On the scaling of drag reduction by reconfiguration in plants

Abstract : Slender flexible structures such as plants are deformed by external flow. When the deformation is significant, this results in a reduction of drag. We give a theoretical value of the exponent that characterizes the drag law. This theoretical value is shown to compare well with experimental data on a very large variety of plants. It is found that reconfiguration affects more the local bending stress than the total drag. Moreover, a non-linearity in the bending law does not affect significantly the mechanism. © 2011 Académie des sciences.