Kinetic dissipation and creation of atomic mix

In computational fluid dynamics (CFD), distinguishing the atomically mixed components in a multi-fluid mixture is essential for accurate predictions of species reactivities and transport coefficients dependent upon sub-grid physical scales. In this work, the Kolmogorov scales for velocity in turbulent mixing are used to construct a model for the evolution of the atomically mixed component where fluid instabilities cascade and dissipate by kinetic processes. At the smallest distinguishable hydrodynamic wavelength, equal to the Kolmogorov scale, a velocity is defined as a classical kinetic diffusivity coefficient over the Kolmogorov length scale. This scale sets the maximum momentum diffusivity length in a complex hydrodynamic or turbulent field where the continuous eddy shearing limits that maximum value of the diffusive gradient scale. This kinetic diffusive velocity relative to a turbulent velocity is shown to scale with a turbulent Reynolds number to the power of -1/4, consistent with the Kolmogorov scaling for velocities, while the mass to momentum diffusivities are related through the Schmidt number and the Batchelor scale. The resulting mass flux associated with the diffusive transport term creates atomic mix, with a specific volume, mass, and molar fraction evolving in time, which can be distinguished from pure unmixed components in the flow, and also distinguished from numerical mixing at fluid interfaces. Example results for the case of a plasma fluid near ICF (Inertial Confinement Fusion) conditions are examined and compared in a CFD resolved flow and in the BHR (Besnard-Harlow-Rauenzahn) turbulent mix model.