Surging Cylinders, Flapping Wings and Gust Encounters: Force Production in Unsteady Flows

Abstract

Unsteady effects occur in many natural and technical flows, for example around flapping wings or during aircraft gust encounters. If the unsteadiness is large, the resulting forces can be quite considerable. However, the exact physical mechanisms underlying the generation of unsteady forces are complex and their accurate prediction remains challenging. One strategy is to identify the dominant effects and describe these with simple analytical models, first proposed a hundred years ago. When used successfully, this approach has the advantage that it also gives us a conceptual understanding of unsteady fluid mechanics.

In this seminar, Prof. Holger Babinsky will explain some of these ideas and demonstrate how they can still be useful today. As a practical example, we will cover how the forces experienced in a wing-gust encounter can be predicted – and how the predictions can be used to mitigate the gust effects. The seminar will be illustrated with images and videos from simple, canonical, experiments.

Speaker

Prof. Holger Babinsky originates from Bavaria and studied Aerospace Engineering at Stuttgart University in Germany. He obtained a PhD in hypersonic aerodynamics from Cranfield University (UK) in 1994. After 18 months as Research Associate at the Shock Wave Research Centre of Tohoku University in Sendai (Japan), he returned to the United Kingdom to take up a position at the University of Cambridge. He is now the Professor of Aerodynamics in the Department of Engineering and the Head of Energy, Fluid Mechanics and Turbomachinery as well as a Fellow of Magdalene College.

His main areas of research are in the field of experimental aerodynamics and associated measurement techniques. Apart from supersonic flows, which he has studied for more than 30 years, his research interests include the aerodynamics of micro-air vehicles, road vehicles, aircraft wings and engine inlets. Prof. Babinsky is a Fellow of the Royal Academy of Engineering, the Royal Aeronautical Society and the American Institute of Aeronautics and Astronautics. He is the Editor-in-Chief of the Royal Aeronautical Society’s Aeronautical Journal (the world’s oldest aeronautical journal in production) and an Associate Editor of Experiments in Fluids.