THESIS
2016
xiii, 126 pages : illustrations ; 30 cm
Abstract
Fluid-particle interaction problems, where solid particles interact with surrounding
fluids, play prominent roles in many scientific and engineering fields. In this
thesis, we present numerical simulations for the dynamics of a solid particle moving
in one or two-phase
flows using an extended finite element method combined
with a temporary arbitrary Lagrangian-Eulerian technique. In this method, the
whole computation including both
fluid and solid motion is carried out on a fixed
regular mesh. It is efficient compared to conventional approaches that require
regeneration or deformation of meshes. The discontinuous characteristics at the
particle surface are captured by Heaviside-enriched finite element basis functions
and the slip or no-slip boundary conditions at the inte...[
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Fluid-particle interaction problems, where solid particles interact with surrounding
fluids, play prominent roles in many scientific and engineering fields. In this
thesis, we present numerical simulations for the dynamics of a solid particle moving
in one or two-phase
flows using an extended finite element method combined
with a temporary arbitrary Lagrangian-Eulerian technique. In this method, the
whole computation including both
fluid and solid motion is carried out on a fixed
regular mesh. It is efficient compared to conventional approaches that require
regeneration or deformation of meshes. The discontinuous characteristics at the
particle surface are captured by Heaviside-enriched finite element basis functions
and the slip or no-slip boundary conditions at the interfaces are imposed by a
penalty method without introducing additional degrees of freedom. In addition,
we apply local mesh subdivisions to improve the accuracy near the interface.
Temporary mesh movement is considered in the arbitrary Lagrangian-Eulerian
formulation of incompressible
flows where field variables at the previous time level
are mapped onto the computational mesh at the current time level. In numerical
experiments, we study the rotation of an ellipsoidal particle in a simple shear
flow, the results show good agreement with the Jeffery orbit theory. We also
model a particle passing through a
fluid-fluid interface and compare the results
with the capillary bridge and splashing phenomena observed in experiments.
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