Vegetation canopies strongly modulate atmospheric boundary layer (ABL) flow, yet the quantitative influence of canopy drag on above-canopy wind and turbulence profiles remains insufficiently constrained. Here we implement a canopy momentum attenuation scheme, parameterized by a form-drag coefficient λ, in the open-source CFD toolbox OpenFOAM and couple it with a RANS \({k-\varepsilon }\) closure for neutral ABL conditions. The results indicate that increasing \({\lambda }_{r}\) systematically reduces the mean velocity and turbulence kinetic energy within the canopy, while accelerating the flow above the canopy and intensifying the canopy-top shear. The above-canopy mean-velocity profile is modeled using a two-layer representation comprising the roughness sublayer and the inertial sublayer. To quantify how canopy resistance reshapes the wind profile, we establish an empirical relationship between \({\lambda }_{r}\) and profile parameters including friction-velocity and aerodynamic roughness length. The proposed empirical model offers a fast, first-order route to predict above-canopy profile characteristics without resolving individual roughness elements.
