Baseline performance of the GPU 3 Stirling engine

The NASA Lewis Research Center has converted a 10 hp single-cylinder rhombic-drive Stirling engine to a research configuration to obtain data for validation of Stirling computer simulations. The engine was originally built by General Motors Research Laboratories for the U.S. Army in 1965 as part of a 3 kW engine-generator set, designated the GPU 3 (Ground Power Unit). Test results for a range of heater gas temperatures, mean compression-space pressures, and engine speeds with both helium and hydrogen as the working fluids are presented. Also shown are initial data comparisons with the NASA-Lewis computer simulation predictions.