沙粒体积分数对离心泵磨损特性影响的数值分析

为了研究含沙水流条件下沙粒体积分数对离心泵磨损特性的影响,采用RNG k-ε湍流模型和SIMPLE算法,基于离散相模型(DPM)和Finnie塑性冲蚀磨损模型,沙粒粒子注入选用R-R分布拟合方法,对一比转数为196的单级单吸离心泵内固液两相流动进行全三维数值模拟．通过对比清水介质时泵外特性试验数据与数值模拟结果,验证了数值计算方法的可靠性．研究结果表明:随着沙粒体积分数的增加,离心泵过流部件的磨损强度逐渐增大,且磨损部位主要集中在叶片进口边、叶片背面、叶片工作面靠近叶片出口的位置以及蜗壳的第2断面和第4断面附近;随着沙粒体积分数的增加,沙粒运动轨迹逐渐趋于紊乱,离心泵的扬程和效率逐渐降低．

Numerical analysis of effect of sand volume fractions on erosion characteristics of centrifugal pump

In order to study the effect of sand volume fractions on erosion characteristics of the centrifugal pump in sand laden water flow, RNG k-ε turbulence model, SIMPLE algorithm, discrete phase model, Finnie ductile material erosion model, and Rosin-Rammler particle size distribution approach were employed. The full three dimensional numerical simulation about solid-liquid two phase flow in the single stage single suction centrifugal pump with a specific speed of 196 was carried out by using Fluent software, and the effect of wall roughness was taken into account. By comparing the test data of the external characteristics of fresh water pump to the numerical simulation result, the reliability of numerical calculation method was verified. The results show that with the increasing of sand volume fractions, the erosion intensity of the centrifugal pump increases gradually, and the key sand erosion position is concentrated on start side of blade, suction side of blade, pressure side of blade close to the blade outlet and the volute near the second section and the fourth section. Additionally, sand tracks tend to be mussy, and head and efficiency of the pump are decreased gradually.