Full-annulus Numerical Investigation of Stall Mechanisms in a Compressor Without Tip Clearance
To investigate the stall mechanisms of compressor without tip clearance,a mixed-flow compressor rotor without tip clearance was studied using full-annulus unsteady simulations.A dynamical outlet pressure varying with time was given on compressor rotor outlet.The unsteady numerical calculative results showed that the compressor rotor has the characteristic of spike-stall.The fundamental flow mechanism was obtained by detailed analyzing flow-field in the process of throttling the compressor.The underlying mechanism is that there is no tip leakage flow but flow separation near rotor trailing edge.Further throttling the compressor rotor,for one thing,the flow separation circumferentially intensifies,for another,the flow separation point moves upward,which leads to serious blockage in the tip region.As a result,the radial vortex is induced by tip leakage flow and backflow stemming from the fluid in adjacent passages at the trailing edge results in rotor spike-stall.
万方数据
维普
