14 CFR 29.1505 - Never-exceed speed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... variation of VNE. (c) For helicopters, a stabilized power-off V NE denoted as V NE (power-off) may be... speed used in meeting the requirements of— (i) § 29.67(a)(3) for Category A helicopters; (ii) § 29.65(a) for Category B helicopters, except multi-engine helicopters meeting the requirements of § 29.67(b...

14 CFR 27.1505 - Never-exceed speed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... enough to allow an operationally practical and safe variation of VNE. (c) For helicopters, a stabilized...) § 27.65(b) for single engine helicopters; and (ii) § 27.67 for multiengine helicopters. (2) VNE (power...

14 CFR 27.1505 - Never-exceed speed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... enough to allow an operationally practical and safe variation of VNE. (c) For helicopters, a stabilized...) § 27.65(b) for single engine helicopters; and (ii) § 27.67 for multiengine helicopters. (2) VNE (power...

14 CFR 27.1505 - Never-exceed speed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... enough to allow an operationally practical and safe variation of VNE. (c) For helicopters, a stabilized...) § 27.65(b) for single engine helicopters; and (ii) § 27.67 for multiengine helicopters. (2) VNE (power...

76 FR 78 - Federal Motor Vehicle Safety Standard; Engine Control Module Speed Limiter Device

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-03

... be equipped with an electronic control module (ECM) that is capable of limiting the maximum speed of the vehicle. 2. The ECM shall be set at no more than 68 mph by the manufacturer. 3. The ECM should be... ECM to be adjusted to let the vehicle exceed 68 mph. 4. Immediately upon the rule taking effect...

An objective method and measuring equipment for noise control and acoustic diagnostics of motorcars. [acoustic diagnostics on automobile engines

NASA Technical Reports Server (NTRS)

Kacprowski, J.; Motylewski, J.; Miazga, J.

1974-01-01

An objective method and apparatus for noise control and acoustic diagnostics of motorcar engines are reported. The method and apparatus let us know whether the noisiness of the vehicle under test exceeds the admissible threshold levels given by appropriate standards and if so what is the main source of the excessive noise. The method consists in measuring both the overall noise level and the sound pressure levels in definite frequency bands while the engine speed is controlled as well and may be fixed at prescribed values. Whenever the individually adjusted threshold level has been exceeded in any frequency band, a self-sustaining control signal is sent.

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.

Development of high-speed rolling-element bearings. A historical and technical perspective

NASA Technical Reports Server (NTRS)

Zaretsky, E. V.

1982-01-01

Research on large-bore ball and roller bearings for aircraft engines is described. Tapered roller bearings and small-bore bearings are discussed. Temperature capabilities of rolling element bearings for aircraft engines have moved from 450 to 589 K (350 to 600 F) with increased reliability. High bearing speeds to 3 million DN can be achieved with a reliability exceeding that which was common in commercial aircraft. Capabilities of available bearing steels and lubricants were defined and established. Computer programs for the analysis and design of rolling element bearings were developed and experimentally verified. The reported work is a summary of NASA contributions to high performance engine and transmission bearing capabilities.

Control Performance of General Electric Fuel and Torque Regulator Operating on T31-3 Turbine-Propeller Engine in Sea-Level Test Stand

NASA Technical Reports Server (NTRS)

Oppenheimer, Frank L.; Lazar, James

1951-01-01

A .General Electric fuel and torque regulator was tested in conjunction with a T31-3 turbine-propeller engine in the sea-level static test stand at the NACA Lewis laboratory. The engine and control were operated over the entire speed range: 11,000 rpm, nominal flight idle, to 13,000 rpm, full power. Steady-state and transient data were recorded and are presented with a description of the four control loops being used in the system. Results of this investigation indicated that single-lever control operation was satisfactory under conditions of test. Transient data presented showed that turbine-outlet temperature did overshoot maximum operating value on acceleration but that the time duration of overshoot did not exceed approximately 1 second. This temperature limiting resulted from a control on fuel flow as a function of engine speed. Speed and torque first reached their desired values 0.4 second from the time of change in power-setting lever position. Maximum speed overshoot was 3 percent.

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Propellers. 25.905 Section 25.905...

14 CFR 25.905 - Propellers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant General § 25.905 Propellers. (a) Each propeller must have a type certificate. (b) Engine power and propeller shaft rotational speed may not exceed the limits... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Propellers. 25.905 Section 25.905...

Self-acting seals for helicopter engines

NASA Technical Reports Server (NTRS)

Lynwander, P.

1975-01-01

An experimental evaluation was conducted with NASA-designed self-acting face and circumferential seals for use in the main shaft positions of advanced gas turbine engines. The seals featured Rayleigh step pads (self-acting geometry) for lift augmentation. The tested seals incorporated design improvements over previous self-acting configurations. Self-acting face seals were tested to speeds of 214 m/s (700 ft/sec, 63700 rpm), air pressures of 216.8 N/sq cm abs (314.7 psia), and air temperatures of 688K (778 F). Self-acting circumferential seals were tested to speeds of 183 m/s (600 ft/sec, 47700 rpm), air pressures of 61.8 N/sq cm abs (89.7 psia), and air temperatures of 711 K (820 F). Self-acting face-seals are capable of operating at conditions exceeding conventional seal capability. The limit on speed capability was found to be the flatness of the seal-seat. The self-acting circumferential seal design tested requires further development for use in advanced engines.

14 CFR 27.1505 - Never-exceed speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Never-exceed speed. 27.1505 Section 27.1505... Never-exceed speed. (a) The never-exceed speed, VNE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward speeds...

14 CFR 27.1505 - Never-exceed speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Never-exceed speed. 27.1505 Section 27.1505... Never-exceed speed. (a) The never-exceed speed, VNE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward speeds...

14 CFR 29.1505 - Never-exceed speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Never-exceed speed. 29.1505 Section 29.1505....1505 Never-exceed speed. (a) The never-exceed speed, V NE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward speeds...

14 CFR 29.1505 - Never-exceed speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Never-exceed speed. 29.1505 Section 29.1505....1505 Never-exceed speed. (a) The never-exceed speed, V NE, must be established so that it is— (1) Not less than 40 knots (CAS); and (2) Not more than the lesser of— (i) 0.9 times the maximum forward speeds...

40 CFR 1039.515 - What are the test procedures related to not-to-exceed standards?

Code of Federal Regulations, 2010 CFR

2010-07-01

...; however, use the power value corresponding to the engine operation at 30% of maximum torque at the B speed... 50% torque/power points) and below the line formed by connecting the two points in paragraphs (b)(2)(ii) and (iii) of this section (the 50% and 70% torque/power points). The 30%, 50%, and 70% torque...

Full scale technology demonstration of a modern counterrotating unducted fan engine concept. Engine test

NASA Technical Reports Server (NTRS)

1987-01-01

The Unducted Fan (UDF) engine is an innovative aircraft engine concept based on an ungeared, counterrotating, unducted, ultra-high-bypass turbofan configuration. This engine is being developed to provide a high thrust-to-weight ratio power plant with exceptional fuel efficiency for subsonic aircraft application. This report covers the successful ground testing of this engine. A test program exceeding 100-hr duration was completed, in which all the major goals were achieved. The following accomplishments were demonstrated: (1) full thrust (25,000 lb); (2) full counterrotating rotor speeds (1393+ rpm); (3) low specific fuel consumption (less than 0.24 lb/hr/lb); (4) new composite fan design; (5) counterrotation of structures, turbines, and fan blades; (6) control system; (7) actuation system; and (8) reverse thrust.

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.

Code of Federal Regulations, 2011 CFR

2011-10-01

... predetermined rate of speed exceeded. 236.503 Section 236.503 Transportation Other Regulations Relating to... § 236.503 Automatic brake application; initiation when predetermined rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when the speed of...

49 CFR 236.503 - Automatic brake application; initiation when predetermined rate of speed exceeded.

Code of Federal Regulations, 2010 CFR

2010-10-01

... predetermined rate of speed exceeded. 236.503 Section 236.503 Transportation Other Regulations Relating to... § 236.503 Automatic brake application; initiation when predetermined rate of speed exceeded. An automatic train control system shall operate to initiate an automatic brake application when the speed of...

Digital holographic interferometry for characterizing deformable mirrors in aero-optics

NASA Astrophysics Data System (ADS)

Trolinger, James D.; Hess, Cecil F.; Razavi, Payam; Furlong, Cosme

2016-08-01

Measuring and understanding the transient behavior of a surface with high spatial and temporal resolution are required in many areas of science. This paper describes the development and application of a high-speed, high-dynamic range, digital holographic interferometer for high-speed surface contouring with fractional wavelength precision and high-spatial resolution. The specific application under investigation here is to characterize deformable mirrors (DM) employed in aero-optics. The developed instrument was shown capable of contouring a deformable mirror with extremely high-resolution at frequencies exceeding 40 kHz. We demonstrated two different procedures for characterizing the mechanical response of a surface to a wide variety of input forces, one that employs a high-speed digital camera and a second that employs a low-speed, low-cost digital camera. The latter is achieved by cycling the DM actuators with a step input, producing a transient that typically lasts up to a millisecond before reaching equilibrium. Recordings are made at increasing times after the DM initiation from zero to equilibrium to analyze the transient. Because the wave functions are stored and reconstructable, they can be compared with each other to produce contours including absolute, difference, and velocity. High-speed digital cameras recorded the wave functions during a single transient at rates exceeding 40 kHz. We concluded that either method is fully capable of characterizing a typical DM to the extent required by aero-optical engineers.

Raising the speed limit from 75 to 80mph on Utah rural interstates: Effects on vehicle speeds and speed variance.

PubMed

Hu, Wen

2017-06-01

In November 2010 and October 2013, Utah increased speed limits on sections of rural interstates from 75 to 80mph. Effects on vehicle speeds and speed variance were examined. Speeds were measured in May 2010 and May 2014 within the new 80mph zones, and at a nearby spillover site and at more distant control sites where speed limits remained 75mph. Log-linear regression models estimated percentage changes in speed variance and mean speeds for passenger vehicles and large trucks associated with the speed limit increase. Logistic regression models estimated effects on the probability of passenger vehicles exceeding 80, 85, or 90mph and large trucks exceeding 80mph. Within the 80mph zones and at the spillover location in 2014, mean passenger vehicle speeds were significantly higher (4.1% and 3.5%, respectively), as were the probabilities that passenger vehicles exceeded 80mph (122.3% and 88.5%, respectively), than would have been expected without the speed limit increase. Probabilities that passenger vehicles exceeded 85 and 90mph were non-significantly higher than expected within the 80mph zones. For large trucks, the mean speed and probability of exceeding 80mph were higher than expected within the 80mph zones. Only the increase in mean speed was significant. Raising the speed limit was associated with non-significant increases in speed variance. The study adds to the wealth of evidence that increasing speed limits leads to higher travel speeds and an increased probability of exceeding the new speed limit. Results moreover contradict the claim that increasing speed limits reduces speed variance. Although the estimated increases in mean vehicle speeds may appear modest, prior research suggests such increases would be associated with substantial increases in fatal or injury crashes. This should be considered by lawmakers considering increasing speed limits. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

Can molecular diffusion explain Space Shuttle plume spreading?

NASA Astrophysics Data System (ADS)

Meier, R. R.; Plane, John M. C.; Stevens, Michael H.; Paxton, L. J.; Christensen, A. B.; Crowley, G.

2010-04-01

The satellite-borne Global Ultraviolet Imager (GUVI) has produced more than 20 images of NASA Space Shuttle main engine plumes in the lower thermosphere. These reveal atomic hydrogen and, by inference, water vapor transport over hemispherical-scale distances with speeds much faster than expected from models of thermospheric wind motions. Furthermore, the hydrogen plumes expand rapidly. We find rates that exceed the horizontal diffusion speed at nominal plume altitudes of 104-112 km. Kelley et al. (2009) have proposed a 2-D turbulence mechanism to explain the observed spreading rates (and rapid advection) of the plumes. But upon further investigation, we conclude that H atom diffusion can indeed account for the observed expansion rates by recognizing that vertical diffusion quickly conveys atoms to higher altitudes where horizontal diffusion is much more rapid. We also find evidence for H atom production directly during the Shuttle's main engine burn.

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.

Control installation for the proportioning of a secondary air quantity for improvement of the combustion in internal combustion engines or the afterburning of the exhaust gases of internal combustion engines

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

Bockelmann, W.; Groezinger, H.; Woebky, P.U.

1977-01-04

A control installation is described for the dosing or proportioning of a secondary air quantity for the improvement of combustion in internal combustion engines, or the after-burning of the exhaust gases of internal combustion engines. An auxiliary arrangement is responsive to an emergency signal for effecting the prompt shutting-off of the secondary air. The emergency signal may be initiated in response to a failure in the ignition voltage of the internal combustion engine; an increase in the hydrocarbon content of the exhaust gases; a disparity between the position of the mixture dosing element and the engine rotational speed; the exceedingmore » of a limiting temperature in the exhaust gas manifold; or the exceeding of a limiting temperature in the afterburner.« less

STS-1 operational flight profile. Volume 5: Descent cycle 3. Appendix D: GRTLS six degree of freedom Monte Carlo dispersion analysis

NASA Technical Reports Server (NTRS)

Montez, M. N.

1980-01-01

The results of a six degree of freedom (6-DOF) nonlinear Monte Carlo dispersion analysis for the latest glide return to landing site (GRTLS) abort trajectory for the Space Transportation System 1 Flight are presented. For this GRTLS, the number two main engine fails at 262.5 seconds ground elapsed time. Fifty randomly selected simulations, initialized at external tank separation, are analyzed. The initial covariance matrix is a 20 x 20 matrix and includes navigation errors and dispersions in position and velocity, time, accelerometer bias, and inertial platform misalinements. In all 50 samples, speedbrake, rudder, elevon, and body flap hinge moments are acceptable. Transitions to autoland begin before 9,000 feet and there are no tailscrapes. Navigation derived dynamic pressure accuracies exceed the flight control system constraints above Mach 2.5. Three out of 50 landings exceeded tire specification limit speed of 222 knots. Pilot manual landings are expected to reduce landing speed by landing farther downrange.

Material requirements for the High Speed Civil Transport

NASA Technical Reports Server (NTRS)

Stephens, Joseph R.; Hecht, Ralph J.; Johnson, Andrew M.

1993-01-01

Under NASA-sponsored High Speed Research (HSR) programs, the materials and processing requirements have been identified for overcoming the environmental and economic barriers of the next generation High Speed Civil Transport (HSCT) propulsion system. The long (2 to 5 hours) supersonic cruise portion of the HSCT cycle will place additional durability requirements on all hot section engine components. Low emissions combustor designs will require high temperature ceramic matrix composite liners to meet an emission goal of less than 5g NO(x) per Kg fuel burned. Large axisymmetric and two-dimensional exhaust nozzle designs are now under development to meet or exceed FAR 36 Stage III noise requirements, and will require lightweight, high temperature metallic, intermetallic, and ceramic matrix composites to reduce nozzle weight and meet structural and acoustic component performance goals. This paper describes and discusses the turbomachinery, combustor, and exhaust nozzle requirements of the High Speed Civil Transport propulsion system.

Oil-Free Turbomachinery Team Passed Milestone on Path to the First Oil-Free Turbine Aircraft Engine

NASA Technical Reports Server (NTRS)

Bream, Bruce L.

2002-01-01

The Oil-Free Turbine Engine Technology Project team successfully demonstrated a foil-air bearing designed for the core rotor shaft of a turbine engine. The bearings were subjected to test conditions representative of the engine core environment through a combination of high speeds, sustained loads, and elevated temperatures. The operational test envelope was defined during conceptual design studies completed earlier this year by bearing manufacturer Mohawk Innovative Technologies and the turbine engine company Williams International. The prototype journal foil-air bearings were tested at the NASA Glenn Research Center. Glenn is working with Williams and Mohawk to create a revolution in turbomachinery by developing the world's first Oil-Free turbine aircraft engine. NASA's General Aviation Propulsion project and Williams International recently developed the FJX-2 turbofan engine that is being commercialized as the EJ-22. This core bearing milestone is a first step toward a future version of the EJ-22 that will take advantage of recent advances in foil-air bearings by eliminating the need for oil lubrication systems and rolling element bearings. Oil-Free technology can reduce engine weight by 15 percent and let engines operate at very high speeds, yielding power density improvements of 20 percent, and reducing engine maintenance costs. In addition, with NASA coating technology, engines can operate at temperatures up to 1200 F. Although the project is still a couple of years from a full engine test of the bearings, this milestone shows that the bearing design exceeds the expected environment, thus providing confidence that an Oil-Free turbine aircraft engine will be attained. The Oil-Free Turbomachinery Project is supported through the Aeropropulsion Base Research Program.

30 CFR 56.19076 - Maximum speeds for hoisting persons in buckets.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Maximum speeds for hoisting persons in buckets... MINES Personnel Hoisting Hoisting Procedures § 56.19076 Maximum speeds for hoisting persons in buckets. When persons are hoisted in buckets, speeds shall not exceed 500 feet per minute and shall not exceed...

30 CFR 56.19076 - Maximum speeds for hoisting persons in buckets.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum speeds for hoisting persons in buckets... MINES Personnel Hoisting Hoisting Procedures § 56.19076 Maximum speeds for hoisting persons in buckets. When persons are hoisted in buckets, speeds shall not exceed 500 feet per minute and shall not exceed...

Preliminary analysis of turbochargers rotors dynamic behaviour

NASA Astrophysics Data System (ADS)

Monoranu, R.; Ştirbu, C.; Bujoreanu, C.

2016-08-01

Turbocharger rotors for the spark and compression ignition engines are resistant steels manufactured in order to support the exhaust gas temperatures exceeding 1200 K. In fact, the mechanical stress is not large as the power consumption of these systems is up to 10 kW, but the operating speeds are high, ranging between 30000 ÷ 250000 rpm. Therefore, the correct turbochargers functioning involves, even from the design stage, the accurate evaluation of the temperature effects, of the turbine torque due to the engine exhaust gases and of the vibration system behaviour caused by very high operating speeds. In addition, the turbocharger lubrication complicates the model, because the classical hydrodynamic theory cannot be applied to evaluate the floating bush bearings. The paper proposes a FEM study using CATIA environment, both as modeling medium and as tool for the numerical analysis, in order to highlight the turbocharger complex behaviour. An accurate design may prevent some major issues which can occur during its operation.

Engine monitoring display study

NASA Technical Reports Server (NTRS)

Hornsby, Mary E.

1992-01-01

The current study is part of a larger NASA effort to develop displays for an engine-monitoring system to enable the crew to monitor engine parameter trends more effectively. The objective was to evaluate the operational utility of adding three types of information to the basic Boeing Engine Indicating and Crew Alerting System (EICAS) display formats: alphanumeric alerting messages for engine parameters whose values exceed caution or warning limits; alphanumeric messages to monitor engine parameters that deviate from expected values; and a graphic depiction of the range of expected values for current conditions. Ten training and line pilots each flew 15 simulated flight scenarios with five variants of the basic EICAS format; these variants included different combinations of the added information. The pilots detected engine problems more quickly when engine alerting messages were included in the display; adding a graphic depiction of the range of expected values did not affect detection speed. The pilots rated both types of alphanumeric messages (alert and monitor parameter) as more useful and easier to interpret than the graphic depiction. Integrating engine parameter messages into the EICAS alerting system appears to be both useful and preferred.

