Flow Characteristics of Tip Injection on Compressor Rotating Spike via Time-Accurate Simulation

Abstract

The performance of gas turbine engines is often limited by compressor stall. Steady tip injection stall control technologies have demonstrated their effectiveness to increase the stable operating range of gas turbine engine compressors. To help understand the fluid mechanic processes of stall with and without stall control and how stall is mitigated by stall control technology, the establishment of a capability to simulate the flow details leading to stall would be extremely helpful. This paper presents results of the simulations of a high- speed single-stage axial compressor. These simulations show the evolution of rotating instabilities and range extension as a result of tip injection. The simulations are time-accurate simulations of the three-dimensional Navier-Stokes equations encompassing the full-annulus grid and are executed using high-performance parallel computing. Computed compressor characteristics are compared to experimental data. The general flow features of the compressor with and without tip injection at the onset of stall are presented using time- accurate pressure traces and visualized by a novel disturbance cell concept.