Interactions of thermodiffusive instabilities and turbulence have been investigated by large-scale Direct Numerical Simulations (DNS) in this work. Two DNS turbulent premixed lean hydrogen/air flames performed a slot burner configuration at the same jet Reynolds number Re=11,000 Karlovitz Ka?15 using detailed chemical mechanism. Realistic transport models are employed one case, which features c...

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding ...

Soot volume fraction and number density in a turbulent diffusion flame burning kerosene/air were predicted using two approaches. The first used a conventional soot inception model based on the acetylene concentration and is referred to as the acetylene model. The second used a soot inception model based on the formation rate of three and two ring aromatics [1] and is referred to as the PAH ince...

The modeling and simulation of methane-oxygen combustion at high pressure requires a dedicated kinetic mechanism to obtain precise description the fuel decomposition. However, using detailed mechanisms literature in high-fidelity simulations, like direct numerical is not possible due cost. Accordingly, reduced chemical required, one proposed this study contains 17 species 44 reactions encompass...

An experimental study of the interaction of a planar diffusion flame with a line vortex is presented. A planar diffusion flame is established between two coflowing, equal velocity streams of acetylene diluted with nitrogen and air. A line vortex is generated on demand by momentarily pulsing one of the flow streams by way of electromagnetic actuation of a piston in the flow apparatus. The flame–...

The statistics of wrinkling flame front is investigated by the quantum field theory methods. We dwell on the WKB approximation in the functional integral which is analogous to the Wyld functional integral in turbulence. The main contribution to statistics is due to a coupled field-force configuration. This configuration is related to a kink between metastable exact pole solutions of the Syvashi...

We investigate numerically the combined effects of supersonic turbulence, strong magnetic fields and ambipolar diffusion on cloud evolution leading to star formation. We find that, in clouds that are initially magnetically subcritical, supersonic turbulence can speed up star formation, through enhanced ambipolar diffusion in shocks. The speedup overcomes a major objection to the standard scenar...

The effect of gravity and thermal expansion on the propagation of a triple flame in a horizontal channel. Combustion and Flame Submitted (2013). [3] Al-Malki, F and Daou, J. Triple-flame propagation against a Poiseuille flow in a channel with porous walls. Submitted (2013). [4] Daou, J. Strained premixed flames: effect of heat-loss, preferential diffusion, and the reversibility of the chemical ...

We consider the competition of the different physical processes that can affect the evolution of a flame bubble in a Type Ia supernovae — burning, turbulence and buoyancy. Even in the vigorously turbulent conditions of a convecting white dwarf, thermonuclear burning that begins at a point near the center (within 100 km) of the star is dominated by the spherical laminar expansion of the flame, u...

A time-resolved numerical analysis of combustion dynamics of double-base homogenous solid propellant in a rocket motor is performed by means of a Large-Eddy Simulation (LES) technique. The physiochemical processes occurring in the flame zone and their influence on the unsteady flow evolution in the chamber are investigated in depth. A five-step reduced reaction mechanism is used to obtain the t...