Estimation of Some Correlations in a Premixed Reactive Turbulent Flow

Abstract

Analysis is made of the rotational and potential fields in an open premixed turbulent flame to deduce the relative strengths of these fluctuating fields. The potential field, loosely described as the acoustic field, is found to be as strong as the rotational field for sufficiently high heat release, in accordance with prior estimates for ducted flames. The potential field decouples from the vortical field enabling separate calculations of correlations involving the potential field which are of importance in turbulence stress equations. For the case of a plane flame orthogonal to the oncoming stream and in the limit of a weak potential field these results are used to form a model for the velocity-pressure gradient correlation. The model differs from and is believed superior to others reported in the literature.