Simulation of a Cold Gas Thruster System and Test Data Correlation

During developmental testing of the Ascent Abort 1 (AA-1) cold gas thruster system, unexpected behavior was detected. Upon further review the design as it existed may not have met the requirements. To determine the best approach for modifying the design, the system was modeled with a dynamic fluid analysis tool (EASY5). The system model consisted of the nitrogen storage tank, pressure regulator, thruster valve, nozzle, and the associated interconnecting line lengths. The regulator and thruster valves were modeled using a combination of the fluid and mechanical modules available in EASY5. The simulation results were then compared against actual system test data. The simulation results exhibited behaviors similar to the test results, such as the pressure regulators response to thruster firings. Potential design solutions were investigated using the analytical model parameters, including increasing the volume downstream of the regulator and increasing the orifice area. Both were shown to improve the regulator response

Test and evaluation of 23 electric vehicles for state-of-the-art assessment

The Electric and Hybrid Research, Development and Demonstration Act of 1976 required ERDA to develop data to determine the state-of-the-art of electric and hybrid vehicles. NASA, in response to ERDA's request, tested 18 electric vehicles. The U.S. Army's MERADCOM tested four electric vehicles and the Canadian Government tested one. Eleven of the electric vehicles were passenger cars and 12 were commerical vans. Tests were conducted in accordance with an ERDA test prodecure which is based on the SAE J227a Test Proceduce. Tests included range, acceleration, coast-down, and braking. The results of the tests and comments on reliability are presented