建立了航空煤油火焰脉动模型,并进行了数值模拟.根据航空煤油的活化能计算平均反应速率,参照火焰温度的实验测量结果,确定以最大燃烧化学反应速率0.077kg·m-3·s-1为航空煤油着火判据.通过对燃料蒸气浓度分布、速度矢量分布、反应速率分布和温度分布数值模拟结果的分析,将航空煤油火焰蔓延脉动过程划分为发展阶段和衰退阶段,并证明主火焰的着火方式主要包括扩散燃烧和预混燃烧,闪燃火焰为预混燃烧.建立了航空煤油火蔓延脉动频率预测模型.证明燃料初温低于闪点时,火焰脉动频率随T00.58正比增长;当燃料初温高于闪点时,脉动频率随T0正比增长.
A model was set up to describe the flame spreading oscillation on an aviation fuel oil pool.The chemical kinetic parameter was deduced by simulation,and,based on the measurement of flame temperature,the average reaction rates of flammable mixture were calculated and taken as a criterion for ignition.The large eddy simulation and mixture fraction model were applied to calculate the oscillations of aviation fuel flame spreading,and the pulsating of flame spread was divided into the development step and the fading step.The result indicated that there are mainly two combustion modes:diffusion and premix.The model for prediction of flame pulsating frequency was also established.