Numerical and experimental study of the influence of incident relative deviation angle on the expansion performance of a gas wave machine.

The wave rotor is where the gas wave refrigeration process occurs. The high-pressure gas enters the wave rotor passage through the nozzle, providing the pressure energy required for expansion. This injection process is accompanied by irreversible flow loss. In previous studies, we learned that the energy transfer process can be optimized by introducing the incident angle of the curved oscillating tube or the nozzle angle. The inclined nozzle provides the pre-rotating tangential component, and the curved passage guides the gas to be rectified quickly. Although the two optimization methods have achieved the effect of energy recovery, the influence amplitude and synchronization on the refrigeration performance are different. There is a lack of research on the coupling relationship between the two analysis methods. Therefore, the angle between the direction of gas incidence velocity and the tangential direction of the rotor is defined as the relative deviation angle. The proposal of this coupling parameter can more accurately and concisely reflect the variation law of structural parameters and refrigeration performance. When the relative deviation angle is slight, the gas wave refrigerator shows more robust refrigeration performance. In the low back pressure area, the improvement effect of the relative deviation angle on refrigeration performance can be amplified. The appearance of high expansion efficiency requires a good fit between performance parameters and structural parameters.