RP-3航空煤油模拟替代燃料的化学反应简化机理

Reduced Chemical Reaction Mechanism of Surrogate Fuel

关键词:  点火特性  RP-3航空煤油  化学反应详细机理  化学反应简化机理  数值计算

Key words:  Ignition characteristics  RP-3 kerosene  Detailed chemical reaction mechanism  Reduced chemical reaction mechanism  Numerical simulation

摘要:

为了建立能适用航空发动机燃烧过程反应动力学计算的国产RP-3航空煤油的化学反应机理,在化学激波管中对国产RP-3航空煤油的着火特性进行了实验测量,获得了多工况下该航空煤油的着火延迟时间。根据RP-3航空煤油的化学组成及物理特性,提出了由正癸烷、甲苯与丙基环己烷(体积百分比为0.65/0.1/0.25)三种组份组成的模拟替代燃料,并形成了该替代燃料的化学反应详细机理。采用敏感性分析方法,对该详细反应机理进行了简化,形成了该替代燃料的简化反应机理。采用该简化机理对该替代燃料多工况下的着火特性进行了数值模拟,并与实验数据以及详细机理的计算结果进行了对比分析。结果表明,在不同压力与当量比下,RP-3航空煤油着火延迟时间的对数与着火温度的倒数呈直线关系,并且随着火温度、着火压力的升高以及当量比的降低,RP-3航空煤油着火延迟时间逐渐缩短；同时,在各工况下采用该简化机理计算得到的该替代燃料的着火延迟与详细反应机理的计算结果以及RP-3航空煤油着火延迟的实验值吻合良好。

Abstract:

In order to build the reaction mechanism of RP-3 kerosene which can be applied to kinetic simulate the combustion process in the aero-engine,the ignition characteristics of RP-3 kerosene were measured in a chemical shock tube and the ignition delay time of this kerosene at various conditions were gained. According to the chemical compositions and physical properties of RP-3 kerosene,a surrogate fuel includes n-decane,toluene and propyl cyclohexane(volume fraction is 0.65/0.1/0.25)was provided,and a detailed reaction mechanism for this surrogate was developed. Through sensitivity analysis,this detailed reaction mechanism was reduced and a reduced reaction mechanism was presented. The ignition characteristics of this surrogate fuel at various conditions were simulated using the reduced reaction mechanism,and the simulation results were compared with the experimental data and the calculated results by the detailed reaction mechanism. The results show that the correlation for the logarithm of the ignition delay time of RP-3 kerosene and the reciprocal ignition temperature is linear under different pressure and equivalence ratios,and with the ignition temperature and pressure increasing and the equivalence ratio decreasing,the ignition delay time of the mixture is shortening. At the same time,the ignition delays of this surrogate fuel computed by the reduced reaction mechanism under different conditions are agreed well with the calculated results by the detailed reaction mechanism and the experimental data of RP-3 kerosene.