Realistic boundary conditions for the simulation of atmospheric boundary layer flows using an improved k-ε model

Atmospheric flow simulations in engineering practice - such as simulations of pollutant dispersion, wind load on buildings, wind climate of urban areas - are fairly sensitive to the inlet boundary conditions. The objective of the present paper is to introduce suitable profiles for velocity and turbulent quantities, which do not only fit the measured vertical distributions, but also guarantee the overall consistency of the turbulence model. If the latter aspect is not verified, the inlet profiles deteriorate rapidly within the computational domain, leading to unrealistic wind profiles in the area of interest. Considering that, in general, the atmospheric boundary layer profiles might not satisfy the equations describing an unperturbed atmospheric boundary layer, turbulence models need to be corrected to guarantee the overall consistency of the approach. Former studies have addressed such a problem via the introduction of source terms in the transport equations of kinetic energy and turbulent dissipation rate, to guarantee consistency between the turbulence model and inlet profiles. In the present study, the formulation is further extended to improve the numerical stability of the approach as well as the realistic character of the produced profiles. (C) 2015 Elsevier Ltd. All rights reserved.