Analysis of Dynamic Characteristics of the 21st Century Maritime Silk Road

NASA Astrophysics Data System (ADS)

Zhang, Xudong; Zhang, Jie; Fan, Chenqing; Meng, Junmin; Wang, Jing; Wan, Yong

2018-06-01

The 21st century Maritime Silk Road (MSR) proposed by China strongly promotes the maritime industry. In this paper, we use wind and ocean wave datasets from 1979 to 2014 to analyze the spatial and temporal distributions of the wind speed, significant wave height (SWH), mean wave direction (MWD), and mean wave period (MWP) in the MSR. The analysis results indicate that the Luzon Strait and Gulf of Aden have the most obvious seasonal variations and that the central Indian Ocean is relatively stable. We analyzed the distributions of the maximum wind speed and SWH in the MSR over this 36-year period. The results show that the distribution of the monthly average frequency for SWH exceeds 4 m (huge waves) and that of the corresponding wind speed exceeds 13.9 m s-1 (high wind speed). The occurrence frequencies of huge waves and high winds in regions east of the Gulf of Aden are as high as 56% and 80%, respectively. We also assessed the wave and wind energies in different seasons. Based on our analyses, we propose a risk factor (RF) for determining navigation safety levels, based on the wind speed and SWH. We determine the spatial and temporal RF distributions for different seasons and analyze the corresponding impact on four major sea routes. Finally, we determine the spatial distribution of tropical cyclones from 2000 to 2015 and analyze the corresponding impact on the four sea routes. The analysis of the dynamic characteristics of the MSR provides references for ship navigation as well as ocean engineering.

AGT100 turbomachinery. [for automobiles

NASA Technical Reports Server (NTRS)

Tipton, D. L.; Mckain, T. F.

1982-01-01

High-performance turbomachinery components have been designed and tested for the AGT100 automotive engine. The required wide range of operation coupled with the small component size, compact packaging, and low cost of production provide significant aerodynamic challenges. Aerodynamic design and development testing of the centrifugal compressor and two radial turbines are described. The compressor achieved design flow, pressure ratio, and surge margin on the initial build. Variable inlet guide vanes have proven effective in modulating flow capacity and in improving part-speed efficiency. With optimum use of the variable inlet guide vanes, the initial efficiency goals have been demonstrated in the critical idle-to-70% gasifier speed range. The gasifier turbine exceeded initial performance goals and demonstrated good performance over a wide range. The radial power turbine achieved 'developed' efficiency goals on the first build.

Circulation control propellers for general aviation, including a BASIC computer program

NASA Technical Reports Server (NTRS)

Taback, I.; Braslow, A. L.; Butterfield, A. J.

1983-01-01

The feasibility of replacing variable pitch propeller mechanisms with circulation control (Coanada effect) propellers on general aviation airplanes was examined. The study used a specially developed computer program written in BASIC which could compare the aerodynamic performance of circulation control propellers with conventional propellers. The comparison of aerodynamic performance for circulation control, fixed pitch and variable pitch propellers is based upon the requirements for a 1600 kg (3600 lb) single engine general aviation aircraft. A circulation control propeller using a supercritical airfoil was shown feasible over a representative range of design conditions. At a design condition for high speed cruise, all three types of propellers showed approximately the same performance. At low speed, the performance of the circulation control propeller exceeded the performance for a fixed pitch propeller, but did not match the performance available from a variable pitch propeller. It appears feasible to consider circulation control propellers for single engine aircraft or multiengine aircraft which have their propellers on a common axis (tractor pusher). The economics of the replacement requires a study for each specific airplane application.

Ultrafast optics. Ultrafast optical control by few photons in engineered fiber.

PubMed

Nissim, R; Pejkic, A; Myslivets, E; Kuo, B P; Alic, N; Radic, S

2014-07-25

Fast control of a strong optical beam by a few photons is an outstanding challenge that limits the performance of quantum sensors and optical processing devices. We report that a fast and efficient optical gate can be realized in an optical fiber that has been engineered with molecular-scale accuracy. Highly efficient, distributed phase-matched photon-photon interaction was achieved in the fiber with locally controlled, nanometer-scale core variations. A three-photon input was used to manipulate a Watt-scale beam at a speed exceeding 500 gigahertz. In addition to very fast beam control, the results provide a path to developing a new class of sensitive receivers capable of operating at very high rates. Copyright © 2014, American Association for the Advancement of Science.

Temperature in a J47-25 Turbojet-engine Combustor and Turbine Sections During Steady-state and Transient Operation in a Sea-level Test Stand

NASA Technical Reports Server (NTRS)

Morse, C R; Johnston, J R

1955-01-01

In order to determine the conditions of engine operation causing the most severe thermal stresses in the hot parts of a turbojet engine, a J47-25 engine was instrumented with thermocouples and operated to obtain engine material temperatures under steady-state and transient conditions. Temperatures measured during rated take-off conditions of nozzle guide vanes downstream of a single combustor differed on the order of 400 degrees F depending on the relation of the blades position to the highest temperature zone of the burner. Under the same operation conditions, measured midspan temperatures in a nozzle guide vane in the highest temperature zone of a combustor wake ranged from approximately 1670 degrees F at leading and trailing edges to 1340 degrees F at midchord on the convex side of the blade. The maximum measured nozzle-guide-vane temperature of 1920degrees at the trailing edge occurred during a rapid acceleration from idle to rated take-off speed following which the tail-pipe gas temperature exceeded maximum allowable temperature by 125 degrees F.

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

Identifying the psychological determinants of risky riding: an application of an extended Theory of Planned Behaviour.

PubMed

Chorlton, Kathryn; Conner, Mark; Jamson, Samantha

2012-11-01

The Theory of Planned Behaviour (TPB) plus moral norms, anticipated regret, past behaviour, self-identity and perceived susceptibility was applied to predicting motorcyclists' intention to ride above the speed limit and ride at inappropriate speeds. Past behaviour, control beliefs, attitudes, moral norm, normative beliefs, age and self-identity explained 60% of the variance in motorcyclists' intention to exceed the speed limit on motorways (N=1381). A total of 62% of the variance in motorcyclists' intention to really go for it on rural roads was accounted for, with past behaviour, attitudes, control beliefs, age, normative beliefs, anticipated regret, self-identity, behavioural beliefs and training status being significant (N=1116). Finally, attitudes, past behaviour, control beliefs, moral norm, anticipated regret, behavioural beliefs, normative beliefs, engine size and self-identity explained 57% of the variance in motorcyclists' intention to ride faster than felt safe in order to keep up with the group (N=1940). The belief-based measures also successfully differentiated between those who intended to speed and those who did not. Theoretical and practical implications of the findings are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.

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.

Jimsphere wind and turbulence exceedance statistic

NASA Technical Reports Server (NTRS)

Adelfang, S. I.; Court, A.

1972-01-01

Exceedance statistics of winds and gusts observed over Cape Kennedy with Jimsphere balloon sensors are described. Gust profiles containing positive and negative departures, from smoothed profiles, in the wavelength ranges 100-2500, 100-1900, 100-860, and 100-460 meters were computed from 1578 profiles with four 41 weight digital high pass filters. Extreme values of the square root of gust speed are normally distributed. Monthly and annual exceedance probability distributions of normalized rms gust speeds in three altitude bands (2-7, 6-11, and 9-14 km) are log-normal. The rms gust speeds are largest in the 100-2500 wavelength band between 9 and 14 km in late winter and early spring. A study of monthly and annual exceedance probabilities and the number of occurrences per kilometer of level crossings with positive slope indicates significant variability with season, altitude, and filter configuration. A decile sampling scheme is tested and an optimum approach is suggested for drawing a relatively small random sample that represents the characteristic extreme wind speeds and shears of a large parent population of Jimsphere wind profiles.

Altitude Investigation of Gas Temperature Distribution at Turbine of Three Similar Axial-Flow Turbojet Engines

NASA Technical Reports Server (NTRS)

Prince, W.R.; Schulze, F.W.

1952-01-01

An investigation of the effect of inlet pressure, corrected engine speed, and turbine temperature level on turbine-inlet gas temperature distributions was conducted on a J40-WE-6, interim J40-WE-6, and prototype J40-WE-8 turbojet engine in the altitude wind tunnel at the NAC.4 Lewis laboratory. The engines were investigated over a range of simulated pressure altitudes from 15,000 to 55,000 feet, flight Mach numbers from 0.12 to 0.64, and corrected engine speeds from 7198 to 8026 rpm, The gas temperature distribution at the turbine of the three engines over the range of operating conditions investigated was considered satisfactory from the standpoint of desired temperature distribution with one exception - the distribution for the J40-WE-6 engine indicated a trend with decreasing engine-inlet pressure for the temperature to exceed the desired in the region of the blade hub. Installation of a compressor-outlet mixer vane assembly remedied this undesirable temperature distribution, The experimental data have shown that turbine-inlet temperature distributions are influenced in the expected manner by changes in compressor-outlet pressure or mass-flow distribution and by changes in combustor hole-area distribution. The similarity between turbine-inlet and turbine-outlet temperature distribution indicated only a small shift in temperature distribution imposed by the turbine rotors. The attainable jet thrusts of the three engines were influenced in different degrees and directions by changes in temperature distributions with change in engine-inlet pressure. Inability to match the desired temperature distribution resulted, for the J40-WE-6 engine, in an 11-percent thrust loss based on an average turbine-inlet temperature of 1500 F at an engine-inlet pressure of 500 pounds per square foot absolute. Departure from the desired temperature distribution in the Slade tip region results, for the prototype J40-WE-8 engine, in an attainable thrust increase of 3 to 4 percent as compared with that obtained if tip-region temperature limitations were observed.

Traffic safety facts 1994 : speed

DOT National Transportation Integrated Search

1995-01-01

Speeding - exceeding the posted speed limit or driving too fast for conditions - is one of the most prevalent factors contributing to traffic crashes. In 1994, speed was a factor in 30 percent of all fatal crashes, and 12,480 lives were lost in speed...

Speed Harmonization--Design Speed vs. Operating Speed.

DOT National Transportation Integrated Search

2016-10-01

When the actual operating speed on the roads exceeds the design speed, which is common on rural highways, the roadway design may become problematic from a safety point of view. This report presents a new methodology that summarizes the relationship b...

49 CFR 236.811 - Speed, medium.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...

49 CFR 236.811 - Speed, medium.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...

49 CFR 236.811 - Speed, medium.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...

Traffic safety facts 1998 : speeding

DOT National Transportation Integrated Search

1998-01-01

Speeding exceeding the posted speed limit or driving too fast for : The economic cost : of speeding-related : crashes is estimated : to be $27.7 billion : each year. : conditions is one of the most prevalent factors contributing to traf...

49 CFR 236.813 - Speed, slow.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour. ...

49 CFR 236.813 - Speed, slow.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, slow. 236.813 Section 236.813 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, slow. A speed not exceeding 20 miles per hour. ...

49 CFR 236.811 - Speed, medium.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...

49 CFR 236.811 - Speed, medium.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Speed, medium. 236.811 Section 236.811 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION... Speed, medium. A speed not exceeding 40 miles per hour. ...

Effects on speed and safety of point-to-point speed enforcement systems: evaluation on the urban motorway A56 Tangenziale di Napoli.

PubMed

Montella, Alfonso; Imbriani, Lella Liana; Marzano, Vittorio; Mauriello, Filomena

2015-02-01

In this paper, we evaluated the effects on speed and safety of the point-to-point (P2P) speed enforcement system activated on the urban motorway A56 in Italy. The P2P speed enforcement is a relatively new approach to traffic law enforcement that involves the calculation of the average speed over a section. To evaluate the speed effects, we performed a before-after analysis of speed data investigating also effects on non-compliance to speed limits. To evaluate the safety effects, we carried out an empirical Bayes observational before-and-after study. The P2P system led to very positive effects on both speed and safety. As far as the effects on the section average travel speeds, the system yielded to a reduction in the mean speed, the 85th percentile speed, the standard deviation of speed, and the proportion of drivers exceeding the speed limits, exceeding the speed limits more than 10km/h, and exceeding the speed limits more than 20km/h. The best results were the decrease of the speed variability and the reduction of the excessive speeding behaviour. The decrease in the standard deviation of speed was 26% while the proportion of light and heavy vehicles exceeding the speed limits more than 20km/h was reduced respectively by 84 and 77%. As far as the safety effects, the P2P system yielded to a 32% reduction in the total crashes, with a lower 95% confidence limit of the estimate equal to 22%. The greatest crash reductions were in rainy weather (57%), on wet pavement (51%), on curves (49%), for single vehicle crashes (44%), and for injury crashes (37%). It is noteworthy that the system produced a statistically significant reduction of 21% in total crashes also in the part of the motorway where it was not activated, thus generating a significant spillover effect. The investigation of the effects of the P2P system on speed and safety over time allowed to develop crash modification functions where the relationship between crash modification factors and speed parameters (mean speed, 85th percentile speed, and standard deviation of speed) was expressed by a power function. Crash modification functions show that the effect of speed on safety is greater on curves and for injury crashes. Even though the study results show excellent outcomes, we must point out that the crash reduction effects decreased over time and speed, speed variability, and non-compliance to speed limits significantly increased over time. To maintain its effectiveness over time, P2P speed enforcement must be actively managed, i.e. constantly monitored and supported by appropriate sanctions. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Two High-Temperature Foil Journal Bearings

NASA Technical Reports Server (NTRS)

Zak, Michail

2006-01-01

An enlarged, high-temperature-compliant foil bearing has been built and tested to demonstrate the feasibility of such bearings for use in aircraft gas turbine engines. Foil bearings are attractive for use in some machines in which (1) speeds of rotation, temperatures, or both exceed maximum allowable values for rolling-element bearings; (2) conventional lubricants decompose at high operating temperatures; and/or (3) it is necessary or desirable not to rely on conventional lubrication systems. In a foil bearing, the lubricant is the working fluid (e.g., air or a mixture of combustion gases) in the space between the journal and the shaft in the machine in which the bearing is installed.

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.

14 CFR 25.1507 - Maneuvering speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c). ...

14 CFR 25.1507 - Maneuvering speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Maneuvering speed. 25.1507 Section 25.1507....1507 Maneuvering speed. The maneuvering speed must be established so that it does not exceed the design maneuvering speed V A determined under § 25.335(c). ...

A storm severity index based on return levels of wind speeds

NASA Astrophysics Data System (ADS)

Becker, Nico; Nissen, Katrin M.; Ulbrich, Uwe

2015-04-01

European windstorms related to extra-tropical cyclones cause considerable damages to infrastructure during the winter season. Leckebusch et al. (2008) introduced a storm severity index (SSI) based on the exceedances of the local 98th percentile of wind speeds. The SSI is based on the assumption that (insured) damage usually occurs within the upper 2%-quantile of the local wind speed distribution (i.e. if the 98th percentile is exceeded). However, critical infrastructure, for example related to the power network or the transportation system, is usually designed to withstand wind speeds reaching the local 50-year return level, which is much higher than the 98th percentile. The aim of this work is to use the 50-year return level to develop a modified SSI, which takes into account only extreme wind speeds relevant to critical infrastructure. As a first step we use the block maxima approach to estimate the spatial distribution of return levels by fitting the generalized extreme value (GEV) distribution to the wind speeds retrieved from different reanalysis products. We show that the spatial distributions of the 50-year return levels derived from different reanalyses agree well within large parts of Europe. The differences between the reanalyses are largely within the range of the uncertainty intervals of the estimated return levels. As a second step the exceedances of the 50-year return level are evaluated and compared to the exceedances of the 98th percentiles for different extreme European windstorms. The areas where the wind speeds exceed the 50-year return level in the reanalysis data do largely agree with the areas where the largest damages were reported, e.g. France in the case of "Lothar" and "Martin" and Central Europe in the case of "Kyrill". Leckebusch, G. C., Renggli, D., & Ulbrich, U. (2008). Development and application of an objective storm severity measure for the Northeast Atlantic region. Meteorologische Zeitschrift, 17(5), 575-587.

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...

Traffic safety facts 1995 : speeding

DOT National Transportation Integrated Search

1996-01-01

Speeding - exceeding the posted speed limit or driving too fast for conditions - is one of the most prevalent factors contributing to traffic crashes. In 1995, speeding was a contributing factor in 31 percent of all fatal crashes, and 13,256 lives we...

Traffic safety facts 1996 : speeding

DOT National Transportation Integrated Search

1997-01-01

Speeding - exceeding the posted speed limit or driving too fast for conditions - is one of the most prevalent factors contributing to traffic crashes. In 1996, speeding was a contributing factor in 30 percent of all fatal crashes, and 12,998 lives we...

Traffic safety facts 1999 : speeding

DOT National Transportation Integrated Search

2000-01-01

Speeding -- exceeding the posted speed limit or driving too fast for conditions -- is one of the most prevalent factors contributing to traffic crashes. In 1999, speeding was a contributing factor in 30% of all fatal crashes, and 12,628 lives were lo...

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

30 CFR 56.19061 - Maximum hoisting speeds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum hoisting speeds. 56.19061 Section 56... Hoisting Procedures § 56.19061 Maximum hoisting speeds. The safe speed for hoisting persons shall be determined for each shaft, and this speed shall not be exceeded. Persons should not be hoisted at a speed...

30 CFR 56.19061 - Maximum hoisting speeds.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Maximum hoisting speeds. 56.19061 Section 56... Hoisting Procedures § 56.19061 Maximum hoisting speeds. The safe speed for hoisting persons shall be determined for each shaft, and this speed shall not be exceeded. Persons should not be hoisted at a speed...

A Mathematical Model of Marine Diesel Engine Speed Control System

NASA Astrophysics Data System (ADS)

Sinha, Rajendra Prasad; Balaji, Rajoo

2018-02-01

Diesel engine is inherently an unstable machine and requires a reliable control system to regulate its speed for safe and efficient operation. Also, the diesel engine may operate at fixed or variable speeds depending upon user's needs and accordingly the speed control system should have essential features to fulfil these requirements. This paper proposes a mathematical model of a marine diesel engine speed control system with droop governing function. The mathematical model includes static and dynamic characteristics of the control loop components. Model of static characteristic of the rotating fly weights speed sensing element provides an insight into the speed droop features of the speed controller. Because of big size and large time delay, the turbo charged diesel engine is represented as a first order system or sometimes even simplified to a pure integrator with constant gain which is considered acceptable in control literature. The proposed model is mathematically less complex and quick to use for preliminary analysis of the diesel engine speed controller performance.

