An experimental and computational study of the flow in a transonic compressor rotor

Abstract

A comprehensive investigation of the flow field produced by an isolated transonic compressor rotor has been completed. This rotor has an overall diameter of two feet, an inlet hub/tip ratio of 0.5, a tip Mach number of 1.2 and a total pressure ratio of 1.65. The time resolved three dimensional exit flow produced by this rotor was experimentally measured with sufficient spatial and temporal resolution to determine velocity components and pressures inside individual blade wakes and in the surrounding flow. A numerical calculation of the steady inviscid three dimensional through-flow was computed using MacCormack's second order accurate time-marching scheme. Comparisons between the numerical solution, the exit flow measurements, and measurements of the intra-blade static density field obtained by gas fluorescence showed that the inviscid computation accurately models transonic compressor aerodynamics and rotor blade pressure distributions in the upstream portion of the passages, the viscous effects influencing mainly the downstream portions. It is felt that such a computation procedure has great potential as a compressor design and development tool especially when coupled with a suitable boundary layer analysis.