叶轮机械颤振稳定性的工程预测方法

Flutter prediction method applied in turbomachinery design

通过求解雷诺平均N-S方程并采用影响系数法,对三个基本正交模态的三维振荡涡轮叶片绕流问题进行了研究。结果表明数值模拟所得非定常气动力与实验吻合较好;基于刚体运动假设和模态叠加法,得到了可用于叶轮机械设计阶段颤振稳定性评估的稳定性参数图/气动阻尼图,即所有可能的刚体运动及其相应气动阻尼的关系图;通过对稳定性参数图/气动阻尼图的分析表明,在一定情况下振型对颤振稳定性有重要影响,应将其作为颤振稳定性设计的重要参数之一。

Numerical simulation of 3-D unsteady viscous flow around oscillating low pressure turbine cascade was carried out in the influence coefficient domain having one blade oscillating in various three-dimensional rigid-body modes,and the numerical result is in well agreement with the experimental data. Then the stability parameter map and the aerodynamic map were obtained,based on the assumption of rigid body mode and using mode superposition method. The stability map can be used to predict flutter in the aerodynamic design phase of turbomachinery. The mode shape has an important effect on flutter stability and it should be regarded as an important parameter in flutter stability design.