High‐Pressure Combustion Studies of Energetic Materials

TLDR: In this paper , the importance of visually observing the combustion process is used to explain slope breaks that appear in the pressure-dependent burning rates of liquid propellants, which are not predicted by current models.

Abstract: Pressure plays a significant role in determining the burning rate of a propellant. Experimental measurements of burning rates are essential for quantifying their magnitudes and defining their functional behavior with pressure, as predictive capabilities from theory and modeling are still not sufficient. Performing measurements over a wide range of conditions including extreme conditions and visually observing the combustion process are beneficial to the fundamental understanding of anomalies in burning rate behavior and to the development of models. There are various methods to measure burning rates, but visual observations have rarely been made above 7 MPa. In this chapter, high-pressure visually aided experiments and burning rate measurements of liquid and solid propellants are discussed and reviewed. The importance of visually observing the combustion process is used to explain slope breaks that appear in the pressure-dependent burning rates of liquid propellants, which are not predicted by current models. The reasons for these breaks can be due to physical and chemical phenomena, and in many cases, the measurements are not representative of fundamental intrinsic rates.