A Risk Assessment Architecture for Enhanced Engine Operation

NASA Technical Reports Server (NTRS)

Litt, Jonathan S.; Sharp. Lauren M.; Guo, Ten-Huei

2010-01-01

On very rare occasions, in-flight emergencies have occurred that required the pilot to utilize the aircraft's capabilities to the fullest extent possible, sometimes using actuators in ways for which they were not intended. For instance, when flight control has been lost due to damage to the hydraulic systems, pilots have had to use engine thrust to maneuver the plane to the ground and in for a landing. To assist the pilot in these situations, research is being performed to enhance the engine operation by making it more responsive or able to generate more thrust. Enabled by modification of the propulsion control, enhanced engine operation can increase the probability of a safe landing during an inflight emergency. However, enhanced engine operation introduces risk as the nominal control limits, such as those on shaft speed, temperature, and acceleration, are exceeded. Therefore, an on-line tool for quantifying this risk must be developed to ensure that the use of an enhanced control mode does not actually increase the overall danger to the aircraft. This paper describes an architecture for the implementation of this tool. It describes the type of data and algorithms required and the information flow, and how the risk based on engine component lifing and operability for enhanced operation is determined.

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.

Engine control system having speed-based timing

DOEpatents

Willi, Martin L [Dunlap, IL; Fiveland, Scott B [Metamora, IL; Montgomery, David T [Edelstein, IL; Gong, Weidong [Dunlap, IL

2012-02-14

A control system for an engine having a cylinder is disclosed having an engine valve movable to regulate a fluid flow of the cylinder and an actuator associated with the engine valve. The control system also has a controller in communication with the actuator. The controller is configured to receive a signal indicative of engine speed and compare the engine speed signal with a desired engine speed. The controller is also configured to selectively regulate the actuator to adjust a timing of the engine valve to control an amount of air/fuel mixture delivered to the cylinder based on the comparison.

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...

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.

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.

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...

Charge control microcomputer device for vehicles

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

Morishita, M.; Kouge, S.

1986-10-14

This patent describes a charge control microcomputer device for a vehicle, comprising: speed changing means for transmitting the output torque of an engine. The speed changing means includes a slip clutch means having an output with a variable slippage amount with respect to its input and controlled in accordance with an operating instruction. The speed changing means further includes a speed change gear for changing the rotational speed input thereto at an output thereto, the speed change gear receiving the output of the slip clutch means; a charging generator driven by the output of the speed change gear; a batterymore » charged by an output voltage of the charging generator; a voltage regulator for controlling the output voltage of the charging generator to a predetermined value; an engine controlling microcomputer for receiving data from the engine, to control the engine, the engine data comprising at least an engine speed signal; a charge control microcomputer for processing engine data from the engine controlling microcomputer and charge system data including terminal voltage data from the battery and generated voltage data from the changing generator; and a display unit for displaying detection data, including fault detection data, form the charge control microcomputer.« less

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...

Matching Countermeasures to Driver Types and Speeding Behavior : Traffic Tech

DOT National Transportation Integrated Search

2017-06-01

Speeding is a common behavior; most drivers exceed the speed limit some of the time. It is also a complicated behavior that varies by driver and situation. Speeding-related crashes take a large annual toll in injuries, lost lives, and high economic c...

45 CFR 3.26 - Speed limit.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 1 2011-10-01 2011-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

30 CFR 57.19061 - Maximum hoisting speeds.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Maximum hoisting speeds. 57.19061 Section 57... Hoisting Hoisting Procedures § 57.19061 Maximum hoisting speeds. The safe speed for hoisting persons shall be determined for each shaft, and this speed shall not be exceeded. Persons shall not be hoisted at a...

30 CFR 57.19061 - Maximum hoisting speeds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum hoisting speeds. 57.19061 Section 57... Hoisting Hoisting Procedures § 57.19061 Maximum hoisting speeds. The safe speed for hoisting persons shall be determined for each shaft, and this speed shall not be exceeded. Persons shall not be hoisted at a...

45 CFR 3.26 - Speed limit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 1 2010-10-01 2010-10-01 false Speed limit. 3.26 Section 3.26 Public Welfare... INSTITUTES OF HEALTH FEDERAL ENCLAVE Traffic Regulations § 3.26 Speed limit. The speed limit is 25 miles per hour, unless otherwise posted. A driver of a vehicle may not exceed the speed limit. ...

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...

Research on H2 speed governor for diesel engine of marine power station

NASA Astrophysics Data System (ADS)

Huang, Man-Lei

2007-09-01

The frequency stability of a marine power system is determined by the dynamic characteristic of the diesel engine speed regulation system in a marine power station. In order to reduce the effect of load disturbances and improve the dynamic precision of a diesel engine speed governor, a controller was designed for a diesel engine speed regulation system using H2 control theory. This transforms the specifications of the system into a standard H2 control problem. Firstly, the mathematical model of a diesel engine speed regulation system using an H2 speed governor is presented. To counter external disturbances and model uncertainty, the design of an H2 speed governor rests on the problem of mixed sensitivity. Computer simulation verified that the H2 speed governor improves the dynamic precision of a system and the ability to adapt to load disturbances, thus enhancing the frequency stability of marine power systems.

Application of physics engines in virtual worlds

NASA Astrophysics Data System (ADS)

Norman, Mark; Taylor, Tim

2002-03-01

Dynamic virtual worlds potentially can provide a much richer and more enjoyable experience than static ones. To realize such worlds, three approaches are commonly used. The first of these, and still widely applied, involves importing traditional animations from a modeling system such as 3D Studio Max. This approach is therefore limited to predefined animation scripts or combinations/blends thereof. The second approach involves the integration of some specific-purpose simulation code, such as car dynamics, and is thus generally limited to one (class of) application(s). The third approach involves the use of general-purpose physics engines, which promise to enable a range of compelling dynamic virtual worlds and to considerably speed up development. By far the largest market today for real-time simulation is computer games, revenues exceeding those of the movie industry. Traditionally, the simulation is produced by game developers in-house for specific titles. However, off-the-shelf middleware physics engines are now available for use in games and related domains. In this paper, we report on our experiences of using middleware physics engines to create a virtual world as an interactive experience, and an advanced scenario where artificial life techniques generate controllers for physically modeled characters.

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...

Two-Dimensional Bifurcated Inlet/Engine Tests Completed in 10- by 10-Foot Supersonic Wind Tunnel

NASA Technical Reports Server (NTRS)

Saunders, John D.

1999-01-01

A Two-Dimensional Bifurcated (2DB) Inlet was successfully tested in NASA Lewis Research Center s 10- by 10-Foot Supersonic Wind Tunnel. These tests were the culmination of a collaborative effort between the Boeing Company, General Electric, Pratt & Whitney, and Lewis. Extensive support in-house at Lewis contributed significantly to the progress and accomplishment of this test. The results, which met or exceeded many of the High-Speed Research (HSR) Program goals, were used to revise system studies within the HSR Program. The HSR Program is focused on developing low-noise, low-polluting, high-efficiency supersonic commercial aircraft. A supersonic inlet is an important component of an efficient, low-noise vehicle.

14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2012 CFR

2012-01-01

... aircraft noise when the wind speed is in excess of 5 knots (9 km/hr). Sec. G36.107Noise Measurement... OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Pt. 36, App..., inclusively; (4) Wind speed may not exceed 10 knots (19 km/h) and cross wind may not exceed 5 knots (9 km/h...

14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2013 CFR

2013-01-01

... aircraft noise when the wind speed is in excess of 5 knots (9 km/hr). Sec. G36.107Noise Measurement... OF TRANSPORTATION AIRCRAFT NOISE STANDARDS: AIRCRAFT TYPE AND AIRWORTHINESS CERTIFICATION Pt. 36, App..., inclusively; (4) Wind speed may not exceed 10 knots (19 km/h) and cross wind may not exceed 5 knots (9 km/h...

Experimental Study on an Unsteady Pressure Gain Combustion Hypergolic Rocket Engine Concept

NASA Astrophysics Data System (ADS)

Kan, Brandon K.

An experimental study is conducted to investigate pulsed combustion in a lab-scale bipropellant rocket engine using hypergolic propellants. The propellant combination is high concentration hydrogen peroxide and a catalyst-laced triglyme fuel. A total of 50 short duration firings have been conducted; the vast majority in an open-chamber configuration. High amplitude pulsations were evident in nearly all cases and have been assessed with high frequency pressure measurements. Both pintle and unlike impinging quadlet injector types have been evaluated although the bulk of the testing was with the latter configuration. Several firings were conducted with a transparent chamber in an attempt to gain understanding using a high-speed camera in the visible spectrum. Peak chamber pressures in excess of 5000 psi have been recorded with surface mounted high frequency gages with pulsation frequencies exceeding 600 Hz. A characterization of time-averaged performance is made for the unsteady system, where time-resolved thrust and pressure measurements were attempted. While prior literature describes this system as a pulse detonation rocket engine, the combustion appears to be more "constant volume" in nature.

50 CFR 38.13 - Speed limits.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Speed limits. 38.13 Section 38.13 Wildlife... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.13 Speed limits. No person on Midway Atoll National Wildlife Refuge will exceed the speed limit for automobiles, trucks...

14 CFR 25.1511 - Flap extended speed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for the...

14 CFR 25.1511 - Flap extended speed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for the...

Development of a speeding-related crash typology

DOT National Transportation Integrated Search

2010-04-01

Speeding, the driver behavior of exceeding the posted speed limit or driving too fast for conditions, has consistently been estimated to be a contributing factor to a significant percentage of fatal and nonfatal crashes. The U.S. Department of Transp...

X-1E on Display Stand at Dryden

NASA Technical Reports Server (NTRS)

1996-01-01

The Bell Aircraft Corporation X-1E is shown in this artistic night photo taken in February 1996. This aircraft is displayed on a pedestal in front of the main building (4800) at NASA Dryden Flight Research Center, Edwards, California. There were four versions of the 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 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.

Development of a speeding-related crash typology : [summary report].

DOT National Transportation Integrated Search

2010-01-01

Speeding, the driver behavior of exceeding the posted speed limit or driving too fast : for conditions, has consistently been shown to be a contributing factor to a signifcant percentage of fatal and nonfatal crashes. Between 1990 and 2006, the frequ...

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.

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.

30 CFR 57.19076 - Maximum speeds for hoisting persons in buckets.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Maximum speeds for hoisting persons in buckets... NONMETAL MINES Personnel Hoisting Hoisting Procedures § 57.19076 Maximum speeds for hoisting persons in buckets. When persons are hoisted in buckets, speeds shall not exceed 500 feet per minute and shall not...

30 CFR 57.19076 - Maximum speeds for hoisting persons in buckets.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Maximum speeds for hoisting persons in buckets... NONMETAL MINES Personnel Hoisting Hoisting Procedures § 57.19076 Maximum speeds for hoisting persons in buckets. When persons are hoisted in buckets, speeds shall not exceed 500 feet per minute and shall not...

49 CFR 174.86 - Maximum allowable operating speed.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 2 2011-10-01 2011-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

49 CFR 174.86 - Maximum allowable operating speed.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Maximum allowable operating speed. 174.86 Section... operating speed. (a) For molten metals and molten glass shipped in packagings other than those prescribed in § 173.247 of this subchapter, the maximum allowable operating speed may not exceed 24 km/hour (15 mph...

Advanced Health Management System for the Space Shuttle Main Engine

NASA Technical Reports Server (NTRS)

Davidson, Matt; Stephens, John; Rodela, Chris

2006-01-01

Pratt & Whitney Rocketdyne, Inc., in cooperation with NASA-Marshall Space Flight Center (MSFC), has developed a new Advanced Health Management System (AHMS) controller for the Space Shuttle Main Engine (SSME) that will increase the probability of successfully placing the shuttle into the intended orbit and increase the safety of the Space Transportation System (STS) launches. The AHMS is an upgrade o the current Block II engine controller whose primary component is an improved vibration monitoring system called the Real-Time Vibration Monitoring System (RTVMS) that can effectively and reliably monitor the state of the high pressure turbomachinery and provide engine protection through a new synchronous vibration redline which enables engine shutdown if the vibration exceeds predetermined thresholds. The introduction of this system required improvements and modification to the Block II controller such as redesigning the Digital Computer Unit (DCU) memory and the Flight Accelerometer Safety Cut-Off System (FASCOS) circuitry, eliminating the existing memory retention batteries, installation of the Digital Signal Processor (DSP) technology, and installation of a High Speed Serial Interface (HSSI) with accompanying outside world connectors. Test stand hot-fire testing along with lab testing have verified successful implementation and is expected to reduce the probability of catastrophic engine failures during the shuttle ascent phase and improve safely by about 23% according to the Quantitative Risk Assessment System (QRAS), leading to a safer and more reliable SSME.

Research on fuzzy PID control to electronic speed regulator

NASA Astrophysics Data System (ADS)

Xu, Xiao-gang; Chen, Xue-hui; Zheng, Sheng-guo

2007-12-01

As an important part of diesel engine, the speed regulator plays an important role in stabilizing speed and improving engine's performance. Because there are so many model parameters of diesel-engine considered in traditional PID control and these parameters present non-linear characteristic.The method to adjust engine speed using traditional PID is not considered as a best way. Especially for the diesel-engine generator set. In this paper, the Fuzzy PID control strategy is proposed. Some problems about its utilization in electronic speed regulator are discussed. A mathematical model of electric control system for diesel-engine generator set is established and the way of the PID parameters in the model to affect the function of system is analyzed. And then it is proposed the differential coefficient must be applied in control design for reducing dynamic deviation of system and adjusting time. Based on the control theory, a study combined control with PID calculation together for turning fuzzy PID parameter is implemented. And also a simulation experiment about electronic speed regulator system was conducted using Matlab/Simulink and the Fuzzy-Toolbox. Compared with the traditional PID Algorithm, the simulated results presented obvious improvements in the instantaneous speed governing rate and steady state speed governing rate of diesel-engine generator set when the fuzzy logic control strategy used.

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.

Variable Speed Limit (VSL) - Best Management Practice

DOT National Transportation Integrated Search

2012-07-01

The Variable Speed Limit (VSL) system on the I-4 corridor in Orlando was implemented by Florida Department of Transportation in 2008, and since its deployment, it was revealed that the majority of traffic exceeds the speed limit by more mph when the ...

Aquatic burst locomotion by hydroplaning and paddling in common eiders (Somateria mollissima).

PubMed

Gough, William T; Farina, Stacy C; Fish, Frank E

2015-06-01

Common eiders (Somateria mollissima) are heavy sea-ducks that spend a large portion of their time swimming at the water surface. Surface swimming generates a bow and hull wave that can constructively interfere and produce wave drag. The speed at which the wavelengths of these waves equal the waterline length of the swimming animal is the hull speed. To increase surface swimming speed beyond the hull speed, an animal must overtake the bow wave. This study found two distinct behaviors that eider ducks used to exceed the hull speed: (1) 'steaming', which involved rapid oaring with the wings to propel the duck along the surface of the water, and (2) 'paddle-assisted flying', during which the ducks lifted their bodies out of the water and used their feet to paddle against the surface while flapping their wings in the air. An average hull speed (0.732±0.046 m s(-1)) was calculated for S. mollissima by measuring maximum waterline length from museum specimens. On average, steaming ducks swam 5.5 times faster and paddle-assisted flying ducks moved 6.8 times faster than the hull speed. During steaming, ducks exceeded the hull speed by increasing their body angle and generating dynamic lift to overcome wave drag and hydroplane along the water surface. During paddle-assisted flying, ducks kept their bodies out of the water, thereby avoiding the limitations of wave drag altogether. Both behaviors provided alternatives to flight for these ducks by allowing them to exceed the hull speed while staying at or near the water surface. © 2015. Published by The Company of Biologists Ltd.

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.

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.

40 CFR 87.21 - Standards for exhaust emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... aircraft gas turbine engine of class T8 manufactured on or after February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each new aircraft gas turbine engine of class TF and of... gas turbine engine of class T3 manufactured on or after January 1, 1978, shall not exceed: Smoke...

40 CFR 87.21 - Standards for exhaust emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... aircraft gas turbine engine of class T8 manufactured on or after February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each new aircraft gas turbine engine of class TF and of... gas turbine engine of class T3 manufactured on or after January 1, 1978, shall not exceed: Smoke...

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.

77 FR 69572 - Special Conditions: Embraer S.A., Model EMB-550 Airplanes; Flight Envelope Protection: High Speed...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-11-20

... Envelope Protection: High Speed Limiting AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Notice... inadvertently or intentionally exceeding a speed approximately equivalent to V FC or attaining V DF . Current Title 14 Code of Federal Regulations (14 CFR) part 25 do not relate to a high speed limiter that might...

Automated section speed control on motorways: an evaluation of the effect on driving speed.

PubMed

De Pauw, Ellen; Daniels, Stijn; Brijs, Tom; Hermans, Elke; Wets, Geert

2014-12-01

Automated section speed control is a fairly new traffic safety measure that is increasingly applied to enforce speed limits. The advantage of this enforcement system is the registration of the average speed at an entire section, which would lead to high speed limit compliances and subsequently to a reduction in the vehicle speed variability, increased headway, more homogenised traffic flow and increased traffic capacity. However, the number of studies that analysed these effects are limited. The present study evaluates the speed effect of two section speed control systems in Flanders, Belgium. Both sections are located in the opposite direction of a three-lane motorway with a posted speed limit of 120 km/h. Speed data were collected at different points: from 6 km before the entrance of the section to 6 km downstream from the section. The effect was analysed through a before- and after comparison of travel speeds. General time trends and fluctuations were controlled through the analysis of speeds at comparison locations. On the enforced sections considerable decreases were found of about 5.84 km/h in the average speed, 74% in the odds of drivers exceeding the speed limit and 86% in the odds of drivers exceeding the speed limit by more than 10%. At the locations up- and downstream from the section also favourable effects were found for the three outcomes. Furthermore a decrease in the speed variability could be observed at all these data points. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Theoretical and Observational Studies of the Central Engines of AGN

NASA Technical Reports Server (NTRS)

Sivron, Ran

1995-01-01

In Active Galactic Nuclei (AGN) the luminosity is so intense that the effect of radiation pressure on a particle may exceed the gravitational attraction. It was shown that when such luminosities are reached, relatively cold (not completely ionized) thermal matter clouds may form in the central engines of AGN, where most of the luminosity originates. We show that the spectrum of emission from cold clouds embedded in hot relativistic matter is similar to the observed spectrum. We also show that within the hot relativistic matter, cold matter moves faster than the speed of sound or the Alfven speed, and shocks form. The shocks provide a mechanism by which a localized perturbation can propagate throughout the central engine. The shocked matter can emit the observed luminosity, and can explain the flux and spectral variability. It may also provide an efficient mechanism for the outward transfer of angular momentum and provide the outward flow of winds. With observations from X-ray satellites, emission features from the cold and hot matter may be revealed. Our analysis of X-ray data from the Seyfert 1 galaxy MCG - 6-30-15 over five years using detectors on the Ginga and Rosat satellites, revealed some interesting variable features. A source with hot matter emits non-thermal radiation which is Compton reflected from cold matter and then absorbed by warm (partially ionized) absorbing matter in the first model, which can be fit to the data if both the cold and warm absorbers are near the central engine. An alternative model in which the emission from the hot matter is partially covered by very warm matter (in which all elements except Iron are mostly ionized) is also successful. In this model the cold and warm matter may be at distances of up to 100 times the size of the central engine, well within the region where broad optical lines are produced. The flux variability is more naturally explained by the second model. Our results support the existence of cold matter in, or near, the central engine of MCG -6-30-15. Cold matter in the central engine, and evidence of the effects of shocks, is probably forthcoming with future X-ray satellites.

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...

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.

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.

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.

