ABSTRACT: Nature is full of thin, flexible objects that bend, flutter, or flap in the wind or the water such as leaves of trees and bushes, insect wings, and fish fins. A remarkable feature that is common to these objects is their ability to deform when interacting with the air or the water in a way that benefits them. Leaves of trees bend in the wind to reduce their resistance and the loads on their stems. The flexibility of insect wings and fish fins can reduce the effort the animals need to stay aloft or to propel themselves and increases their performance and agility. Leaves, insect wings, and fish fins come in a myriad of different shapes and sizes. Surprisingly, the influence of the shape of thin flexible objects on their fluid structure interactions has not yet received much attention. In our lab, we design unsteady fluid-structure interaction experiments to close that gap and fundamentally study how the shape of flexible structures and their ability to reconfigure changes their fluid dynamic performance and resilience in dynamic fluid environments. I will present recent work including experimental investigations of the fluid-structure interactions of deformable flapping wings, reconfiguring disks, and flapping flags.

BIOSKETCH: Karen Mulleners is an associate professor in the institute of mechanical engineering in the school of engineering at EPFL and the head of the unsteady flow diagnostics laboratory (UNFoLD). She received her PhD in mechanical engineering from the Leibniz Universität Hannover in Germany in 2010 for her work on dynamic stall on pitching airfoils that she conducted as a member of the German aerospace centre (DLR) in Göttingen. Her group is known for carefully designed and precisely controlled experiments of unsteady vortex dominated flows with applications in bio-inspired propulsion and wind energy. Their recent work has expanded to cover experimental fluid-structure interaction questions in collaboration with roboticists