AP/HTPB 复合推进剂低压燃烧特性数值研究

In order to study the combustion characteristics of AP/HTPB composite propellant at low pressure，a two-dimensional sandwich model was used for numerical simulation. A four-step kinetic mechanism was implemented into this model. This model assumed a homogeneous binder to represent the fine AP and HTPB，and took the average size of coarse AP as the size of pure AP. The unsteady non-planar regressing surface is considered. The simulation was carried out under the pressure of 0.02～0.08MPa，and compared with the simulation under high pressure （5MPa）. The results show that under low pressure，the heat transfer from AP to binder leads to the subsidence of the burning surface at AP/Binder interface，with the decrease of pressure，the subsidence degree increase. As the combustion progresses，the burning rates at various location of the burning surface tend to be the same and the shape of the burning surface does not change. The gas phase reaction under low pressure is premixed combustion，and the primary flame is the dominant reaction. The simulation results of burning rate at low pressure are similar to the experimental data，the pressure index is smaller than that at high pressure.