Abstract

During the talk two different techniques inspired by nature and aimed to flow control will be presented. The first one, motivated by the undulated shape of humpback whales flippers , concerns the control of the stall of an high angle of attack wing. It will be shown, via numerical results obtained by a Large Eddy Simulation, that strongly improved aerodynamic performances of a wing are obtained at in an otherwise stalled condition when proper undulations are introduced. A deeper physical insight on the flow modification will also be presented. The second set of control techniques is based on the use of elastic filaments in the trailing zone of bluff bodies. The idea of using fluid structure interaction for flow control arises from the observation on the way birds use feathers in landing situations. Some examples will be introduced together with a discussion of the potential use of flexible hairs also for the control of viscous drag in wall bounded turbulent flows inspired by the fur of seals.