A consistent formulation of the G-equation approach for LES is developed. The unfiltered G-equation is valid only at the instantaneous flame front location. Hence, in a filtering procedure applied to derive the appropriate LES equation, only the instantaneous unfiltered flame surface can be considered. A new filter kernel is provided, which averages along the flame surface. The filter kernel is...

The dynamic behavior of freely propagating premixed flames with large Lewis numbers was computationally simulated using a sixth-order central difference scheme and non-reflective boundary conditions. Results in the linear stage of the instability growth show that the growth rate dramatically decreases with increasing Lewis number and that the large activation energy excites the pulsating instab...

Mesoscale internal combustion engines for a variety of new combustion system applications have dimensions that are far smaller than conventional macroscale engines, yet unlike true microscale engines allow significant mean flow and turbulence to be created in the combustion chamber by the injection process. The resulting flow allows minimization of the combustion time by augmenting flame propag...

Experiments have been carried out with extremely lean, quiescent propane-air mixtures to examine the behavior of irregular flame propagation and to examine the lean limits of flame propagation in a tube under microgravity. The microgravity technique achieved in a freely falling chamber is employed because the realizations of symmetrical flame propagations in a tube are possible. Experimental co...

Ignition, flame propagation and stabilisation have been simulated and analysed in a turbulent jet of non-premixed methane and air. The first order Conditional Moment Closure (CMC) turbulent combustion model was fully coupled with a Reynolds-Averaged Navier Stokes (RANS) flow simulation. A CMC model was developed to account for spark ignition. The over-prediction of turbulent flame propagation w...

        In the present study, the effect of random distribution of reactants and products on laminar, 2D and steady-state flame propagation in aluminium particles has been investigated. The equations are solved only for lean mixture. The flame structure is assumed to consist of a preheat zone, a reaction zone and a post flame zone. It is presumed that in the preheat zone particles are heated an...

In this work, the effects of the electric fields on the flame propagation and combustion characteristics of lean premixed methane–air mixtures were experimentally investigated in a constant volume chamber. Results show that the flame front is remarkably stretched by the applied electric field, the stretched flame propagation velocity and the average flame propagation velocity are all accelerate...