Evaluation of Wray-Agarwal turbulence model for simulation of neutral and non-neutral atmospheric boundary layers

Abstract

Wray-Agarwal (WA) turbulence model is a one-equation eddy-viscosity model derived from a blended k−ω/k−ε formulation. The model performance is better than the commonly used Spalart-Allmaras one-equation model and comparable to shear stress transport (SST) model, for a wide range of canonical flows in aerodynamics. This study proposes a Monin-Obukhov similarity theory (MOST) consistent modification of the buoyancy production/destruction term in this model to simulate the atmospheric boundary layer under different stratifications. The rough wall function is also modified to be consistent with MOST. A benchmark case for testing the streamwise homogeneity evaluated the model performance. In the tests, the wind and turbulence profiles did not decay along the stretch due to the model consistency with MOST. Adoption of the model for urban flow and wind energy simulations requires further testing.