J. Phys. IV France 11 (2001) Pr6-331-Pr6-338
Direct numerical simulation of a laminar diffusion flame established over a horizontal flat plate in micro-gravity environmentH.Y. Wang, P. Corderio and P. Joulain
Laboratoire de Combustion et de Détonique, UPR 9028 du CNRS, ENSMA, Université de Poitiers, Site du Futuroscope, BP. 109, 86960 Futuroscope cedex, France
A numerical study of a laminar diffusion flame established over a horizontal flat plate in micro-gravity environment is performed. Three dimensional, time-dependent numerical solutions to the Navier-Stokes equations are used to simulate the experiments. In the experiment, fuel is injected through the burner and the oxidiser (air) is provided by a forced flow parallel to the surface. The experiments were conducted in a range of oxygen concentration from 23 to 30 % at two different wind velocities of 2.6 and 4 cm/s in a 5 s drop tower. Combustion process is described by a global one-step, finite-rate reaction given by the Arrhenius expression. Direct Numerical Simulation (DNS) is used to provid a detailed description of the transition process of the flame in micro-gravity environment. The model results show that after the imposition of the micro-gravity, a plume region is maintained momentarily due to the dominant inertia. The transition time is about 2.5 s for reducing the overall air flow velocity to that of the forced boundary layer flow. The model results reflect the qualitative features of the experiments.
© EDP Sciences 2001