Direct Determination of Burning Velocity during Aluminium Flame Propagation

Abstract : Numerical simulations are needed to model accurately the consequences of dust explosions. One key parameter for modelling the flame propagation is the burning velocity (ie the consumption rate of the reactants by the flame front). Most of the methods used for experimentally determining this burning velocity are based on rough assumptions. In this paper, the determination of burning velocity during aluminium flame propagation is directly determined by the measurement of two velocities: the flame propagation velocity (ie flame front velocity in the laboratory referential) and the unburned flow velocity. Data of unburned flow velocity are obtained by Pitot tube and PIV (Particle Image Velocimetry) and are fairly close. An increase of burning velocity during aluminium flame propagation in the tube is observed. This increase is probably due to an increase of the turbulent intensity in front of the flame front during the propagation.