Numerical Investigation for Effect of Tip Clearance on Aerodynamic Performance in Compressor Modeling Process

To reveal the effect of tip clearance on compressor performance during the scaled modeling process, the performance variation with different scaled model is numerically investigated by taking the first 1.5 stages compressor as the object. It is found that the performance of the scaled model is weakened if the tip clearance size is kept constant during the scaling process, resulting in a decrease of about 1.4%-3.38% for the peak variable efficiency and a decrease of 0.88%-3.17% for the pressure ratio of converted prototype. The influence of tip clearance on the flow field similarity is mainly concentrated in the flow passage area at the blade tip, resulting in a flow out of the similar conditions there. The flow field analysis indicates that with the increasing model shrinkage, the relative leakage flow rate of the tip clearance increases, the range of low-speed zone in the tip passage expands, and the radial influence range and intensity of leakage vortex also increase. This is the main reason for the aggravation of flow clogging and performance degradation after the scale modeling. The increasing model shrinkage ratio also facilitates weakening shock wave for the tip leakage flow. © 2021, Editorial Office of Journal of Xi'an Jiaotong University. All right reserved.