雷诺数对涡轮叶尖流场影响的数值研究

采用基于压力修正的三维计算流体力学程序，结合雷诺应力湍流模型和剪切应力传输湍流模型加壁面函数的方法，对某一轴流涡轮转子叶尖间隙流场进行了数值计算研究，详细计算了不同涡轮叶尖间隙高度和来流湍流度条件下雷诺数对涡轮转子间隙流场的影响，最后计算了转子效率。结果表明：当泄漏流流经叶尖时因为叶尖剪切力做功有块总压增大区；雷诺数带来的影响比湍流度和叶尖间隙高度带来的影响要大，湍流度的变化对流场影响不大；雷诺数对泄漏涡尺寸的影响不大，但低雷诺数会引起流动分离，带来损失，当雷诺数在文中的范围内变化时，效率下降近八个百分点。

Numerical simulation for effects of Reynolds numbers on tip leakage flows in turbine

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.