14 CFR 25.335 - Design airspeeds.

Code of Federal Regulations, 2010 CFR

2010-01-01

... must be conservative. (a) Design cruising speed, V C. For V C, the following apply: (1) The minimum value of V C must be sufficiently greater than V B to provide for inadvertent speed increases likely to... exceed the maximum speed in level flight at maximum continuous power for the corresponding altitude. (3...

32 CFR 636.22 - Speed regulations.

Code of Federal Regulations, 2011 CFR

2011-07-01

.... (b) Drivers will operate their vehicles at a reasonable and prudent speed based on traffic and road... drivers will obey posted speed limits; however, drivers will not exceed 40 miles per hour on paved roads and 25 miles per hour on unpaved roads and tank trails. Commercial Utility Cargo Vehicles (CUCV's) are...

32 CFR 636.22 - Speed regulations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... operate their vehicles at a reasonable and prudent speed based on traffic and road conditions, regardless... obey posted speed limits; however, drivers will not exceed 40 miles per hour on paved roads and 25 miles per hour on unpaved roads and tank trails. Commercial Utility Cargo Vehicles (CUCV's) are tactical...

33 CFR 84.01 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... meters per second (m/s) equal to or exceeding: 3.7▽0.1667; where ▽=displacement corresponding to the... maximum speed in knots (kts) equal to exceeding 1.98 (lbs) ▽0.1667; where ▽=displacement corresponding to...

33 CFR 84.01 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... meters per second (m/s) equal to or exceeding: 3.7▽0.1667; where ▽=displacement corresponding to the... maximum speed in knots (kts) equal to exceeding 1.98 (lbs) ▽0.1667; where ▽=displacement corresponding to...

33 CFR 84.01 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... meters per second (m/s) equal to or exceeding: 3.7▽0.1667; where ▽=displacement corresponding to the... maximum speed in knots (kts) equal to exceeding 1.98 (lbs) ▽0.1667; where ▽=displacement corresponding to...

33 CFR 84.01 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... meters per second (m/s) equal to or exceeding: 3.7▽0.1667; where ▽=displacement corresponding to the... maximum speed in knots (kts) equal to exceeding 1.98 (lbs) ▽0.1667; where ▽=displacement corresponding to...

33 CFR 84.01 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... meters per second (m/s) equal to or exceeding: 3.7▽0.1667; where ▽=displacement corresponding to the... maximum speed in knots (kts) equal to exceeding 1.98 (lbs) ▽0.1667; where ▽=displacement corresponding to...

Gaussian and Lognormal Models of Hurricane Gust Factors

NASA Technical Reports Server (NTRS)

Merceret, Frank

2009-01-01

A document describes a tool that predicts the likelihood of land-falling tropical storms and hurricanes exceeding specified peak speeds, given the mean wind speed at various heights of up to 500 feet (150 meters) above ground level. Empirical models to calculate mean and standard deviation of the gust factor as a function of height and mean wind speed were developed in Excel based on data from previous hurricanes. Separate models were developed for Gaussian and offset lognormal distributions for the gust factor. Rather than forecasting a single, specific peak wind speed, this tool provides a probability of exceeding a specified value. This probability is provided as a function of height, allowing it to be applied at a height appropriate for tall structures. The user inputs the mean wind speed, height, and operational threshold. The tool produces the probability from each model that the given threshold will be exceeded. This application does have its limits. They were tested only in tropical storm conditions associated with the periphery of hurricanes. Winds of similar speed produced by non-tropical system may have different turbulence dynamics and stability, which may change those winds statistical characteristics. These models were developed along the Central Florida seacoast, and their results may not accurately extrapolate to inland areas, or even to coastal sites that are different from those used to build the models. Although this tool cannot be generalized for use in different environments, its methodology could be applied to those locations to develop a similar tool tuned to local conditions.

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.

40 CFR 51.164 - Stack height procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 51.164 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... source's stack height that exceeds good engineering practice or by any other dispersion technique, except... source based on a good engineering practice stack height that exceeds the height allowed by § 51.100(ii...

Determination of combustion parameters using engine crankshaft speed

NASA Astrophysics Data System (ADS)

Taglialatela, F.; Lavorgna, M.; Mancaruso, E.; Vaglieco, B. M.

2013-07-01

Electronic engine controls based on real time diagnosis of combustion process can significantly help in complying with the stricter and stricter regulations on pollutants emissions and fuel consumption. The most important parameter for the evaluation of combustion quality in internal combustion engines is the in-cylinder pressure, but its direct measurement is very expensive and involves an intrusive approach to the cylinder. Previous researches demonstrated the direct relationship existing between in-cylinder pressure and engine crankshaft speed and several authors tried to reconstruct the pressure cycle on the basis of the engine speed signal. In this paper we propose the use of a Multi-Layer Perceptron neural network to model the relationship between the engine crankshaft speed and some parameters derived from the in-cylinder pressure cycle. This allows to have a non-intrusive estimation of cylinder pressure and a real time evaluation of combustion quality. The structure of the model and the training procedure is outlined in the paper. A possible combustion controller using the information extracted from the crankshaft speed information is also proposed. The application of the neural network model is demonstrated on a single-cylinder spark ignition engine tested in a wide range of speeds and loads. Results confirm that a good estimation of some combustion pressure parameters can be obtained by means of a suitable processing of crankshaft speed signal.

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.

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.

Emissions of Transport Refrigeration Units with CARB Diesel, Gas-to-Liquid Diesel, and Emissions Control Devices

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

Barnitt, R. A.; Chernich, D.; Burnitzki, M.

2010-05-01

A novel in situ method was used to measure emissions and fuel consumption of transport refrigeration units (TRUs). The test matrix included two fuels, two exhaust configurations, and two TRU engine operating speeds. Test fuels were California ultra low sulfur diesel and gas-to-liquid (GTL) diesel. Exhaust configurations were a stock muffler and a Thermo King pDPF diesel particulate filter. The TRU engine operating speeds were high and low, controlled by the TRU user interface. Results indicate that GTL diesel fuel reduces all regulated emissions at high and low engine speeds. Application of a Thermo King pDPF reduced regulated emissions, sometimesmore » almost entirely. The application of both GTL diesel and a Thermo King pDPF reduced regulated emissions at high engine speed, but showed an increase in oxides of nitrogen at low engine speed.« less

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.

Breaking the speed limit--comparative sprinting performance of brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta)

USGS Publications Warehouse

Castro-Santos, Theodore; Sanz-Ronda, Francisco Javier; Ruiz-Legazpi, Jorge

2013-01-01

Sprinting behavior of free-ranging fish has long been thought to exceed that of captive fish. Here we present data from wild-caught brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta), volitionally entering and sprinting against high-velocity flows in an open-channel flume. Performance of the two species was nearly identical, with the species attaining absolute speeds > 25 body lengths·s−1. These speeds far exceed previously published observations for any salmonid species and contribute to the mounting evidence that commonly accepted estimates of swimming performance are low. Brook trout demonstrated two distinct modes in the relationship between swim speed and fatigue time, similar to the shift from prolonged to sprint mode described by other authors, but in this case occurring at speeds > 19 body lengths·s−1. This is the first demonstration of multiple modes of sprint swimming at such high swim speeds. Neither species optimized for distance maximization, however, indicating that physiological limits alone are poor predictors of swimming performance. By combining distributions of volitional swim speeds with endurance, we were able to account for >80% of the variation in distance traversed by both species.

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.

Can enforced behaviour change attitudes: exploring the influence of Intelligent Speed Adaptation.

PubMed

Chorlton, Kathryn; Conner, Mark

2012-09-01

The Theory of Planned Behaviour model (Ajzen, 1985) was used to determine whether long-term experience with Intelligent Speed Adaption (ISA) prompts a change in speed related cognitions. The study examines data collected as part of a project examining driver behaviour with an intervening but overridable ISA system. Data was collected in four six-month field trials. The trials followed an A-B-A design (28 days driving with no ISA, 112 days driving with ISA, 28 days driving without ISA) to monitor changes in speeding behaviour as a result of the ISA system and any carry-over effect of the system. Findings suggested that following experience with the system, drivers' intention to speed significantly weakened, beyond the removal of ISA support. Drivers were also less likely to believe that exceeding the speed would 'get them to their destination more quickly' and less likely to believe that 'being in a hurry' would facilitate speeding. However, the positive change in intentions and beliefs failed to translate into behaviour. Experience with the ISA system significantly reduced the percentage of distance travelled whilst exceeding the speed limit but this effect was not evident when the ISA support was removed. Copyright © 2010 Elsevier Ltd. All rights reserved.

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2014 CFR

2014-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... suitable tire of proper fit with a speed rating approved by the Administrator that is not exceeded under... wheel with brakes capable of producing this ground reaction. This nose tire load may not exceed 1.5...

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2013 CFR

2013-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... suitable tire of proper fit with a speed rating approved by the Administrator that is not exceeded under... wheel with brakes capable of producing this ground reaction. This nose tire load may not exceed 1.5...

14 CFR 25.733 - Tires.

Code of Federal Regulations, 2012 CFR

2012-01-01

... and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... suitable tire of proper fit with a speed rating approved by the Administrator that is not exceeded under... wheel with brakes capable of producing this ground reaction. This nose tire load may not exceed 1.5...

A discrete gust model for use in the design of wind energy conversion systems

NASA Technical Reports Server (NTRS)

Frost, W.; Turner, R. E.

1982-01-01

A discrete gust model has been designed which includes an expression for the number of times per unit time thy wind exceeds a specific value. This expression, based on Rice's (1944, 1945) number-of-crossings model, assumes that the yearly mean wind speed is averaged over a period of 10 minutes to 1 (one) hour. Vertical and lateral coherence functions are the basis for a mathematical filter which isolates atmospheric disturbances of a characteristic size (e. g., those which would completely engulf a rotor). Predictions are calculated usising the given definition of cut-off frequency, then they are compared with actual data, showing that the model is reliable. The expression is provided in a format such that it may be used for engineering design calculations.

An investigation of the speeding-related crash designation through crash narrative reviews sampled via logistic regression.

PubMed

Fitzpatrick, Cole D; Rakasi, Saritha; Knodler, Michael A

2017-01-01

Speed is one of the most important factors in traffic safety as higher speeds are linked to increased crash risk and higher injury severities. Nearly a third of fatal crashes in the United States are designated as "speeding-related", which is defined as either "the driver behavior of exceeding the posted speed limit or driving too fast for conditions." While many studies have utilized the speeding-related designation in safety analyses, no studies have examined the underlying accuracy of this designation. Herein, we investigate the speeding-related crash designation through the development of a series of logistic regression models that were derived from the established speeding-related crash typologies and validated using a blind review, by multiple researchers, of 604 crash narratives. The developed logistic regression model accurately identified crashes which were not originally designated as speeding-related but had crash narratives that suggested speeding as a causative factor. Only 53.4% of crashes designated as speeding-related contained narratives which described speeding as a causative factor. Further investigation of these crashes revealed that the driver contributing code (DCC) of "driving too fast for conditions" was being used in three separate situations. Additionally, this DCC was also incorrectly used when "exceeding the posted speed limit" would likely have been a more appropriate designation. Finally, it was determined that the responding officer only utilized one DCC in 82% of crashes not designated as speeding-related but contained a narrative indicating speed as a contributing causal factor. The use of logistic regression models based upon speeding-related crash typologies offers a promising method by which all possible speeding-related crashes could be identified. Published by Elsevier Ltd.

The Physics of Colonel Kittinger's Longest Lonely Leap

ERIC Educational Resources Information Center

Robinson, A. W.; Patrick, C. G.

2008-01-01

We present a case study of the physical principles necessary to model the high altitude parachute jump made by Colonel Joseph Kittinger, USAF, in 1960, in order to determine the maximum speed attained and to calculate whether this speed was sufficient to exceed the speed of sound at that altitude. There is considerable discrepancy in the value of…

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.

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...

High-speed optical 3D sensing and its applications

NASA Astrophysics Data System (ADS)

Watanabe, Yoshihiro

2016-12-01

This paper reviews high-speed optical 3D sensing technologies for obtaining the 3D shape of a target using a camera. The focusing speed is from 100 to 1000 fps, exceeding normal camera frame rates, which are typically 30 fps. In particular, contactless, active, and real-time systems are introduced. Also, three example applications of this type of sensing technology are introduced, including surface reconstruction from time-sequential depth images, high-speed 3D user interaction, and high-speed digital archiving.

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.

Small-scale heat detection using catalytic microengines irradiated by laser

NASA Astrophysics Data System (ADS)

Liu, Zhaoqian; Li, Jinxing; Wang, Jiao; Huang, Gaoshan; Liu, Ran; Mei, Yongfeng

2013-01-01

We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection.We demonstrate a novel approach to modulating the motion speed of catalytic microtubular engines via laser irradiation/heating with regard to small-scale heat detection. Laser irradiation on the engines leads to a thermal heating effect and thus enhances the engine speed. During a laser on/off period, the motion behaviour of a microengine can be repeatable and reversible, demonstrating a regulation of motion speeds triggered by laser illumination. Also, the engine velocity exhibits a linear dependence on laser power in various fuel concentrations, which implies an application potential as local heat sensors. Our work may hold great promise in applications such as lab on a chip, micro/nano factories, and environmental detection. Electronic supplementary information (ESI) available. See DOI: 10.1039/c2nr32494f

48 CFR 1436.602-5 - Short selection processes for contracts not to exceed the simplified acquisition threshold.

Code of Federal Regulations, 2010 CFR

2010-10-01

... for contracts not to exceed the simplified acquisition threshold. 1436.602-5 Section 1436.602-5... for contracts not to exceed the simplified acquisition threshold. At each occurrence, CO approval...-engineer contracts not expected to exceed the simplified acquisition threshold. ...

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 ...

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.

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.

A nonlinear model for top fuel dragster dynamic performance assessment

NASA Astrophysics Data System (ADS)

Spanos, P. D.; Castillo, D. H.; Kougioumtzoglou, I. A.; Tapia, R. A.

2012-02-01

The top fuel dragster is the fastest and quickest vehicle in drag racing. This vehicle is capable of travelling a quarter mile in less than 4.5 s, reaching a final speed in excess of 330 miles per hour. The average power delivered by its engine exceeds 7000 Hp. To analyse and eventually increase the performance of a top fuel dragster, a dynamic model of the vehicle is developed. Longitudinal, vertical, and pitching chassis motions are considered, as well as drive-train dynamics. The aerodynamics of the vehicle, the engine characteristics, and the force due to the combustion gases are incorporated into the model. Further, a simplified model of the traction characteristics of the rear tyres is developed where the traction is calculated as a function of the slip ratio and the velocity. The resulting nonlinear, coupled differential equations of motion are solved using a fourth-order Runge-Kutta numerical integration scheme. Several simulation runs are made to investigate the effects of the aerodynamics and of the engine's initial torque in the performance of the vehicle. The results of the computational simulations are scrutinised by comparisons with data from actual dragster races. Ultimately, the proposed dynamic model of the dragster can be used to improve the aerodynamics, the engine and clutch set-ups of the vehicle, and possibly facilitate the redesign of the dragster.

The Influence of Directed Air Flow on Combustion in Spark-Ignition Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Spencer, R C

1939-01-01

The air movement within the cylinder of the NACA combustion apparatus was regulated by using shrouded inlet valves and by fairing the inlet passage. Rates of combustion were determined at different inlet-air velocities with the engine speed maintained constant and at different engine speeds with the inlet-air velocity maintained approximately constant. The rate of combustion increased when the engine speed was doubled without changing the inlet-air velocity; the observed increase was about the same as the increase in the rate of combustion obtained by doubling the inlet-air velocity without changing the engine speed. Certain types of directed air movement gave great improvement in the reproducibility of the explosions from cycle to cycle, provided that other variables were controlled. Directing the inlet air past the injection valve during injection increased the rate of burning.

Investigation of the I-40 Jet-Propulsion Engine in the Cleveland Altitude Wind Tunnel. V - Operational Characteristics. 5; Operational Characteristics

NASA Technical Reports Server (NTRS)

Golladay, Richard L.; Gendler, Stanley L.

1947-01-01

An investigation has been conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of the I-40 jet-propulsion engine over a range of pressure altitudes from 10,000 to 50,000 feet and ram-pressure ratios from 1.00 to 1.76. Engine operational data were obtained with the engine in the standard configuration and with various modifications of the fuel system, the electrical system, and the combustion chambers. The effects of altitude and airspeed on operating speed range, starting, windmilli.ng, acceleration, speed regulation, cooling, and vibration of the standard and modified engines were determined, and damage to parts was noted. Maximum engine speed was obtainable at all altitudes and airspeeds wi th each fuel-control system investigated. The minimum idling speed was raised by increases in altitude and airspeed. The lowest minimum stable speeds were obtained with the standard configuration using 40-gallon nozzles with individual metering plugs. The engine was started normally at altitudes as high as 20,000 feet with all of the fuel systems and ignition combinations except one. Ignition at 70,000 feet was difficult and, although successful ignition occurred, acceleration was slow and usually characterized by excessive tail-pipe temperature. During windmilling investigations of the engine equipped with the standard fuel system, the engine could not be started at ram-pressure ratios of 1.1 to 1.7 at altitudes of 10,000, 20,000 and 30,000 feet. When equipped with the production barometric and Monarch 40-gallon nozzles, the engine accelerated in 12 seconds from an engine speed of 6000 rpm to 11,000 rpm at 20,000 feet and an average tail-pipe temperature of 11000 F. At the same altitude and temperature, all the engine configurations had approximately the same rate of acceleration. The Woodward governor produced the safest accelerations, inasmuch as it could be adjusted to automatically prevent acceleration blow out. The engine speed was held constant by the Woodward governor and the Edwards regulator during simulated dives and climbs at constant throttle position. The bearing cooling system was satisfactory at all altitudes and airspeeds. The engines operated without serious failure, although the exhaust cone, the tail pipe, and the airplane fuselage were damaged during altitude starts.

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

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.

40 CFR 51.118 - Stack height provisions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... exceeds good engineering practice or by any other dispersion technique, except as provided in § 51.118(b... based on a good engineering practice stack height that exceeds the height allowed by § 51.100(ii) (1) or... actual stack height of any source. (b) The provisions of § 51.118(a) shall not apply to (1) stack heights...

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.

D-558-I in flight

NASA Technical Reports Server (NTRS)

1957-01-01

The Douglas D-558-1 Skystreak is seen close-up in this early 1950s inflight photograph. Although less well known than the X-1, the D-558-1 could carry out research roles that complemented those of the more glamorous, rocket-powered craft. The D-558-1 was relatively slow, with only one flight exceeding a speed of Mach 1 (the speed of sound). However, the jet-powered Skystreak could fly for sustained periods at transonic speeds, increasing the amount of data a single flight could yield. By contrast, the rocket-powered X-1 could only provide transonic data for brief periods on each flight. Conceived in 1945, the D558-1 Skystreak was designed by the Douglas Aircraft Company for the U.S. Navy Bureau of Aeronautics, in conjunction with the National Advisory Committee for Aeronautics (NACA). The Skystreaks were turojet powered aircraft that took off from the ground under their own power and had straight wings and tails. All three D-558-1 Skystreaks were powered by Allison J35-A-11 turbojet engines producing 5,000 pounds of thrust. All the Skystreaks were initially painted scarlet, which lead to the nickname 'crimson test tube.' NACA later had the color of the Skystreaks changed to white to improve optical tracking and photography. The Skystreaks carried 634 pounds of instrumentation and were ideal first-generation, simple, transonic research airplanes. Much of the research performed by the D-558-1 Skystreaks, was quickly overshadowed in the public mind by Chuck Yeager and the X-1 rocketplane. However, the Skystreak performed an important role in aeronautical research by flying for extended periods of time at transonic speeds, which freed the X-1 to fly for limited periods at supersonic 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.

