HTPB固体燃料冲压发动机流场仿真与燃速分析

基于守恒方程建立了固体燃料冲压发动机燃速仿真模型,采用二维轴对称模型和二方程化学反应模型开展了HTPB(端羟基聚丁二烯)固体燃料冲压发动机流场数值仿真,分析了不同空气来流条件对流场分布及燃速的影响.结果表明:火焰层在氧气和固体燃料壁面之间形成,随着来流空气流量和空气总温的增加,火焰层厚度变薄并向固体燃料壁面侧移动;随着发动机轴向位置的增加,燃速先迅速增加后缓慢增加,最后在补燃室附近快速减小,变化趋势与文献中试验结果吻合较好;固体燃料平均燃速随来流空气总温及发动内空气流率的增加而增大,并根据仿真结果拟合得到了燃速公式. 

Flow field simulation and fuel regression rate analysis of HTPB solid fuel ramjet

A fuel regression rate simulation model of solid fuel ramjet was constructed based on the conservation laws. With two-dimensional axisymmetric model and two-equation chemical reaction model, numerical simulations of HTPB (hydroxyl terminated polybutadiene) solid fuel ramjet flow field were performed and the influences of inlet air conditions on flow field distributions and fuel regression rate characteristics were analyzed. Results show that combustion flame layer is developed between the central oxygen region and solid fuel wall. The thickness of the combustion layer decreases and shifts toward the fuel wall with the increase of inlet air mass flow rate and total temperature. With the increasing axial location, the fuel regression rate increases sharply first and then increases slowly. At last, the fuel regression rate decreases quickly near the aft-mixing chamber. This trend matchs well with the experimental results of the reference. The average fuel regression rate increases with the increase of inlet air total temperature and air mass flux. An average fuel regression rate formula is fitted with the simulation results.