Development and validation of Navier-Stokes procedure for turbomachinery unsteady flow

Abstract

An unsteady viscous flow solver based on the Runge-Kutta scheme has been developed. Three low-Reynolds-number κ-e turbulence models have been assessed for their ability to predict unsteady transitional flow. The κ-e model has been modified to incorporate leading-edge effects. A pseudo time approach has been used to accelerate the numerical algorithm for unsteady flows. A sensitivity study has been carried out, including the effects of the artificial dissipation, the grid density, and the physical and pseudo time steps. The numerical simulation of the unsteady transitional flow in a compressor cascade has been carried out successfully. The numerical solver has been able to prediet major features, associated with the wake-induced transition on a compressor blade (wake-induced transitional strip, wake-induced turbulent strip, etc.). An analysis and an interpretation of the results from the unsteady flow simulation have been carried out to understand additional flow physics associated with the transitional flow