The Study Of Combustion Characteristics Of Solid Propellants Under Laser Radiation

The combustion characteristics and combustion law of SQ-2 propellant and HTPB propellant under the laser radiation were studied in this paper.The main contents as follows:(1)Through comparative test,the role of laser radiation in the combustion of the solid propellants was researched.The result showed that the burning rate of the solid propellants increased markedly under laser radiation.(2)The combustion process of SQ-2 propellant and HTPB propellant was studied by using high speed photographic technique.(3)The effects of some factors,such as laser power densities and environment pressure, on the combustion characteristics of the solid propellant were studied.Some rules about the combustion characteristics of SQ-2 propellant under laser radiation were obtained.It showed that the relation between the burning rate of SQ-2 propellant and laser power densities can be described two different slopes of lines which intersect together.The results showed that some factors,such as gasification,evaporation and carbonous layer which absorbs a portion of energy were main reasons induced a piece-wise function and the break point.It is because that a portion of energy lost before the radiant energy of laser reaches the combustion surface.The burning rate of the solid propellant increased accordingly as the pressure increased at the same laser power density.The position of the break point which corresponds in the relation between the burning rate and laser power density moves to right and up,however,the loss of laser power density decreased accordingly as the pressure increased.(4)Compared to the combustion of SQ-2 propellant under laser radiation,the combustion of HTPB propellant was more radical which accompanied dazzling flame at the same environment.A piece-wise function in the dependence of burning rate on the laser power densities can be successfully stated when the pressure is 0.3MPa and 0.6MPa.When the pressure is 0.1MPa,a linear function in the dependence of burning rate on the laser power densities can be obtained.Under the circumstance,the burning rate increased accordingly as the laser power density increased.However,the experiments showed that the flame which is much too dazzling would shadow the combustion surface.As a result,the position of the combustion surface is hard to confirm.(5)The combustion model under laser radiation was formulated.The values of combustion characteristics(q_g,Q_g &σ_p) and the values of chemical reaction characteristics of the condensed phase in the reaction(x,η,Q,Φ& Q_s) were calculated The results exactly correspond to the data obtained from the experiments.The reliability of the results calculated greatly depends on the accuracy of the initial parameters.