叶片排干涉对叶片颤振和强迫响应影响的研究

 叶片排干涉对叶片颤振和强迫振动具有显著影响，采用多叶片排三维和二维半激盘模型对此进行了研究。分析表明，叶片排干涉效应与非定常扰动的传播特征及叶片相对轴向位置有关。对稳定性问题，能量法分析结果说明叶片排干涉使叶片更易失稳，但适当调整叶片相对轴向位置有可能提高叶片气动弹性稳定性。在由相邻叶片排尾迹诱导的强迫响应问题中，主要由阵风响应流场决定叶片的气动弹性行为，在亚共振模态下，占主导作用的势流阵风响应随叶片排轴向间距减小而迅速增强，故在叶轮机设计中，叶片排轴向间距不应低于一定的安全值，以免诱导过强的阵风载荷和叶片强迫响应

INVESTIGATION ON BLADE ROW INTERACTION EFFECT ON FLUTTER AND FORCED RESPONSE

In multiple blade row environment, neighboring blade rows interaction can significantly affect the aeroelastic stability and forced response of a blade row. A two dimensional semi actuator disk model of forced response and three dimensional semi actuator disk model of flutter in multiple blade row environment have been developed and used to investigate the above effect in this paper. Analyses shown that the blade row interaction effect is influenced by the characteristics of disturbance propagation and relative axial position of the blade row. By applying energy method to flutter analysis, it is shown that the effect of neighboring blade rows interaction is destabilizing, but, blade row aeroelastic stability can also be enhanced by properly adjusting the blade row relative axial position. To the problem of forced response induced by the wake of the neighboring blade row, the aeroelastic character of a blade row is mainly determined by gust response. To subresonant modes, potential gust response which plays a major role relative to vortical gust response is strengthened rapidly as blade row spacing is reduced, therefore, blade row spacing should not be designed to be less than a “safe” value, which is determined by blade aerodynamic load, flow angle, rotor speed and blade number ratio of neighboring blade rows, in order to avoid inducing too strong gust load and forced response.