Experimental Study On Temperature Measurement And Combustion Characteristics Of Aluminum Particles In Solid Propellant

At present,aluminum powder has been widely used as additive in solid propellant to improve the energy density of propellant and the specific impulse of engine.However,the interaction mechanism of aluminum particles is complex under different environmental conditions.Therefore,the study of temperature measurement method and combustion characteristics of aluminum particles in solid propellant is of guiding significance for the optimization of propellant performance and improvement of combustion efficiency.Based on radiation imaging principle and image processing technology,this paper analyzes the radiation characteristics of aluminum particle in reaction zone.And the Monte Carlo probability simulation method is used to track the process of absorption,scattering and reflection of the radiation rays in space,realize analyzing and simulating the radiation transfer process in combustion chamber.Thus establishing aluminum particle temperature measurement model under the condition of the combustion chamber.And the feasibility of the method has been validated through simulation and NEPE high energy propellant combustion test.A start with the basic theory of radiation temperature measurement,the paper analyzes the radiation characteristics of AlO and other gas phase products during aluminum combustion.Based on the principle of invariability of the base function of the emissivity model and spectrum identification technology,the emissivity of logarithm polynomial model is determined,and then four wavelength temperature measurement model is established.And put forward a simple and effective multi-wavelength temperature measuring method,also the feasibility of the method has been validated through the actual measurement of aluminum base propellant combustion spectrum test.On the basis of summarizing the experimental study of ignition combustion process of solid propellant and metal particles,referring to the domestic and foreign methods of ignition combustion test of solid propellant and metal particles,combining the existing test conditions of this research group,the ignition combustion test system of aluminum solid propellant under closed conditions was designed and improved.The flame morphology of solid propellant and the process of aluminum agglomeration on burning surface were observed and analyzed by using high speed camera system.By using digital image processing technology,the position of combustion surface and particle profile are identified automatically,and the burning rate and the size distribution of agglomerated aluminum particles of solid propellant under different pressure are measured and obtained.Based on the temperature measurement method of radiation imaging,the surface temperature data of aluminum particles under different working conditions were obtained,and the influence of propellant formulation,pressure and particle size on the surface temperature of particles was analyzed.