基于滑移网格研究双流道泵内非定常流动特性

为研究双流道泵内由叶轮/蜗壳相互作用引起的非定常流动特性，基于滑移网格和RNG湍流模型计算双流道泵内的非定常流动。计算结果表明：在一个周期内，随叶轮流道相对于隔舌位置不同，其内相对速度、静压及总压分布呈周期性变化；当叶轮流道靠近蜗壳出口侧时，相对速度、静压及总压分布规律性较强；喉部为蜗壳内循环流体与叶轮排出流体的混合区域，流动最为复杂；蜗壳内各监测点的静压呈周期性变化，远离蜗壳出口的监测点的静压脉动明显大于靠近蜗壳出口的监测点的静压脉动，且越靠近喉部的监测点的静压变化越大，非定常流动特性越强烈；与定常计算相比，非定常计算所得有效扬程更符合实际情况，大于实测扬程且相对偏差仅为10%。

Unsteady flow characteristics in double-channel pumps based on sliding mesh

To study the unsteady flow characteristics caused by interaction between the impeller and volute, the unsteady flow field of a double-channel pump was simulated based on sliding mesh and RNG turbulence model. It was found that the velocity and pressure distribution in the impeller changed periodically according to the relative position of the impeller channel to the tongue. When the impeller channel was near to the volute outlet, a more regular velocity and pressure distribution was observed. The flow discharged from the impeller mixed with the re-circulated fluid in the volute at the tongue, which exhibited obvious unsteady characteristics. Pressures on the calculation monitors in the volute change periodically. Pressure fluctuations on monitors far from the volute outlet were more obvious than those near to the volute outlet, and became more and more stronger as drawing near the tongue. Comparing with the steady simulation, the calculated averaged head by unsteady simulation is more accord with the reality, which is larger than the tested head with a relative deviation of 10%.