离心泵气液混输瞬态过渡过程水力特性研究

摘要

为研究离心泵进口管路因漏气而出现气液混输瞬态过渡过程的水力特性,采用Pro/E软件完成离心泵内部流道三维造型,利用雷诺时均N-S方程和RNG k-ε两方程及SIMPLEC算法,应用计算流体力学软件CFX对离心泵叶轮流道内的气液混输过渡过程的汽液两相湍流进行值模拟计算,并与试验结果进行对比.结果表明:离心泵发生含气量连续增大的气液混输过渡过程时,在离心力和惯性力共同作用下,叶轮进口的气泡相偏向叶片压力面的运动；叶轮流道内的气泡相的气体体积分数Cvol从零逐渐增加到一定值后急剧增加到最大值,缓慢下降到一定值保持不变；叶轮内部和出口处压力变化规律是先逐渐下降一定值后开始出现大幅度压力波动,而速度变化规律是逐渐变大到一定值后开始剧烈震荡.%In order to study the transient gas-liquid mixed flow hydraulic characteristics of centrifugal pump on the import pipeline leak, The Pro/E software were used for three-dimensional modeling of centrifugal pump chamber, the unstructured tetrahedral mesh, computational fluid dynamics software CFX, RNG k - e two-equation turbulence model, Reynolds time-averaged N-S equations and SIMPLEC algorithm was used for calculating the gas-liquid two-phase turbulent unsteady mixed flow transition process of centrifugal pump, the transient gas-liquid two-phase transition process of centrifugal pump was reserched on gas volume fraction continuously increases, the results show that numerical simulation results and experimental results of the change is consistent in trend. When the gas-liquid mixed flow transition occurs, bubbles phase flow line in the impeller deviation from the normal trajectory under the action of centrifugal force and inertia force, movement along the blade pressure surface, the gas phase volume fraction Cvol gradually increased from zero to maximum value rapidly in impeller, then decreased slowly to a certain value unchanged, the impeller and the outlet of centrifugal pump occur pressure fluctuations violently after the pressure decreased gradually to a certain value, the velocity occurred dramatically vibration after gradually increases to a certain value.