连续流-离散法耦合的喷雾仿真分析

Spray Simulation on Continuous-flow and Discrete Coupling Method

液体雾化广泛应用于内燃机、燃气轮机、航空发动机、海水淡化、热交换设备、医疗设备等重要场景,由于使用条件与对象介质物性差异较大,很难抽象出通用性较强的流场分布与液滴破碎模型。针对实验过程中出现的喷雾圈层和破碎形式,提出采用欧拉-拉格朗日多相流模型方法,对喷孔内的流场和喷射后的破碎过程进行耦合仿真分析,探究了在喷嘴针阀运动过程中的孔内流场特性,探索了喷雾液滴速度分布与孔内流动之间的关系。通过搭建的低喷射压力环境下的可视化喷雾实验平台验证,耦合模型与实验现象在喷雾特性以及液核结构上有很好的兼容性,分析得出喷嘴内部扰动对喷雾的破碎起着重要影响,扰动的加剧导致喷射后的更适合使用离散液滴模型。

a general flow field distribution and droplet breakup model.Aiming at the spray“circling”layer and droplet breakup form in the experiment,the Euler-Lagrange multiphase flow model method was proposed to simulate the flow field in the nozzle and the breakup process after injection,to investigate the characteristics of the flow field in the nozzle during the movement of nozzle-needle valve,and to explore the relationship between the velocity distribution of the spray droplets and the flow in the nozzle.The coupled model and the experimental phenomenon have good compatibility in terms of spray characteristics and liquid core structure,as verified by the visualized spray experimental platform built in a low spray pressure environment.The analysis concludes that the internal disturbance of the nozzle plays an important role in the breakup of the spray,and the intensification of the disturbance leads to the more suitable use of the discrete droplet model after the injection.