中文摘要：

轴向力是影响透平稳定运行的主要因素之一,为了实现透平轴向力的定量求解,研究其轴向力受介质的影响和随介质的变化规律.以一个比转速为41的离心泵反转作液力透平为研究对象,选用清水和两相流含气体水作为介质,应用计算流体力学软件CFD,建立相对坐标系下的时均连续方程及N-S方程,采用Mixture两相流模型和SIMPLE算法进行数值模拟,得到泵在透平工况下的外特性和内部流场压力分布,计算出轴向力,解决了实际测量难以及浪费时间和资金等问题.在此前提下,研究透平在气液两相介质中,不同流量及气体体积分数对轴向力的影响和变化规律.结果表明：透平的轴向力在两相流介质中是随着流量的增大而增大;随着气体体积分数的增大先变大后减小.该结论对提高透平的稳定性和延长寿命具有重要意义.

英文摘要：

The axial force is one of the main factors that affects the stable operation of the turbine.In order to realize its quantitative solution,the influence of medium on it and its variation pattern were investigated.A reverse-running centrifugal pump with specific speed of 41 is taken as a hydraulic turbine-employing the object of investigation.Selecting fresh water and two-phase air-laden water as media and employing numeric fluid mechanics software CFD,the time-averaged continuity equation and Navier-Stokes equation in relative coordinate system are established.Two-phase flow model mixture and SIMPLE algorithm are used in numerical simulations to obtain the external characteristic and the pressure distributions in the inner flow field of the pump working under turbine condition.The axial force is determined and the problems such as the difficulty of measurement in practice,time wasting,and funds are resolved.On this premise,the effect of flow rate and gas volume-fraction on the axial force and its variation pattern of the turbine working with two-phase medium is investigated.The result indicates that the axial force will rise with flow rate in the two-phase condition,but it rises at first and then reduces with the gas volume fraction.This conclusion is of great significance for improving the operation stability of the turbine and its service life and extending its lifespan.