多组分生物燃料液滴微爆的数值研究  

Numerical Study on Micro Explosions in Multi-component Biofuel Droplets

作　　者：李煜[1,2,3,4] 龚金科[2] 刘冠麟[4] 袁文华[1] 沈彩[3] 张彬[1,2] 李光明[1] 

机构地区：[1]邵阳学院机械与能源工程系,湖南邵阳422004 [2]湖南大学机械与运载工程学院,湖南长沙410082 [3]美国伊利诺伊大学厄巴那-香槟分校机械科工系,伊利诺伊厄巴那61801 [4]湖南涉外经济学院机械工程学院,湖南长沙410205

出　　处：《邵阳学院学报（自然科学版）》2016年第1期41-49,共9页Journal of Shaoyang University：Natural Science Edition

基　　金：国家自然科学基金项目(51276056;51176045;91541121);湖南省教育厅资助科研项目(13C492);国家留学基金委员会公派研究生项目([2013]3009)

摘　　要：文章开展了多组分生物燃料液滴微爆的数值研究.依据均匀成核理论来确定微爆的起始点,为阐述气泡成核后的长大过程,引入了修正的Rayleigh方程.气泡-液滴系统的液滴最终破碎模型是基于最小表面能的方法来得出的.在液滴破碎模型的基础上,提出了一种估算子液滴索特平均半径(SMR)的简单方法并将其与已知的有限实验数据相比较验证.之后分析了燃油组成比例和周边环境压力对微爆产生的影响,研究发现微爆起始点存在一个最优的燃油组成比例和环境压力,并且将生物柴油掺入乙醇-正十四烷与丁醇-正十四烷的混合燃料中有利于加强微爆.仿真结果表明典型柴油机实际工况下的生物燃料与柴油的混合物的二次雾化由于微爆的发生而能来实现,而这与实验结果相吻合.The Micro- explosion process in multi- component bio- fuel droplets is numerically studied in the paper and the homogeneous nucleation theory is introduced to determine the onset of micro- explosion. Then in order to describe the bubble expansion process,a modified Rayleigh equation is employed. A final breakup model of the bubble- droplet system is derived from the minimal surface energy approach. Based on it,a simple way of estimating the Sauter mean radius of the secondary droplets is proposed and verified against limited available experimental data. The effects of mixture composition and ambient pressure on micro- explosion are examined in this study. For the onset of micro- explosion,there exists an optimal fuel composition and ambient pressure. Besides,after adding biodiesel into both of ethanol- tetradecane and butanol- tetradecane blends,the possibility of micro- explosion can be increased. The simulation results,which is in accordance with the experimental ones,show that the secondary atomization of bio- fuel and diesel blends can be realized due to micro- explosion under typical operation conditions of diesel engines.

关 键 词：微爆 多组分 生物燃料 SMR 表面能 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]