The Characteristics Of Ignition And Combustion On Base-Bleed Composite Propellant

The efficiency of Base-bleed unit mainly depends on the stability, consistency and high efficiency of the composite propellant. In this paper, the characteristic of ignition and combustion on a AP/HTPB composite propellant is studied, in addition, analyzing the characteristic of combustion on the propellant containing aluminum. The main work is as follows:(1) The specific heat and thermal conductivity is measured by the method of differential scanning calorimetry and quasi-steady heat conduction respectively. With the help of Scanning Electron Microscopy (SEM) along with image processing, the size as well as the size distribution of AP particle in the propellant is studied, which provides the basic data about the characteristic of ignition and combustion.(2) Implementing the experiment of ignition on a AP/HTPB composite propellant by applying Carbon-dioxide Laser; On the basis of the model of laser ignition about energetic materials, the ignition delay time of the propellant is studied at normal temperature and under 1 atm. The relationship between ignition delay time and ignition energy is given.(3) According to the burning rate pre-estimated model, the impact of burning rate and burning structure on the size of AP particle in the propellant is studied. The factor of burning rate on AP/HTPB composite propellant containing aluminum is discussed. An idea about multi-grain structure propellant is presented, which is expected to improve the efficiency of base-bleed unit.(4) Based on a kinetic model about the combustion of AP/HTPB composite propellant, the chemical reacting of gas component on the propellant is simulated by CHEMKIN. The finally adiabatic flame temperature and the species concentration of the product is studied.(5) The test devices used to collect and observe aluminum agglomeration on the process of combustion of AP/HTPB composite propellant containing aluminum particles are designed. The modeling method of the propellant based on random pocket theory is introduced. The combustion model of the condensed and gaseous phase is given, which is used to compute the size of aluminum agglomeration, but the further testing and numerical verification is need.Overall, the research results have important reference value for improving the formulations of the propellant and the efficiency of base-bleed unit in this paper.