周向单槽机匣处理调控高压涡轮叶尖泄漏流的数值研究

Numerical Investigations on Tip Leakage Flow Control of High-Pressure Turbine with Single Circumferential Groove Casing Treatment

关键词:  高压涡轮  叶尖泄漏流  周向单槽  涡轮效率  数值模拟  非设计工况

Key words:  High pressure turbine  Tip leakage flow  Single circumferential groove  Efficiency of turbine  Numerical simulation  Off-design conditions

摘要:

为了验证周向单槽机匣处理调控高压涡轮叶尖泄漏流的效果，本文在GE-E³高压涡轮第一级的机匣上引入周向单槽式机匣处理，通过数值模拟手段研究了周向单槽的轴向位置、槽宽和槽深对叶尖泄漏流调控的影响及周向单槽调控叶尖泄漏流的物理机制。结果表明：周向单槽的引入虽然会使叶尖泄漏涡尺寸变大，但会显著降低叶尖泄漏涡及机匣通道涡的强度，使得涡轮转子通道内流动总损失降低，涡轮级效率提高。在设计工况下获得的最优结构参数的周向单槽，可以使涡轮转子通道内的流动损失相对减小9.10%，涡轮转子的效率提高0.40%，级效率提高0.85%。同时发现设计工况下获得的最优结构参数的周向单槽结构，在非设计工况时也有良好的控制效果。

Abstract:

In order to verify the control effects of single circumferential groove casing treatment on tip leakage flow in high-pressure turbine， the single circumferential groove casing treatment was introduced into the first stage of GE-E³ high pressure turbine. The control effects of different location， width and depth of single circumferential groove on tip leakage flow was studied by computational fluid dynamics. Meanwhile， the mechanism of the single circumferential groove controlling tip leakage flow was investigated too. Numerical results indicate that the single circumferential groove configuration will increase the size of tip leakage vortex，and it will diminish the intensity of tip leakage vortex and casing passage vortex significantly， thereby leading to a decrease in overall flow losses at rotor channel and a corresponding improvement in stage efficiency. The optimum groove structure obtained at the design condition can reduce the overall flow losses at rotor channel by 9.10%， meanwhile increase the turbine rotor efficiency and the stage efficiency by 0.4% and 0.85%， respectively. Furthermore， the optimum groove structure obtained at the design condition can achieve good control effect at off-design conditions.