Influence of Propagation Velocity and Peak Pressure of the Rotating Pressure Wave on the Flow Characteristics of a Centrifugal Compressor

Abstract

Rotating detonation turbine engine represents an innovative advancement in the state-of-art gas turbines. When a rotating detonation combustor is coupled with turbomachinery, the rotating detonation wave propagates upstream toward the compressor, affecting its aerodynamic and overall performance. In the present study, a three-dimensional numerical simulation is carried out to study the flow characteristics of a centrifugal compressor with the presence of a rotating pressure wave (RPW) at the outlet based on the unsteady Reynolds-Averaged Navier−Stokes method. Effects of RPW propagation velocity and peak pressure are investigated. The results showed that the rotating pressure wave forms a forward propagating wave (FPW) in the compressor, interacting with the diffuser and impeller blades. In the diffuser, the peak pressure of the FPW initially decreases with a slight recovery. It then decreases rapidly in the impeller. Effects of FPW are distinct from those of the unsteady rotor−stator interaction. A decrease in the propagation velocity enhances the strength of FPW passing through the diffuser channel while lowering the peak pressure mitigates the influence of FPW on the compressor flow field. The FPW leads to the decline of the mass flowrate and the rise of the total pressure ratio. While the mass flowrate and efficiency rise with the increase of propagation velocity, the peak pressure decreases. The isentropic efficiency can increase by up to 2.8% under high propagation velocity and low peak pressure conditions.