A method to reduce the fluid mass transfer loss of rotating jet: A kind of microstructure design and research for wave rotor refrigerator

Wave rotor refrigerator (WRR) is a device that uses compressed flow and pressure wave to produce low-temperature gas. When the high-pressure nozzle gradually approached the wave tube, two vortices are generated in the high-pressure gas incidence stage which caused jet mass transfer loss, which is an important factor that causes the loss of cooling efficiency of the wave rotors. By studying the utility of microstructures in fluid mass transfer field, a method for improving the cooling efficiency of WRR from the mesoscopic aspect has been proposed. The addition of microstructures has the effect of hindering the development of vortices in the tubes. The optimal size parameters of the microstructure were found, and feasible processing conditions were synthesized through numerical simulation. And then, a wave rotor with the microstructure was created, and a comparative test was performed. The results reveal that the rotor with microstructure efficiently undercut the vortices in the tubes and increased the expansion depth of the high-pressure gas, consequently boosting the WRR's cooling performance. With varying pressure ratios and rotational speeds, the approach has a gain impact. When the pressure ratio reaches 2.6 and the relative rotating speed reaches 2900 rpm, the isentropic expansion efficiency of this type of WRR can be boosted by up to 19.04 %, and the temperature drop is increased by a maximum of 3℃, which is significant for reducing jet loss and promoting efficiency for the wave equipment.