Physics of alumimum particle combustion at zero-gravity

Abstract

Experimental set up for studying alunlinum particle combustion consists of a free-falling platform with the combustion chamber, ruby laser for particle ignition, apparatus for combustion parameters registrations and control system. Combustion of single aluminum particles of 185-35011~ in diameter was studied at pressures l-70atm in atmospheres Oz+Nz, CO2 and Oz+Ar under the condition of zero-gravity. The following parameters were obtained: times of particle combustion, values of aluminum oxide accumulated on burning particle surface, sizes of combustion zone, some characteristics of condensed products. It was found that amount of accumulated aluminum oxide depends on gas content and significantly increases when pressure increases. It was obtained that the aluminum oxide is porous for gases Oz+Nz and CO 2. Experiments showed that time of particle combustion does not depends on pressure and depends on initial alumunum particle diameter d as d1T5 in atmospheres Oz+Nz and CO* and as d2 in atmosphere Oz+Ar. Size distributions of high dispersed fraction of aluminum oxide in combustion products were obtained. The obtained data can be useful in modelling of aluminum particle combustion.