Combustion performance studies of aluminum and boron based composite solid propellants in sub-atmospheric pressure regimes

Pratim Kumar ^a,*, Mayank Varshney ^b, Aniket Manash ^c

a. Department of Aerospace Engineering and Applied Mechanics, IIEST, Shibpur, Howrah, West Bengal, 711103, India
         b. Indian Institute of Technology (Indian School of Mines), Dhanbad, Jharkhand, 862004, India
         c. Aryabhatta Center for Nanoscience & Technology, AKU, Patna, Bihar, 800001, India

Abstract: The aim of present study is to investigate the burning rate, ignition delay, and flame characteristics of ammonium perchlorate (AP)-hydroxyl terminated poly-butadiene (HTPB) [AP/HTPB] based composite propellants (CSP’s) in sub-atmospheric pressure regimes (13 kPa to 100 kPa). Several fuels and catalyzed were used to evaluate their effects on the combustion characteristics of AP based propellants in sub-atmospheric pressure regimes. In fuels, aluminum (Al) and boron (B) were selected as metallic and non-metallic fuel respectively. While in catalyst, butyl ferrocene (B.F.) and ferric oxide (F.O.) were selected as liquid and solid catalyst respectively. Apart from these, other ingredients that were used are di-octyl adipate (DOA), toluene di-isocyanate (TDI), and glycerol. The article throws some light on the burning rate and ignition delay properties for these new classes of prepared propellant samples. At sub-atmospheric pressures, all propellants are susceptible to irregular burning with the ejection of soot’s, fumes, and unburned particles. F.O. based catalyzed propellants can sustain its combustion up to the lowest pressure.

Keywords: AP/HTPB; Metallic/non-metallic fuel; Catalyst; Sub-atmospheric pressure; Burning rate; Base-bleed