Laminar diffusion flame in microgravity: The results of the minitexus 6 sounding rocket experiment

Numerical Evaluation Of The Influence Of Fuel Generation On The Geometry Of A Diffusion Flame: Implications To Micro-gravity Fire Safety

“…The studies summarized in the introduction [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24] show that three different parameters seem to affect the flow structure, the geometry of the plate leading edge, the fuel injection and thermal expansion induced by combustion. These three parameters will be studied systematically and the results described independently in the following sections.…”

“…x=X max , y=0, y=Y max and z=Z max , is that of a passive opening: ambient temperature, ambient pressure and zero velocity gradients. This set up has been chosen in order to stick as much as possible to experimental condition used by Torero et al [22] and Vietoris et al [11,24].…”

“…An early attempt to model these experiments numerically did not show separation of the flow [23] but the discrepancy was attributed to the assumption that the flow was of parabolic nature. By conducting experiments with PMMA in micro-gravity, Vietoris et al [11,24] showed that flow separation occurred for 284 free stream velocities greater than 0.1 m/s and was induced by an enhancement of radiative feedback generated by the glowing of soot. For lower velocities, the selfregulating nature of fuel pyrolysis serves to retain the original flow assumptions proposed by Emmons and therefore makes possible the use of this theoretical development to describe micro-gravity fires.…”

Effects of Gravity on Soot Formation in a Coflow Laminar Methane/Air Diffusion Flame

“…Thus, modeling the effects of gravity on soot formation is of significant importance for understanding the influences of buoyancy on soot processes and flame structure in general. More recently, Vietoris et al (2000) and Brahmi et al (2005) conducted studies of a diffusion flame established in a non-buoyant laminar flat plate boundary layer, which is closer to a fire scenario aboard a spacecraft. They focused on the visible emission of the flame and showed that for low velocity air flows the luminosity of the flame increased with the oxidizer velocity for both solid (Vietoris et al 2000) and gaseous (Brahmi et al 2005) fuels.…”

“…More recently, Vietoris et al (2000) and Brahmi et al (2005) conducted studies of a diffusion flame established in a non-buoyant laminar flat plate boundary layer, which is closer to a fire scenario aboard a spacecraft. They focused on the visible emission of the flame and showed that for low velocity air flows the luminosity of the flame increased with the oxidizer velocity for both solid (Vietoris et al 2000) and gaseous (Brahmi et al 2005) fuels. Legros et al (2006) extended the above studies to quantify the influence of the oxidizer velocity on soot concentrations showing that increasing the oxidizer velocity enhanced both soot oxidation and soot formation.…”