Understanding the role of porosity in vortex-shedding behaviour through URANS approaches

Modelling porous elements in the Computational Fluid Dynamics (CFD) environment usually requires relying on a porous media model to address the multi-scale nature of the problem, due to the scale separation between openings’ size and the overall dimension of the structure they are applied to. This study investigates the capability of the Darcy-Forchheimer porosity model in predicting the aerodynamics of a rectangular cylinder covered by a perforated metal, representative of a rectangular building with a Permeable Double Skin Façade (PDSF). Specifically, we focus on the vortex-shedding mechanism and how it is affected by the porous layer. Using Unsteady Reynolds Averaged Navier Stokes Equations (URANS), results are validated against experimental results from wind tunnel tests. Results show strong agreement in mean and oscillating pressure distributions, affirming the model’s accuracy in capturing porosity effects. The study underscores CFD’s potential for efficient wind load estimation and wind-induced oscillation analysis in porous-element environments.