Large Scale Flame Acceleration Modeling by a New Combined Combustion Model

In a vapor cloud explosion، flame propagation phenomenon and turbulence flow field occur simultaneously. At the same time، the existence of obstacles in the flame propagation direction، leads to wrinkling of the flame front. The mechanism of flame wrinkling phenomenon occurs due to the effect of the flame-vortex interactions. Large scale vortices deform the flame front and increase its surface area. Increasing flame surface area ends in an increase of burning velocity and intensification of pressure build up. The major challenge in modeling of large scale vapor cloud explosion is calculation of turbulent flame speed. In this paper a combined model of Weller''s wrinkling factor transport equation and SCOPE3 model was utilized to calculate this parameter. The SCOPE3 model considers high intensity turbulence. Therefore،the combined model is suitable for modeling of the vapor cloud explosion in presence of significant obstacles. Numerical results also confirm the ability of this model to accurately predict pressure history