Results 111 to 120 of about 252,548 (168)

High-Lewis number premixed flame instabilities

2021
Lean premixtures of high-molecular weight practical fuels typically have an associated Lewis number (Le) in excess of one and are susceptible to diffusive-thermal instabilities depending on the heat loss and hydrodynamic strain. These instabilities may lead to incomplete combustion, an increase in undesirable emissions and complex pressure oscillations.
Yi Ma, Howard Pearlman
openaire   +1 more source

The Lewis number under supercritical conditions

International Journal of Heat and Mass Transfer, 1999
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Harstad, K., Bellan, J.
openaire   +3 more sources

The Lewis number in reacting systems

Chemical Engineering Science, 1966
Abstract A single diffusion coefficient, D ′ applicable to steady-state processes in both equilibrium and non-equilibrium, multicomponent reacting systems is presented. This diffusion coefficient can be used to define the frozen Lewis number in its conventional form.
Christopher C. Shih, David M. Mason
openaire   +1 more source

Fingering instability in nonadiabatic low-Lewis-number flames

Physical Review E, 1995
Employing the formal similarity between the dispersion relations for the hydrodynamic (Darrieus-Landau) and the diffusive instabilities at the quenching threshold, a phenomenological model for the nonlinear evolution of the near-limit premixed flame is proposed.
, Frankel, , Sivashinsky
openaire   +2 more sources

Lewis number effects on turbulent burning velocity

Symposium (International) on Combustion, 1985
Experimental values of turbulent burning velocities for propane, hydrogen and iso-octane mixtures with air are reported under conditions of high turbulence and high turbulent Reynolds number. The measurements were made by the double kernel method during explosions in a fan-stirred bomb, with four fans, capable of speeds of up to 10,000 rpm.
R.G. Abdel-Gayed, D. Bradley, M.N. Hamid, M. Lawes   +3 more
openaire   +1 more source

Lewis-number effects on edge-flame propagation

Journal of Fluid Mechanics, 2002
Activation-energy asymptotics is employed to explore effects of the Lewis number, the ratio of thermal to fuel diffusivity, in a one-dimensional model of steady motion of edges of reaction sheets. The propagation velocity of the edge is obtained as a function of the relevant Damköhler number, the ratio of the diffusion time to the chemical time ...
Nayagam, Vedha, Williams, F. A.
openaire   +1 more source

Anomalous lewis number effects in tribrachial flames

Symposium (International) on Combustion, 1989
Tribrachial (three-armed) flames are generated when a premixed flame propagates into a nonuniform mixture, and consist of a fuel-rich branch joined to a fuel-lean branch, with a diffusion flame trailing from the junction (the stoichiometric point). They are important in the context of ‘laminar flamelet’ models of turbulent non-premixed flames.
J. Buckmaster, M. Matalon
openaire   +1 more source

Diffusion Flame Calculations for Nonunity Lewis Number

Combustion Science and Technology, 1982
Abstract Numerical solutions for the problem of a free convection, diffusion flame burning on a vertical fuel surface have been obtained for Lewis number from 0·05 to 10. Results are presented for the effect of Lewis number on the temperature and concentration profiles and on the burning rate.
M. SIBULKIN, S. F. MALARY
openaire   +1 more source