基于数值模拟的单叶片离心泵能量损失分析

Energy loss analysis of single-blade centrifugal pump based on numerical simulation

为揭示单叶片离心泵效率偏低的主要原因,采用数值模拟的方法对单叶片泵的能量损失进行了详细分析,建立了单叶片离心泵水力损失模型.基于SIMPLEC算法和标准k-ε湍流模型,利用Ansys CFX软件求解三维N-S方程,分析单叶片离心泵在不同流量工况下的湍流耗散损失和壁面摩擦损失,并搭建单叶片离心泵的外特性试验台,验证了数值模拟的准确性.结果表明:单叶片离心泵的能量损失形式主要为耗散损失和摩擦损失,并且泵内的耗散损失明显大于叶片摩擦损失;效率偏低的主要原因是耗散损失较大,具体表现为单叶片离心泵叶轮流道内存在明显的低速区及流动分离区,且压力呈圆周非对称分布;单叶片离心泵从其叶片进口处到出口处的耗散损失、摩擦损失均不断增大;耗散功率、摩擦功率占总功率百分比及叶轮水力效率呈抛物线分布.

In order to reveal the main reasons for the low efficiency of single-blade centrifugal pumps,a detailed energy loss analysis on single-blade pump based on numerical simulation method was conducted,and the hydraulic loss model of the single-blade centrifugal pump was established.Based on the SIMPLEC algorithm and the standard k-εturbulence model,the Ansys CFX software was used to solve and analyze the 3D N-S equation,the turbulent dissipation loss and wall friction loss of the single-blade centrifugal pump under different flow conditions.And a single-blade centrifugal pump hydraulic performance test bench was used to verify and establish the accuracy of the numerical simulation.The results show that the energy loss of a single-blade centrifugal pump is mainly dissipation loss and friction loss,and the dissipation loss in the pump is obviously greater than the friction loss of the blade.The main reason for the low efficiency is the large dissipation loss,which is manifested as single-blade centrifugal pump.There are obvious low-speed zones and flow separation zones in the impeller flow channel of the vane centrifugal pump,and the pressure is distributed asymmetrically on the circumference.The dissipation loss and friction loss of the single-blade centrifugal pump from the inlet to the outlet of the blade show an increase.The dissipated power,the percentage of frictional power to the total power and the hydraulic efficiency of the impeller are found to be distributed in a parabola.