具有蒸发喷雾过程的大涡数值模拟  

Large eddy simulation of evaporating spray

作　　者：单聪慧 徐宝鹏[1] 

机构地区：[1]大连理工大学能源与动力学院,辽宁大连116024

出　　处：《大连理工大学学报》2018年第2期111-117,共7页Journal of Dalian University of Technology

基　　金：大连理工大学重大项目培育基金资助项目(DUT17ZD307)

摘　　要：采用大涡数值模拟方法对不同气体密度条件下无蒸发和有蒸发燃油喷雾进行了数值模拟,重点研究喷雾形状、喷雾贯穿距离以及粒子索特平均半径的预测值与计算网格的相关性以及亚网格脉动速度对喷雾过程的影响.计算公式采用单方程亚网格湍流模型、ETAB破碎模型和基于粒子云的碰撞模型.在有无蒸发两种喷雾条件下贯穿距离和索特平均半径的预测值与实验值吻合较好,并实现了预测值与计算网格无关性.亚网格脉动速度对喷雾贯穿距离和索特平均半径影响较小,但是影响喷雾形状和粒子分布.具有蒸发的喷雾贯穿距离与无蒸发喷雾情况类似,但是由于蒸发作用,索特平均半径预测值表现出波动现象.Large eddy simulation approach is employed to simulate fuel sprays with and without evaporation under different gas densities,and emphasis is placed on spray shape,the grid dependency of predicted spray tip penetration and Sauter mean radius(SMR)and the effect of sub-grid scale(SGS)fluctuating velocity on spray process.The numerical formulation adopts single equation SGS turbulence model,ETAB breakup model and collision model based on particle cloud.The predicted spray tip penetration and SMR are in good agreement with experimental data,and grid-independent results are achieved for both non-evaporating and evaporating sprays.It is found that SGS fluctuating velocity has little influence to the predictions of both spray tip penetration and SMR,but affects the spray shapes and particle distribution.The predicted spray tip penetration behaves similarly for both non-evaporating and evaporating sprays,although the prediction of SMS shows more vigorous fluctuations for the evaporating case due to the effect of evaporation.

关 键 词：燃油喷雾 大涡数值模拟 蒸发 网格相关性 碰撞模型 

分 类 号：TK402[动力工程及工程热物理—动力机械及工程]