Leakage Assessment of Pressure-Exchange Wave Rotors

Abstract

Control of leakage within waw rotors is recognized as a key requirement for efficient operation. Previous studies suggest that experimentally observed perfonnance degradation is substantially due to flow leakage. This work presents a leakage model for predicting leakage-attributed performance degradation of four-port pressureexchange '":ave roto.rs more accurately than previous single-cavity leakage models. The methodology comprehensively considers the leakage paths of the entire device. It combines a wave-rotor quasi-one-dimensional computational fluid dynamics prediction code, experimentally validated for internal gas dynamics with the generalized How-circuit-modeling capability of a leakage-How network solver. The computational fluid dynamics program and the network solver step through a series of iterations by sharing common leakage information. ~pplication to a well-instrumented wave-rotor rig is brieHy summarized, providing important guidance for the Irnpro~ement of le~kage and performance. The new approach is anticipated to be useful in enhancing the design, operation, and efficiency of a broad class of wave rotors by better understanding leakage and hence designing sealing features to control leakage Hows.