SCALAR DISSIPATION RATE MODELLING IN TURBULENT JETS
USING FIRST-ORDER MODELS
M. H. Gazzah*, A. Hidouri, M. Sassi
LESTE, ENI-Monastir, Route de Kairouan, 5019, Monastir, Tunisie
* Corresponding author. E-mail :Mohamed.Gazzah@fsg.rnu.tn
Received : 19 April 2002; revised version accepted : 02 August 2002
The Transport of a scalar quantity in a turbulent round jet is addressed by testing and applying the non-equal scales model based on the two-Scale-Direct-Interaction-Approximation (TSDIA) of Yoshizawa for three first order models. In this way the assumption of equal time scales for mechanical and scalar turbulence, leading to a constant turbulent Schmidt number is no longer needed. It is shown that the trends, which are observed in the experiments, are reproduced qualitatively by the non-equal scales model.
Keywords: Scalar; Jet; Equal scales; Non-equal scales; TSDIA; Schmidt number.