RANS Modeling of Stably Stratified Turbulent Boundary Layer Flows in OpenFOAM®
Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523-1372, USA
a Corresponding author: email@example.com
b Current affiliation: Department of Mechanical Engineering, Lipscomb University, 1 University Park Drive, Nashville, TN 37204, USA
Quantifying mixing processes relating to the transport of heat, momentum, and scalar quantities of stably stratified turbulent geophysical flows remains a substantial task. In a stably stratified flow, such as the stable atmospheric boundary layer (SABL), buoyancy forces have a significant impact on the flow characteristics. This study investigates constant and stability-dependent turbulent Prandtl number (Prt) formulations linking the turbulent viscosity (νt) and diffusivity (κt) for modeling applications of boundary layer flows. Numerical simulations of plane Couette flow and pressure-driven channel flow are performed using the Reynolds-averaged Navier-Stokes (RANS) framework with the standard k-ε turbulence model. Results are compared with DNS data to evaluate model efficacy for predicting mean velocity and density fields. In channel flow simulations, a Prandtl number formulation for wall-bounded flows is introduced to alleviate overmixing of the mean density field. This research reveals that appropriate specification of Prt can improve predictions of stably stratified turbulent boundary layer flows.
© Owned by the authors, published by EDP Sciences, 2015
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