Cognitive, emotion control, and motor performance of adolescents in the NCANDA study: Contributions from alcohol consumption, age, sex, ethnicity, and family history of addiction

PubMed Central

Sullivan, Edith V.; Brumback, Ty; Tapert, Susan F.; Fama, Rosemary; Prouty, Devin; Brown, Sandra A.; Cummins, Kevin; Thompson, Wesley K.; Colrain, Ian M.; Baker, Fiona C.; De Bellis, Michael D.; Hooper, Stephen R.; Clark, Duncan B.; Chung, Tammy; Nagel, Bonnie J.; Nichols, B. Nolan; Rohlfing, Torsten; Chu, Weiwei; Pohl, Kilian M.; Pfefferbaum, Adolf

2015-01-01

Objective To investigate development of cognitive and motor functions in healthy adolescents and to explore whether hazardous drinking affects the normal developmental course of those functions. Method Participants were 831 adolescents recruited across five United States sites of the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA): 692 met criteria for no/low alcohol exposure, and 139 exceeded drinking thresholds. Cross-sectional, baseline data were collected with computerized and traditional neuropsychological tests assessing eight functional domains expressed as composite scores. General additive modeling evaluated factors potentially modulating performance (age, sex, ethnicity, socioeconomic status, and pubertal developmental stage). Results Older no/low-drinking participants achieved better scores than younger ones on five Accuracy composites (General Ability, Abstraction, Attention, Emotion, and Balance). Speeded responses for Attention, Motor Speed, and General Ability were sensitive to age and pubertal development. The exceeds-threshold group (accounting for age, sex, and other demographic factors) performed significantly below the no/low-drinking group on Balance accuracy and on General Ability, Attention, Episodic Memory, Emotion, and Motor speed scores and showed evidence for faster speed at the expense of accuracy. Delay Discounting performance was consistent with poor impulse control in the younger no/low drinkers and in exceeds-threshold drinkers regardless of age. Conclusions Higher achievement with older age and pubertal stage in General Ability, Abstraction, Attention, Emotion, and Balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems. Whether low scores by the exceeds-threshold group resulted from drinking or from other pre-existing factors requires longitudinal study. PMID:26752122

Cognitive, emotion control, and motor performance of adolescents in the NCANDA study: Contributions from alcohol consumption, age, sex, ethnicity, and family history of addiction.

PubMed

Sullivan, Edith V; Brumback, Ty; Tapert, Susan F; Fama, Rosemary; Prouty, Devin; Brown, Sandra A; Cummins, Kevin; Thompson, Wesley K; Colrain, Ian M; Baker, Fiona C; De Bellis, Michael D; Hooper, Stephen R; Clark, Duncan B; Chung, Tammy; Nagel, Bonnie J; Nichols, B Nolan; Rohlfing, Torsten; Chu, Weiwei; Pohl, Kilian M; Pfefferbaum, Adolf

2016-05-01

To investigate development of cognitive and motor functions in healthy adolescents and to explore whether hazardous drinking affects the normal developmental course of those functions. Participants were 831 adolescents recruited across 5 United States sites of the National Consortium on Alcohol and NeuroDevelopment in Adolescence 692 met criteria for no/low alcohol exposure, and 139 exceeded drinking thresholds. Cross-sectional, baseline data were collected with computerized and traditional neuropsychological tests assessing 8 functional domains expressed as composite scores. General additive modeling evaluated factors potentially modulating performance (age, sex, ethnicity, socioeconomic status, and pubertal developmental stage). Older no/low-drinking participants achieved better scores than younger ones on 5 accuracy composites (general ability, abstraction, attention, emotion, and balance). Speeded responses for attention, motor speed, and general ability were sensitive to age and pubertal development. The exceeds-threshold group (accounting for age, sex, and other demographic factors) performed significantly below the no/low-drinking group on balance accuracy and on general ability, attention, episodic memory, emotion, and motor speed scores and showed evidence for faster speed at the expense of accuracy. Delay Discounting performance was consistent with poor impulse control in the younger no/low drinkers and in exceeds-threshold drinkers regardless of age. Higher achievement with older age and pubertal stage in general ability, abstraction, attention, emotion, and balance suggests continued functional development through adolescence, possibly supported by concurrently maturing frontal, limbic, and cerebellar brain systems. Determination of whether low scores by the exceeds-threshold group resulted from drinking or from other preexisting factors requires longitudinal study. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

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.

Noise exposure in convertible automobiles.

PubMed

Mikulec, A A; Lukens, S B; Jackson, L E; Deyoung, M N

2011-02-01

To quantify the noise exposure received while driving a convertible automobile with the top open, compared with the top closed. Five different convertible automobiles were driven, with the top both closed and open, and noise levels measured. The cars were tested at speeds of 88.5, 104.6 and 120.7 km/h. When driving with the convertible top open, the mean noise exposure ranged from 85.3 dB at 88.5 km/h to 89.9 dB at 120.7 km/h. At the tested speeds, noise exposure increased by an average of 12.4-14.6 dB after opening the convertible top. Driving convertible automobiles at speeds exceeding 88.5 km/h, with the top open, may result in noise exposure levels exceeding recommended limits, especially when driving with the convertible top open for prolonged periods.

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.

Legal Issues Raised by ORBIS, a Motor Vehicle Speed Detection Device Taking Photos of Speeders

DOT National Transportation Integrated Search

1973-12-01

The report reviews the legal basis for certain potential challenges to the use of unmanned mechanical devices which (a) detect motor vehicles exceeding predetermined speed limits, and (b) photograph both the front portion of these vehicles and the fa...

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

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...

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.

Validation of an ambient measurement system (AMS) for walking speed.

PubMed

Varsanik, Jonathan S; Kimmel, Zebadiah M; de Moor, Carl; Gabel, Wendy; Phillips, Glenn A

2017-07-01

Walking speed is an important indicator of worsening in a variety of neurological and neuromuscular diseases, yet typically is measured only infrequently and in a clinical setting. Passive measurement of walking speed at home could provide valuable information to track the progression of many neuromuscular conditions. The purpose of this study was to validate the measurement of walking speed by a shelf-top ambient measurement system (AMS) that can be placed in a patient's home. Twenty-eight healthy adults (16 male, 12 female) were asked to walk three pre-defined routes two times each (total of 168 traversals). For each traversal, walking speed was measured simultaneously by five sources: two independent AMSs and three human timers with stopwatches. Measurements across the five sources were compared by generalised estimating equations (GEE). Correlation coefficients compared pairwise for walking speeds across the two AMSs, three human timers, and three routes all exceeded 0.86 (p < .0001), and for AMS-to-AMS exceeded 0.92 (p < .0001). Aggregated across all routes, there was no significant difference in measured walking speeds between the two AMSs (p = .596). There was a statistically significant difference between the AMSs and human timers of 8.5 cm/s (p < .0001), which is comparable to differences reported for other non-worn sensors. The tested AMS demonstrated the ability to automatically measure walking speeds comparable to manual observation and recording, which is the current standard for assessing walking speed in a clinical setting. The AMS may be used to detect changes in walking speed in community settings.

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

Experimental Investigation of a High Pressure Ratio Aspirated Fan Stage

NASA Technical Reports Server (NTRS)

Merchant, Ali; Kerrebrock, Jack L.; Adamczyk, John J.; Braunscheidel, Edward

2004-01-01

The experimental investigation of an aspirated fan stage designed to achieve a pressure ratio of 3.4:1 at 1500 ft/sec is presented in this paper. The low-energy viscous flow is aspirated from diffusion-limiting locations on the blades and flowpath surfaces of the stage, enabling a very high pressure ratio to be achieved in a single stage. The fan stage performance was mapped at various operating speeds from choke to stall in a compressor facility at fully simulated engine conditions. The experimentally determined stage performance, in terms of pressure ratio and corresponding inlet mass flow rate, was found to be in good agreement with the three-dimensional viscous computational prediction, and in turn close to the design intent. Stage pressure ratios exceeding 3:1 were achieved at design speed, with an aspiration flow fraction of 3.5 percent of the stage inlet mass flow. The experimental performance of the stage at various operating conditions, including detailed flowfield measurements, are presented and discussed in the context of the computational analyses. The sensitivity of the stage performance and operability to reduced aspiration flow rates at design and off design conditions are also discussed.

NATIONAL GEODATABASE OF TIDAL STREAM POWER RESOURCE IN USA

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

Smith, Brennan T; Neary, Vincent S; Stewart, Kevin M

2012-01-01

A geodatabase of tidal constituents is developed to present the regional assessment of tidal stream power resource in the USA. Tidal currents are numerically modeled with the Regional Ocean Modeling System (ROMS) and calibrated with the available measurements of tidal current speeds and water level surfaces. The performance of the numerical model in predicting the tidal currents and water levels is assessed by an independent validation. The geodatabase is published on a public domain via a spatial database engine with interactive tools to select, query and download the data. Regions with the maximum average kinetic power density exceeding 500 W/m2more » (corresponding to a current speed of ~1 m/s), total surface area larger than 0.5 km2 and depth greater than 5 m are defined as hotspots and documented. The regional assessment indicates that the state of Alaska (AK) has the largest number of locations with considerably high kinetic power density, followed by, Maine (ME), Washington (WA), Oregon (OR), California (CA), New Hampshire (NH), Massachusetts (MA), New York (NY), New Jersey (NJ), North and South Carolina (NC, SC), Georgia (GA), and Florida (FL).« 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.; 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.

Altitude-Wind-Tunnel Investigation of a 4000-Pound-Thrust Axial-Flow Turbojet Engine. II - Operational Characteristics. II; Operational Characteristics

NASA Technical Reports Server (NTRS)

Fleming, William A.

1948-01-01

An investigation was conducted in the Cleveland altitude wind tunnel to determine the operational characteristics of an axial flow-type turbojet engine with a 4000-pound-thrust rating over a range of pressure altitudes from 5,000 to 50,OOO feet, ram pressure ratios from 1.00 to 1.86, and temperatures from 60 deg to -50 deg F. The low-flow (standard) compressor with which the engine was originally equipped was replaced by a high-flow compressor for part of the investigation. The effects of altitude and airspeed on such operating characteristics as operating range, stability of combustion, acceleration, starting, operation of fuel-control systems, and bearing cooling were investigated. With the low-flow compressor, the engine could be operated at full speed without serious burner unbalance at altitudes up to 50,000 feet. Increasing the altitude and airspeed greatly reduced the operable speed range of the engine by raising the minimum operating speed of the engine. In several runs with the high-flow compressor the maximum engine speed was limited to less than 7600 rpm by combustion blow-out, high tail-pipe temperatures, and compressor stall. Acceleration of the engine was relatively slow and the time required for acceleration increased with altitude. At maximum engine speed a sudden reduction in jet-nozzle area resulted in an immediate increase in thrust. The engine started normally and easily below 20,000 feet with each configuration. The use of a high-voltage ignition system made possible starts at a pressure altitude of 40,000 feet; but on these starts the tail-pipe temperatures were very high, a great deal of fuel burned in and behind the tail-pipe, and acceleration was very slow. Operation of the engine was similar with both fuel regulators except that the modified fuel regulator restricted the fuel flow in such a manner that the acceleration above 6000 rpm was very slow. The bearings did not cool properly at high altitudes and high engine speeds with a low-flow compressor, and bearing cooling was even poorer with a high-flow compressor.

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.

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.

46 CFR 119.200 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... without exceeding its designed limitations. (b) All engines must have at least two means for stopping the engine(s) under any operating conditions. The fuel oil shutoff required at the engine by § 119.455(b)(3) of this part will satisfy one means of stopping the engine. ...

Gravitational radiation and the ultimate speed in Rosen's bimetric theory of gravity

NASA Technical Reports Server (NTRS)

Caves, C. M.

1980-01-01

In Rosen's bimetric theory of gravity the (local) speed of gravitational radiation is determined by the combined effects of cosmological boundary values and nearby concentrations of matter. It is possible for the speed of gravitational radiation to be less than the speed of light. It is here shown that the emission of gravitational radiation prevents particles of nonzero rest mass from exceeding the speed of gravitational radiation. Observations of relativistic particles place limits on the speed of gravitational radiation and the cosmological boundary values today, and observations of synchroton radiation from compact radio sources place limits on the cosmological boundary values in the past.

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...

Advanced Turbine Technology Applications Project (ATTAP)

NASA Technical Reports Server (NTRS)

1990-01-01

Advanced Turbine Technology Application Project (ATTAP) activities during the past year were highlighted by test-bed engine design and development activities; ceramic component design; materials and component characterization; ceramic component process development and fabrication; component rig testing; and test-bed engine fabrication and testing. Although substantial technical challenges remain, all areas exhibited progress. Test-bed engine design and development activity included engine mechanical design, power turbine flow-path design and mechanical layout, and engine system integration aimed at upgrading the AGT-5 from a 1038 C metal engine to a durable 1371 C structural ceramic component test-bed engine. ATTAP-defined ceramic and associated ceramic/metal component design activities include: the ceramic combustor body, the ceramic gasifier turbine static structure, the ceramic gasifier turbine rotor, the ceramic/metal power turbine static structure, and the ceramic power turbine rotors. The materials and component characterization efforts included the testing and evaluation of several candidate ceramic materials and components being developed for use in the ATTAP. Ceramic component process development and fabrication activities are being conducted for the gasifier turbine rotor, gasifier turbine vanes, gasifier turbine scroll, extruded regenerator disks, and thermal insulation. Component rig testing activities include the development of the necessary test procedures and conduction of rig testing of the ceramic components and assemblies. Four-hundred hours of hot gasifier rig test time were accumulated with turbine inlet temperatures exceeding 1204 C at 100 percent design gasifier speed. A total of 348.6 test hours were achieved on a single ceramic rotor without failure and a second ceramic rotor was retired in engine-ready condition at 364.9 test hours. Test-bed engine fabrication, testing, and development supported improvements in ceramic component technology that will permit the achievement of program performance and durability goals. The designated durability engine accumulated 359.3 hour of test time, 226.9 of which were on the General Motors gas turbine durability schedule.

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…

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...

JPRS Report, Soviet Union Economic Affairs.

DTIC Science & Technology

1988-11-22

I believe that under these conditions the ministry has decided to clip our wings . Viktor Yeremenko, deputy director for personnel of the combine...production? Does the " stork bring" them? The idea, according to which commodity-money relationships exist not in their own, but in a foreign, medium...installation of a small canard wing —its speed in the airport traffic zone and its approach speed did not exceed the speeds of modern subsonic jet

14 CFR 23.1545 - Airspeed indicator.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) The following markings must be made: (1) For the never-exceed speed V NE, a radial red line. (2) For the caution range, a yellow arc extending from the red line specified in paragraph (b)(1) of this... gear and wing flaps retracted, and the upper limit at the maximum structural cruising speed V NO...

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

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.

Women in Flight Research at NASA Dryden Flight Research Center from 1946 to 1995. Number 6; Monographs in Aerospace History

NASA Technical Reports Server (NTRS)

Powers, Sheryll Goecke

1997-01-01

This monograph discusses the working and living environment of women involved with flight research at NASA Dryden Flight Research Center during the late 1940s and early 1950s. The women engineers, their work and the airplanes they worked on from 1960 to December 1995 are highlighted. The labor intensive data gathering and analysis procedures and instrumentation used before the age of digital computers are explained by showing and describing typical instrumentation found on the X-series aircraft from the X-1 through the X-15. The data reduction technique used to obtain the Mach number position error curve for the X-1 aircraft and which documents the historic first flight to exceed the speed of sound is described and a Mach number and altitude plot from an X-15 flight is shown.

Effects of vehicle power on passenger vehicle speeds.

PubMed

McCartt, Anne T; Hu, Wen

2017-07-04

During the past 2 decades, there have been large increases in mean horsepower and the mean horsepower-to-vehicle weight ratio for all types of new passenger vehicles in the United States. This study examined the relationship between travel speeds and vehicle power, defined as horsepower per 100 pounds of vehicle weight. Speed cameras measured travel speeds and photographed license plates and drivers of passenger vehicles traveling on roadways in Northern Virginia during daytime off-peak hours in spring 2013. The driver licensing agencies in the District of Columbia, Maryland, and Virginia provided vehicle information numbers (VINs) by matching license plate numbers with vehicle registration records and provided the age, gender, and ZIP code of the registered owner(s). VINs were decoded to obtain the curb weight and horsepower of vehicles. The study focused on 26,659 observed vehicles for which information on horsepower was available and the observed age and gender of drivers matched vehicle registration records. Log-linear regression estimated the effects of vehicle power on mean travel speeds, and logistic regression estimated the effects of vehicle power on the likelihood of a vehicle traveling over the speed limit and more than 10 mph over the limit. After controlling for driver characteristics, speed limit, vehicle type, and traffic volume, a 1-unit increase in vehicle power was associated with a 0.7% increase in mean speed, a 2.7% increase in the likelihood of a vehicle exceeding the speed limit by any amount, and an 11.6% increase in the likelihood of a vehicle exceeding the limit by 10 mph. All of these increases were highly significant. Speeding persists as a major factor in crashes in the United States. There are indications that travel speeds have increased in recent years. The current findings suggest the trend toward substantially more powerful vehicles may be contributing to higher speeds. Given the strong association between travel speed and crash risk and crash severity, this is cause for concern.

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...

Active control system for high speed windmills

DOEpatents

Avery, D.E.

1988-01-12

A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed. 4 figs.

Active control system for high speed windmills

DOEpatents

Avery, Don E.

1988-01-01

A pump stroke is matched to the operating speed of a high speed windmill. The windmill drives a hydraulic pump for a control. Changes in speed of a wind driven shaft open supply and exhaust valves to opposite ends of a hydraulic actuator to lengthen and shorten an oscillating arm thereby lengthening and shortening the stroke of an output pump. Diminishing wind to a stall speed causes the valves to operate the hydraulic cylinder to shorten the oscillating arm to zero. A pressure accumulator in the hydraulic system provides the force necessary to supply the hydraulic fluid under pressure to drive the actuator into and out of the zero position in response to the windmill shaft speed approaching and exceeding windmill stall speed.

40 CFR 88.105-94 - Clean-fuel fleet emission standards for heavy-duty engines.

Code of Federal Regulations, 2010 CFR

2010-07-01

... exceed 3.8 grams per brake horsepower-hour. (2) Combined emissions of oxides of nitrogen and nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 3.5 grams per brake horsepower-hour when... nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 2.5 grams per brake...

40 CFR 88.105-94 - Clean-fuel fleet emission standards for heavy-duty engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... exceed 3.8 grams per brake horsepower-hour. (2) Combined emissions of oxides of nitrogen and nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 3.5 grams per brake horsepower-hour when... nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 2.5 grams per brake...

