航空发动机叶片-机匣碰摩摩擦热效应仿真分析

Simulation Analysis of Friction Thermal Effect of Aeroengine Blade to Case Rub-Impact

为了分析航空发动机叶片-机匣碰摩摩擦热对叶片的影响,基于有限元法建立了叶片-机匣碰摩摩擦的热-结构直接耦合模型,分析了不同偏心距和转速对模型应力场和温度场的影响,并与未考虑摩擦热效应的碰摩模型进行对比。结果表明:当叶片与机匣之间发生摩擦时,需考虑材料参数随温度变化的影响;摩擦热主要分布在接触表面较小的区域,温度分布沿接触面向四周呈递减趋势,且温度梯度越来越小。并在该区域产生了较大的热应力;随着偏心距和转速的增大,叶片-机匣的摩擦热效应越发明显。在实际工程问题中,需考虑摩擦热效应对叶尖表面损伤的影响。

In order to analyze the friction thermal effect of aeroengine blade to case rub-impact on blade, a coupled thermal-structural model of blade to case rub-impact was established by using finite element method. The influences of different eccentricity and rotational speed on the stress field and temperature field were studied. The calculated results with friction thermal effect were compared with that without friction thermal effect. Results show that when the blade to case is under friction, the influence of the material parameter changing with temperature should be taken into account. Friction heat was mainly distributed in the small region of the contact surface. The temperature distribution expands around in descending tendency, and temperature gradient is getting smaller and smaller, and produced large thermal stress in the region. With the increase of eccentricity and rotational speed, the friction thermal effect of blade to case was more obvious. In practice, it is suggested that the friction thermal effect on blade-tip surface damage should be considered.