Numerical Prediction of Turbine Vane-Blade Aerodynamic Interaction

Abstract

A time-accurate analysis for turbine vane-blade interaction is presented. The analysis simultaneously solves the unsteady isentropic Euler equations in the vane and blade rows on a blade-to-blade surface of revolution. The equations are integrated on overlapped O-type grids using a rapid and robust explicit hopscotch algorithm. Vane and blade rows with unequal numbers of airfoils in each row are treated using a single passage model with phase-lagged periodic boundary conditions. Boundary conditions between the rows are set by a combination of bilinear interpolation and a reference plane method of characteristics. Nonreflective inflow and outflow boundary point calculation procedures are incorporated to ensure that outward-radiating planar waves pass out of the solution domain without reflection. Presented results for a turbine stage show significant effects of the interaction on the time-mean airfoil surface pressure distributions.