RP-3航空煤油替代燃料简化机理及其验证

Reduced mechanism of surrogate fuel for RP-3 aviation kerosene and verification

选定正癸烷作为RP-3航空煤油单组分替代燃料,建立了一种包含36组分62步基元反应的简化机理.并设计了本生灯预混预蒸发试验系统对RP-3航空煤油的火焰进行了试验研究.同时,采用两种已被验证的煤油简化机理(分别为23步和38步)及62步简化机理对本生灯预混预蒸发燃烧火焰进行数值模拟,并将计算结果和试验数据相对比.结果表明:在轴向,温度和CO_2体积分数呈先上升后下降的趋势,并且温度在距喷口轴向距离为0.020m时达到最大值;而O_2体积分数呈现下降后上升的趋势,并且距喷口轴向距离为0.025m时达到最小值.与38步简化机理和23步简化机理所获得的数据相比,在各工况下,62步简化机理计算所获得的火焰温度分布和O_2体积分数分布与试验数据能很好地吻合;同时,62步简化机理计算的CO_2体积分数分布与试验数据变化规律基本一致,而23步和38步机理的计算结果只能保持和试验数据变化趋势的一致性.因此,选定的正癸烷可作为RP-3航空煤油的单组分替代燃料,并且所获得的62步简化机理能在较大范围内反映RP-3航空煤油的燃烧性能.

N-decane was chosen as the surrogate fuel of RP-3 aviation kerosene, and a reduced mechanism （36 species and 62 steps） was established. A Bunsen burner with premixed pre-evaporation combustion was designed to study the combustion flame of RP-3 a viation kerosene. And two verified kerosene simplified mechanisms （23 steps and 38 steps respectively） and the 62 steps mechanism were used by numerical simulation. The numerical results were compared with the experimental data. Results show that, the distributions of temperature and volume fraction of CO2 first increase and then decrease in the axial direction, and the temperature reaches the maximum at axial distance from nozzle of 0. 020 m. While the volume fraction of O2 first decreases and then increases, the volume fraction rea ches the minimum at axial distance from nozzle of 0. 025 m. Compared with the 38 steps and 23 steps reduced mechanisms, the distributions of temperature and volume fraction of O2 are in good agreement with the experiment data when 62 steps reduced mechanism is applied. At the same time, the numerical results with 62 steps reduced mechanism can also well simulate the volume fraction of CO2, but the numerical results of 23 steps and 38 steps can only predict the change trend of the experimental results. Therefore, n-decane can be used as the surrogate fuel of RP-3 aviation kerosene and the 62 steps reduced mechanism can accurately predict the combustion characteristics of RP-3 aviation kerosene.