AEM Seminar: Dynamic Stall Onset and the Road to Recovery
Karen Mulleners, Tenure Track Assistant Professor, Unsteady Flow Diagnostics Laboratory; Tenure Track Assistant Professor, SGM - Teaching; Safety Delegate, COSEC - STI; EPFL
2:30 PM on 2018-11-16
Abstract:
Dynamic stall on pitching airfoils is an important practical problem that affects for example rotary wing aircraft and wind turbines. It also comprises a number of interesting fundamental fluid dynamical phenomena such as unsteady flow separation, vortex formation and shedding, unsteady flow reattachment, and dynamic hysteresis. Experimental time-resolved velocity field and surface pressure data for a two-dimensional sinusoidally pitching airfoil with various reduced frequencies was analysed using different Eulerian, Lagrangian, and modal decomposition methods. These complementary analyses resulted in the identification of the chain of events that play a role in the stall onset and the stall recovery process. A detailed description of that role and characterisation of the individual events by the governing time-scales and flow features will be presented.
Bio:
Since 2016, Karen Mulleners is an assistant professor in the institute of mechanical engineering at EPFL in Switzerland. She is the head of the unsteady flow diagnostics laboratory (UNFoLD) where she focusses on unfolding the origin and development of unsteady flow separation. Karen studied physics in Belgium (UHasselt) and the Netherlands (TU Eindhoven) and received her PhD in mechanical engineering from the Leibniz Universität Hannover in Germany for her research conducted at the German aerospace centre (DLR) in Göttingen.