Thermomechanical analysis of boron particle combustion in oxidizing atmospheres

A series of calculations of B/O and B/C/H/O system thermal equilibrium were conducted based on the Gibbs principle of minimum free energy. Some results were obtained. In B/O system, when B/O mole ratio is 2:3, the main gas phase boron contained products turn from B ₂O ₃(g) to BO(g) and BO ₂(g) with the rise of temperature. Improving the environmental pressure helps to increase the heat release of boron combustion. When the temperature is kept at 2400 K, B ₂O ₃ (g) and BO ₂ are the main products in poor fuel condition while B ₂O ₂(g), BO(g) and B ₂O ₂(g) are the major products in rich fuel condition. As to B/C/H/O system, B/G/H/O mole ratio is settled to be 2:1:2:6. The main combustion products are HBO ₂(g), GO ₂(g), H ₂O and B ₂O ₃ (g) when environmental temperature is relatively low and when ambient temperature rises, the major combustion products are GO (g), BO(g) and so on. It shows that high temperature is unfavorable for heat release of boron combustion. Like B/O system, improving the environmental pressure helps to increase the heat release of B/G/H/O system combustion. When the temperature is kept at 2400 K, HBO ₂ (g), B ₂O ₃ and BO ₂(g) are the main products in poor fuel condition while B ₂O ₃ (g), B ₂O ₂ (g), BO(g) and HBO(g) are the main products in rich fuel condition.