Aluminum (Al) particles as a metal fuel are easy to agglomerate at the burning surface of composite propellants. The diameters of the agglomerated Al particles are larger than that of the initial Al particle. It is known that the luminous flames are nearly spherical in shape at the average diameter of the luminous flames. The heterogeneity of the gas phase influences the distance from the luminous flames to the agglomerated Al particles in the lateral direction of the plane surface. The gas phase composition influences the intensity of the brightness of the luminous flames.
luminous flame, brightness, mole fraction, aluminum particle, agglomeration