Transition from Countergradient to Gradient Scalar Transport in Developing Premixed Turbulent Flames
Journal article, 2013

A simple model of turbulent scalar flux developed recently by the present authors is applied to determine the direction of the flux in a statistically planar one-dimensional premixed flame that does not affect turbulence and has self-similar mean structure. Results obtained in the case of statistically stationary turbulence indicate that transition from countergradient to gradient turbulent scalar transport may occur during flame development, as the peak mean rate of product creation moves to the trailing edge of the flame brush. In the case of decaying turbulence, the opposite transition (from gradient to countergradient transport) was simulated in line with available DNS data. In both cases, transition instant depends strongly on turbulence and mixture characteristics. In particular, countergradient transport is suppressed by an increase in the rms turbulent velocity and by a decrease in the laminar flame speed or density ratio, in line with available experimental and DNS data. The obtained results lend qualitative support to the model of turbulent scalar flux addressed in the present work. © 2012 Springer Science+Business Media Dordrecht.

Author

Andrei Lipatnikov

Chalmers, Applied Mechanics, Combustion and Propulsion Systems

Vladimir Sabelnikov

ONERA Centre de Palaiseau

Flow, Turbulence and Combustion

1386-6184 (ISSN) 1573-1987 (eISSN)

Vol. 90 2 401-418

Driving Forces

Sustainable development

Areas of Advance

Transport

Energy

Roots

Basic sciences

Subject Categories

Fluid Mechanics and Acoustics

DOI

10.1007/s10494-012-9425-9

More information

Created

10/8/2017