1 research outputs found
Shape-Morphing Dynamics of Soft Compliant Membranes for Drag and Turbulence Modulation
We study the kinematics and dynamics of a highly compliant membrane disk
placed head-on in a uniform flow. With increasing flow velocity, the membrane
deforms nonlinearly into increasingly parachute-like shapes. These
aerodynamically elongated materials exhibit a modified drag law, which is
linked to the elastohydrodynamic interactions. We predict the unsteady
structural response of the membranes using a nonlinear, aeroelastic model -- in
excellent agreement with experimental measurements of deformations and force
fluctuations. With simultaneous membrane interface tracking, force measurements
and flow tracing, we reveal that a peculiar skewness in the membrane's
oscillations triggers turbulence production in the wake, thereby modulating the
drag. The present work provides a demonstration of the complex interplay
between soft materials and fluid turbulence, leading to new, emergent system
properties.Comment: 5 pages, 4 figures, Phys. Rev. Lett. (in press