导叶时序位置对离心泵叶片载荷影响的数值模拟

采用结构化网格及SST湍流模型,对不同导叶时序位置下离心泵内部流场进行三维非定常数值模拟,并对模拟结果进行试验验证,研究时序效应对叶轮叶片和导叶叶片载荷的影响.结果表明:当隔舌大约处在2个导叶中间(cl0,cl5位置)时,蜗壳不对称作用对叶轮内部流场影响降低,叶轮叶片压力面载荷增大,叶轮做功能力较好; 当叶片逐渐靠近蜗壳隔舌时,蜗壳不对称作用对叶轮内部流场影响增大,叶片出口吸力面大于压力面载荷的位置逐渐向叶片中段偏移,导致叶轮做功能力逐渐降低; 导叶叶片载荷分布受导叶与隔舌相对位置的影响较为明显.当导叶叶片尾缘靠近蜗壳隔舌时,导叶叶片载荷出现吸力面大于压力面的情况.

Numerical prediction of clock effect of diffuser in volute on blade loading in centrifugal pump

Unsteady numerical simulations of internal flow field in a centrifugal pump in different clock positions of a diffuser related to the volute tongue were carried out by using structured-grid and the SST turbulence model and influence of clock effect on blade loadings in the impeller and radial diffuser was studied. The results show that with increasing flow rate the pressure loading on impeller blades and diffuser vanes is decreased gradually, indicating gradually reduced work done by the impeller. The pressure on the diffuser vane suction side is higher than on the pressure side due to influence of the volute tongue. When the tongue is located in the middle of two diffuser vanes, the pressure side of impeller blades is subject to a larger loading, suggesting the impeller has a better capability of working. When a diffuser vane is positioned closely to the volute tongue gradually, the region of the loading on the vane suction side being higher than on the pressure side in the diffuser is extended into the diffusion section from the spiral section. The pressure pulsation intensity in the spiral section increases gradually, however, the intensity in diffusion section is decreased steadily. This phenomenon indicates that the pressure pulsation intensity in the diffusion section is affected mainly by the volute tongue, but the intensity in the spiral section is done basically by the leading edge of diffuser vane.