单介质螺旋离心泵能量转换机理

为了研究螺旋离心泵叶轮各段做功能力和能量转换机理,从理论上分析了流体机械内部的流体流动情况,应用欧拉方程,将流体在叶轮中的能量分为动压头和静压头来处理,为采用数值模拟来研究螺旋离心泵内部流动和叶轮各段的做功能力提供了理论基础.在欧拉方程的基础上,采用Navier-Stokes方程和标准的k-ε湍流模型对螺旋离心泵内部流场进行数值模拟计算.通过模拟具体探讨了设计工况下,选取单介质为清水,在叶轮的作用下流场的速度、压力等变化规律,并将螺旋离心泵叶轮的轮缘线和轮毂线分段取监测点,从所取监测点之间各段的动压头和静压头变化来研究螺旋离心泵内的能量沿叶轮包角的转换能力.结果表明:螺旋离心泵流体的能量主要是由螺旋段提供的,叶轮前部螺旋段起到了多级加能的作用,叶轮使流体完成了从轴向至径向的过渡,液流的轴向速度由大变小,径向速度则相反.

Energy conversion mechanism of screw centrifugal pump under single-phase

In order to research screw centrifugal pump impeller power capability and energy conversion mechanism, the internal flow in fluid machinery is analyzed theoretically. Based on Eulerian equation adopted, the fluid energy in the impeller was divided into the dynamic pressure and static pressure head, which provides a theoretical foundation for the application of numerical simulation on analyzing the internal flow and the acting ability of various impeller fragments. Navier-Stokes equation and standard k-ε equation turbulence model are used to simulate the screw centrifugal pump internal flow. Taking water as medium, the flow filed including pressure and velocity was simulated under design condition. The monitoring points were taken at screw centrifugal impeller tip and hub, and dynamic head and static head change at the segments between the monitoring points were obtained to analyze the energy conversion capability along the impeller. The results show that the energy of fluid of the screw centrifugal pump is provided by helical segments, and the front helical segments of the impeller played a multi-level role. The impeller makes fluid from axial to radial completion of the transition, in which fluid velocity of axial changes from large to small while radial velocity is vise versa.