How does flutter impose a limit on drag reduction by reconfiguration

Trees and plants bend and deform under the wind, we say that they reconfigure. This elastic reconfiguration enables a drag reduction. However, a flag fluttering in the wind is a good example that flexibility can lead to flow-induced vibrations with its accompanying dynamic loads.
In her new paper, Maryam Boukor investigates the ideal flexibility that enables the best compromise between drag reduction and flutter instability. The work is the fruit of collaborative work with Augustin Choimet and my colleague Éric Laurendeau
Watch the 2min summary video below and read the full paper in Physics of Fluids.