Self-acceleration and fractal structure of outward freely propagating flames

• Flame acceleration associated with development of the Landau-Darrieus hydrodynamic instability is studied by means of direct numerical simulation of the Navier-Stokes equations including chemical kinetics in the form of the Arrhenius law. The fractal excess for radially expanding flames in cylindrical geometry is evaluated. Two-dimensional (2-D) simulation of radially expanding flames in cylindrical geometry displays a radial growth with 1.25 power law temporal behavior after some transient time. It is shown that the fractal excess for 2-D geometry obtained in the numerical simulation is in good agreement with theoretical predictions. The difference in fractal dimension between 2-D cylidrical and three-dimensional spherical radially expanding flames is outlined. Extrapolation of the obtained results for the case of spherical expanding flames gives a radial growth power law that is consistent with temporal behavior obtained in the survey of experimental data.

Subject headings

NATURVETENSKAP  -- Fysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences (hsv//eng)

Keyword

Computational geometry

Computer simulation

Extrapolation

Hydrodynamics

Navier Stokes equations

Reaction kinetics

Cylindrical geometry

Fractal dimensions

Power law

Physics

Fysik

Publication and Content Type

ref (subject category)

art (subject category)