Amirkabir University of Technology Amirkabir Journal of Mechanical Engineering 2008-6032 52 4 2018 09 14 Analysis and Simulation of Surge Phenomena in the First Stage of Axial Compressor of GE-frame 6 Gas Turbine Analysis and Simulation of Surge Phenomena in the First Stage of Axial Compressor of GE-frame 6 Gas Turbine 785 796 3074 10.22060/mej.2018.14183.5815 FA Saeid Nasiri University of Zanjan / Mechanical Engineering Department Esmaeil Poursaeidi University of Zanjan / Mechanical Engineering Department Ehsan Khavasi Mechanical engineering department, University of Zanjan Journal Article 2018 03 08 One of the important subjects in the analysis of compressor performance is estimating the surge limit. If the angle of attack changes for any reason, air jets separate from the blades and the cross-section area of the passing air becomes small and causes the alteration of the angle of attack in the next stage blades; this phenomenon is known as stall. When stall completed on a row, a pressure drop occurs at the rearward of that row. So, high-pressure air goes from the next row to the lower pressure area, which associated with a lot of noise and can cause the failure of the blades which is called surge. In this paper, the numerical simulation of surge in the first stage blades of the axial compressor of GE- Frame 6 gas turbine has been done. Simulations are done with a 34 degree angle of attack and k-ѡ 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 the 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. One of the important subjects in the analysis of compressor performance is estimating the surge limit. If the angle of attack changes for any reason, air jets separate from the blades and the cross-section area of the passing air becomes small and causes the alteration of the angle of attack in the next stage blades; this phenomenon is known as stall. When stall completed on a row, a pressure drop occurs at the rearward of that row. So, high-pressure air goes from the next row to the lower pressure area, which associated with a lot of noise and can cause the failure of the blades which is called surge. In this paper, the numerical simulation of surge in the first stage blades of the axial compressor of GE- Frame 6 gas turbine has been done. Simulations are done with a 34 degree angle of attack and k-ѡ 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 the 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. https://mej.aut.ac.ir/article_3074_639d79cc857a6c76c2723b7e014fccb0.pdf