Clarification of Vortex Structure and Evaporation Process of Unsteady Spray and Analysis of Chemical Reaction of its Flame

非定常喷雾火焰的特点是产生烟尘。因此，从化学反应的角度分析火焰特性具有重要的意义。本学期对这类火焰的分析采用了以下方法：另一位研究者提出的火焰模型被应用到计算中。1、2、3、4环多环芳烃的生长量采用了其他研究者提出的模型进行计算。CHMKIN-III应用于初等反应的计算。采用SENKIN计算化学物质的浓度分布。根据稳定燃烧器火焰的实验结果给出了温度分布。环境气体为空气，初始温度为900 [K]，初始压力为8.3 [MPa]，当量比为4.0。燃烧保持在恒压下。以十六烷值为56的正庚烷为CI发动机的代表燃料。将这种燃料的结果与含氧燃料的结果进行了比较。通过上述方法得出的主要结论如下：a)能够计算出正庚烷的消耗、正庚烷热热解生成低不饱和烃、芳烃的生长以及主要物种的生产和消耗的顺序过程。b)与正庚烷相比，含氧燃料中低不饱和烃的数量减少了50[%]以上。值得注意的是，在含氧燃料的情况下，多环芳烃的减少是明显的。c)由于其分子结构的不同，含氧燃料的多环芳烃产量不同。

The special feature of the flame of unsteady spray is the generation of soot. As a consequence, it is very significant to analyze the flame characteristics under the standpoint of the chemical reaction.The analysis of this kind of flame was carried out under the following means in this term :1.The model of the flame proposed by the other researcher was applied to the calculation.2.The polycyclic aromatic hydrocarbon with 1, 2, 3 and 4 rings was calculated by use of the model of its growth proposed by the other researcher.3.CHMKIN-III was applied to the calculation of elementary reaction.4.SENKIN was used to calculate the profile of concentration of chemical species.5.The temperature profile was given by the experimental results of the steady burner flame.6.The ambient gas was air, the initial temperature was 900 [K], the initial pressure was 8.3 [MPa] and the equivalence ratio was 4.0. The combustion was kept at the constant pressure.7.N-heptane whose cetane number was 56 was referenced as the representative fuel for a CI engine. The results of this fuel was compared to that of the oxygenated fuel.The main conclusions through the means mentioned above are as follows.a)It is able to calculate the sequential processes of the consumption of n-heptane, the heat pyrolysis from n-heptane to lower unsaturated hydrocarbons, the growth to aromatic hydrocarbns and the production and consumption of main species.b)The quantity of lower unsaturated hydrocarbons in the case of oxygenated fuel decrease over 50 [%] comparing with case of n-heptane. It is notable that the decrease in the polycyclic aromatic hydrocarbons is distinguished in the case of oxygenated fuel.c)The production of polycyclic aromatic hydrocarbons of oxygenated fuel is differen due to its molecular structure.