft on the lakebed at the High Speed Research Station in 1955: Left to right: X-1E, D-558-2, X-1B There were four versions of the original Bell X-1 rocket-powered research aircraft that flew at the NACA High-Speed Flight Research Station, Edwards, California. The bullet-shaped X-1 aircraft were built by Bell Aircraft Corporation, Buffalo, N.Y. for the U.S. Army Air Forces (after 1947, U.S. Air Force) and the National Advisory Committee for Aeronautics (NACA). The X-1 Program was originally designated the XS-1 for EXperimental Supersonic. The X-1's mission was to investigate the transonic speed range (speeds from just below to just above the speed of sound) and, if possible, to break the 'sound barrier.' Three different X-1s were built and designated: X-1-1, X-1-2 (later modified to become the X-1E), and X-1-3. The basic X-1 aircraft were flown by a large number of different pilots from 1946 to 1951. The X-1 Program not only proved that humans could go beyond the speed of sound, it reinforced the understanding that technological barriers could be overcome. The X-1s pioneered many structural and aerodynamic advances including extremely thin, yet extremely strong wing sections; supersonic fuselage configurations; control system requirements; powerplant compatibility; and cockpit environments. The X-1 aircraft were the first transonic-capable aircraft to use an all-moving stabilizer. The flights of the X-1s opened up a new era in aviation. The first X-1 was air-launched unpowered from a Boeing B-29 Superfortress on January 25, 1946. Powered flights began in December 1946. On October 14, 1947, the X-1-1, piloted by Air Force Captain Charles 'Chuck' Yeager, became the first aircraft to exceed the speed of sound, reaching about 700 miles per hour (Mach 1.06) and an altitude of 43,000 feet. The number 2 X-1 was modified and redesignated the X-1E. The modifications included adding a conventional canopy, an ejection seat, a low-pressure fuel system of increased capacity, and a thinner high-speed wing. The X-1E was used to obtain in-flight data at twice the speed of sound, with particular emphasis placed on investigating the improvements achieved with the high-speed wing. These wings, made by Stanley Aircraft, were only 3-3/8-inches thick at the root and had 343 gauges installed in them to measure structural loads and aerodynamic heating. The X-1E used its rocket engine to power it up to a speed of 1,471 miles per hour (Mach 2.24) and to an altitude of 73,000 feet. Like the X-1 it was air-launched. The X-1 aircraft were almost 31 feet long and had a wingspan of 28 feet. The X-1 was built of conventional aluminum stressed-skin construction to extremely high structural standards. The X-1E was also 31 feet long but had a wingspan of only 22 feet, 10 inches. It was powered by a Reaction Motors, Inc., XLR-8-RM-5, four-chamber rocket engine. As did all X-1 rocket engines, the LR-8-RM-5 engine did not have throttle capability, but instead, depended on ignition of any one chamber or group of chambers to vary speed. The X-1A, X-1B, and the X-1D were growth versions of the X-1. They were almost five feet longer, almost 2,500 pounds heavier and had conventional canopies. The X-1A and X-1B were modified to have ejection seats. Their mission was to continue the X-1 studies at higher speeds and altitudes. The X-1A began this research after the X-1D was destroyed in an explosion on a captive flight before it made any research flights. On December 12, 1953, Major Charles Yeager flew the X-1A up to a speed of 1,612 miles per hour (almost two-and-a-half times the speed of sound). Then on August 26, 1954, Major Arthur Murray took the X-1A up to an altitude of 90,440 feet. Those two performances were the records for the X-1 program. Later the X-1A was also destroyed after being jettisoned from the carrier aircraft because of an explosion. The X-1B was fitted with 300 thermocouples for exploratory aerodynamic heating tests. It also was the first aircraft to fly with a reaction control system, a prototype of the system used on the X-15. The X-1C was cancelled before production. Three D-558-2 'Skyrockets' were built by Douglas Aircraft, Inc. for NACA and the Navy. The mission of the D-558-2 program was to investigate the flight characteristics of a swept-wing aircraft at high supersonic speeds. Particular attention was given to the problem of 'pitch-up,' a phenomenon often encountered with swept-wing configured aircraft. The D-558-2 was a single-place, 35-degree swept-wing aircraft measuring 42 feet in length. It was 12 feet, 8 inches in height and had a wingspan of 25 feet. Fully fueled it weighed from about 10,572 pounds to 15,787 pounds depending on configuration. The first of the three D-558-IIs had a Westinghouse J34-40 jet engine and took off under its own power. The second was equipped with a turbojet engine replaced in 1950 with a Reaction Motors Inc. LR8-RM-6 rocket engine. This aircraft was modified so it could be air-launched from a P2B-1S (Navy designation for the B-29) carrier aircraft. The third Skyrocket had the jet engine and the rocket engine but was also modified so it could be air-launched. The jet engine was for takeoff and climbing to altitude and the four-chambered rocket engine was for reaching supersonic speeds. The rocket engine was rated at 6,000 pounds of thrust. The D-558-2 was first flown on Feb. 4, 1948, by John Martin, a Douglas test pilot. A NACA pilot, Scott Crossfield, became the first person to fly faster than twice the speed of sound when he piloted the D-558-II to its maximum speed of 1,291 miles per hour on Nov. 20, 1953. Its peak altitude, 83,235 feet, a record in its day, was reached with USMC Lt. Col. Marion Carl behind the controls.