Effect of Aluminum Particle Size on Solid Rocket Combustion

Small particles of metals such as aluminum (Al) are often chosen as the fuel in solid rocket propellants because of their high energy density. Experimental conclusions have shown promising results for the use of nano aluminum particles to increase burning rates. Computational Fluid Dynamic (CFD) studies validating these experimental findings are limited. A numerical simulation comparing conventional and nano size Al particles is conducted using the Euler-Lagrange method in the CFD software Star CCM+. The model uses a multicomponent reactive gas flow to simulate the essential combustion reactions and an evaporation model to simulate the Al droplet evaporation. The simulation confirms the correlation between small particle diameter size on an increase in burn rate and combustion characteristics.