槽道射流及端壁抽吸对角区分离的组合控制研究

In order to optimize the flow separation structure on the suction surface of the blade and explore a better flow control method for corner separation, a diffusion stator cascade with large camber angle is selected as the research object. Afterwards, the original blade is treated with a full-span slot structure, and on the basis of which the end wall suction slot structure is set up before the slot outlet. At last, the performance computations and comparisons of the original cascade, full-span slotted cascade and combined flow control cascade are carried out at the constant Mach number of 0.7, when the incidence angle range is -8°~6°. The results show that the full-span slotted scheme can effectively eliminate the midspan boundary layer separation on the suction surface of the blade and suppress the corner separation, reducing the total pressure loss and enhancing the pressure diffusing capability for the original cascade. However, compared with the full-span slotted scheme, the combined flow control scheme can better suppress the development of the end wall secondary flow on the suction surface before the slot outlet, hence further eliminating the corner separation and optimizing the flow field near end wall. Therefore, the combined flow control scheme of end wall suction and full-span slot jet has stronger adaptability to wide incidence range, it can more effectively reduce the total pressure loss for the original cascade, broadening its available incidence angle range and improving its pressure diffusing capability.