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Full-Text Articles in Mechanical Engineering
Modeling Multiple Reactive Scalar Mixing With The Generalized Iem Model, Kuochen Tsai, Rodney O. Fox
Modeling Multiple Reactive Scalar Mixing With The Generalized Iem Model, Kuochen Tsai, Rodney O. Fox
Rodney O. Fox
An outstanding feature of the amplitude mapping closure is its ability to relax an arbitrary initial probability density function (PDF) to a Gaussian PDF asymptotically. Due to the difficulties in computing either the analytical or numerical solution, the mapping closure has never been applied to multiple scalars with finite reaction rates. In this work, the generalized IEM (GIEM) model is combined with the mapping closure to model the molecular mixing terms in the PDF balance equation. The GIEM model assumes a linear relationship between the rates of change of the reactive scalars and an inert scalar (shadow scalar) during the …
The Spectral Relaxation Model Of The Scalar Dissipation Rate In Homogeneous Turbulence, Rodney O. Fox
The Spectral Relaxation Model Of The Scalar Dissipation Rate In Homogeneous Turbulence, Rodney O. Fox
Rodney O. Fox
A model for the effect of scalar spectral relaxation on the scalar dissipation rate of an inert, passive scalar (Sc>1) in fully developed homogeneous turbulence is presented. In the model, wave-number space is divided into a finite number [the total number depending on the turbulence Reynolds number Re, and the Schmidt number (SC)] of intermediate stages whose time constants are determined from the velocity spectrum. The model accounts for the evolution of the scalar spectrum from an arbitrary initial shape to its fully developed form and its effect on the scalar dissipation rate for finite Re, and Sc>1. …