叶顶间隙对高压涡轮动叶应力影响的数值研究

针对叶顶间隙直接影响高压涡轮动叶气动特性及结构可靠性的问题,对不同叶顶间隙下的涡轮动叶进行了气热耦合数值计算.通过对流体域与固体域在物理边界上能量的传递进行耦合计算,揭示了泄漏涡流运动对叶片所受温度、压力分布的影响规律,分析了叶片热应力、气动力变化对结构强度的影响.结果表明:随着叶顶间隙高度的增加,泄漏流速增加,热应力变化明显,叶顶间隙高度在0.3%~3.0%变化过程中,叶片最大等效应力增大2.6%.所得结果可为叶顶间隙控制提供理论依据.

Numerical investigation of effect of tip clearance on stress of high pressure turbine rotor

For the problem that tip clearance of the high pressure turbine rotors has a significant effect on the aerodynamic characteristic and structural reliability, numerical simulation based on conjugate heat transfer method of turbine rotors with different tip clearance sizes was performed. Coupled caculation of the energy transferred from physical interface between fluid and solid was made. The effects of leadage vortex flow on the distribution of temperature and pressure were presented, and the effects of thermal stress and aerodynamic stress on the structure intensity of blades were analyzed. It showed that, with the increase of tip clearance height, the leakage flow velocity increased and the thermal stress changed significantly. The maximum equivalent stress increased by 2.6% increase while the tip clearance height changed from 0.3% to 3.0%. The acquired results can provide a theoretical basis for tip clearance control.