Results 261 to 270 of about 82,213 (306)
Some of the next articles are maybe not open access.
Detailed numerical simulations of cellular flames
Symposium (International) on Combustion, 1989Time-dependent, two-dimensional simulations of perturbed premixed laminar flames have been used to study the development of cellular structures in rich and lean hydrogen flames. The model includes detailed hydrogen-oxygen combustion with 24 elementary reactions of eight reactive species and a nitrogen diluent, molecular diffusion of all species ...
G. Patnaik +3 more
openaire +1 more source
On Disintegration of Cellular Flames
2003A three-dimensional reaction-diffusion model for premixed flames with radiative heat losses is studied numerically. In accordance with previous analytical predictions and two-dimensional numerical simulations, it is shown that cellular flames occurring in low Lewis number premixtures can propagate at heat-loss rates greater than the maximum that ...
L. Kagan, S. Minaev, G. Sivashinsky
openaire +1 more source
Sound Generated by Cellular Flames
1991It has been observed that flames propagating in tubes can spontaneously produce acoustic oscillations (Mallard and le Chatelier1). Rayleigh2 gave a general criterion for acoustic amplification by any local heat source: When heat is released locally and periodically in a gaseous medium, an acoustic oscillation is amplified if the oscillating components ...
Pierre Pelcé, Daniel Rochwerger
openaire +1 more source
2008
Laminar premixed flames exhibit cellular instabilities for sufficiently small Lewis-numbers. In the present article we study a modified Kuramoto-Sivashinsky-equation describing curved, cellular flames near the instability threshold. Pattern formation is strongly influenced by the sign of flame curvature.
openaire +1 more source
Laminar premixed flames exhibit cellular instabilities for sufficiently small Lewis-numbers. In the present article we study a modified Kuramoto-Sivashinsky-equation describing curved, cellular flames near the instability threshold. Pattern formation is strongly influenced by the sign of flame curvature.
openaire +1 more source
Flame Velocity of Cellular Flames at Low Lewis Numbers
Combustion Science and Technology, 2001The flame velocity of cellular flames at low Lewis numbers is numerically studied, based on the compressible Navier-Stokes equation including a one-step chemical reaction. The flame velocity of a cellular flame is always larger than that of a plane flame and increases as the Lewis number becomes lower. When the Lewis number is unity, the flame velocity
openaire +1 more source
Modal decomposition of hopping states in cellular flames
Chaos: An Interdisciplinary Journal of Nonlinear Science, 1999We use Karhunen–Loeve (KL) decomposition of video images from an experiment to analyze a spatiotemporal dynamic state, unique to cellular flames, referred to as a “hopping state.” Ordered states of cellular flames on a circular burner consist of one or two concentric rings of luminous cells.
Palacios, Antonio +2 more
openaire +2 more sources
Extinction and cellular instability of premixed tubular flames
Proceedings of the Combustion Institute, 2008Extinction and cellular instabilities are investigated in premixed tubular flames. A tubular burner has recently been designed and constructed to be capable of operating under a wide range of conditions that allow more accurate and detailed study of tubular premixed and non-premixed flames.
Yu Wang, Shengteng Hu, Robert Pitz
openaire +1 more source
The cellular nature of hydrodynamic flame instability
Physica D: Nonlinear Phenomena, 1990Abstract The nonlinear evolution of a weakly perturbed planar flame under the influence of the Landau-Darrieus instability is studied numerically. It is shown that in sufficiently small-scale systems spontaneous instability appears in the guise of a cusp-shape flame.
Gutman, S., Sivashinsky, G. I.
openaire +1 more source
Cellularization of 2-methylfuran expanding spherical flame
Combustion and Flame, 2019Abstract Flame instabilities in 2-methylfuran (MF) outwardly propagating laminar flames have been investigated experimentally and theoretically at the initial pressures of 1–4 bar, temperatures of 363–423 K and equivalence ratios of 0.7–1.4. The flame topography and the effects of flame instability on MF burning speeds have been examined.
Francis Oppong +5 more
openaire +1 more source
On disintegration of near-limit cellular flames
Physics Letters A, 2003A strongly non-linear geometrically-invariant model for the dynamics of near-limit cellular flame is proposed, where the flame evolution is governed by a system of equations for the flame interface and its temperature. The model generalizes its earlier weakly non-linear version pertinent to a mildly perturbed planar flame.
Michael L Frankel +2 more
openaire +1 more source