Experimental observation of viscoelastic fluid–structure interactions. (26th January 2017)

• Record Type: Journal Article
• Authors: Dey, Anita A.; Modarres-Sadeghi, Yahya; Rothstein, Jonathan P.
• Is Part Of: Journal of fluid mechanics. Volume 813(2017)
• Publication Date: 2017-01-26
• Subjects: flow–structure interactions, -- low-Reynolds-number flows, -- viscoelasticity; Fluid mechanics -- Periodicals; 532.005
• DOI: 10.1017/jfm.2017.15
• Languages: English
• ISSNs: 0022-1120

Abstract

Abstract : It is well known that when a flexible or flexibly mounted structure is placed perpendicular to the flow of a Newtonian fluid, it can oscillate due to the shedding of separated vortices. Here, we show for the first time that fluid–structure interactions can also be observed when the fluid is viscoelastic. For viscoelastic fluids, a flexible structure can become unstable in the absence of fluid inertia, at infinitesimal Reynolds numbers, due to the onset of a purely elastic flow instability. Nonlinear periodic oscillations of the flexible structure are observed and found to be coupled to the time-dependent growth and decay of viscoelastic stresses in the wake of the structure.