民机废水系统气-液-固三相流流动特性仿真计算研究

Gas-liquid-solid three-phase simulation on water waste system

民机废水系统是保障乘员舒适性和个人卫生的重要系统,而废水系统管路气-液-固三相流动特性分析是其关键技术难点之一。通过对民用飞机废水系统进行研究,采用CFD-DEM模型对马桶底部和废水输送管路中的气-液-固三相流动过程进行仿真计算,对废水系统管路的气液固三相的流动形态和流动特性进行分析,得到了液相和固相的流动时间。结果表明:废水管路中固相和液相沿运动方向呈贴壁螺旋流动,并且气相速度大的区域湍动能越大,因此对于气-液-固三相流动而言,气相的运动占主导;截面平均速度气相最大,液相次之,固相最小;系统静压沿管路轴向不断下降,总压损失随时间不断减小。通过对民机废水系统流动性能的分析,为废水系统设计提供设计输入,具有指导意义。

Civil aircraft water waste system is an important system to ensure comfort and personal hygiene, and research on gas-liquid-solid three-phase flow characteristics of water waste system pipeline is one of the key technologies.This paper takes the civil aircraft water waste system as the research object.We used the CFD-DEM model to simulate the gas-liquid-solid three-phase flow process of water waste system.We analyzed the flow pattern and flow characteristics of the gas-liquid-solid three-phase of the water waste system pipeline, and obtained the flow time of the liquid phase and the solid phase.The results show that the solid phase and the liquid phase flow in the wastewater pipeline in an adherent spiral along the moving direction, and the greater the turbulent energy in the region with high gas velocity, so the gas phase motion is dominant for gas-liquid-solid three-phase flow;the average cross-section velocity is the largest in gas phase, the second in the liquid phase and the smallest in solid phase;the static pressure of the system continuously decreases along the axial direction of the pipeline, and the total pressure loss decreases with time.Through the analysis of the flow performance of civil aircraft wastewater system, this paper provides design input for the design of wastewater system, which has guiding significance.