Cluster-based network reduced order modeling for flow fields around airfoil profiles

A Reduced Order Model investigation of the flow field over a NACA 0012 airfoil at moderate Reynolds number and angle of attack α = 8° is presented in this work. Numerical simulations have been carried out by means of the finite-volume solver OpenFOAM. Two main reduction techniques have been employed for this analysis, the standard Galerkin projection of the governing equations onto proper orthogonal decomposition modes (POD-ROM) and an original application of the cluster-based network model (CNM), a fully data-driven nonlinear methodology. The topology of the leading POD modes is analyzed, revealing the travelling wave pattern of the wake dynamics. Performances of both ROMs techniques are compared in terms of flow fields behaviours and integral quantities.