A Hybrid Framework of CFD Numerical Methods and its Application to the Simulation of Underwater Explosions
| dc.contributor.author | Si, Nan | en |
| dc.contributor.committeechair | Brown, Alan J. | en |
| dc.contributor.committeemember | Wang, Kevin Guanyuan | en |
| dc.contributor.committeemember | Canfield, Robert Arthur | en |
| dc.contributor.committeemember | Gilbert, Christine Marie | en |
| dc.contributor.department | Aerospace and Ocean Engineering | en |
| dc.date.accessioned | 2022-02-09T09:00:22Z | en |
| dc.date.available | 2022-02-09T09:00:22Z | en |
| dc.date.issued | 2022-02-08 | en |
| dc.description.abstract | Underwater explosions (UNDEX) and a ship's vulnerability to them are problems of interest in early-stage ship design. A series of events occur sequentially in an UNDEX scenario in both the fluid and structural domains and these events happen over a wide range of time and spatial scales. Because of the complexity of the physics involved, it is a common practice to separate the description of UNDEX into early-time and late-time, and far-field and near-field. The research described in this dissertation is focused on the simulation of near-field and early-time UNDEX. It assembles a hybrid framework of algorithms to provide results while maintaining computational efficiency. These algorithms include Runge-Kutta, Discontinuous Galerkin, Level Set, Direct Ghost Fluid and Embedded Boundary methods. Computational fluid dynamics (CFD) solvers are developed using this framework of algorithms to demonstrate the computational methods and their ability to effectively and efficiently solve UNDEX problems. Contributions, made in the process of satisfying the objective of this research include: the derivation of eigenvectors of flux Jacobians and their application to the implementation of the slope limiter in the fluid discretization; the three-dimensional extension of Direct Ghost Fluid Method and its application to the multi-fluid treatment in UNDEX flows; the enforcement of an improved non-reflecting boundary condition and its application to UNDEX simulations; and an improvement to the projection-based embedded boundary method and its application to fluid-structure interaction simulations of UNDEX problems. | en |
| dc.description.abstractgeneral | Underwater explosions (UNDEX) and a ship's vulnerability to them are problems of interest in early-stage ship design. A series of events occur sequentially in an UNDEX scenario in both the fluid and structural domains and these events happen over a wide range of time and spatial scales. Because of the complexity of the physics involved, it is a common practice to separate the description of UNDEX into early-time and late-time, and far-field and near-field. The research described in this dissertation is focused on the simulation of near-field and early-time UNDEX. It assembles a hybrid framework of algorithms to provide results while maintaining computational efficiency. These algorithms include Runge-Kutta, Discontinuous Galerkin, Level Set, Direct Ghost Fluid and Embedded Boundary methods. Computational fluid dynamics (CFD) solvers are developed using this framework of algorithms to demonstrate these computational methods and their ability to effectively and efficiently solve UNDEX problems. | en |
| dc.description.degree | Doctor of Philosophy | en |
| dc.format.medium | ETD | en |
| dc.identifier.other | vt_gsexam:32969 | en |
| dc.identifier.uri | http://hdl.handle.net/10919/108234 | en |
| dc.language.iso | en | en |
| dc.publisher | Virginia Tech | en |
| dc.rights | In Copyright | en |
| dc.rights.uri | http://rightsstatements.org/vocab/InC/1.0/ | en |
| dc.subject | Underwater explosion | en |
| dc.subject | Fluid-structure interaction | en |
| dc.subject | Computational fluid dynamics | en |
| dc.subject | Discontinuous Galerkin method | en |
| dc.subject | Level set method | en |
| dc.subject | Direct ghost fluid method | en |
| dc.subject | Embedded boundary method | en |
| dc.subject | Shock wave | en |
| dc.subject | Rarefaction wave | en |
| dc.subject | Explosive gaseous bubble | en |
| dc.title | A Hybrid Framework of CFD Numerical Methods and its Application to the Simulation of Underwater Explosions | en |
| dc.type | Dissertation | en |
| thesis.degree.discipline | Aerospace Engineering | en |
| thesis.degree.grantor | Virginia Polytechnic Institute and State University | en |
| thesis.degree.level | doctoral | en |
| thesis.degree.name | Doctor of Philosophy | en |