在尾流激振情况下叶片振动应力预估技术

研究了前排静子叶片的尾流对后排转子叶片振动的影响.采用参数多项式方法和振荡流体力学理论, 求解静子叶片后的尾流场及尾流场作用下转子叶片通道内的非定常流场.把非定常气动分析给出的压力场, 转化为结构动力分析中的载荷压力场形式.根据试验结果得出响应分析中的阻尼, 先求解出各阶谐波作用下转子叶片的响应结果, 再把各阶响应结果进行叠加, 得到总响应.从流场求解到响应求解, 为工程应用初步建立起了一个尾流激振情况下叶片振动应力预估的半经验方法. 

Method to predict the blade vibration stress induced by wake flow

This paper aims at researching the influence of the wake flow from the stator vanes of the previous stage acting on the following rotor blades.The wake flow of stator vanes and the unsteady flow in the passage of rotor blades were solved by using oscillating fluid mechanics theory and parametric polynomial method.Then the aerodynamic pressure field obtained from the analysis of unsteady aerodynamics was transformed to the form of load pressure field which is suitable to the analysis of structure dynamics.The damping coefficient of response applied to the analysis was achieved from the experimental result.Thus,the response of each harmonic can be calculated first,and then the whole response can be achieved by superimposing the responses of all harmonics.From solving the flow fluid to solving the structure response,a semi-empirical method for engineering application was established to predict the vibration stress of blades induced by wake flow.