Flame stability inside a cylindrical micro-combustor was studied. Considering occurrence of heat recirculation, the respective relations were written and with parameters such as motion speed of reactants, flame propagation speed and thermal conductivity of the combustor’s wall, flame stability and its location inside micro-combustor were studied. It was found that for each thermal conductivity ...

Various flame tracking techniques are often used in hydrodynamic simulations. Their use is indispensable when resolving actual scale of the flame is impossible. We show that parameters defining “artificial flame” propagation found from model systems may yield flame velocities several times distinct from the required ones, due to matter expansion being ignored in the models. Integral effect of m...

We present a numerical investigation of the cellular burning regime in Type Ia supernova explosions. This regime holds at small scales (i.e. below the Gibson scale), which are unresolved in large-scale Type Ia supernova simulations. The fundamental effects that dominate the flame evolution here are the Landau-Darrieus instability and its nonlinear stabilization, leading to a stabilization of th...

In this investigation, the structure of one-dimensional flame propagation in uniform cloud of volatile organic particles has been analyzed in which the structure of flame is divided into three zones. The first zone is preheat zone which is divided into three subzones itself. In first subzone (heating), particle cloud heated until the moisty particles reach to vapor vaporization temperature. In ...

where ~ = (Kp/rR ) '~ is the weighted nongreyness, K p and r R are the Planck mean and the Rosseland mean of the absorption coefficient, r = rM6 K is optical thickness, r M = (rprR)'/~ the mean absorption, 8 K the conduction flame thickness, P = 4o TM3/(~5 K) the Planck number, T M the adiabatic flame temperature, ~ the thermal conductivity, and w the albedo, the ratio of scattering to extinction.

Edge flames were investigated in a methane/O2/N2 counterflow diffusion flame burner. In a typical experiment, a stable counterflow diffusion flame in an axysymmetric configuration was perturbed by lowering the relevant Damköhler number slightly below the extinction value, Daext. As a result, the flame extinguished in the vicinity of the burner axis where conditions were uniform. An edge flame e...

The effects of H2 enrichment on the propagation of laminar CH4–air triple flames in axisymmetric coflowing jets are numerically investigated. A comprehensive, time-dependent computational model, which employs a detailed description of chemistry and transport, is used to simulate the transient ignition and flame propagation phenomena. Flames are ignited in a jet-mixing layer far downstream of th...

The combustion mechanisms of clouds of metal particles are addressed in this research. A microgravity environment was used to create a “stationary model aerosol” consisting of relatively large (100–300 mm diameter), initially motionless particles. The development of individual particle flames, motion of individual particles, and overall aerosol combustion process could be observed simultaneousl...

The structure and propagation properties of triple flames subject to buoyancy effects are studied numerically using a high accuracy scheme. A wide range of gravity conditions, heat release, and mixing widths for a scalar mixing layer are computed for ’upright’ and ’inverted’ triple flames (i.e, gravity pointed in parallel and in opposite directions of flame propagation). These results are used ...

The speed of propagation of a premixed turbulent flame correlates with the intensity of the turbulence encountered by the flame. One consequence of this property is that premixed flames in both laboratory experiments and practical combustors require some type of stabilization mechanism to prevent blow-off and flashback. The stabilization devices often introduce a level of geometric complexity t...