低比转速污水泵叶片包角对水力性能的影响

利用商用软件FLUENT 6.2,在双坐标系下,对雷诺时均N-S方程进行离散,采用标准的湍流模型和SIMPLE方法进行求解,对5种不同的叶片包角叶轮与同一个蜗壳的耦合流场进行了数值模拟,得出了低比转速污水泵叶轮与蜗壳内的压力和速度分布规律,为低比转速污水泵的性能预测,水力设计和优化设计提供了依据.包角为190°的叶片工作面流速分布优于其他包角叶片工作面的流速分布,且该叶轮在隔舌附近产生高压区的面积明显小于其他包角的叶轮,选择优化后包角为190°的叶轮试验并与泵外特性模拟预测结果进行了对比.结果表明：若不改变泵水力部件其他几何参数,随着低比转速叶片包角由小向大变化,泵的内流特性存在较明显的差异,泵效率存在极大值.

Study on performance of low specific speed sewage pump with different vane wrap angles

To study the coupling flow filed of impellers with different vane wrap angles in the same vo- lute, numerical simulations were performed for a sewage pump by using commercial software FLUENT 6. 2. The Reynolds-averaged Navier-Stokes equations was discretized, solved with standard k -~ turbulence model and the SIMPLE algorithm in double coordinate system. The pressure and velocity distributions both in impeller and in volute were gained providing basis for the performance prediction, the hydraulic design and optimal design of a low specific speed sewage pump. The velocity distribution on the side of the impeller with 190° vane wrap angle is better than with other vane wrap angles, and the pressure dis- tribution near the volute tongue of this impeller produces a certain obviously smaller high-pressure zone. Furthermore, the optimal scheme pump character gained experimentally was compared with simulating prediction. The results show that while other hydraulic geometrical parameters of a low specific speed sewage pump fixed, with the vane wrap angle adding, there exist significant differences of inner flow and a maximum value of pump efficiency.