| The present work focuses on the numerical simulations of spherical flames and on the investigation of various aspects of these flames, especially on flame movement, flame radius, speed of propagation, flame stretching and diameter of cell formed on flame front after a critical flame size. These simulations were successfully used to gather a more detailed insight in the behavior of spherically expanding flames. The ignition is expected to be controlled, at least for lean mixture of heavy fuel by the existence of an unstable equilibrium spherical radius 'r'. The critical radius 'rc' is calculated as a function of various physiochemical parameters together with a characteristics evolution time 't' of the flame. We provide an expression for the critical flame radius and show its dependence on thermal expansion coefficient and on the Lewis number. (Abstract shortened by UMI.)... |
