Subgrid models for mass and thermal diffusion in turbulent mixing

Subgrid models for mass and thermal diffusion in turbulent mixing∗

Subgrid models in turbulent mixing

We are concerned with the chaotic flow fields of turbulent mixing. Chaotic flow is found in an extreme form in multiply shocked Richtmyer-Meshkov unstable flows. The goal of a converged simulation for this problem is to obtain converged solutions for such micro solution features as the joint probability distributions of the temperature and species concentration, as well as the macro features su...

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...

Dynamic Models for Subgrid-scale Transport and Mixing of Reactants in Atmospheric Turbulent Reacting Flows

Large-eddy simulation (LES) can provide valuable highresolution spatial and temporal information required to study the effects of turbulent transport and mixing on the chemical transformation of reacting scalars in the atmospheric boundary layer (ABL). LES consists of explicitly resolving all scales of turbulent transport larger than the grid scale (on the order of tens of meters in the ABL), w...

Thermal Equilibrium Curves and Turbulent Mixing in Keplerian Accretion Disks

We consider vertical heat transport in Keplerian accretion disks, including the effects of radiation, convection, and turbulent mixing driven by the Balbus-Hawley instability, in astronomical systems ranging from dwarf novae (DNe), and soft X-ray transients (SXTs), to active galactic nuclei (AGN). In order to account for the interplay between convective and turbulent energy transport in a shear...