CFD investigation of an axial compressor with casing treatment for the enhancement of the stall margin

Casing treatment is an effcient technique which is used to increase the compressor stall margin with a minor reduction in the effciency. Various researches have indicated that the interaction between the blade passage and the groove is the main cause of the stall margin improvement. In this study a numerical study is conducted on a single circumferential casing groove using NASA rotor 37. The performance of the two circumferential groove models is studied by discretizing RANS 3D equations using a nite volume technique. The inception of the stall is predicted according to the criteria of convergence. Two models of the circumferential groove have been suggested and numerically tested. A single passage simulation is selected for the two models. The performance of the smooth casing and the two models are analyzed. Moreover, the stall margin, total pressure ratio and peak adiabatic effciency of the normal casing, and the two models are analyzed to determine the in uence of the groove on the axial compressor performance and stability. Models 1 and 2 stall margins are enhanced by 6.62% and 4.45% respectively. The adiabatic effciency of Models 1 and 2 is decreased by 0.79% and 1.08% respectively.