Numerical and experimental study on the refrigeration performance of a variable-section gas wave oscillation tube

This paper introduces the refrigeration cycle process of the gas wave oscillation tube (GWOT). Aiming at the problem that the strong reverse compression waves generated during the refrigeration process affect the performance, this paper proposes a variable-section GWOT that weakens the reverse compression waves and a variable-section structure designed using a numerical method. Results showed that the variable-section structure could reduce the intensity of the incident shock wave by approximately 7% and the total entropy production in the refrigeration cycle by approximately 8% under the design condition. Moreover, the variable-section structure can effectively weaken the strength of the reverse compression waves and improve the refrigeration efficiency by approximately 4% under the same working conditions. The variable-section structure can also widen the high-performance working range of the GWOT. The experimental results reveal that the high-performance working range can be expanded by more than two times under the design condition. The research can guide the subsequent development of gas wave refrigeration technology and a reference for other wave rotor application technologies.