基于CFD耦合现象学碳烟模型研究温度对碳烟生成的影响  

Investigation of Temperature Effect on Soot Formation on the Basis of CFD Coupling with Phenomenological Soot Model

作　　者：赵智超[1,2] 刘敬平[1,2] 何廷谱 付建勤 陈征[1,2] 李佳峰 

机构地区：[1]湖南大学先进动力总成技术研究中心,湖南长沙410082 [2]湖南大学汽车电子与控制教育部工程中心,湖南长沙410082 [3]伊利诺伊大学香槟分校机械科学与工程学院,美国厄巴纳61801

出　　处：《内燃机学报》2015年第3期224-231,共8页Transactions of Csice

基　　金：国家高技术研究发展计划(863)资助项目(2012AA111801);国家自然科学基金资助项目(51376057)

摘　　要：基于9步法现象学碳烟模型,根据4种情况考虑了碳烟表面氧化对碳烟数密度的影响,并将改进后的模型耦合到KIVA-3V Release 2程序中.应用该模型,对柴油在定容弹中不同初始温度(800、900和1,000,K)下的燃烧和碳烟生成进行了多维数值模拟,并通过对应的试验结果进行校准.结果表明:各工况下预测的碳烟生成过程与试验值能定性地吻合.随着初始温度降低,点火时刻推迟,燃烧持续期缩短,燃烧模式由扩散燃烧向预混燃烧转变,碳烟生成降低.低初始温度下,碳烟的生成和氧化机理均受到抑制,然而局部燃烧温度峰值的降低和高温区域的缩减并不明显,碳烟的降低主要由于高燃油当量比区域的缩减.On the basis of nine-step phenomenological soot model,the surface oxidation influence on soot number density was considered for four operating conditions. The revised phenomenological soot model was implemented into KIVA-3V Release 2 code,with which multi-dimensional computational fluid dynamics simulations were conducted to investigate the combustion characteristics and soot behavior of diesel spray combustion in a constant volume chamber,at different initial temperatures(800,900,1,000,K). Meanwhile,experiments were conducted under the same conditions to validate the model. Results indicate that ignition delay increases while combustion duration decreases with the decrease of ambient temperature,indicating the transition of combustion type from diffusion combustion to premixed combustion. Under lower ambient temperature,both soot formation and oxidation mechanism were suppressed,while local peak temperature and high temperature regions do not obviously decay. However,the area of local fuel-rich region shrank dramatically,directly causing the reduction of soot emission at low ambient temperature.

关 键 词：柴油燃烧 碳烟机理 现象学碳烟模型 定容弹 

分 类 号：TK421.5[动力工程及工程热物理—动力机械及工程]