斜流泵叶轮和导叶叶片数对压力脉动的影响

为了研究斜流泵叶轮和导叶由于动静相干作用(RSI)而引起的压力脉动规律,基于标准k-ε湍流模型、SIMPLEC算法和滑移网格技术,根据叶轮和导叶叶片数及其叶片厚度设计了多种计算方案,并对不同方案的斜流泵模型进行了非定常数值模拟.采用叶轮进口、叶轮出口和导叶内部布点监测压力的方法获得了压力脉动曲线,并基于时域图分析了叶轮叶片数、导叶叶片数及其厚度对斜流泵内部压力脉动特性的影响.数值计算结果表明:斜流泵叶轮叶片动静干涉对整个流场的压力脉动影响较大,叶轮叶片数越少,叶轮进、出口压力脉动幅值越大;在设计工况下,导叶内部的压力脉动波形主要受叶轮叶片数影响,而导叶厚度对导叶内部压力脉动影响较小.研究结论将为斜流泵的设计和稳定运行提供参考.

Influence of impeller and guide vane blade number on pressure fluctuation in mixed-flow pump

To investigate into the pressure fluctuation feature caused from the rotor-stator interaction between the impeller and the diffuser in a mixed-flow pump,the unsteady flow field in the pump with different numbers of blades in the impeller and the diffuser were numerically simulated based on the standard k-ε turbulence model,SIMPLEC algorithm and sliding mesh model.The pressure fluctuation data were acquired by monitoring fluid pressure at the points located at the impeller and diffuser.The influence of number of blades and blade thickness on the pressure fluctuation was discussed in time-domain.The results show that the number of impeller blades is the main factor causing pressure fluctuation in the whole flow field.The pressure fluctuation amplitudes in the inlet and outlet to the impeller is consistently increased when the number of impeller blades is reduced;while the pressure fluc-tuation at the impeller outlet and in the diffuser is less affected by the number of guide vanes.Those conclusions will provide a reference for hydraulic design of mixed-flow pumps and their stable operations.