Numerical Simulation of Dynamic Stall Phenomena in Axial Flow Compressor Blade Rows

This article explores the simulation of stall phenomena in axial compressor blade rows. The approach is based on the numerical solution of the compressible, two-dimensional Navier-Stokes equations. The results of both unforced and forced low-speed rotor stall are presented. In unforced cases, substantial ow separation is observed before the maximum pressure rise operating point is reached. These unsteady separation events manifest as oscillations in blade lift and pressure rise, at frequencies within an order of magnitude of the blade passing frequency. The introduction of stationary perturbations to the free-stream reference ow creates disturbances in the out ow which propagate at speeds di erent from the blade speed. An assessment of the variations in forced response with disturbance length scale shows that low frequency propagating waves in axial ow velocity develop as the disturbance wavelength is increased.