Thermodynamic prediction and experimental validation of load characteristics in a liquid-piston Stirling engine.

A liquid-piston Stirling engine (LPSE) is a thermoacoustic heat engine characterized by its distinctive low-frequency and large-amplitude liquid-gas oscillations. This study developed a compact thermodynamic framework for predicting load characteristics using a minimal set of parameters obtained independently from no-load and orifice plate measurements. The model predictions were validated against measurements of the temperature-dependent acoustic power delivered to the orifice-plate load. The framework was further applied to examine the change in optimal loading under fixed-temperature and fixed-heat-input conditions, illustrating feasible operating ranges under practical constraints. The results provide experimentally validated guidance for the design and optimization of LPSE-based thermoacoustic energy conversion systems.