Deepening stirling engine analysis: optimized model offers more accurate performance predictions

Advancing Stirling Engine Design Through Enhanced Modeling
Researchers optimized the classical Simple second-order analysis method by coupling multiple loss models, developing a Stirling cycle analysis program that more accurately captures the real-world operating behavior of the engine.

From Idealized Cycles to Real-World Performance
Stirling engines, known for their high efficiency and fuel versatility, are prime candidates for advanced power systems, including Space Nuclear Reactor Power Systems (SNRPS). However, accurately predicting their real-world performance has been challenging. This study bridges the gap between idealized thermodynamic cycles and operational reality by creating a model that meticulously accounts for various energy dissipation factors, crucial for designing engines that can meet the stringent demands of space exploration and other critical applications.

A More Accurate Lens on Engine Dynamics
Utilizing a sophisticated second-order analysis, the team integrated multiple loss considerations—including shuttle heat loss, seal leakage, flow resistance, and finite piston speed—into the model. The model is validated against experimental data from established engines, GPU-3 and RE-1000. "Our refined model offers a much clearer picture of how various design parameters, such as regenerator porosity and working fluid choice, affect Stirling engine efficiency and power output. This advancement provides critical reference and data support for the application of Stirling engines in advanced compact energy systems," explains Professor Feng.

Advancing Nuclear Physics Research
The team plans to further leverage this model to explore dynamic operational scenarios, such as engine start-up and transient responses, which are critical for real-world applications.

"Future research will focus on understanding and managing thermal balance across all operational stages within an integrated reactor system, with particular attention to startup in sensitive environments such as space. This includes investigating the influence of the heat pipe reactor's output characteristics on the Stirling engine's performance, efficiency, and stability," stated Professor Feng.

The complete study is accessible via DOI：10.1007/s41365-025-01711-6

Nuclear Science and Techniques (NST) is a peer-reviewed international journal sponsored by the Shanghai Institute of Applied Physics, Chinese Academy of Sciences. The journal publishes high-quality research across a broad range of nuclear science disciplines, including nuclear physics, nuclear energy, accelerator physics, and nuclear electronics. Its Editor-in-Chief is the renowned physicist, Professor Yu-Gang Ma.