Book Description

Direct numerical simulations are performed on a NACA 2412 airfoil with an attack angle of 12 degrees and Reynolds numbers between 300 and 35.000. The details of the flow separation, formation and destabilization of the detached shear layer and formation of separation bubbles via flow re- attachment are studied among other phenomena. Results are then post- processed using a data analysis and visualization application. Computational fluid dynamics has proven a handy tool to analyze, characterize and understand the flow over airfoils. A block-structured mesh to run the simulations is created from scratch and presented in this report. The mesh is fully parameterized to save time for future modifications or adaptations. A mesh independence study is undertaken to ensure the mesh does not affect the outcome of the simulations. The lift and drag of the airfoil, as well as the wall shear stress and velocity profiles are calculated and presented in this report. The study is done at varying Re to characterize the transition of the lift and drag coefficients from steady to periodic and then to chaotic. We also present the formation and migration of the separation bubble, which gets closer to the leading edge as the Re increases. Open source software distributed under open public licensing (GPL) is exclusively exploited. The mesh has been created using Gmsh, the simulations have been done with OpenFOAM and the post-processing is done with paraView and grace.