对角泵叶轮基本流态研究

Research on the basic flow patterns of diagonal impeller pumps

在介绍对角泵基本特征的基础上,运用计算流体动力学方法,对一组对角泵叶轮的基本流态进行了数值分析,对不同叶片夹角的对角泵叶轮纵断面、出口断面速度分布及叶片压力面静压力分布特性进行了定性比较和定量计算。研究发现,对应于不同的叶片夹角,对角泵叶轮的能量性能差异很大。轴流泵叶片对角布置后,离心力的作用使对角泵叶轮的扬程提高。与对应的轴流泵相比,对角泵的最优效率点向小流量方向偏移,高效区变宽。过大或过小的叶片夹角都不利于叶轮效率的提高,应通过优化设计确定最优夹角。计算结果表明,叶片夹角为150°的对角泵叶轮能获得较高的流量加权平均效率。随着叶片夹角和流量的减小,对角泵叶轮的功率不是增加而是减小,功率特性由轴流泵逐步向离心泵过渡。

The basic flow patterns of diagonal impellers at different diagonal angles are numerically simulated and an analysis is made on the velocity distributions on the longitudinal profiles and outlet section and the static pressure on the pressure side of blades. The analysis shows a great difference in energy performance for different angles. Work head of an axial-flow pump impeller increases under the action of centrifugal force if the blades are arranged in the diagonal direction, while the best efficiency of diagonal impellers occurs at smaller flow rates with a widen high efficiency zone. Thus a too large or too small impeller angle results in lower efficiency, and the best angle should be determined through optimization. This study also shows that a higher flow rate-weighted efficiency is achieved at a blade angle of 150 degrees. As the angle or flow rate is decreased, the pump power decreases rather than increases and the power characteristics shift from that of -xial-flow pump to centrifugal pump.