Experimental Investigation of Burning Rate of RDX/AP/Al/HTPB Nitramine Propellants

In this study, the combustion characteristics and burning rate of RDX/AP/Al/HTPB composite solid propellant were studied experimentally. Five different RDX-based propellant compositions have been formulated and the burning rate and calorimetric value were evaluated. The burning rates of RDX composite solid propellants increased with increasing RDX content. The data obtained from experimental tests indicates that increasing weight percentage of RDX in the formulation increases the pressure exponent and decreases the burning rate constant. The mentioned parameters related to the propellant without RDX compared with other formulations including RDX. The results show that the burning rate of the propellant without RDX at the constant pressure of 800Psi was 7.2 mm/s and as RDX content increased by 13.6%, the burning rate decreased to 5.5 mm/s. The relationship between the burning rate and RDX content was not linear. It was also found that the pressure exponent increased by increasing RDX content. As a result, the pressure exponent belonged to the based propellant was 0.22 that by increasing the percent of RDX to 13.6%, the pressure exponent increases up to 0.3.