Second order modeling of a passive scalar in a turbulent shear flow
Abstract
A realizability concept for the scalar flux is described, and a new model form of the pressure correlation term in the passive scalar flux equations is carefully derived based on realizability. A modeled scalar dissipation equation is proposed based on the idea that the ratio of mechanical time scale to scalar time scale tends toward an equilibrium value during the evolution of turbulence. As test flows, the slightlyheated plane and axisymmetric jets are considered, so that the temperature can be treated as a passive scaler. The calculations show that the profiles of mean velocity, mean temperature, shear stress, component energies, temperature variance, heat flux, and dissipations of turbulent energy and temperature variance are approaching selfpreservation and are in good agreement with existing measurements.
 Publication:

27th AIAA Aerospace Sciences Meeting
 Pub Date:
 January 1989
 Bibcode:
 1989aiaa.meetQR...S
 Keywords:

 Scalars;
 Shear Flow;
 Turbulence Models;
 Turbulent Flow;
 Axisymmetric Flow;
 Computational Fluid Dynamics;
 Flow Velocity;
 Shear Stress;
 Fluid Mechanics and Heat Transfer