Implementation of immersed boundaries via volume penalization in the industrial aeronautical computational fluid dynamics solver CODA

We present the implementation and validation of an immersed boundary volume penalization method in the computational fluid dynamics solver CODA (from ONERA, DLR, and Airbus). Our goal is to model and simulate turbulent fluid flows in complex 3D aerodynamic configurations through the numerical solution of the Reynolds-averaged Navier-Stokes equations using the Spalart-Allmaras turbulent model. To do that, an immersed boundary method has been implemented in CODA and an efficient preprocessing tool for the construction of unstructured hexahedral meshes with adaptive mesh refinement around immersed geometries has been developed. We report several numerical examples, including subsonic flow past the NACA0012 airfoil, transonic flow past the RAE2822 airfoil, subsonic flow past the MDA30P30N multi-element airfoil, and subsonic flow around the NASA high-lift CRM aircraft. These simulations have been performed in the CODA solver with a second-order finite volume scheme as spatial discretization and an implicit backward Euler scheme based on the matrix-free GMRES block-Jacobi iterative method. The reported numerical simulations are in good agreement with their corresponding experimental data. These encouraging results allow us to conclude that the implemented immersed boundary method is efficient, flexible, and accurate and can therefore be used for aeronautical applications in industry.