Numerical study of flows around bluff bodies using a « porous medium » approach

This work aims to study flows around bluff bodies simulated via the single-domain porous medium approach proposed by Antoniadis and Papalexandris. According to their approach, the solid body is modelled as a porous medium of very low porosity. This method simplifies the computational grid and avoids the prescription of a boundary condition at the surface of the body. On the downside, transition cells that alter the behaviour of the flow in the vicinity of the body must be added to limit numerical instabilities. In this work, the possibility to use the single-domain porous medium approach to simulate flows around solid bodies is discussed. In order to restrict the approach to 2D computations, the Reynolds numbers considered are between 100 and 300. Only incompressible and isothermal flows are considered. Regarding the geometry of the body, square and circular cylinders are implemented. The flows around both shapes are evaluated and compared with previous works. The drag and lift coefficients, the Strouhal number, the separation points as well as the velocity profiles in the vicinity of the body are investigated. The results reveal the interesting potential of the proposed model. Despite some discrepancies observed for a couple of numerical values, the typical flow patterns highlighted for flows around solid bodies are spotted in our results.