2,465 research outputs found

    A laboratory facility for electric vehicle propulsion system testing

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    The road load simulator facility located at the NASA Lewis Research Center enables a propulsion system or any of its components to be evaluated under a realistic vehicle inertia and road loads. The load is applied to the system under test according to the road load equation: F(net)=K1F1+K2F2V+K3 sq V+K4(dv/dt)+K5 sin theta. The coefficient of each term in the equation can be varied over a wide range with vehicle inertial representative of vehicles up to 7500 pounds simulated by means of flywheels. The required torque is applied by the flywheels, a hydroviscous absorber and clutch, and a drive motor integrated by a closed loop control system to produce a smooth, continuous load up to 150 horsepower

    Characterization of the near-term electric vehicle (ETV-1) breadboard propulsion system over the SAE J227a driving schedule D

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    The electric test vehicle one (ETV-1) was built from the ground up with present state of the art technology. Two vehicles were built and are presently being evaluated by NASA's Jet Propulsion Laboratory (JPL). A duplicate set of propulsion system components was built, mounted on a breadboard, and delivered to NASA's Lewis Research Center for testing on the road load simulator (RLS). Driving cycle tests completed on the system are described

    Results of the ETV-1 breadboard tests under steady-state and transient conditions

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    Steady state tests were run to characterize the system and component efficiencies over the complete speed-torque capabilities of the propulsion system in both motoring and regenerative modes of operation. The steady state data were obtained using a battery simulator to separate the effects on efficiency caused by changing battery state-of-charge and component temperature. Transient tests were performed to determine the energy profiles of the propulsion system operating over the SAE J227a driving schedules

    Baseline tests of the AM General DJ-5E electruck electric delivery van

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    An electric quarter ton truck designed for use as a postal delivery vehicle was tested to characterize the state of the art of electric vehicles. Vehicle performance test results are presented. It is powered by a single-module, 54 volt industrial battery through a silicon controlled rectifier continuously adjustable controller with regenerative braking applied to a direct current compound wound motor

    Preliminary results of steady state characterization of near term electric vehicle breadboard propulsion system

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    The steady state test results on a breadboard version of the General Electric Near Term Electric Vehicle (ETV-1) are discussed. The breadboard was built using exact duplicate vehicle propulsion system components with few exceptions. Full instrumentation was provided to measure individual component efficiencies. Tests were conducted on a 50 hp dynamometer in a road load simulator facility. Characterization of the propulsion system over the lower half of the speed-torque operating range has shown the system efficiency to be composed of a predominant motor loss plus a speed dependent transaxle loss. At the lower speeds with normal road loads the armature chopper loss is also a significant factor. At the conditions corresponding to a cycle for which the vehicle system was specifically designed, the efficiencies are near optimum

    Effects of forward velocity on noise for a J85 turbojet engine with multitube suppressor from wind tunnel and flight tests

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    Flight and wind tunnel noise tests were conducted using a J85 turbojet engine as a part of comprehensive programs to obtain an understanding of forward velocity effects on jet exhaust noise. Nozzle configurations of primary interest were a 104-tube suppressor with and without an acoustically-treated shroud. The installed configuration of the engine was as similar as possible in the flight and wind tunnel tests. Exact simultaneous matching of engine speed, exhaust velocity, and exhaust temperature was not possible, and the wind tunnel maximum Mach number was approximately 0.27, while the flight Mach number was approximately 0.37. The nominal jet velocity range was 450 to 640 m/sec. For both experiments, background noise limited the jet velocity range for which significant data could be obtained. In the present tests the observed directivity and forward velocity effects for the suppressor are more similar to predicted trends for internally-generated noise than unsuppressed jet noise

    Effect of configuration variation on externally blown flap noise

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    The sensitivity of flap interaction noise to variations in engine-under-the-wing externally blown flap geometry was investigated with a large cold-flow model. Both 2- and 3-flap wing sections (7-ft chord) with trailing flap angles up to 60 deg were employed. Exhaust nozzles included coaxial, plug, and 8- and 13-inch diameter conical configurations. These nozzles were tested at two positions below the wing. The effects of these geometry variations on noise level, directivity, and spectral shape are summarized in terms of exhaust flow parameters evaluated at the nozzle exit and at the flap impingement station. The results are also compared with limited flap noise data available from tests using real engines

    Baseline tests of the C. H. Waterman Renault 5 electric passenger vehicle

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    The Waterman vehicle, a four passenger Renault 5 GTL, performance test results are presented and characterized the state-of-the-art of electric vehicles. It was powered by sixteen 6-volt traction batteries through a two-step contactor controller actuated by a foot throttle to change the voltage applied to the 6.7 -kilowatt motor. The motor output shaft was connected to a front-wheel-drive transaxle that contains a four-speed manual transmission and clutch. The braking system was a conventional hydraulic braking system

    Results of baseline tests of the Lucas Limousine

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    The Lucas Limousine, an electric vehicle, was tested to assess the state-of-the-art of electric vehicles. All tests were made without the regenerative braking system and were conducted at the gross vehicle weight of 7,700 pounds. Over a 30 mph stop and go driving cycle the vehicle went 48.4 miles. The vehicle was able to accelerate to 30 mph in about 15 seconds with a gradeability limit of 16.5 percent. As determined by coast down tests the road power and road energy consumption for the vehicle were 2.92 kilowatts and 0.146 kWh/mi, respectively, at 20 mph. At 40 mph the road power requirement was 11.12 kilowatts and the road energy requirement was 0.278 kWh/mi. The maximum energy economy measured 0.45 kilowatt hours per mile at 30 mph and increased to 0.76 kilowatt hours per mile at 50 mph. Over the 30 mph stop and go driving cycle the energy economy was 0.92 kilowatt hours per mile

    Noise measurements for various configurations of a model of a mixer nozzle externally blown flap system

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    Noise data were taken for variations to a large scale model of an externally blown flap lift augmentation system. The variations included two different mixer nozzles (7 and 8 lobes), two different wing models (2 and 3 flaps), and different lateral distances between the wing chord line and the nozzle centerline. When the seven lobe was used with the trailing flap in the 60 deg position, increasing the wing to nozzle distance had no effect on the sound level. When the eight lobe nozzle was used there was a decrease in sound level. With the 20 deg flap setting the noise level decreased when the distance was increased using either nozzle
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