40 CFR 88.105-94 - Clean-fuel fleet emission standards for heavy-duty engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

... exceed 3.8 grams per brake horsepower-hour. (2) Combined emissions of oxides of nitrogen and nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 3.5 grams per brake horsepower-hour when... nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 2.5 grams per brake...

40 CFR 88.105-94 - Clean-fuel fleet emission standards for heavy-duty engines.

Code of Federal Regulations, 2014 CFR

2014-07-01

... exceed 3.8 grams per brake horsepower-hour. (2) Combined emissions of oxides of nitrogen and nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 3.5 grams per brake horsepower-hour when... nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 2.5 grams per brake...

40 CFR 88.105-94 - Clean-fuel fleet emission standards for heavy-duty engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

... exceed 3.8 grams per brake horsepower-hour. (2) Combined emissions of oxides of nitrogen and nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 3.5 grams per brake horsepower-hour when... nonmethane hydrocarbons (or nonmethane hydrocarbon equivalent) shall not exceed 2.5 grams per brake...

40 CFR 85.2113 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... vehicle to exceed applicable emission standards with such parts installed. (h) Engine family means the... emission-data vehicle or engine selection and as determined in accordance with 40 CFR 86.078-24. (i) Vehicle or engine configuration means the specific subclassification unit of an engine family or certified...

40 CFR 85.2113 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... vehicle to exceed applicable emission standards with such parts installed. (h) Engine family means the... emission-data vehicle or engine selection and as determined in accordance with 40 CFR 86.078-24. (i) Vehicle or engine configuration means the specific subclassification unit of an engine family or certified...

40 CFR 85.2113 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... vehicle to exceed applicable emission standards with such parts installed. (h) Engine family means the... emission-data vehicle or engine selection and as determined in accordance with 40 CFR 86.078-24. (i) Vehicle or engine configuration means the specific subclassification unit of an engine family or certified...

40 CFR 85.2113 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... vehicle to exceed applicable emission standards with such parts installed. (h) Engine family means the... emission-data vehicle or engine selection and as determined in accordance with 40 CFR 86.078-24. (i) Vehicle or engine configuration means the specific subclassification unit of an engine family or certified...

40 CFR 85.2113 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... vehicle to exceed applicable emission standards with such parts installed. (h) Engine family means the... emission-data vehicle or engine selection and as determined in accordance with 40 CFR 86.078-24. (i) Vehicle or engine configuration means the specific subclassification unit of an engine family or certified...

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.

Inlet Flow Control and Prediction Technologies for Embedded Propulsion Systems

NASA Technical Reports Server (NTRS)

McMillan, Michelle L.; Mackie, Scott A.; Gissen, Abe; Vukasinovic, Bojan; Lakebrink, Matthew T.; Glezer, Ari; Mani, Mori; Mace, James L.

2011-01-01

Fail-safe, hybrid, flow control (HFC) is a promising technology for meeting high-speed cruise efficiency, low-noise signature, and reduced fuel-burn goals for future, Hybrid-Wing-Body (HWB) aircraft with embedded engines. This report details the development of HFC technology that enables improved inlet performance in HWB vehicles with highly integrated inlets and embedded engines without adversely affecting vehicle performance. In addition, new test techniques for evaluating Boundary-Layer-Ingesting (BLI)-inlet flow-control technologies developed and demonstrated through this program are documented, including the ability to generate a BLI-like inlet-entrance flow in a direct-connect, wind-tunnel facility, as well as, the use of D-optimal, statistically designed experiments to optimize test efficiency and enable interpretation of results. Validated improvements in numerical analysis tools and methods accomplished through this program are also documented, including Reynolds-Averaged Navier-Stokes CFD simulations of steady-state flow physics for baseline, BLI-inlet diffuser flow, as well as, that created by flow-control devices. Finally, numerical methods were employed in a ground-breaking attempt to directly simulate dynamic distortion. The advances in inlet technologies and prediction tools will help to meet and exceed "N+2" project goals for future HWB aircraft.

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.

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.

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.

14 CFR 23.201 - Wings level stall.

Code of Federal Regulations, 2012 CFR

2012-01-01

... produce and to correct roll by unreversed use of the rolling control and to produce and to correct yaw by unreversed use of the directional control, up to the time the airplane stalls. (b) The wings level stall... speed, the elevator control must be pulled back so that the rate of speed reduction will not exceed one...

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.

A one year pay-as-you-speed trial with economic incentives for not speeding.

PubMed

Stigson, Helena; Hagberg, Jan; Kullgren, Anders; Krafft, Maria

2014-01-01

The objective was to identify whether it was possible to change driver behavior by economic incentives and thereby reduce crash risk. Furthermore, the objective was to evaluate the participants' attitudes toward the pay-as-you-speed (PAYS) concept. A one-year PAYS trial with economic incentives for keeping speed limits using intelligent speed assistance (ISA) was conducted in Sweden during 2011-2012. The full incentive was a 30 percent discount off the insurance premium. The participants were private insurance customers and were randomized into a test group (initial n = 152, final n = 128) and a control group (initial n = 98, final n = 68). When driving, the drivers in the test group were informed and warned visually when the speed limit was exceeded. They could also follow their driving results on a personal website. The control group was not given any feedback at all. To reflect the impact of the PAYS concept the proportion of distance driven above the speed limit was compared between the 2 groups. The introduction of a PAYS concept shows that the test group significantly reduced the proportion of distance driven above the speed limit. The proportion of driving at a speed exceeding 5 km/h over the speed limit was 6 percent for the test group and 14 percent for the control group. It also showed that the effect was higher the higher the violation of speed. The result remained constant over time. It was shown that a PAYS concept is an effective way to reduce speed violations. Hence, it has the possibility to reduce crash severity and thereby to save lives. This could be an important step toward a safer road transport system. The majority of the participants were in favor of the concept, which indicates the potential of a new insurance product in the future.

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.

30 CFR 57.5067 - Engines.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Agents, and Diesel Particulate Matter Diesel Particulate Matter-Underground Only § 57.5067 Engines. (a... (2) Meet or exceed the applicable particulate matter emission requirements of the Environmental...

33 CFR 211.24 - Disposition of claims.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 211.24 Navigation and Navigable Waters CORPS OF ENGINEERS, DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE REAL ESTATE ACTIVITIES OF THE CORPS OF ENGINEERS IN CONNECTION WITH CIVIL WORKS PROJECTS Real... damages not exceeding $1,000 may be settled by the Division Engineer. If the Division Engineer allows the...

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…

Performance of gigabit FDDI

NASA Technical Reports Server (NTRS)

Game, David; Maly, Kurt J.

1990-01-01

Great interest exists in developing high speed protocols which will be able to support data rates at gigabit speeds. Hardware currently exists which can experimentally transmit at data rates exceeding a gigabit per second, but it is not clear as to what types of protocols will provide the best performance. One possibility is to examine current protocols and their extensibility to these speeds. Scaling of Fiber Distributed Data Interface (FDDI) to gigabit speeds is studied. More specifically, delay statistics are included to provide insight as to which parameters (network length, packet length or number of nodes) have the greatest effect on performance.

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

Acoustic Database for Turbofan Engine Core-Noise Sources. I; Volume

NASA Technical Reports Server (NTRS)

Gordon, Grant

2015-01-01

In this program, a database of dynamic temperature and dynamic pressure measurements were acquired inside the core of a TECH977 turbofan engine to support investigations of indirect combustion noise. Dynamic temperature and pressure measurements were recorded for engine gas dynamics up to temperatures of 3100 degrees Fahrenheit and transient responses as high as 1000 hertz. These measurements were made at the entrance of the high pressure turbine (HPT) and at the entrance and exit of the low pressure turbine (LPT). Measurements were made at two circumferential clocking positions. In the combustor and inter-turbine duct (ITD), measurements were made at two axial locations to enable the exploration of time delays. The dynamic temperature measurements were made using dual thin-wire thermocouple probes. The dynamic pressure measurements were made using semi-infinite probes. Prior to the engine test, a series of bench, oven, and combustor rig tests were conducted to characterize the performance of the dual wire temperature probes and to define and characterize the data acquisition systems. A measurement solution for acquiring dynamic temperature and pressure data on the engine was defined. A suite of hardware modifications were designed to incorporate the dynamic temperature and pressure instrumentation into the TECH977 engine. In particular, a probe actuation system was developed to protect the delicate temperature probes during engine startup and transients in order to maximize sensor life. A set of temperature probes was procured and the TECH977 engine was assembled with the suite of new and modified hardware. The engine was tested at four steady state operating speeds, with repeats. Dynamic pressure and temperature data were acquired at each condition for at least one minute. At the two highest power settings, temperature data could not be obtained at the forward probe locations since the mean temperatures exceeded the capability of the probes. The temperature data were processed using software that accounts for the effects of convective and conductive heat transfer. The software was developed under previous NASA sponsored programs. Compensated temperature spectra and compensated time histories corresponding to the dynamic temperature of the gas stream were generated. Auto-spectral and cross-spectral analyses of the data were performed to investigate spectral features, acoustic circumferential mode content, signal coherence, and time delays. The dynamic temperature data exhibit a wideband and fairly flat spectral content. The temperature spectra do not change substantially with operating speed. The pressure spectra in the combustor and ITD exhibit generally similar shapes and amplitudes, making it difficult to identify any features that suggest the presence of indirect combustion noise. Cross-spectral analysis reveal a strong correlation between pressure and temperature fluctuations in the ITD, but little correlation between temperature fluctuations at the entrance of the HPT and pressure fluctuations downstream of it. Temperature fluctuations at the entrance of the low pressure turbine were an order of magnitude smaller than those at the entrance to the high pressure turbine. Time delay analysis of the temperature fluctuations in the combustor was inconclusive, perhaps due to the substantial mixing that occurs between the upstream and downstream locations. Time delay analysis of the temperature fluctuations in the ITD indicate that they convect at the mean flow speed. Analysis of the data did not reveal any convincing indications of the presence of indirect combustion noise. However, this analysis has been preliminary and additional exploration of the data is recommended including the use of more sophisticated signal processing to explore subtle issues that have been revealed but which are not yet fully understood or explained.

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.

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.

Bidirectional control system for energy flow in solar powered flywheel

NASA Technical Reports Server (NTRS)

Nola, Frank J. (Inventor)

1987-01-01

An energy storage system for a spacecraft is provided which employs a solar powered flywheel arrangement including a motor/generator which, in different operating modes, drives the flywheel and is driven thereby. A control circuit, including a threshold comparator, senses the output of a solar energy converter, and when a threshold voltage is exceeded thereby indicating the availability of solar power for the spacecraft loads, activates a speed control loop including the motor/generator so as to accelerate the flywheel to a constant speed and thereby store mechanical energy, while also supplying energy from the solar converter to the loads. Under circumstances where solar energy is not available and thus the threshold voltage is not exceeded, the control circuit deactivates the speed control loop and activates a voltage control loop that provides for operation of the motor as a generator so that mechanical energy from the flywheel is converted into electrical energy for supply to the spacecraft loads.

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.

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

33 CFR 169.5 - How are terms used in this part defined?

Code of Federal Regulations, 2011 CFR

2011-07-01

... § 169.15). Gross tons means vessel tonnage measured in accordance with the method utilized by the flag... water and is capable of a maximum speed equal to or exceeding V=3.7×displ .1667, where “V” is the maximum speed and “displ” is the vessel displacement corresponding to the design waterline in cubic meters...

33 CFR 169.5 - How are terms used in this part defined?

Code of Federal Regulations, 2012 CFR

2012-07-01

... § 169.15). Gross tons means vessel tonnage measured in accordance with the method utilized by the flag... water and is capable of a maximum speed equal to or exceeding V=3.7×displ .1667, where “V” is the maximum speed and “displ” is the vessel displacement corresponding to the design waterline in cubic meters...

33 CFR 169.5 - How are terms used in this part defined?

Code of Federal Regulations, 2013 CFR

2013-07-01

... § 169.15). Gross tons means vessel tonnage measured in accordance with the method utilized by the flag... water and is capable of a maximum speed equal to or exceeding V=3.7×displ .1667, where “V” is the maximum speed and “displ” is the vessel displacement corresponding to the design waterline in cubic meters...

33 CFR 169.5 - How are terms used in this part defined?

Code of Federal Regulations, 2014 CFR

2014-07-01

... § 169.15). Gross tons means vessel tonnage measured in accordance with the method utilized by the flag... water and is capable of a maximum speed equal to or exceeding V=3.7×displ .1667, where “V” is the maximum speed and “displ” is the vessel displacement corresponding to the design waterline in cubic meters...

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...

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

Investigation of the NACA 4-(3)(8)-045 Two-blade Propellers at Forward Mach Numbers to 0.725 to Determine the Effects of Compressibility and Solidity on Performance

NASA Technical Reports Server (NTRS)

Stack, John; Draley, Eugene C; Delano, James B; Feldman, Lewis

1950-01-01

As part of a general investigation of propellers at high forward speeds, tests of two 2-blade propellers having the NACA 4-(3)(8)-03 and NACA 4-(3)(8)-45 blade designs have been made in the Langley 8-foot high-speed tunnel through a range of blade angle from 20 degrees to 60 degrees for forward Mach numbers from 0.165 to 0.725 to establish in detail the changes in propeller characteristics due to compressibility effects. These propellers differed primarily only in blade solidity, one propeller having 50 percent and more solidity than the other. Serious losses in propeller efficiency were found as the propeller tip Mach number exceeded 0.91, irrespective of forward speed or blade angle. The magnitude of the efficiency losses varied from 9 percent to 22 percent per 0.1 increase in tip Mach number above the critical value. The range of advance ratio for peak efficiency decreased markedly with increase of forward speed. The general form of the changes in thrust and power coefficients was found to be similar to the changes in airfoil lift coefficient with changes in Mach number. Efficiency losses due to compressibility effects decreased with increase of blade width. The results indicated that the high level of propeller efficiency obtained at low speeds could be maintained to forward sea-level speeds exceeding 500 miles per hour.

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.

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

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2014 CFR

2014-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2012 CFR

2012-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2011 CFR

2011-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1521 - Powerplant limitations.

Code of Federal Regulations, 2013 CFR

2013-01-01

... operation due to the design of the installation or to another established limitation. (c) Turbine engine installations. Operating limitations relating to the following must be established for turbine engine... section must be established so that they do not exceed the corresponding limits for which the engines or...

14 CFR 25.1043 - Cooling tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... (a)(1) of this section may exceed established limits. (3) For reciprocating engines, the fuel used during the cooling tests must be the minimum grade approved for the engines, and the mixture settings... engine fluids and powerplant components (except cylinder barrels) for which temperature limits are...

14 CFR 25.1043 - Cooling tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (a)(1) of this section may exceed established limits. (3) For reciprocating engines, the fuel used during the cooling tests must be the minimum grade approved for the engines, and the mixture settings... engine fluids and powerplant components (except cylinder barrels) for which temperature limits are...

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...

Polymer Surface Textured with Nanowire Bundles to Repel High-Speed Water Drops.

PubMed

Li, Y P; Li, X Y; Zhu, X P; Lei, M K; Lakhtakia, A

2018-05-22

Water drops impacting windshields of high-speed trains and aircraft as well as blades in steam turbine power generators obliquely and at high speeds are difficult to repel. Impacting drops penetrate the void regions of nanotextured and microtextured superhydrophobic coatings, with this pinning resulting in the loss of drop mobility. In order to repel high-speed water drops, we nanotextured polymer surfaces with nanowire bundles separated from their neighbors by microscale void regions, with the nanowires in a bundle separated from their neighbors by nanoscale void regions. Water drops with speeds below a critical speed rebound completely. Water drops with speeds exceeding a critical speed rebound partially, but residual droplets that begin to be pinned undergo a spontaneous dewetting process and slide off. The natural oscillations of residual droplets drive this dewetting process in the interbundle void regions, resulting in a transition from the sticky Wenzel state to the slippery Cassie state without external stimuli.

Covariance of engineering management characteristics with engineering employee performance

NASA Astrophysics Data System (ADS)

Hesketh, Andrew Arthur

1998-12-01

As business in the 1990's grapples with the impact of continuous improvement and quality to meet market demands, there is an increased need to improve the leadership capabilities of our managers. Engineers have indicated desire for certain managerial characteristics in their leadership but there have been no studies completed that approached the problem of determining what managerial characteristics were best at improving employee performance. This study addressed the idea of identifying certain managerial characteristics that enhance employee performance. In the early 1990's, McDonnell Douglas Aerospace in St. Louis used a forced distribution system and allocated 35% of its employees into a "exceeds expectations" category and 60% into a "meets expectations" category. A twenty-question 5 point Likert scale survey on managerial capabilities was administered to a sample engineering population that also obtained their "expectations" category. A single factor ANOVA on the survey results determined a statistical difference between the "exceeds" and "meets" employees with four of the managerial capability questions. The "exceeds expectations" employee indicated that supervision did a better job of supporting subordinate development, clearly communicating performance expectations, and providing timely performance feedback when compared to the "meets expectations" employee. The "meets expectations" employee felt that their opinions, when different from their supervisor's, were more often ignored when compared to the "exceeds expectations" employee. These four questions relate to two specific managerial characteristics, "gaining (informal) authority and support" or "control" characteristic and "providing assistance and guidance" or "command" characteristic, that can be emphasized in managerial training programs.

Speed control of an induction motor by 6-switched 3-level inverter

NASA Astrophysics Data System (ADS)

Saygin, Ali; Kerem, Alper

2017-12-01

This paper presents speed control analysis of an induction motor by a 6-switched 3-level inverter. In the analysis of topology, the study used the field oriented control technique which is widely used in the literature, easy and stable for operating systems. The field weaking technique was used for speeds exceeding nominal speed to reduce magnetic saturation and thermal losses. At the end of the process, it was observed to increase motor torque and inverter efficiency. Instead of using 12 switches in conventional 3-level inverters, 6 switches are used in this topology. Reduced number of switches is the greatest contribution of this study.

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.

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.

14 CFR 27.1043 - Cooling tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... (a)(1) of this section may exceed established limits. (3) For reciprocating engines, the fuel used during the cooling tests must be of the minimum grade approved for the engines, and the mixture settings... applies, temperatures of engine fluids and power-plant components (except cylinder barrels) for which...

14 CFR 27.1043 - Cooling tests.

Code of Federal Regulations, 2012 CFR

2012-01-01

... (a)(1) of this section may exceed established limits. (3) For reciprocating engines, the fuel used during the cooling tests must be of the minimum grade approved for the engines, and the mixture settings... applies, temperatures of engine fluids and power-plant components (except cylinder barrels) for which...

Methods and apparatus for reducing peak wind turbine loads

DOEpatents

Moroz, Emilian Mieczyslaw

2007-02-13

A method for reducing peak loads of wind turbines in a changing wind environment includes measuring or estimating an instantaneous wind speed and direction at the wind turbine and determining a yaw error of the wind turbine relative to the measured instantaneous wind direction. The method further includes comparing the yaw error to a yaw error trigger that has different values at different wind speeds and shutting down the wind turbine when the yaw error exceeds the yaw error trigger corresponding to the measured or estimated instantaneous wind speed.

