Experimental Study for Effects of Straight Jets on Flow Field Structure in a Compressor Cascade

To understand the effects of excitation jets from straight hole on compressor cascade, experimental study was used with both flow field visualization methods and aerodynamic parameter measurement methods. The flow structure and aerodynamic performance of a linear compressor cascade were analyzed under both original case and the cases with excitation jets under positive attack angle. The results support the following conclusions. Three spiral nodes appeared on the blade suction surface under the original case without excitation, while the number of spiral nodes and the position of the nodes differed among the cases with excitation jets at different jet hole position. A separation zone that originated from the blade suction side existed on the endwall under the original case without excitation. With the arrangement of the excitation jet, horse shoe vortex appeared before the jet hole on the endwall. The development of the branches of the horse shoe vortex differed with different excitation schemes and showed different influences on the flow field structure. The excitation jet hole position played an important role on the management of the corner separation. The optimum case reduced the total pressure loss coefficient by 3.2% and increased the passage mass flow rate by 1.86%. Meanwhile, the number of spiral nodes on the blade suction surface was reduced to one and no wake was observed on the endwall. The over-turning near the endwall and the insufficient turning in the high loss zone at the outlet were also weakened. © 2020, Editorial Department of Journal of Propulsion Technology. All right reserved.