摘要
建立了汽油多组分油膜蒸发模型,并运用该模型对进气道喷射式汽油机冷起动首循环的气流运动、喷雾过程、油膜形成和发展过程、混合气形成过程及缸内燃烧进行了三维数值模拟,详细解析了油滴和油膜中每种组分的蒸发规律,给出了每种组分的浓度分布。模拟结果表明:冷起动时轻组分的蒸发主导首循环混合气的形成质量,中、重组分的蒸发情况仅起辅助作用;汽油的轻组分越多,燃料蒸发量越大,有利于形成稳定可靠的可燃混合气,改善缸内燃烧过程,提高起动稳定性;计算所得的缸压曲线与试验结果吻合良好,说明开发的多组分汽油蒸发模型具有较高的模拟精度。
An evaporation model for multi-component wall film was developed.Based on it the three-dimension numerical simulation on air flow,fuel spray,wall film behavior,mixture formation and combustion of the first cycle during cold starting in an actual PFI engine were conducted.The evaporation of each component in droplet and wall film was analyzed individually and the concentration distribution of each component was also obtained.Numerical simulation results show that the mixture formation quality during cold starting is dominated by the evaporation process of the light component.The middle and weight components have only a little contribution.The more the light component in the gasoline,the more the fuel evaporation fraction,and the more beneficial to formation of stable combustible mixture,consequently,engine combustion and starting stability are improved.The calculated cylinder pressure curves agree with the measured,thus proving the developed multi-component evaporation model for wall film has good accuracy.
出处
《内燃机工程》
EI
CAS
CSCD
北大核心
2011年第3期17-22,共6页
Chinese Internal Combustion Engine Engineering
基金
北京市重大科技项目"满足北京第四阶段排放标准的汽油组成与排放关系的研究"(D0405002040221)
关键词
内燃机
多组分
油滴
油膜
蒸发
冷起动
数值模拟
IC engine
multi-component
droplet
wall film
evaporation
cold starting
numerical simulation