Influence of squealer tip on tip leakage flow in axial turbine

In order to reduce the tip leakage loss,a pressure-correction based,3-D Reynolds-averaged Navier-Stokes equations CFDcode with Reynolds stress model and wall function was used to simulate the effects of the passive control of a partial squealer tip around tip platform on the tip leakage flow in a turbine rotor.The effect of squealer tip with different rim heights and widths on the tip leakage flow was sequentially simulated.The results show that recirculation region appeared in the tip region and the rim near suction side could block the tip leakage flow,which decrease the tip leakage loss.The height of tip platform rim had more influence on the turbine efficiency,and it had an optimal value,where the turbine efficiency could increase by 0.13 percent.The rim width had less influnce on the flow field,but it made the cavum became large,so the turbine efficiency slightly increased.