关键词: 叶尖间隙高度+;湍流度;叶尖泄漏涡+;雷诺数;数值仿真

Abstract: A pressure-correction based 3D Reynolds-averaged Navier-Stokes equations CFD code with Reynolds stress model or shear-stress transport model and wall function is used to simulate the effects of turbine parameters on the tip leakage flow and vortex in a turbine rotor.With different tip clearance heights and different turbulence intensities,the effects of Reynolds number on the tip leakage flow,especially on the efficiency,are sequentially simulated.The results shows that when the tip leakage flow comes out from the suction side,the total pressure increases.Effects of Renauld number are relatively sereve compared to that of tip clearance height and mainflow turbulence intensity,and effects of mainflow turbulence intensity are almost negligible in flow field.Low Reynolds number results in flow separation,which increases the aerothermal loss,so the efficiency decreases obviously.When Renaulds number is within the ranges shown in the paper,the efficiency decreases nearly by eight percent.

Key words: Tip clearance height+;Turbulence intensity;Tip leakage vortex+;Reynolds number;Numerical simulation