International Scientific Journal

Thermal Science - Online First

online first only

Performance prediction and parametric optimization of γ-type free piston Stirling engine

The free piston Stirling engine (FPSE) is a complex system with multiple parameters strongly coupled. In this study, linear dynamic model and root locus technique are combined to investigate a γ-type FPSE. Firstly, brief expressions are derived to predict the operating frequency (f), phase angle (φ), amplitude ratio (η) and output power (PV) of γ-type FPSE using linear dynamic model. The dynamic parameters are analyzed in detail to reveal their influence on the output performance of the system. Meanwhile, the starting conditions are obtained by root locus technique. Combining the results of the above two methods, a set of optimized design parameters is identified. The optimum values of f, φ, η and PV are 74.82 Hz, 65.38°, 1.92 and 108 W, respectively. Further more, a 60 W γ-type FPSE prototype is developed and tested to validate the current model. Compared with the predicted results, the relative errors are less than 4.0% for f, less than 5.0% for φ, less than 2.0% for η, and less than 10.0% for PV. This research provides a reliable approach for the further design of γ-type FPSE.
PAPER REVISED: 2023-09-17
PAPER ACCEPTED: 2023-09-21
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