Hybrid Reynolds-Averaged Navier-Stokes/Kinetic-Eddy Simulation of Stall Inception in Axial Compressors

A hybrid Reynolds-averaged Navier-Stokes/kinetic-eddy simulation turbulence model is used for the stall predictions in a transonic axial compressor stage. This hybrid Reynolds-averaged Navier-Stokes/kinetic-eddy simulation model solves Menter's k-ω-shear-stress-transport model near walls and switches to the kinetic-eddy simulation model away from walls. The kinetic-eddy simulation model solves directly for local turbulent kinetic energy and local turbulent length scales, thus alleviating the grid spacing dependency found in other detached-eddy simulation and hybrid Reynolds-averaged Navier-Stokes/large-eddy simulation models. The current methodology is used in the prediction of the performance map and the stall inception for the NASA stage 35 compressor configuration as a representative of a modern compressor stage. The present approach is found to satisfactorily predict the onset of stall. It is found that the rotor blade-tip leakage vortex and its interaction with the shock wave is the main reason behind the stall inception in this compressor stage.