Direct Numerical and Large Eddy Simulations of Helicity-Induced Stably Stratified Turbulent Flows

Subgrid-scale (SGS) turbulence models for large eddy simulations (LES) are quantitatively assessed for the strongly-stratified helical transition-to-turbulence, Arnold-Beltrami-Childress (ABC) problem through comparisons to in-house direct numerical simulations (DNS). LES predictions using the classical non-dynamic and dynamic Smagorinsky models (SSM and DSM, respectively) are compared to a modified Smagorinsky model (MSM) designed specifically for natural convection. DSM predicts the best results when compared to DNS, although none of the SGS models are able to predict the peak of nonlinearities.