A steady-state combustion modelling of composite solid propellants

By depicting the transfer of heat and combustion reaction to take place wit hin thin gas layers close to the propellant surface burning in a steady-sta te fashion, a mathematical equation has been deduced to describe the burnin g rate of solid propellant as a function of initial grain temperature and c hamber pressure. It has been also assumed that chemical reaction could take place in premixing-diffusing zone but were carried out mainly in the react ion-flame zone. All these phenomena taken place in each zone of combustion have been assumed to be steady-state. In the present investigation, the equ ation, gamma = k(.)(1/R(T-i + C))(n.)exp( -E-a/R(T-i + C))(P/z) is being pr esented and it is compared with experimental data. The proposed model has b een tested and evaluated vis-a-vis strand burner data for three different p ropellants based on CTPB, and it has been found that the deviation of the c omputed burning rates from the measured rates ranged up to 2%.