气液脉冲两相流耦合激振数值模拟与试验

Numerical Simulation and Experimental Study on Coupled Excitation of Gas⁃Liquid Pulse Two⁃Phase Flow

提出了一种气液耦合激振方式,通过控制气路和液路交替产生的高压脉冲两相振荡流,利用其产生的激振力实现对液压系统管道内壁的污染物去除。首先,建立了高压脉冲两相流动力学模型,开发了气液脉冲两相流试验系统,利用Ansys Fluent模块进行数值模拟与仿真分析;其次,湍流模型采用k‑ε二方程模型,气液两相流采用流体体积函数(volume of fluid,简称VOF)模型,用Simple算法对双流体控制方程组进行迭代求解,对气液脉冲两相振荡流的压力场、速度场及流态进行了分析;最后,采用压力变送器和数据采集卡对气液入口处不同流体压力下管道中部的混合流体激振压力进行测量,对实测压力信号进行滤波,并与数值模拟进行对比。分析表明:混合流体激振压力随着进气口和进油口流体压力的增大而增大,变化趋势与数值模拟基本吻合;在气液交替混合过程中,随着通气时间的增加,混合流体激振压力逐渐增大。数值模拟和试验研究揭示了气液脉冲两相流的动力学特性,为气液两相流激振的可控性提供了理论依据和试验基础。

A gas-liquid coupling excitation method is proposed to remove the pollutant from the inner wall of the pipeline by the high pressure gas-liquid pulse two-phase flow,which is alternated through the gas path and the liquid path.The dynamic model of the gas-liquid pulse two-phase flow is established,and its test system is developed.The simulation is carried out by using fluent module in specialized software ANSYS,where the k-εtwo-equation turbulence model is considered,the volume of fluid(VOF)model is selected for the gas-liquid two-phase flow model,and the simple algorithm is used to solve the two-fluid control equations.Specifically,the pressure field,velocity field and flow regime of gas-liquid pulse two-phase flow is analyzed.Then,the pressure of the mixed fluid in the middle of the pipeline under different fluid pressures is measured by the pressure transmitter and the data acquisition card.The measured pressure signals are filtered and compared with the numerical simulation.It shows that the excitation pressure of the mixed fluid increases with the increasing mixed fluid pressure,and the measured pressure trend is basically consistent with the numerical simulation.It is also found that the excitation pressure of the mixed fluid gradually increased with the increasing ventilation time.The numerical simulation and experimental study reveal the kinetic characteristics of gas-liquid pulsed two-phase flow.So,it provides a theoretical basis and experimental study for the excitation pressure controllability of gas-liquid pulse two-phase flow.