Interaction between deformable bodies and fluids
The trajectory of deformable object in a fluid is a fascinating question as it results in subtle interactions between the object's shape and the fluid's flow. I have recently developped an experiment in which a ball is straddled at the water surface through a deformable string. Although simple, this experimental setup reserves many surprises due to the interplay between the string's deformation and the generated flow. A clear Magnus effect occurs, and tends to diminsih the ball's effective intertial. We also uncovered the existence of self-trapped states in which the ball traps itself in the flow it generates ! This reveals that stirring faster does not always lead to more efficient mixing.
Publication: Motion of a floating sphere pulled by a string and induced flows