Abstract

One of the important subject in the analysis of compressor performance is estimating the surge limit. In this paper, the numerical simulation of surge in the first stage blades of axial compressor of GE-Frame 6 gas turbine has been done. Simulations done with 34 degrees angle of attack and k-ω (sst) turbulence model has been used. Obtained velocity vectors indicate that during the surge, the reverse flow which is the most important characteristic of surge occurs and the flow returns backward. Also, in this paper the coupled ordinary differential equations of pressure and flow changes for different values of the stability parameter B has been solved. It was found that for B = 0.6, which is less than critical value, rotating stall occurs and the pressure fluctuations damp after several fluctuations. While for B = 1.6, which is more than its critical value, a deep surge occurs and the pressure and flow disturbances fluctuate with constant amplitudes. These fluctuations of pressure and flow can cause fatigue or failure of the compressor blades.