A numerical study of auto-ignition in turbulent lifted flames issuing into a vitiated coflow

Abstract

A numerical study of auto-ignition in a simple jet of hydrogen-nitrogen mixture issuing into a vitiated co-flowing stream was carried out. The calculations employed a composition probability density function approach coupled to the commercial computational fluid dynamics package, FLUENT. The budget analysis performed in the stabilization region of these flames showed reaction balanced by convection with minimal diffusion. This was indicative of auto-ignition regimes. Despite some disagreement to parametric experimental measurements with respect to lift-off heights, the numerical results were still useful in highlighting aspects of auto-ignition. The budgets were presented for excess H2O, def..