Theoretical Remarks on a Phenomenological Model of Turbulent Mixing

Abstract

In the pdf approach to turbulent combustion the molecular diffusion is to be modeled. In recent years, several authors have employed the Curl model (Curl, 1963) for closure. A modified version of the Curl model has been introduced by Pope (1982b). The modified model contains an unspecified function A∥α) [cf. Eq. (la)] which has been defined in the context of Monte-Carlo simulation. The paper Clarifies the physical meaning of this function by relating it to the physics of the initial phase of mixing of an inert scalar in homogeneous turbulence. A relationship is established between the modified Curl model and the linear mean square estimation closure introduced by Dopazo and O'Brien (1976). The asymptotic behavior of the pdf is discussed.