质量不平衡对单叶片叶轮径向受力的影响

Influence of mass imbalance on radial force of single-blade impeller

为了寻找改善单叶片离心叶轮径向受力的方法,通过对一单端面配重的单叶片叶轮进行研究,在外特性试验验证定常数值计算精度的前提下,进行非定常数值计算,获得了单叶片叶轮的径向力矢量分布规律,发现设计工况附近,叶轮所受径向力的方向与叶片相对位置基本固定.基于整周期内径向力的矢量平均,获得平均径向受力的大小和方向.利用虚拟样机仿真技术,获得了质量平衡的叶轮,以及质量不平衡的叶轮;该叶轮的不平衡质量在旋转作用下产生的离心力,正好与平均水力径向力大小接近、方向相反.通过单向流固耦合仿真,发现偏心质量叶轮在实际运行中径向受力大幅度减小,证明了通过精确控制不平衡质量大小及相位角,减小和改善单叶片叶轮径向受力的方法是可行的.

To find a way to improve the radial force of single-blade centrifugal impeller,a single-blade impeller with single-end counterweight was studied.The unsteady numerical calculation was carried out on the premise of verifying the accuracy of the steady-state numerical calculation by hydraulic characteristic test.The radial force vector distribution of the single-blade impeller was obtained;and it was found that the direction of the radial force was fixed with the relative position of the blade near the design condition.Based on the vector average of radial force in the whole period,the magnitude and direction of the average radial force were obtained.By using virtual prototype simulation technology,the impeller with balanced mass and eccentric mass were obtained;the centrifugal force generated by the eccentric mass of the impeller under the action of rotation was just closed to the average hydraulic radial force and the direction was opposite.Through the unidirectional fluid-solid coupling simulation,it was found that the radial force of impeller with eccentric mass greatly decreased in the actual operation,which proved that the method of reducing and adjusting the radial force of single-blade impeller through mass eccentricity was feasible.