On the Physics of Jet Diffusion Flames (original) (raw)

Abstract

A physical model for the laminar jet diffusion flame including chemical kinetics effectsis provided. We produce the appropriate set of dimensionless groups needed to discuss the role of buoyancy and jet outlet velocity U o on such flames. We are particularly interested in flame lengths L; the behaviour of the flame is shown to split in two regimes. The regime of short flames is buoyancy controlled and the flame length scales with the intensity of the gravity g as Lg-I/3 in the reaction sheet limit. The regime of long flames is governed by the outlet velocity as L '" U o . The predictions compare well with published experimental data and the extension of our model to the candle flame problem reveals that the flux of consumplion of the candle is decreasing with increasing gravity. A possible mechanism leading to this result is proposed.

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