Near wake dynamics around a vibrating airfoil by means of PIV and Oscillation Pattern Decomposition at Reynolds number of 65 000

Flow around steady and vibrating airfoil NACA 0012 with a 10° angle of attack has been studied experimentally, using a time-resolved PIV technique at Reynolds number of 65 000. In this situation, a strong interaction between the airfoil and the flow-field is typically observed. Dynamics of flow in the airfoil wake has been investigated in details. Besides statistical analysis of the flow field point-by-point in space, we have explored complex spatial dynamics of the flow using the Oscillation Pattern Decomposition (OPD) method applied on the entire velocity vector field. The flow field spatial dynamics is characterized by the OPD modes of oscillating and non-oscillating characters, capturing traveling and pulsating patterns. Topology and frequencies of dynamical modes are to be shown. The unsteady velocity field is affected by both wing vibrations and inherent flow dynamics. Role of the airfoil vibrations in the flow dynamics is demonstrated.