Analyzing the effect of free stream turbulence on gaseous non-premixed flames

Abstract

The effects of free stream turbulence on non-premixed flames are numerically analyzed. The Spalding eddy dissipation mathematical model is used to control the reaction rate by the large-eddy time scale. The turbulence energy production and dissipation rates are simulated by the ?-e turbulence model in order to investigate the dependence of the combustion properties on free stream turbulence. The reacting NS equations were spatially discretized and solved through a finite volume scheme and a decoupled pressure-velocity approach, respectively. The flame was assumed to be steady-state, two dimensional and axisymmetric. The reported results include the velocity, temperature and turbulent reaction rate along the flame propagation field. It is found that the increase of free stream turbulence intensity reduces the reaction zone significantly, hence, induces the flame extinction process.