A New Method for Modeling Free Surface Flows and Fluid-structure Interaction with Ocean Applications

dc.contributor.advisor

Dolbow, John

dc.contributor.author

Lee, Curtis

dc.date.accessioned

2016-09-29T14:40:06Z

dc.date.available

2016-09-29T14:40:06Z

dc.date.issued

2016

dc.department

Civil and Environmental Engineering

dc.description.abstract

The computational modeling of ocean waves and ocean-faring devices poses numerous challenges. Among these are the need to stably and accurately represent both the fluid-fluid interface between water and air as well as the fluid-structure interfaces arising between solid devices and one or more fluids. As techniques are developed to stably and accurately balance the interactions between fluid and structural solvers at these boundaries, a similarly pressing challenge is the development of algorithms that are massively scalable and capable of performing large-scale three-dimensional simulations on reasonable time scales. This dissertation introduces two separate methods for approaching this problem, with the first focusing on the development of sophisticated fluid-fluid interface representations and the second focusing primarily on scalability and extensibility to higher-order methods.

We begin by introducing the narrow-band gradient-augmented level set method (GALSM) for incompressible multiphase Navier-Stokes flow. This is the first use of the high-order GALSM for a fluid flow application, and its reliability and accuracy in modeling ocean environments is tested extensively. The method demonstrates numerous advantages over the traditional level set method, among these a heightened conservation of fluid volume and the representation of subgrid structures.

Next, we present a finite-volume algorithm for solving the incompressible Euler equations in two and three dimensions in the presence of a flow-driven free surface and a dynamic rigid body. In this development, the chief concerns are efficiency, scalability, and extensibility (to higher-order and truly conservative methods). These priorities informed a number of important choices: The air phase is substituted by a pressure boundary condition in order to greatly reduce the size of the computational domain, a cut-cell finite-volume approach is chosen in order to minimize fluid volume loss and open the door to higher-order methods, and adaptive mesh refinement (AMR) is employed to focus computational effort and make large-scale 3D simulations possible. This algorithm is shown to produce robust and accurate results that are well-suited for the study of ocean waves and the development of wave energy conversion (WEC) devices.

dc.identifier.uri

https://hdl.handle.net/10161/12894

dc.subject

Engineering

dc.subject

Applied mathematics

dc.subject

computational fluid dynamics

dc.subject

fluid-structure interaction

dc.subject

high performance computing

dc.subject

numerical modeling

dc.subject

wave energy harvesting

dc.title

A New Method for Modeling Free Surface Flows and Fluid-structure Interaction with Ocean Applications

dc.type

Dissertation

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Lee_duke_0066D_13669.pdf
Size:
5.78 MB
Format:
Adobe Portable Document Format

Collections