Hydrodynamically Coupled Shape-Morphing Beams Oscillating in a Viscous Fluid
type: CreativeWork
description: In this thesis, we study the fluid-structure interaction (FSI) of a pair of hydrodynamically coupled parallel beams immersed in a quiescent, incompressible, viscous, Newtonian fluid. The beams have two concurrent motions: a rigid oscillation in the vertical direction and a harmonic shape-morphing deformation to an arc of a circle. We perform a comprehensive computational fluid dynamics (CFD) simulation campaign to estimate the hydrodynamic function describing the added mass effect and hydrodynamic damping effect of the problem. Hydrodynamic loading increases when two beams are placed in close proximity due to the squeeze film effect. Our study found that the shape-morphing deformation is an effective strategy to reduce the hydrodynamic loadings on both beams. Previous literature introduced a simplified methodology based on the superposition principle to estimate forces for this class of problems with small amplitude oscillation. In this approach, one beam is in motion while the other beam remains stationary. Thus, a hydrodynamic function is calculated for the actions on the beam in motion (direct effect) and on the stationary beam (coupling effect). Any combination of motion can then be obtained by properly combining these two prototypical hydrodynamic functions. Our findings show that superposition methodology is an effective strategy for estimating the hydrodynamic loadings for small amplitude oscillation in the case of shape-morphing. We validate our findings from CFD simulations with the results obtained utilizing the superposition technique through a boundary element method (BEM), whose algorithm was previously developed by our group. We expand our simulation campaign to the moderately large amplitude oscillation to study the limits of applicability of the superposition treatment. Our findings show that due to the interplay of vortex shedding and convection phenomenon, the estimation of complex hydrodynamic loading using superposition strategy is not a reliable…
abstract: In this thesis, we study the fluid-structure interaction (FSI) of a pair of hydrodynamically coupled parallel beams immersed in a quiescent, incompressible, viscous, Newtonian fluid. The beams have two concurrent motions: a rigid oscillation in the vertical direction and a harmonic shape-morphing deformation to an arc of a circle. We perform a comprehensive computational fluid dynamics (CFD) simulation campaign to estimate the hydrodynamic function describing the added mass effect and hydrodynamic damping effect of the problem. Hydrodynamic loading increases when two beams are placed in close proximity due to the squeeze film effect. Our study found that the shape-morphing deformation is an effective strategy to reduce the hydrodynamic loadings on both beams. Previous literature introduced a simplified methodology based on the superposition principle to estimate forces for this class of problems with small amplitude oscillation. In this approach, one beam is in motion while the other beam remains stationary. Thus, a hydrodynamic function is calculated for the actions on the beam in motion (direct effect) and on the stationary beam (coupling effect). Any combination of motion can then be obtained by properly combining these two prototypical hydrodynamic functions. Our findings show that superposition methodology is an effective strategy for estimating the hydrodynamic loadings for small amplitude oscillation in the case of shape-morphing. We validate our findings from CFD simulations with the results obtained utilizing the superposition technique through a boundary element method (BEM), whose algorithm was previously developed by our group. We expand our simulation campaign to the moderately large amplitude oscillation to study the limits of applicability of the superposition treatment. Our findings show that due to the interplay of vortex shedding and convection phenomenon, the estimation of complex hydrodynamic loading using superposition strategy is not a reliable…
author: Ghani, Walid A.
keywords: coupled beam, fsi, hydrodynamic force, Shape morphing
date published: 2019
date modified: 2026-07-27T21:46:41Z
provider: University of Nevada - Reno
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Nevada - Reno

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property ID: Handle
value: http://hdl.handle.net/11714/5672