Bumblebee in flight and in digit
Flight as a mode of animal locomotion emerges from interaction of internal biological systems with the external environment. Although it is currently, or even generally, unrealistic to fully reduce this problem to first principles, it proves possible and useful to combine low-dimensional models of biological components with first-principle fluid dynamics models, for advancing our understanding of animal flight. In this talk, I will present flight experiments, numerical simulations and theoretical modelling of bumblebees. The experiments have been conducted in a free-flight channel connecting a bumblebee hive with a foraging chamber. Video recordings of hovering, forward flight and maneuvering have been acquired and analyzed to reconstruct the three-dimensional body motion and wing kinematics. The numerical simulations using FluSI, a pseudo-spectral Navier-Stokes solver with volume penalization, have allowed to assess the aerodynamic performance and the role of passive wing rotation. The theoretical analysis has brought new insights in the function and the dynamics of leading-edge vortices, and this topic will close the talk.