周向非均匀流动引起的转子动力学载荷分析

以轴流涡轮为分析对象,分析了流动沿周向分布不均匀的条件下涡轮转子受到的气动载荷。假设涡轮级内的流动沿周向呈1次谐波形式的余弦函数分布,考虑转子叶片叶顶间隙,利用双耦合激励盘模型描述叶片通道中的流动,采用谐波分析方法求得涡轮转子受到的气动载荷。分析了不同轴向位置处、不同非均匀流动参数的影响,讨论了转子偏心所产生的非均匀流动,给出了非稳态流动条件下的气动载荷。结果表明:1次谐波形式的非均匀流动会产生附加载荷作用于转子,从而影响转子的动力学性能;非稳态不均匀流动会影响附加载荷的大小,但不改变其在动坐标系中的方向。

Analysis of Rotordynamic Loadings from Circumferentially Non-uniform Flow

The dynamic loadings on axial turbine rotors were analyzed with circumferentially non-uniform flow conditions. Assuming the circumferential distribution of the flow could be expressed as a cosine function in the first harmonic form, the flow in the blade passage with blade tip clearances was described by two-coupled-actuator-disk model, and the dynamic loadings on the turbine rotor were obtained by the harmonic analysis method. The effects of several flow parameters in different axial positions were analyzed, and the non-uniform flow due to the eccentric rotor was discussed, and then the dynamic loadings were predicted under the condition of unsteady flow. The results show that non-uniform flow with the form of first harmonic can produce additional forces on the rotor, which may exert influences on the rotordynamic performance. The additional loadings can be affected by the unsteady non-uniform flow, which can't change their directions in the moving coordinate system.