DOI: 10.1615/ICHMT.2006.TurbulHeatMassTransf
ISBN Print: 978-1-56700-229-4
ISSN: 2377-2816
Numerical Modelling of Flame Products Propagation in the Non-Uniform Atmosphere
RÉSUMÉ
This paper is devoted to some aspects of the instantaneous heat release in an isolated volume in the nonuniform atmosphere, burning real oil deposit with impurity ejected during gas combustion. As mathematical model the full system of unsteady 3-D Navier-Stokes equations considered. For modeling of turbulence usual k - ε approach is chosen to which the equation for the passive impurity simulating soot distribution in an atmosphere added. The numerical solution of Navier-Stokes equation set based on combination of the operator-splitting technique or the fractional step schemes. The time step is divided on three subsets. First and second step is solution of convective part of equations subject to corresponding initial and boundary condition. The third step take into account the influence of viscous terms ( [1-3] ). The suggested numerical method is based on scheme of Lax-Wendroff combining 3-D generalization with dissipation obtained from the intermediate stage.
The generation of vortex field, formation of thermal and his evolution under the gravity forces obtained. Vortex field generation caused by the unsteadiness and buoyancy dynamics studied. Movement of the ascending jet in an atmosphere is investigated at presence of an intensive horizontal wind stream. The results of numerical predictions of burning flare products spreading in an exponential atmosphere presented. Two models of its distribution - laminar and turbulent considered. The flow structures analyzed. Characteristics for laminar and turbulent flame compared.