电站轴流风机动叶异常偏转及失速状态下的叶轮应力特性分析

Static Characteristics Analysis of Rotor with Abnormal Blade Angle in Axial Fan Under Stall Conditions

基于N-S方程和Realizable k-ε湍流模型,采用数值计算方法模拟了某电站轴流风机相邻两动叶+9°异常偏转及失速工况下叶轮内部的非定常流场特征,并研究了动叶异常偏转及失速工况下的叶轮应力特性,研究结果表明,失速发生后,叶轮流道内产生一个大约占据一半流道的完整失速团;+9°异常偏转叶片能够减弱失速团带来的气动载荷扰动,但最大等效应力值增加幅度较大,降低了叶轮的安全系数;旋转失速发生后,正常叶轮和异常叶轮的最大等效应力均小于屈服强度,未达到屈服状态。

Based on N-S equation and Realizable k turbulence model, using the numerical method to study the unsteady flow characteristics in the impeller of an axial fan under two 2-9 degrees blade deflection in stall condition.And give a research on im- peller stress characteristics under moving blades abnormal deflection and stall conditions.The results show that there is a corn- plete stall cell which taken up about half of the impeller channel after stall.The ＋9 degrees abnormal deflection blade can atten- uate aerodynamic load disturbance caused by stall cluster, while reducing the safety factor of the impeller by increasing the max- imum equivalent stress.The maximum equivalent stress of normal impeller and abnormal impeller is less than yield strength af- ter rotating stall.