中文摘要：

为研究柴油在O2/CO2氛围下的着火特性,提出了柴油表征燃料（正庚烷）在65%O2/35%CO2氛围下的着火延迟时间模型.该模型考虑到了O2和CO2对燃烧反应速率的影响,得到了温度和着火延迟时间的关系,推导出了着火延迟时间的计算公式,运用稳定状态法对正庚烷的基元反应进行缩减,计算了正庚烷在空气和65%O2/35%CO2氛围下的着火延迟时间;搭建了定容燃烧弹可视化试验系统,对柴油在空气和65%O2/35%CO2氛围下的着火过程进行了可视化研究;对试验所得的着火延迟时间、火焰浮起长度和燃烧压力变化进行了比较分析.结果表明：该着火延迟时间模型可以很好地模拟柴油在65%O2/35%CO2氛围下的着火过程,柴油在此氛围下的着火延迟时间变化非常明显,比在空气氛围下缩短了50%;柴油在此氛围下的火焰浮起长度短于在空气氛围中的;喷油压力的改变会对柴油的着火延迟时间及定容燃烧弹内的最大燃烧压力产生影响.

英文摘要：

To calculate the ignition characteristics of diesel fuel in O2/CO2 atmosphere, an ignition delay model was proposed for n-heptane in the atmosphere of 65% O2 and 35% CO2. The effects of 02 and CO2 on the chemical reaction rate were considered. Then, the relationship between the temperature and the ignition delay was obtained and the cal- culation formula of ignition delay time was also derived. After using the steady state method to reduce the chemical reaction process of diesel fuel, the ignition delay time of diesel fuel in the atmosphere of air and of 65% O2 plus 35% CO2 were determined respectively. Besides, a constant volume combustion bomb test system was established to visualize the ignition process of diesel fuel in the atmosphere of air and of 65% O2 plus 35% CO2 respectively. The ignition delay time, the flame lift-off length and the combustion pressure variation were compared and analyzed by the visualization tests. The Results show that the new ignition delay model can well predict the ignition process of diesel fuel in the atmosphere of 65% 02 and 35% CO2. In this atmosphere, the ignition delay time is 50% shorter than that in the air atmosphere and the flame lift-off length is also shorter. It is also found that the injection pressure has an effect on the ignition delay time and the peak combustion pressure in the constant volume combustion bomb.