Effect of Oxidizer on the Combustion Performance of Boron-Based Fuel-Rich Propellant

Abstract

Different boron-based fuel-rich propellants were prepared by replacing part of ammonium perchlorate with different content of cyclotrimethylenetrinitramine, cyclotetramethylenetetranitramine, potassium nitrate, and potassium perchlorate. The burning rate of the propellants under different pressures was measured in the strand burner, the combustion temperature of the propellants under 1 MPa was measured by microthermocouple, and differential scanning calorimetry/thermogravimetric analysis experiments of the propellants in argon atmosphere were carried out. The experimental results show that the effect of each oxidizer on the burning rate of the propellant is different; cyclotetramethylenetetranitramine and cyclotrimethylenetrinitramine could increase the combustion temperature and the gaseous products, whereas potassium nitrate, and potassium perchlorate have the opposite effect. The composition of the combustion products under different pressures was calculated based on the minimization of Gibbs free-energy principle, and the results indicate that, although cyclotetramethylenetetranitramine and cyclotrimethylenetrinitramine could decrease the content of boron carbide in the combustion products, cyclotetramethylenetetranitramine and cyclotrimethylenetrinitramine have a lower effect on the heat release of boron because more boron nitride is produced during the combustion process; potassium perchlorate could decrease the content of boron nitride in the combustion products, obviously.