Results from baseline tests of the SPRE I and comparison with code model predictions

The space power research engine (SPRE), a free-piston Stirling engine with a linear alternator, is being tested as a candidate high-capacity power supply for space systems. Results of baseline engine tests at design and off-design operating conditions are presented. The test results are compared with HFAST code model predictions and show fairly good agreement. The trends in measured data generally follow the same trends as the code predictions. The code, however, does not account for effects of gas bearing flows and mass transport between volumes of the engine