Dynamic stability of stacked disk type flywheels

NASA Astrophysics Data System (ADS)

Younger, F. C.

1981-04-01

A flywheel assembly formed from adhesively bonded stacked fiber composite disks was analyzed. The stiffness and rigidity of the assembly required to prevent uncontrolled growth in the deformations due to centrifugal force was determined. It is shown that stacked disk type flywheels become unstable when the speed exceeds a critical value. This critical value of speed depends upon the stiffness of the bonded attachments between the disks. It is found that elastomeric bonds do not provide adequate stiffness to insure dynamic stability for high speed stacked disk type flywheels.

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

Aircraft and Engine Development Testing

DTIC Science & Technology

1986-09-01

Control in Flight * Integrated Inlet- engine * Power/weight Exceeds Unity F-lll * Advanced Engines * Augmented Turbofan * High Turbine Temperature...residence times). Also, fabrication of a small scale "hot" engine with rotating components such as compressors and turbines with cooled blades , is...capabil- ities are essential to meet the needs of current and projected aircraft and engine programs. The required free jet nozzles should be capable of

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.

Experiment evaluation of impact attenuator for a racing car under static load

NASA Astrophysics Data System (ADS)

Imanullah, Fahmi; Ubaidillah, Prasojo, Arfi Singgih; Wirawan, Adhe Aji

2018-02-01

The automotive world is a world where one of the factors that must be considered carefully is the safety aspect. In the formula student car one of the safety factor in the form of impact attenuator. Impact attenuator is used as anchoring when a collision occurs in front of the vehicle. In the rule of formula society of automotive engineer (FSAE) student, impact attenuator is required to absorb the energy must meet or exceed 7350 Joules with a slowdown in speed not exceeding 20 g average and peak of 40 g. The student formula participants are challenged to pass the boundaries so that in designing and making the impact attenuator must pay attention to the strength and use of the minimum material so that it can minimize the expenditure. In this work, an impact attenuator was fabricated and tested using static compression. The primary goal was evaluating the actual capability of the impact attenuator for impact energy absorption. The prototype was made of aluminum alloy in a prismatic shape, and the inside wall was filled with rooftop plastic slices and polyurethane hard foam. The compression test has successfully carried out, and the load versus displacement data could be used in calculating energy absorption capability. The result of the absorbent energy of the selected impact attenuator material. Impact attenuator full polyurethane absorbed energy reach 6380 Joule. For impact attenuator with aluminum polyurethane with a slashed rooftop material as section absorbed energy reach 6600 Joule. Impact attenuator with Aluminum Polyurethane with aluminum orange peel partitions absorbed energy reach 8800 Joule. From standard student formula, energy absorbed in this event must meet or exceed 7350 Joules that meet aluminum polyurethane with aluminum orange peel partitions with the ability to absorb 8800 Joule.

Microwave emissions from police radar.

PubMed

Fink, J M; Wagner, J P; Congleton, J J; Rock, J C

1999-01-01

This study evaluated police officers' exposures to microwaves emitted by traffic radar units. Exposure measurements were taken at approximated ocular and testicular levels of officers seated in patrol vehicles. Comparisons were made of the radar manufacturers' published maximum power density specifications and actual measured power densities taken at the antenna faces of those units. Four speed-enforcement agencies and one transportation research institute provided 54 radar units for evaluation; 17 different models, encompassing 4 frequency bands and 3 antenna configurations, were included. Four of the 986 measurements taken exceeded the 5 mW/cm2 limit accepted by the International Radiation Protection Association and the National Council on Radiation Protection and Measurement, though none exceeded the American Conference of Governmental Industrial Hygienists, American National Standards Institute, Institute of Electrical and Electronic Engineers, or Occupational Safety and Health Administration standard of 10 mW/cm2. The four high measurements were maximum power density readings taken directly in front of the radar. Of the 812 measurements taken at the officers' seated ocular and testicular positions, none exceeded 0.04 mW/cm2; the highest of these (0.034 mW/cm2) was less than 1% of the most conservative current safety standards. High exposures in the limited region directly in front of the radar aperture are easily avoided with proper training. Results of this study indicate that police officer exposure to microwave radiation is apparently minimal. However, because of uncertainty in the medical and scientific communities concerning nonionizing radiation, it is recommended that law enforcement agencies implement a policy of prudent avoidance, including purchasing units with the lowest published maximum power densities, purchasing dash/rear deck-mounted units with antennae mounted outside the patrol vehicle, and training police officers to use the "stand-by" mode when not actually using radar.

The Nutating Engine-Prototype Engine Progress Report and Test Results

NASA Technical Reports Server (NTRS)

Meitner, Peter L.; Boruta, Mike

2006-01-01

A prototype of a new, internal combustion (IC) engine concept has been completed. The Nutating Engine features an internal disk nutating (wobbling) on a Z-shaped power shaft. The engine is exceedingly compact, and several times more power dense than any conventional (reciprocating or rotary) IC engine. This paper discusses lessons learned during the prototype engine's development and provides details of its construction. In addition, results of the initial performance tests of the various components, as well as the complete engine, are summarized.

"I drove after drinking alcohol" and other risky driving behaviours reported by young novice drivers.

PubMed

Scott-Parker, Bridie; Watson, Barry; King, Mark J; Hyde, Melissa K

2014-09-01

Volitional risky driving behaviours such as drink- and drug-driving (i.e. substance-impaired driving) and speeding contribute to the overrepresentation of young novice drivers in road crash fatalities, and crash risk is greatest during the first year of independent driving in particular. To explore the: (1) self-reported compliance of drivers with road rules regarding substance-impaired driving and other risky driving behaviours (e.g., speeding, driving while tired), one year after progression from a Learner to a Provisional (intermediate) licence; and (2) interrelationships between substance-impaired driving and other risky driving behaviours (e.g., crashes, offences, and Police avoidance). Drivers (n=1076; 319 males) aged 18-20 years were surveyed regarding their sociodemographics (age, gender) and self-reported driving behaviours including crashes, offences, Police avoidance, and driving intentions. A relatively small proportion of participants reported driving after taking drugs (6.3% of males, 1.3% of females) and drinking alcohol (18.5% of males, 11.8% of females). In comparison, a considerable proportion of participants reported at least occasionally exceeding speed limits (86.7% of novices), and risky behaviours like driving when tired (83.6% of novices). Substance-impaired driving was associated with avoiding Police, speeding, risky driving intentions, and self-reported crashes and offences. Forty-three percent of respondents who drove after taking drugs also reported alcohol-impaired driving. Behaviours of concern include drink driving, speeding, novice driving errors such as misjudging the speed of oncoming vehicles, violations of graduated driver licensing passenger restrictions, driving tired, driving faster if in a bad mood, and active punishment avoidance. Given the interrelationships between the risky driving behaviours, a deeper understanding of influential factors is required to inform targeted and general countermeasure implementation and evaluation during this critical driving period. Notwithstanding this, a combination of enforcement, education, and engineering efforts appear necessary to improve the road safety of the young novice driver, and for the drink-driving young novice driver in particular. Copyright © 2014 Elsevier Ltd. All rights reserved.

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.

Monitoring techniques for the X-29A aircraft's high-speed rotating power takeoff shaft

NASA Technical Reports Server (NTRS)

Voracek, David F.

1990-01-01

The experimental X-29A forward swept-wing aircraft has many unique and critical systems that require constant monitoring during ground or flight operation. One such system is the power takeoff shaft, which is the mechanical link between the engine and the aircraft-mounted accessory drive. The X-29A power takeoff shaft opertes in a range between 0 and 16,810 rpm, is longer than most jet engine power takeoff shafts, and is made of graphite epoxy material. Since the X-29A aircraft operates on a single engine, failure of the shaft during flight could lead to loss of the aircraft. The monitoring techniques and test methods used during power takeoff shaft ground and flight operations are discussed. Test data are presented in two case studies where monitoring and testing of the shaft dynamics proved instrumental in discovering and isolating X-29A power takeoff shaft problems. The first study concerns the installation of an unbalanced shaft. The effect of the unbalance on the shaft vibration data and the procedure used to correct the problem are discussed. The second study deals with the shaft exceeding the established vibration limits during flight. This case study found that the vibration of connected rotating machinery unbalances contributed to the excessive vibration level of the shaft. The procedures used to identify the contributions of other rotating machinery unbalances to the power takeoff shaft unbalance are discussed.

The structure and propagation of laminar flames under autoignitive conditions

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

Krisman, Alex; Hawkes, Evatt R.; Chen, Jacqueline H.

Tmore » he laminar flame speed s l is an important reference quantity for characterising and modelling combustion. Experimental measurements of laminar flame speed require the residence time of the fuel/air mixture (τ f) to be shorter than the autoignition delay time (τ). his presents a considerable challenge for conditions where autoignition occurs rapidly, such as in compression ignition engines. As a result, experimental measurements in typical compression ignition engine conditions do not exist. Simulations of freely propagating premixed flames, where the burning velocity is found as an eigenvalue of the solution, are also not well posed in such conditions, since the mixture ahead of the flame can autoignite, leading to the so called “cold boundary problem”. In this paper, a numerical method for estimating a reference flame speed, s R, is proposed that is valid for laminar flame propagation at autoignitive conditions. wo isomer fuels are considered to test this method: ethanol, which in the considered conditions is a single-stage ignition fuel; and dimethyl ether, which has a temperature-dependent single- or two-stage ignition and a negative temperature coefficient regime for τ. Calculations are performed for the flame position in a one-dimensional computational domain with inflow-outflow boundary conditions, as a function of the inlet velocity U I and for stoichiometric fuel–air premixtures. he response of the flame position, L F, to U I shows distinct stabilisation regimes. For single-stage ignition fuels, at low U I the flame speed exceeds U I and the flame becomes attached to the inlet. Above a critical U I value, the flame detaches from the inlet and L f becomes extremely sensitive to U I until, for sufficiently high U I, the sensitivity decreases and L f corresponds to the location expected from a purely autoignition stabilised flame. he transition from the attached to the autoignition regimes has a corresponding peak dL f/dU I value which is proposed to be a unique reference flame speed s R for single-stage ignition fuels. For two-stage ignition fuels, there is an additional stable regime where a high-temperature flame propagates into a pool of combustion intermediates generated by the first stage of autoignition. his results in two peaks in dL f/dU I and therefore two reference flame speed values. he lower value corresponds to the definition of s R for single-stage ignition fuels, while the higher value exists only for two-stage ignition fuels and corresponds to a high temperature flame propagating into the first stage of autoignition and is denoted s R ' . Finally, a transport budget analysis for low- and high-temperature radical species is also performed, which confirms that the flame structures at U I = s R and U I = s R ' do indeed correspond to premixed flames (deflagrations), as opposed to spontaneous ignition fronts which do not have a unique propagation speed.« less

The structure and propagation of laminar flames under autoignitive conditions

DOE PAGES

Krisman, Alex; Hawkes, Evatt R.; Chen, Jacqueline H.

2017-11-05

Tmore » he laminar flame speed s l is an important reference quantity for characterising and modelling combustion. Experimental measurements of laminar flame speed require the residence time of the fuel/air mixture (τ f) to be shorter than the autoignition delay time (τ). his presents a considerable challenge for conditions where autoignition occurs rapidly, such as in compression ignition engines. As a result, experimental measurements in typical compression ignition engine conditions do not exist. Simulations of freely propagating premixed flames, where the burning velocity is found as an eigenvalue of the solution, are also not well posed in such conditions, since the mixture ahead of the flame can autoignite, leading to the so called “cold boundary problem”. In this paper, a numerical method for estimating a reference flame speed, s R, is proposed that is valid for laminar flame propagation at autoignitive conditions. wo isomer fuels are considered to test this method: ethanol, which in the considered conditions is a single-stage ignition fuel; and dimethyl ether, which has a temperature-dependent single- or two-stage ignition and a negative temperature coefficient regime for τ. Calculations are performed for the flame position in a one-dimensional computational domain with inflow-outflow boundary conditions, as a function of the inlet velocity U I and for stoichiometric fuel–air premixtures. he response of the flame position, L F, to U I shows distinct stabilisation regimes. For single-stage ignition fuels, at low U I the flame speed exceeds U I and the flame becomes attached to the inlet. Above a critical U I value, the flame detaches from the inlet and L f becomes extremely sensitive to U I until, for sufficiently high U I, the sensitivity decreases and L f corresponds to the location expected from a purely autoignition stabilised flame. he transition from the attached to the autoignition regimes has a corresponding peak dL f/dU I value which is proposed to be a unique reference flame speed s R for single-stage ignition fuels. For two-stage ignition fuels, there is an additional stable regime where a high-temperature flame propagates into a pool of combustion intermediates generated by the first stage of autoignition. his results in two peaks in dL f/dU I and therefore two reference flame speed values. he lower value corresponds to the definition of s R for single-stage ignition fuels, while the higher value exists only for two-stage ignition fuels and corresponds to a high temperature flame propagating into the first stage of autoignition and is denoted s R ' . Finally, a transport budget analysis for low- and high-temperature radical species is also performed, which confirms that the flame structures at U I = s R and U I = s R ' do indeed correspond to premixed flames (deflagrations), as opposed to spontaneous ignition fronts which do not have a unique propagation speed.« less

14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2011 CFR

2011-01-01

... excessive sound absorption characteristics such as those caused by thick, matted, or tall grass, by shrubs..., inclusively; (4) Wind speed may not exceed 10 knots (19 km/h) and cross wind may not exceed 5 knots (9 km/h... level atmospheric pressure of 1013.25 mb (013.25 hPa); (2) Ambient air temperature of 59 °F (15 °C); (3...

14 CFR Appendix G to Part 36 - Takeoff Noise Requirements for Propeller-Driven Small Airplane and Propeller-Driven, Commuter...

Code of Federal Regulations, 2010 CFR

2010-01-01

... excessive sound absorption characteristics such as those caused by thick, matted, or tall grass, by shrubs..., inclusively; (4) Wind speed may not exceed 10 knots (19 km/h) and cross wind may not exceed 5 knots (9 km/h... level atmospheric pressure of 1013.25 mb (013.25 hPa); (2) Ambient air temperature of 59 °F (15 °C); (3...

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.

Calculation of wind speeds required to damage or destroy buildings

NASA Astrophysics Data System (ADS)

Liu, Henry

Determination of wind speeds required to damage or destroy a building is important not only for the improvement of building design and construction but also for the estimation of wind speeds in tornadoes and other damaging storms. For instance, since 1973 the U.S. National Weather Service has been using the well-known Fujita scale (F scale) to estimate the maximum wind speeds of tornadoes [Fujita, 1981]. The F scale classifies tornadoes into 13 numbers, F-0 through F-12. The wind speed (maximum gust speed) associated with each F number is given in Table 1. Note that F-6 through F-12 are for wind speeds between 319 mi/hr (mph) and the sonic velocity (approximately 760 mph; 1 mph = 1.6 km/kr). However, since no tornadoes have been classified to exceed F-5, the F-6 through F-12 categories have no practical meaning [Fujita, 1981].

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.

Dynamic Speed Adaptation for Path Tracking Based on Curvature Information and Speed Limits.

PubMed

Gámez Serna, Citlalli; Ruichek, Yassine

2017-06-14

A critical concern of autonomous vehicles is safety. Different approaches have tried to enhance driving safety to reduce the number of fatal crashes and severe injuries. As an example, Intelligent Speed Adaptation (ISA) systems warn the driver when the vehicle exceeds the recommended speed limit. However, these systems only take into account fixed speed limits without considering factors like road geometry. In this paper, we consider road curvature with speed limits to automatically adjust vehicle's speed with the ideal one through our proposed Dynamic Speed Adaptation (DSA) method. Furthermore, 'curve analysis extraction' and 'speed limits database creation' are also part of our contribution. An algorithm that analyzes GPS information off-line identifies high curvature segments and estimates the speed for each curve. The speed limit database contains information about the different speed limit zones for each traveled path. Our DSA senses speed limits and curves of the road using GPS information and ensures smooth speed transitions between current and ideal speeds. Through experimental simulations with different control algorithms on real and simulated datasets, we prove that our method is able to significantly reduce lateral errors on sharp curves, to respect speed limits and consequently increase safety and comfort for the passenger.

75 FR 54462 - Airworthiness Directives; Bombardier-Rotax GmbH 912 F Series and 912 S Series Reciprocating Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-08

... Airworthiness Directives; Bombardier-Rotax GmbH 912 F Series and 912 S Series Reciprocating Engines AGENCY... result in exceeding of the fuel pressure and might cause engine malfunction and/or massive fuel leakage... engine malfunction or a massive fuel leak. These conditions could cause loss of control of the airplane...

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...

SR-71 Ship #1 on Ramp

NASA Technical Reports Server (NTRS)

1994-01-01

This photo shows a head-on shot of NASA's SR-71A aircraft on the ramp at NASA's Dryden Flight Research Center, Edwards, California. NASA operated two SR-71s, an SR-71A and an SR- 71B pilot trainer aircraft, both based at Dryden, at that particular point in time. The SR-71 was designed and built by the Lockheed Skunk Works, now the Lockheed Martin Skunk Works. Studies have shown that less than 20 percent of the total thrust used to fly at Mach 3 is produced by the basic engine itself. The balance of the total thrust is produced by the unique design of the engine inlet and 'moveable spike' system at the front of the engine nacelles, and by the ejector nozzles at the exhaust which burn air compressed in the engine bypass system. Data from the SR-71 high speed research program will be used to aid designers of future supersonic/hypersonic aircraft and propulsion systems, including a high speed civil transport. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

STS-55 pad abort: Engine 2011 oxidizer preburner augmented spark igniter check valve leak

NASA Technical Reports Server (NTRS)

1993-01-01

The STS-55 initial launch attempt of Columbia (OV102) was terminated on KSC launch pad A March 22, 1993 at 9:51 AM E.S.T. due to violation of an ME-3 (Engine 2011) Launch Commit Criteria (LCC) limit exceedance. The event description and timeline are summarized. Propellant loading was initiated on 22 March, 1993 at 1:15 AM EST. All SSME chill parameters and launch commit criteria (LCC) were nominal. At engine start plus 1.44 seconds, a Failure Identification (FID) was posted against Engine 2011 for exceeding the 50 psia Oxidizer Preburner (OPB) purge pressure redline. The engine was shut down at 1.50 seconds followed by Engines 2034 and 2030. All shut down sequences were nominal and the mission was safely aborted. The OPB purge pressure redline violation and the abort profile/overlay for all three engines are depicted. SSME Avionics hardware and software performed nominally during the incident. A review of vehicle data table (VDT) data and controller software logic revealed no failure indications other than the single FID 013-414, OPB purge pressure redline exceeded. Software logic was executed according to requirements and there was no anomalous controller software operation. Immediately following the abort, a Rocketdyne/NASA failure investigation team was assembled. The team successfully isolated the failure cause to the oxidizer preburner augmented spark igniter purge check valve not being fully closed due to contamination. The source of the contaminant was traced to a cut segment from a rubber O-ring which was used in a fine clean tool during valve production prior to 1992. The valve was apparently contaminated during its fabrication in 1985. The valve had performed acceptably on four previous flights of the engine, and SSME flight history shows 780 combined check valve flights without failure. The failure of an Engine 3 (SSME No. 2011) check valve to close was sensed by onboard engine instruments even though all other engine operations were normal. This resulted in an engine shutdown and safe sequential shutdown of all three engines prior to ignition of the solid boosters.

