液气射流泵内部流场的数值计算

通过闪频仪观测,泵内部流动可分为分层流、液滴流和泡状流.为了简化模拟和计算,将计算区域分为部分喉管和扩散管两块.对液气射流泵喉管内部射流流动,建立抛物型流动方程组,采用控制容积法将方程组离散,并用TDMA法求解;对扩散管内部泡状流,采用双流体模型建立液气两相流方程组,混合有限分析法离散,压力耦合半隐式方法(SIMPLE)求解.数值模拟获得液气射流泵内部流速分布.计算预测的射流碎裂位置与试验观测结果一致;壁面压力分布计算值与试验值吻合较好,趋势相近.计算结果能够较好地反映液气射流泵外部水力性能,为液气射流泵的优化设计与运行提供参考.

Numerical simulation of liquid jet gas pump

The complicated inner flow state of the liquid jet gas pump is numerically and experimentally studied.To simplify the problem,the computational domain was divided into two blocks: the pump throat and the diffuser.Jet flow in the throat was simulated by parabolic equations with the control volume method,and the equations were solved by tridiagonal matrix algorithm.In the diffuser,where the flow state is bubbly flow,equations were established by the two-fluid model,the discretization scheme was the hybrid finite analysis method,and the equations were solved by SIMPLE algorithm.The velocity distribution and the position where jet breakup takes place were obtained.The calculated wall pressure distributions were in good agreement with the experimental data,which shows that the simulation results can reflect the external hydraulic characteristics for the liquid jet gas pump.