无过载离心泵内部流场的三维数值模拟

Three-dimensional numerical simulation of internal flow field in non-overloading centrifugal pump

采用标准k-ε湍流模型和SIMPLEC算法,对最大轴功率值小于1.1倍的额定功率值的无过载离心泵进行数值模拟,得出叶轮内流道的压力和速度分布规律,为无过载离心泵的性能预测、水力设计及优化设计提供依据.根据泵进出口速度、压力分布规律,预测泵的能量特性曲线.结果表明,叶轮内工作面相对速度较小,背面相对速度较大;从工作面到背面,相对速度大小变化较大;从进口到出口,沿相对运动流线方向上相对速度变化不明显;叶轮内没有出现边界层分离;蜗壳几何结构的非对称性以及蜗壳与叶轮的相互作用是导致泵内流场不对称的主要原因.

By using standard k-ε turbulence model and SIMPLEC algorithm numerical simulation was conducted in connection with non-overloading centrifugal pump with maximal axial power being 1.1 times less than its rated power. Distribution patterns of pressure and velocity in the internal flow field of the pump were obtained, providing a basis for performance prediction, hydraulic design, and optimization design of the non-overloading centrifugal pump. Based on the distribution patterns of pressure and velocity at pump in let and outlet, the power performance curve of the pump was predicted. The result showed that the relative velocity on pressure surface of vane was relatively small in the impeller, the relative velocity on suction surface was relatively large, the change of relative velocity from pressure to suction surface was relatively great, the change of relative velocity from inlet to outlet of the impeller did not change obviously along the streamline direction in relative motion of the flow, the boundary layer did not separate from the impeller＇s vane, and the asymmetry of the volute＇s geometry structure and interaction between the volute and impeller were the main reasons that caused the asymmetry of the flow.