Theoretical Prediction of Pressure Fluctuations in a Diffuser Pump based on Rotor-Stator Interaction Analysis

采用标准k-e湍流模型求解二维和三维非定常雷诺平均Navier-Stokes(RANS)方程，研究了扩散泵叶片与叶轮相互作用引起的压力脉动。采用任意滑移网格，在不近似叶轮叶片数比的情况下，对部件间相互作用的瞬变流动进行了全解。此外，还将二维涡量方法应用于扩散泵的整个级。将非定常数值计算结果与奇异点法计算结果和实验数据进行了比较。结果表明，采用k-e模型和涡量方法的Navier-Stokes程序能够预测扩散器内的压力波动。此外，广泛的数值研究找出了导致扩散器内压力波动的原因，并有助于了解扩散器泵中叶轮-扩散器相互作用的机理。

Two-dimensional and three-dimensional, unsteady Reynolds-averaged navier-Stokes (RANS) equations with standard k-e turbulence models were solved within a whole stage of a diffuser pump to investigate pressure fluctuations due to interaction between impeller and diffuser vanes. The arbitrary sliding mesh was employed for the full solution of transient flow due to the interaction between components without approximating the blade count ratio of impeller to diffuser. In addition, two-dimensional vorticity method was applied to the whole stage of diffuser pump. The unsteady numerical results were compared with ones calculated by singularity method and experimental data. As a result of the present study, the Navier-Stokes code with the k-e model as well as vorticity method is found to be capable of predicting pressure fluctuations in the diffuser. Further, extensive numerical studies identified sources contributing to the pressure fluctuations in the diffuser, and help understand the mechanism of impeller-diffuser interactions in the diffuser pump.