Experimental Determination of Aluminum Burning Velocity During Flame Propagation in a Tube

Abstract

Modeling the consequences of dust explosions is a challenging research topic. A key parameter of these models is the burning velocity, which represents the consumption rate of the reactants by the flame front. Especially, a relation between burning velocity and RMS (root-mean square) air velocity fluctuations has to be implemented in such models; RMS velocity fluctuations representing the turbulence of the fresh air flow in front of the flame front.This paper focuses on the experimental determination of this relation in the case of dust flames propagating in a tube. The most commonly used method is the “open-tube method”, which assumes a constant thermal expansion coefficient and the estimation of a 3D flame surface. These assumptions are discussed, and a new method is proposed, based on the measurement of the fresh flow velocity in front of the flame front. The corresponding optical setup implemented for analyzing aluminum burning velocity is then exposed. Analysis method for obtaining burning velocity and RMS velocity fluctuations is detailed. Finally, first results obtained are presented and commented.