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Finite element modelling of three dimensional fluid-structure interaction. / Richard Taylor

Swansea University Author: Richard Taylor

Abstract

This work is focused on the numerical modelling of fluid-structure interaction in three dimensions. Both internal and external laminar flow around flexible bodies are considered. The fluid flow simulated is based on the incompressible Navier-Stokes equations and the general focus is on laminar Newto...

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Published: 2013
Institution: Swansea University
Degree level: Doctoral
Degree name: Ph.D
URI: https://cronfa.swan.ac.uk/Record/cronfa42308
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Abstract: This work is focused on the numerical modelling of fluid-structure interaction in three dimensions. Both internal and external laminar flow around flexible bodies are considered. The fluid flow simulated is based on the incompressible Navier-Stokes equations and the general focus is on laminar Newtonian flow. The streamline upwind/ pressure stabilising Petrov-Galerkin (SUPG/PSPG) method is employed to achieve a stable low order finite element discretisation of the fluid, while the solid is discretised spatially by a standard Galerkin finite element approach. The behavior of the solid is governed by Neo-Hooke elasticity. For temporal discretisation the discrete implicit generalised-alpha method is employed for both the fluid and the solid domains. The motion of the fluid mesh is solved using an arbitrary Lagrangian-Eulerian (ALE) scheme employing a nonlinear pseudo-elastic mesh update method. The fluid-solid interface is modelled using a finite element interpolation method that allows for non-matching meshes and satisfies the required conservation laws. The resulting sets of fully implicit strongly coupled nonlinear equations are then decomposed into a general framework consisting of fluid, interface and solid domains. These equations are then solved using different solution techniques consisting of strongly coupled monolithic Newton and block Gauss-Seidel methods as well as a weakly coupled novel staggered scheme. These solvers are employed to solve a number of three dimensional numerical examples consisting of: External flow: o a soft elastic beam fixed at both ends o a thin cantilever plate.
Keywords: Applied mathematics.;Fluid mechanics.
College: College of Engineering