Development of AP/HTPB based Fuel-rich Propellant for Solid Propellant Ramjet

TLDR: In this article, pyral was added as a metal fuel which resulted in propellants having higher burn rates and their density variations along the length were absent contrary to those without pyral.

Abstract: It is well known that reduction of Ammonium Perchlorate (AP) content in composite propellant reduces the burn rate of solid composite propellants. Below a certain level of AP content the propellant does not burn. This paper explores ways to enhance the burn rate of fuel-rich composite solid propellant. The methods employed to enhance the burn rate of the propellant in the study are 1) Use of pyral 2) Recrystallization of AP, 3) Method to add catalyst into the propellant and 4) Addition of AC with moisture. Pyral was added as a metal fuel which resulted in propellants having higher burn rates and their density variations along the length were absent contrary to those without pyral. Addition of AC with moisture in these propellants increases the burn rate pressure index. The highest burn rate achieved is 3.8 mm/s at 70 bar with the propellant comprised of AP (particle size < 15 μm) and nanosized catalyst.