壁面温度和撞壁距离对柴油喷雾燃烧特性的影响  

Effects of Wall Temperature and Impingement Distance on Impinged Diesel Spray Ignition and Combustion Characteristics

作　　者：杨灿[1] 李庆旗 龚涛 成晓北[1] 王英达 Yang Can;Li Qingqi;Gong Tao;Cheng Xiaobei;Wang Yingda(School of Energy and Power Engineering,Huazhong University of Science and Technology,Wuhan 430074,China;Dongfeng Commercial Vehicle Technical Center,Wuhan 430074,China)

机构地区：[1]华中科技大学能源与动力工程学院,武汉430074 [2]东风商用车技术中心,武汉430074

出　　处：《燃烧科学与技术》2023年第4期373-380,共8页Journal of Combustion Science and Technology

基　　金：国家自然科学基金资助项目(51906077).

摘　　要：根据撞壁距离L与自由喷雾液相贯穿距L_(liquid)之比,将喷雾撞壁模式分为严重湿壁、轻微湿壁、临界湿壁、未湿壁.通过高温高压定容弹试验和OpenFOAM仿真,研究了高、低壁温条件下,4种喷雾撞壁模式对着火特性、火焰发展特性以及燃油分布特性的影响.结果表明:提高壁面温度可以促进喷雾着火及燃烧过程,且其促进作用随L/L_(liquid)增大而减小;高壁温条件下,一定程度的喷雾撞壁有利于油气混合和燃烧,低壁温条件下则相反.This study examines experimentally the interactions of wall temperature and impingement distance and their effects on the impinged diesel spray ignition and combustion characteristics in a modified constant-volume combustion chamber.Two wall temperatures of 570K and 800 K and four impingement distances that correspond to severe wall-wetting,slight wall-wetting,critical wall-wetting,and non-wall-wetting separately are tested.The results indicate that increasing wall temperature can promote auto-ignition and the following combustion process,denoted by shorter ignition delays and higher flame area and spatially integrated natural luminosity values,but the promotional effect generally weakens with the increase of impingement distance.When the wall temperature is high enough,the spray/wall impingement can accelerate the evaporation of fuel and its mixing with the entrained air,and decreasing the impingement distance will promote auto-ignition and combustion.The trend is basically the opposite in low-wall temperature cases where the cooling effect plays a leading role.

关 键 词：壁面温度 撞壁距离 燃烧特性 定容弹 OPENFOAM 

分 类 号：TK11[动力工程及工程热物理—热能工程]