Verification and validation of a method for the simulation of turbulent mixing

Abstract

We present the highlights of and supplementary material related to two recent studies yielding verification and validation of a new approach to the simulation of turbulent mixing. The verification is based on (i) a mesh refinement study of the circular Richtmyer–Meshkov unstable flow, (ii) comparison of the code to a well-documented code and (iii) comparison to a simple analytic model. The validation is based on the simulation's agreement with the Rayleigh–Taylor unstable experiments of Smeeton–Youngs and of Mueschke–Andrews. The mesh refinement verification gives convergence for such molecular level variables as the probability density functions for concentration, temperature and a chemical reaction rate. The validation study, beyond obtaining nearly perfect agreement with experiment, explores the various factors in the simulations that lead to the agreement and to differences between the two experiments. The important variables are fluid transport parameters, dimensionless groups (not widely recognized to be significant) to characterize the dominant short-wavelength initial perturbations and experimentally measured (long-wavelength) initial perturbations.