A study on Friction Boundary Conditions with Unicorn/FEniCS-HPC

Abstract: The aim of this thesis is to present and validate a boundary condition formulation for CFD problems that includes a friction parameter. In the first part of the thesis the incompressible Navier-Stokes system of equations and the friction boundary conditions are presented. Then the Finite Element methodology that is used to discretize the problem is given, with particular emphasis to the a-posteriori error estimate, the adaptive algorithm and the numerical tripping included in the flow. Moreover, since FEniCS-HPC is the software on which this thesis leans on, its framework is explained, together with its powerful parallelization strategy. Then the weak formulation of the Navier Stokes system of equation coupled with friction boundary conditions is presented, together with an initial theoretical derivation of the friction coefficient optimal values. Furthermore, in the last chapter, the preliminary results of a validation study for the lift coefficient of the NACA0012 airfoil benchmark model are included and commented in detail. Even if there still are some aspects to be elucidated, we believe that our preliminary results are very promising and that they open a new pathway for simulation development in aerodynamics-related models.