关键词: 叶尖间隙高度+;叶尖泄漏涡+;被动控制;数值仿真

Abstract: In order to reduce the tip leakage loss by means of the injection active control measure in tip platform,a dense-correction based,3D Reynolds-averaged Navier-Stokes equations CFD code with Reynolds stress model and wall function was used to simulate the effects of the passive control of a partial squealer tip around suction side on the tip leakage flow in a turbine rotor.With different rim height in a squealer tip,the effect of squealer tip on the tip leakage flow,especially on the efficiency,was sequentially simulated and compared with the baseline flow without partial squealer tip.The results show that the passive control on tip leakage flow using a partial squealer tip around suction side can increase the turbine efficiency relative to that of the baseline flow with equivalent relative tip clearance height.The height of suction side rim has more influence on the turbine efficiency,and the increase of rim height can result in the increase to turbine efficiency relative to that of the baseline flow field with equivalent absolute tip clearance height.Recirculation region formed by the blockage on tip leakage flow exists in the former half of the tip platform near the rim,while it disappears in the later half of the tip platform.

Key words: Tip clearance height+;Tip leakage vortex+;Passive control;Numerical simulation