Investigation of pressure wave behaviors in the rotational speed effects on a pressure-exchange wave rotor

A wave rotor is suitable for compact and efficient pressure-exchange between gas flows. This work measured the circumferential pressure distribution of the rotor/stator interfaces and utilized a CFD method to simulate the unsteady pressure waves. The experimental and CFD results showed some slopes in the circumferential pressure distributions, and the slopes indicated the traces of specific unsteady pressure waves. Such traces varied regularly if the rotational speed varied within a range from −11% to +11% off the baseline value, but they were seriously disturbed if the rotational speed varied by −45% from the baseline value. It verified that a pressure wave in a wave rotor tended to keep its pressure ratio and propagation velocity unchanged if the rotational speed varied by a small extent, and that the pressure wave could not keep its propagation patterns if the rotational speed varied by a large extent. Because of the pressure wave behaviors, the wave rotor demonstrated specific regulations of the rotational speed effects on its operational states.