Research on the Application Performance of the Helmholtz High-Efficiency Wave-Elimination Chamber in Gas Wave Tubes

A gas wave refrigerator is a device that uses gas pressure to expand and refrigerate; the moving shock wave in the gas wave tube is the key to cooling. If the shock wave is reflected to the open mouth of the gas wave tube, it will heat the expanded refrigeration gas at the open end, severely reducing the refrigeration efficiency. In order to reduce this effect, a Helmholtz middle wave chamber-type gas wave tube is presented here. This study describes the performance of this structure in the gas wave refrigeration process. The refrigeration performance of the structure’s gas wave tube use was evaluated experimentally and numerically using computational fluid dynamics (CFD). The function of the middle wave elimination chamber was studied and explained: the chamber turns the reflected shock wave back to the end section of the tube and converts part of the incoming shock wave to an expansion wave, which may counteract the reflected shock wave by escaping from wave elimination chamber. The experimental results showed that the structure increased refrigeration efficiency by about 2.9% (50 Hz), 2% (40 Hz), and 2.2% (25 Hz) at the corresponding ejection frequencies, and reduced the reflected shock wave intensity by 11%, which proves the high-efficiency energy dissipation performance and the significant increase in refrigeration efficiency of the Helmholtz-type gas wave tube.