Title: "Modal Reduction of Flow during Dynamic Stall in NACA 4412 Airfoil and Interpretation of the ongoing Aerodynamic Phenomena ", 2022

Abstract: The phenomenon of dynamic stall is a complicated problem without a complete picture till the date. The intricacy of the phenomenon has been widely studied but the study using modal decomposition has not been opted undermining its great potential. In this project, dynamic stall has been studied using Proper Orthogonal Decomposition. The flow field data required to perform modal decomposition has been obtained from CFD Modelling using OpenFOAM, for five different cases with reduced frequencies of 0.1 and 0.0025. After obtaining the snapshots, POD has been implemented separately for the inner and the outer zone to omit complications due to the changing spatial position of nodes. The aerodynamic phenomenon during dynamic stall has been interpreted with the help of lift coefficient and drag coefficient, where all the discontinuities are found to be the result of primary and secondary vortices around the airfoil. The modes with higher energy content are analyzed to determine the dominant phenomenon in the flow field. The flow around the airfoil is mostly shear dominant and the wake region is dominated by the vortex shedding