Abstract: The leakage loss between the high-pressure port of a dual-port gas wave refrigerator and the wave rotor channel is investigated, with emphasis on the associated flow characteristics and underlying leakage mechanisms. This leakage not only leads to energy dissipation but also adversely affects the cooling efficiency of the entire system, highlighting the importance of understanding and mitigating such losses. In this work, a novel nozzle baffle configuration incorporating a sealing structure is proposed, aiming to reduce high-pressure gas leakage and improve the overall thermal performance of the gas wave refrigerator. A comprehensive numerical and experimental analysis is conducted to evaluate the influence of the baffle-rotor gap on leakage behavior. The results reveal that the clearance between the sealing baffle and the rotor plays a crucial role in determining the magnitude of leakage loss. Specifically, the introduction of a labyrinth-type sealing structure proves to be effective in impeding the undesired flow of high-pressure gas into the low-temperature expansion region, thereby significantly enhancing the cooling capability of the device. Moreover, the sealing performance is found to degrade with increasing expansion ratio and rotor speed, due to the intensification of internal pressure differentials and flow turbulence. The isentropic efficiency of the system exhibits a non-monotonic variation-rising initially and then declining—with respect to both the expansion ratio and rotational speed. Quantitatively, the application of the sealing structure leads to a maximum improvement in cooling efficiency of 2.4%, and up to 2.3% at the optimal design speed of 2500 r/min. These findings provide theoretical and practical insights into the structural optimization of gas wave refrigeration systems, and demonstrate the critical role of precision-designed sealing features in improving performance.

Key words: wave rotor refrigeration, gap leakage, labyrinth seal, numerical simulation, cooling efficiency

摘要： 本工作研究了双开口气波制冷机高压端口与波转子流道之间的泄漏损失，分析了泄漏损失的流动特性和机理。同时，提出利用带有密封结构的喷嘴挡板来抑制高压气体的泄漏，提升波转子的制冷效率。结果表明，挡板与转子的间隙宽度对泄漏损失有较大影响，迷宫密封结构能显著抑制高压气体向低温腔泄漏，进而提升制冷效率。密封结构的密封性能随膨胀比与转速增大而减弱。设备的等熵效率随膨胀比和转速增加呈先增大后减小的变化趋势，密封结构可使气波机制冷效率最大提升2.4%；在最佳设计转速2500 r/min时，密封结构对制冷效率最大可提升约2.3%。综上，在喷嘴挡板上设计合理的密封结构对提升波转子的制冷性能具有指导意义。

关键词: 波转子制冷, 间隙泄漏, 迷宫密封, 数值模拟, 制冷效率