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...

49 CFR 238.431 - Brake system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... dynamic brake does not result in exceeding the allowable stopping distance; (2) The friction brake alone... speed for safe operation of the train using only the friction brake portion of the blended brake with no...

49 CFR 238.431 - Brake system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... dynamic brake does not result in exceeding the allowable stopping distance; (2) The friction brake alone... speed for safe operation of the train using only the friction brake portion of the blended brake with no...

49 CFR 238.431 - Brake system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... dynamic brake does not result in exceeding the allowable stopping distance; (2) The friction brake alone... speed for safe operation of the train using only the friction brake portion of the blended brake with no...

Not So Fast: Swimming Behavior of Sailfish during Predator-Prey Interactions using High-Speed Video and Accelerometry.

PubMed

Marras, Stefano; Noda, Takuji; Steffensen, John F; Svendsen, Morten B S; Krause, Jens; Wilson, Alexander D M; Kurvers, Ralf H J M; Herbert-Read, James; Boswell, Kevin M; Domenici, Paolo

2015-10-01

Billfishes are considered among the fastest swimmers in the oceans. Despite early estimates of extremely high speeds, more recent work showed that these predators (e.g., blue marlin) spend most of their time swimming slowly, rarely exceeding 2 m s(-1). Predator-prey interactions provide a context within which one may expect maximal speeds both by predators and prey. Beyond speed, however, an important component determining the outcome of predator-prey encounters is unsteady swimming (i.e., turning and accelerating). Although large predators are faster than their small prey, the latter show higher performance in unsteady swimming. To contrast the evading behaviors of their highly maneuverable prey, sailfish and other large aquatic predators possess morphological adaptations, such as elongated bills, which can be moved more rapidly than the whole body itself, facilitating capture of the prey. Therefore, it is an open question whether such supposedly very fast swimmers do use high-speed bursts when feeding on evasive prey, in addition to using their bill for slashing prey. Here, we measured the swimming behavior of sailfish by using high-frequency accelerometry and high-speed video observations during predator-prey interactions. These measurements allowed analyses of tail beat frequencies to estimate swimming speeds. Our results suggest that sailfish burst at speeds of about 7 m s(-1) and do not exceed swimming speeds of 10 m s(-1) during predator-prey interactions. These speeds are much lower than previous estimates. In addition, the oscillations of the bill during swimming with, and without, extension of the dorsal fin (i.e., the sail) were measured. We suggest that extension of the dorsal fin may allow sailfish to improve the control of the bill and minimize its yaw, hence preventing disturbance of the prey. Therefore, sailfish, like other large predators, may rely mainly on accuracy of movement and the use of the extensions of their bodies, rather than resorting to top speeds when hunting evasive prey. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

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...

Laboratory in the sky. New frontiers in measurements aloft

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

Spicer, C.W.; Kenny, D.V.; Shaw, W.J.

1994-09-01

This article describes a research aircraft for airborne measurements and the challenges that were overcome to deploy state-of-the-art measurement technology in an aircraft environment. We also focus on the chemical instrumentation and the recent addition of tandem mass spectrometry to the capabilities available for atmospheric characterization. The plane that we use to study atmospheric physical and chemical processes is a Grumman Gulfstream 1 (G-1), which is a twin-engine turboprop. The G-1 has a visual flight rule range exceeding 1500 nautical mi (endurance of about 6 h). It carries as much as 2800 lb of scientific payload with seats for fourmore » scientists and has a sampling speed range of 160-250 knots. The data acquisition system on the G-1 contains special interfaces to log data from a Long-Range Navigation system, the Global Positioning System, and an inertial navigation system, as well as particle measurement systems and other scientific probes. 3 refs., 7 figs., 2 tabs.« less

F-86 Sabre on lakebed, front view

NASA Technical Reports Server (NTRS)

1954-01-01

With the NACA High-Speed Flight Station (HSFS) main building (4800) in the background the North American F-86F (Serial #52-5426) Sabre sits on the Rogers Dry lakebed just off the NACA ramp in 1954. This was soon after the National Advisory Committee for Aeronautics unit moved from South Base at Edwards Air Force Base to the new building that still houses the NASA Dryden Flight Research Center, successor to the HSFS. The F-86F performed both pitch-up research and duties as a chase aircraft for the D-558-2. Its stay at the HSFS was brief. It arrived on June 23, 1954, and left on September 10 the same year. The F-86 had a 35 degree sweptwing and a wing span of 37 feet 1 inch with a General Electric J47-GE engine. It was the first U.S. sweptwing fighter and saw extensive action in the Korean War. It could slightly exceed Mach 1 in a dive.

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.

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...

40 CFR 87.31 - Standards for exhaust emissions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Gas Turbine Engines) § 87.31 Standards for exhaust emissions. (a) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class T8, beginning February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of class TF and...

40 CFR 87.31 - Standards for exhaust emissions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Gas Turbine Engines) § 87.31 Standards for exhaust emissions. (a) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class T8, beginning February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of class TF and...

40 CFR 87.31 - Standards for exhaust emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Gas Turbine Engines) § 87.31 Standards for exhaust emissions. (a) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class T8, beginning February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of class TF and...

40 CFR 87.31 - Standards for exhaust emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Gas Turbine Engines) § 87.31 Standards for exhaust emissions. (a) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of Class T8, beginning February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each in-use aircraft gas turbine engine of class TF and...

40 CFR 87.21 - Standards for exhaust emissions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... (CONTINUED) Definitions. Exhaust Emissions (New Aircraft Gas Turbine Engines) § 87.21 Standards for exhaust... each new aircraft gas turbine engine of class T8 manufactured on or after February 1, 1974, shall not exceed: Smoke number of 30. (b) Exhaust emissions of smoke from each new aircraft gas turbine engine of...

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.

Flight thresholds and seasonal variations in flight activity of the light-brown apple moth, Epiphyas postvittana (Walk.) (Tortricidae), in Victoria, Australia.

PubMed

Danthanarayana, W

1976-12-01

The flight activity of Epiphyas postvittana was studied at two sites near Melbourne with the aid of suction traps, over a period of 4 years. Maximum numbers were found to fly during the period September to March with peak activity coinciding with the emergence of winter, spring and summer generation moths. E. postivittana is predominantly a nocturnal flier with maximum activity around 20.00-24.00 h. The lower temperature threshold of flight was 8-11°C. The upper temperature threshold varied from 20-21°C, 24-25°C and 27-28°C for the winter, spring and summer generation moths respectively. Flight was highly influenced by the prevailing wind. The lower wind speed threshold was 0.5-0.8 m -s and the upper wind speed threshold was 2.6-2.7 m -s . The relationship between wind speed and the amount of flight was non-linear, with the frequency of flights decreasing sharply with increasing wind speed. No flights occurred at wind speeds greater than 2.8 m -s . Variation in relative humidity had no influence on flight, but lack of rain favoured flight. The amount of flight activity and the amount of rainfall were negatively correlated; flights did not occur when the daily precipitation exceeded 32.5 mm, and with a precipitation exceeding 39 mm no flights could be expected. The value of these findings to pest control programmes is discussed.

SR-71 Pilots and Crew (Smith, Meyer, Bohn-Meyer, Ishmael)

NASA Technical Reports Server (NTRS)

1991-01-01

The two pilot-engineer teams that flew the SR-71 aircraft at the NASA Ames-Dryden Flight Research Facility (later, Dryden Flight Research Center), Edwards, California, are, from top of ladder, pilot Rogers Smith, flight engineer Robert Meyer, pilot Steven Ishmael, and flight engineer Marta Bohn-Meyer. The Meyers are the first husband-wife team of aeronautical engineers at Dryden on flight status. Two SR-71 aircraft have been used by NASA as testbeds for high-speed and high-altitude aeronautical research. The aircraft, an SR-71A and an SR-71B pilot trainer aircraft, have been based here at NASA's Dryden Flight Research Center, Edwards, California. They were transferred to NASA after the U.S. Air Force program was cancelled. As research platforms, the aircraft can cruise at Mach 3 for more than one hour. For thermal experiments, this can produce heat soak temperatures of over 600 degrees Fahrenheit (F). This operating environment makes these aircraft excellent platforms to carry out research and experiments in a variety of areas -- aerodynamics, propulsion, structures, thermal protection materials, high-speed and high-temperature instrumentation, atmospheric studies, and sonic boom characterization. The SR-71 was used in a program to study ways of reducing sonic booms or over pressures that are heard on the ground, much like sharp thunderclaps, when an aircraft exceeds the speed of sound. Data from this Sonic Boom Mitigation Study could eventually lead to aircraft designs that would reduce the 'peak' overpressures of sonic booms and minimize the startling affect they produce on the ground. One of the first major experiments to be flown in the NASA SR-71 program was a laser air data collection system. It used laser light instead of air pressure to produce airspeed and attitude reference data, such as angle of attack and sideslip, which are normally obtained with small tubes and vanes extending into the airstream. One of Dryden's SR-71s was used for the Linear Aerospike Rocket Engine, or LASRE Experiment. Another earlier project consisted of a series of flights using the SR-71 as a science camera platform for NASA's Jet Propulsion Laboratory in Pasadena, California. An upward-looking ultraviolet video camera placed in the SR-71's nosebay studied a variety of celestial objects in wavelengths that are blocked to ground-based astronomers. Earlier in its history, Dryden had a decade of past experience at sustained speeds above Mach 3. Two YF-12A aircraft and an SR-71 designated as a YF-12C were flown at the center between December 1969 and November 1979 in a joint NASA/USAF program to learn more about the capabilities and limitations of high-speed, high-altitude flight. The YF-12As were prototypes of a planned interceptor aircraft based on a design that later evolved into the SR-71 reconnaissance aircraft. Dave Lux was the NASA SR-71 project manger for much of the decade of the 1990s, followed by Steve Schmidt. Developed for the USAF as reconnaissance aircraft more than 30 years ago, SR-71s are still the world's fastest and highest-flying production aircraft. The aircraft can fly at speeds of more than 2,200 miles per hour (Mach 3+, or more than three times the speed of sound) and at altitudes of over 85,000 feet. The Lockheed Skunk Works (now Lockheed Martin) built the original SR-71 aircraft. Each aircraft is 107.4 feet long, has a wingspan of 55.6 feet, and is 18.5 feet high (from the ground to the top of the rudders, when parked). Gross takeoff weight is about 140,000 pounds, including a possible fuel weight of 80,280 pounds. The airframes are built almost entirely of titanium and titanium alloys to withstand heat generated by sustained Mach 3 flight. Aerodynamic control surfaces consist of all-moving vertical tail surfaces, ailerons on the outer wings, and elevators on the trailing edges between the engine exhaust nozzles. The two SR-71s at Dryden have been assigned the following NASA tail numbers: NASA 844 (A model), military serial 61-7980 and NASA 831 (B model), military serial 61-7956. From 1990 through 1994, Dryden also had another 'A' model, NASA 832, military serial 61-7971. This aircraft was returned to the USAF inventory and was the first aircraft reactivated for USAF reconnaissance purposes in 1995. It has since returned to Dryden along with SR-71A 61-7967.

40 CFR 1054.235 - What exhaust emission testing must I perform for my application for a certificate of conformity?

Code of Federal Regulations, 2014 CFR

2014-07-01

... specified in subpart F of this part. In the case of dual-fuel engines, measure emissions when operating with each type of fuel for which you intend to certify the engine. In the case of flexible-fuel engines, measure emissions when operating with the fuel mixture that is most likely to cause the engine to exceed...

40 CFR 1054.235 - What exhaust emission testing must I perform for my application for a certificate of conformity?

Code of Federal Regulations, 2012 CFR

2012-07-01

... specified in subpart F of this part. In the case of dual-fuel engines, measure emissions when operating with each type of fuel for which you intend to certify the engine. In the case of flexible-fuel engines, measure emissions when operating with the fuel mixture that is most likely to cause the engine to exceed...

40 CFR 1054.235 - What exhaust emission testing must I perform for my application for a certificate of conformity?

Code of Federal Regulations, 2010 CFR

2010-07-01

... specified in subpart F of this part. In the case of dual-fuel engines, measure emissions when operating with each type of fuel for which you intend to certify the engine. In the case of flexible-fuel engines, measure emissions when operating with the fuel mixture that is most likely to cause the engine to exceed...

40 CFR 1054.235 - What exhaust emission testing must I perform for my application for a certificate of conformity?

Code of Federal Regulations, 2013 CFR

2013-07-01

... specified in subpart F of this part. In the case of dual-fuel engines, measure emissions when operating with each type of fuel for which you intend to certify the engine. In the case of flexible-fuel engines, measure emissions when operating with the fuel mixture that is most likely to cause the engine to exceed...

40 CFR 1054.235 - What exhaust emission testing must I perform for my application for a certificate of conformity?

Code of Federal Regulations, 2011 CFR

2011-07-01

... specified in subpart F of this part. In the case of dual-fuel engines, measure emissions when operating with each type of fuel for which you intend to certify the engine. In the case of flexible-fuel engines, measure emissions when operating with the fuel mixture that is most likely to cause the engine to exceed...

40 CFR 1045.107 - What are the not-to-exceed emission standards?

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 33 2011-07-01 2011-07-01 false What are the not-to-exceed emission standards? 1045.107 Section 1045.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.107 - What are the not-to-exceed emission standards?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false What are the not-to-exceed emission standards? 1045.107 Section 1045.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.107 - What are the not-to-exceed emission standards?

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 34 2013-07-01 2013-07-01 false What are the not-to-exceed emission standards? 1045.107 Section 1045.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.107 - What are the not-to-exceed emission standards?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false What are the not-to-exceed emission standards? 1045.107 Section 1045.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

40 CFR 1045.107 - What are the not-to-exceed emission standards?

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 34 2012-07-01 2012-07-01 false What are the not-to-exceed emission standards? 1045.107 Section 1045.107 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR POLLUTION CONTROLS CONTROL OF EMISSIONS FROM SPARK-IGNITION PROPULSION MARINE ENGINES AND VESSELS...

77 FR 43550 - Airworthiness Directives; Turbomeca S.A. Turboshaft Engines

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-25

... dust collected during cleaning exceeds 8 grams. This proposed AD also includes an optional terminating... dust collected during any cleaning inside the gas generator hollow shaft exceeds 8 grams; and If there... gas generator hollow shaft is more than 8 grams, replace the gas generator rear bearing before further...

40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., shall exceed either 2.5 mg/l or a concentration equal to 25 times the limit of detection for the HPLC..., shall exceed either 2.5 mg/l or a concentration equal to 25 times the limit of detection for the HPLC...

40 CFR 86.1309-90 - Exhaust gas sampling system; Otto-cycle and non-petroleum-fueled engines.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., shall exceed either 2.5 mg/l or a concentration equal to 25 times the limit of detection for the HPLC..., shall exceed either 2.5 mg/l or a concentration equal to 25 times the limit of detection for the HPLC...

24 CFR 3285.306 - Design procedures for concrete block piers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... top to the bottom of the pier must not exceed one-half inch. (5) Mortar is not required, unless... not exceeded. Mortar is not required for concrete block piers, unless otherwise specified in the..., in accordance with acceptable engineering practice. Mortar is not required for concrete block piers...

24 CFR 3285.306 - Design procedures for concrete block piers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... top to the bottom of the pier must not exceed one-half inch. (5) Mortar is not required, unless... not exceeded. Mortar is not required for concrete block piers, unless otherwise specified in the..., in accordance with acceptable engineering practice. Mortar is not required for concrete block piers...

24 CFR 3285.306 - Design procedures for concrete block piers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... top to the bottom of the pier must not exceed one-half inch. (5) Mortar is not required, unless... not exceeded. Mortar is not required for concrete block piers, unless otherwise specified in the..., in accordance with acceptable engineering practice. Mortar is not required for concrete block piers...

24 CFR 3285.306 - Design procedures for concrete block piers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... top to the bottom of the pier must not exceed one-half inch. (5) Mortar is not required, unless... not exceeded. Mortar is not required for concrete block piers, unless otherwise specified in the..., in accordance with acceptable engineering practice. Mortar is not required for concrete block piers...

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...

Propfan Test Assessment (PTA)

NASA Technical Reports Server (NTRS)

Little, B. H.; Poland, D. T.; Bartel, H. W.; Withers, C. C.; Brown, P. C.

1989-01-01

The objectives of the Propfan Test Assessment (PTA) Program were to validate in flight the structural integrity of large-scale propfan blades and to measure noise characteristics of the propfan in both near and far fields. All program objectives were met or exceeded, on schedule and under budget. A Gulfstream Aerospace Corporation GII aircraft was modified to provide a testbed for the 2.74m (9 ft) diameter Hamilton Standard SR-7 propfan which was driven by a 4475 kw (600 shp) turboshaft engine mounted on the left-hand wing of the aircraft. Flight research tests were performed for 20 combinations of speed and altitude within a flight envelope that extended to Mach numbers of 0.85 and altitudes of 12,192m (40,000 ft). Propfan blade stress, near-field noise on aircraft surfaces, and cabin noise were recorded. Primary variables were propfan power and tip speed, and the nacelle tilt angle. Extensive low altitude far-field noise tests were made to measure flyover and sideline noise and the lateral attenuation of noise. In coopertion with the FAA, tests were also made of flyover noise for the aircraft at 6100m (20,000 ft) and 10,668m (35,000 ft). A final series of tests were flown to evaluate an advanced cabin wall noise treatment that was produced under a separate program by NASA-Langley Research Center.

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.

Job Prospects for Manufacturing Engineers.

ERIC Educational Resources Information Center

Basta, Nicholas

1985-01-01

Coming from a variety of disciplines, manufacturing engineers are keys to industry's efforts to modernize, with demand exceeding supply. The newest and fastest-growing areas include machine vision, composite materials, and manufacturing automation protocols, each of which is briefly discussed. (JN)

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.

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.

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.

Matching optical flow to motor speed in virtual reality while running on a treadmill.

PubMed

Caramenti, Martina; Lafortuna, Claudio L; Mugellini, Elena; Abou Khaled, Omar; Bresciani, Jean-Pierre; Dubois, Amandine

2018-01-01

We investigated how visual and kinaesthetic/efferent information is integrated for speed perception in running. Twelve moderately trained to trained subjects ran on a treadmill at three different speeds (8, 10, 12 km/h) in front of a moving virtual scene. They were asked to match the visual speed of the scene to their running speed-i.e., treadmill's speed. For each trial, participants indicated whether the scene was moving slower or faster than they were running. Visual speed was adjusted according to their response using a staircase until the Point of Subjective Equality (PSE) was reached, i.e., until visual and running speed were perceived as equivalent. For all three running speeds, participants systematically underestimated the visual speed relative to their actual running speed. Indeed, the speed of the visual scene had to exceed the actual running speed in order to be perceived as equivalent to the treadmill speed. The underestimation of visual speed was speed-dependent, and percentage of underestimation relative to running speed ranged from 15% at 8km/h to 31% at 12km/h. We suggest that this fact should be taken into consideration to improve the design of attractive treadmill-mediated virtual environments enhancing engagement into physical activity for healthier lifestyles and disease prevention and care.

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.