柴油喷雾撞击高温壁面的瞬态传热特性  

Transient Heat Transfer Characteristics of Diesel Spray Impingement on a High Temperature Wall

作　　者：郭镇瑶 张卫正[1] 靳爽 颜杰 石智成 原彦鹏[1] Guo Zhenyao;Zhang Weizheng;Jin Shuang;Yan Jie;Shi Zhicheng;Yuan Yanpeng(School of Mechanical Engineering,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学机械与车辆学院,北京100081

出　　处：《内燃机学报》2024年第6期481-488,共8页Transactions of CSICE

基　　金：国防基础产品创新资助项目(20242032906195).

摘　　要：通过瞬态测温技术对定容燃烧室中柴油喷雾撞击高温壁面的瞬态传热特性进行了研究.结果表明:初始壁面温度从250℃升高到550℃,壁面上传热模式由膜态蒸发转化为核态沸腾,进而转化为过渡沸腾,这种转化使表面热流密度和换热系数先增大后减小,且分别在440℃和400℃达到最大值.增大喷射压力、减小撞壁距离和环境温度有助于提高表面热流密度和换热系数.初始表面温度的升高增加了喷射压力和撞壁距离对传热特性的影响,但降低了环境温度的作用.以毕渥数和傅里叶数表示的量纲为1表面热流密度曲线形态高度相似,且揭示了喷雾撞击高温壁面过程中的内部传热机制.此外,建立了一种准确性高、适用壁面温度范围广的预测最大表面热流密度的量纲为1模型.The transient heat transfer characteristics of diesel spray-wall impingement on a high temperature wall in a constant volume combustion chamber were studied by transient temperature measurement technique.Results show that as the initial surface temperature increases from 250℃to 550℃,the heat transfer mode on the wall changes from film evaporation to nucleate boiling,and then to transition boiling.This transformation causes the surface heat flux and heat transfer coefficient first increases and then decreases,reaching maximum values at 440℃and 400℃respectively.Increasing injection pressure,decreasing impingement distance and ambient temperature can improve the surface heat flux and the heat transfer coefficient.An increase in initial surface temperature increases the effect of injection pressure and impingement distance on heat transfer characteristics,but reduces the effect of ambient temperature.The dimension of 1 surface heat flux expressed as Biot and Fourier numbers is highly similar.A dimension of 1 correlation was established to reveal the internal heat transfer mechanism of the spray-wall impingement.An accurate and wider applicable prediction dimension of 1 model was also established for predicting the maximum surface heat flux of the spray-wall impingement.

关 键 词：喷雾撞壁 高温壁面 表面热流密度 换热系数 

分 类 号：TK421.4[动力工程及工程热物理—动力机械及工程]