Measurement of Turbulent Diffusion Coefficients in Mixing Vessels

Turbulent mixing with physical mass diffusion.

Simulated mixing rates of the Rayleigh-Taylor instability for miscible fluids with physical mass diffusion are shown to agree with experiment; for immiscible fluids with physical values of surface tension the numerical data lie in the center of the range of experimental values. The simulations are based on an improved front tracking algorithm to control numerical surface tension and on improved...

Subgrid models for mass and thermal diffusion in turbulent mixing∗

3. Mixing in Rivers: Turbulent Diffusion and Dispersion

In previous chapters we considered the processes of advection and molecular diffusion and have seen some example problems with so called “turbulent diffusion” coefficients, where we use the same governing equations, but with larger diffusion (mixing) coefficients. In natural rivers, a host of processes lead to a non-uniform velocity field, which allows mixing to occur much faster than by molecu...

Radiation modeling of a turbulent diffusion flame in diesel engine

The purpose of this study is to investigate the effect of radiation heat transfer on temperature distribution and heat flux to the walls of a diesel engine. A diffusion flame is modeled in a simple cylindrical geometry and boundary conditions are defined. A specific solver which can model the turbulent diffusion flame by considering radiation in participating media is used to solve the problem....

Diffusion measurement in ferrous infused gel dosimeters

Background: The compositions of Ferrous sulphate, Agarose and Xylenol orange dye (FAX) and Ferrous sulphate, Gelatin and Xylenol orange dye (FGX) in solution of distilled water and sulphuric acid are two tissue-equivalent gel dosimeters. Ionizing radiation causes oxidation of Fe2+ ion to Fe3+ ions which diffuse through the gel matrix and blur the image of absorbed dose over a period of hours af...