LARMOR LECTURE - Surging cylinders, flapping wings and gust encounters: Force production in unsteady flows

Mon 28 October 2024

Department of Chemistry

The Larmor Lecture by Professor Holger Babinsky, Professor of Aerodynamics, Department of Engineering, University of Cambridge.

The second talk in a series of lectures organised by the Cambridge Philosophical Society in the Michaelmas Term 2024.

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 lecture I will explain some of these ideas and demonstrate how they can still be useful today. As a practical example, I will show 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 lecture will be illustrated with images and videos from simple, canonical, experiments.

Cost: Free