VANE-BLADE INTERACTION IN A TRANSONIC TURBINE .1. AERODYNAMICS

Part I of this article presents results of a computational investigati on of the effects of blade row interaction on the aerodynamics of a tr ansonic turbine stage. The predictions are obtained using a two-dimens ional unsteady Navier-Stokes code based on an explicit Runge-Kutta alg orithm and an overlapping O-H grid system. This code simulates the flo w in time-accurate fashion using nonreflective stage inflow and outflo w boundary conditions and phase-lagging procedures for modeling arbitr ary airfoil counts in the vane and blade rows. The 0-H grid provides h igh spatial resolution of the high gradient regions near the airfoil s urfaces and allows for arbitrary placement of stage inflow and outflow boundaries. Unsteady and time-averaged airfoil surface pressure predi ctions are compared with those from an older version of the code based on the explicit hopscotch algorithm and an O-grid system, and experim ental data obtained in a short-duration shock tunnel facility.