非光滑表面离心泵叶轮的流动减阻特性

为了分析非光滑表面对离心泵性能的影响,基于仿生凹坑表面的减阻特性,将凹坑型非光滑单元体排布于离心泵叶片的工作面,建立具有非光滑表面的叶轮离心泵的流动减阻特性分析模型,通过RNGk-ε湍流模型对离心泵内部流场进行数值模拟,分析具有非光滑表面叶轮的流动减阻特性,研究不同流量下非光滑表面对叶片近壁面的速度分布、剪应力和离心泵内部流场的影响.结果表明:凹坑型非光滑表面能够降低因黏性阻力产生的叶轮扭矩,其扭矩的最大降幅为5.8%;非光滑表面能够有效控制叶片近壁面边界层的流体流动,减小叶片的壁面剪应力;凹坑型非光滑表面能够降低离心泵叶轮内部流体的湍动程度,减小湍动产生的能量耗散,使叶轮内部的流体流动更加稳定并提高离心泵的效率.

Characteristics of Non Smooth Surface Drag Reduction Influence on Centrifugal Pump Impeller

Abstract： To analyze the influence of non smooth surface on the performance of centrifugal pump, a non smooth surface centrifugal pump impeller calculation model with flow drag reduction effect was established based on the characteristic of bionic pit surface drag reduction. The internal flow field of it was numerically simulated through RNG k ε turbulence model, the flow regularity in non smooth unit cell was analyzed, and the near wall influences of non smooth unit cell on the velocity distribution, shear stress, internal flow field of the centrifugal pump were studied. The results show that the pit shaped non smooth surface can reduce the torque caused by viscous resistance by maximumly 5.8%. The non smooth surface well controls the near blade wall boundary layer flow and reduces the wall shear stress of the blade. The pit shaped non smooth surface can reduce the fluid turbulent flow in the centrifugal pump impeller, reduce the energy dissipation caused by the turbulent, make the fluid flow more stable in the impeller, and improve the efficiency of the centrifugal pump.