Transonic Flow Analysis in Axial-Flow Turbomachinery Cascades by a Time-Dependent Method of Characteristics

Abstract

Solutions for transonic flow in cascades are determined by a second-order time-dependent method of characteristics using bicharacteristics. The analysis method is based on unsteady, two-dimensional, compressible, inviscid flow with steady-state solutions computed as the asymptotic limit in time of transient solutions. Two turbine cascade cases are presented. The first involves subsonic flow throughout the cascade; the second involves subsonic inlet and discharge flows with transonic flow over a portion of the cascade passage. In both cases, the computed results for blade surface pressure distribution are compared with experimental data. Generally good agreement is shown.