Response of radiation driven transient burning of AP and HMX using flame modeling

The radiation driven response function (R _q ) for AP and HMX propellant was obtained and compared with experimental results by using a simple αβγ flame model rather than with detailed chemistry. For an AP propellant, the profile of heat release was assumed by the experimental data. The calculatedR _q shows a frequency shift of the peak amplitude to the higher frequency and a decrease in the maximum amplitude as radiation increases. In addition, it was found the increase in the total flux could enhance the mean burning rate`(r)]_b\bar r_b while the phase differences between the radiation and resulting conduction could consequently reduce the fluctuation amplitude Δy _b . Fortunately, this is the qualitative duplication of the behavior recently observed in the experiments of RDX propellants. For HMX, the response functionR _q has been calculated and showed a quite good agreement with the experimental data. Even though the fairly good agreement ofR _q with experimental ones, the unsteady behavior of HMX was not reproduced as the radiation input increased. This is due to lack of the material properties of HMX or the physical understanding of HMX burning at high pressure.