中文摘要：

为研究叶片不等间距对离心泵性能及压力脉动影响,以一比转数为132.7的离心泵为研究对象,基于转子自动平衡理论建立了3种叶片不等间距叶轮模型,并对模型泵全流场进行了CFD数值计算,获得了模型泵外特性、叶轮内流分布及蜗壳内压力脉动信息。利用外特性试验验证了计算方法的准确性,并对叶片不等间距与原等间距叶轮模型计算结果进行了对比分析。分析表明:叶片不等间距布置会使泵扬程降低,效率升高,且最小角间距越小,扬程下降越明显,效率上升越明显,但最小角间距为45°、50°、55°时,3个工况下的扬程、效率计算值变化幅度均保持在5%以内,满足设计要求;叶片不等间距布置后叶轮工作面附近的低速区更明显,且主要存在于较宽流道,最小角间距越小,低速区范围越大;叶片不等间距模型在145 Hz及其谐频处产生新的压力脉动峰值,一定程度上改善了压力脉动频谱平稳性,其中最小角间距为45°、50°的2种模型在此处的脉动量整体比叶频处脉动量还大。该研究结果可为离心泵优化设计提供参考。

英文摘要：

In order to analyze the effect of unequal spacing blade on the performance of a centrifugal pump, a centrifugal pump with specific speed of 132.7 was chosen as the research object. Three kinds of unequal spacing blade models were established based on automatic rotor balance theory, and the whole flow field in the model pump under 0.8, 1.0 and 1.2 times of designed flow was simulated by the computational fluid dynamics (CFD) method. Based on the simulation results, the performance, the internal flow distribution and the pressure fluctuation in the model pump were obtained. The performance experiments of the model pump were conducted in an open loop, which consisted of a reservoir open to air, a suction valve, a test pump, a discharge pipe, and a discharge valve. The test performance results were used to check the CFD results and they showed good agreement. Then the simulation results of unequal spacing blade models and the original equal spacing blade model were compared and analyzed in detail. The results showed that unequal blade spacing arrangement would reduce the pump head and increase pump efficiency, and the smaller the minimum angular separation, the more obviously the head declined and the efficiency increased. When the minimum angular spacing was 45°, 50° and 55°, the variation ranges of the head and efficiency under the 3 flow rates were all less than 5%, which could meet the design requirements. At the design point, the internal flow in each impeller model was more regular, and the flow from impeller inlet to outlet was very smooth. The velocity at impeller inlet was relatively low, and the velocity at exit was relatively high. Compared with the original model, there was a certain range of low-speed area near the pressure side of unequal spacing impeller, especially in the wider flow channel, which could result in a large pressure gradient and pressure pulsation. The smaller the minimum angular spacing, the larger the range of low-speed area. Compared with equal spacing model, in addition to BPF (bl