Parallel algorithms for fluid and rigid body interaction
This thesis is based on the implementation of a computational system to numerically simulate the interaction between a fluid and an arbitrary number of rigid bodies. This implementation was performed in a distributed memory parallelization context, which makes the process and its description especia...
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| Tipo de recurso: | tesis doctoral |
| Fecha de publicación: | 2015 |
| País: | España |
| Institución: | Universitat Politècnica de Catalunya (UPC) |
| Repositorio: | UPCommons. Portal del coneixement obert de la UPC |
| Idioma: | inglés |
| OAI Identifier: | oai:upcommons.upc.edu:2117/96054 |
| Acceso en línea: | https://hdl.handle.net/2117/96054 https://dx.doi.org/10.5821/dissertation-2117-96054 |
| Access Level: | acceso abierto |
| Palabra clave: | Algorismes paral·lels Àrees temàtiques de la UPC::Informàtica |
| Sumario: | This thesis is based on the implementation of a computational system to numerically simulate the interaction between a fluid and an arbitrary number of rigid bodies. This implementation was performed in a distributed memory parallelization context, which makes the process and its description especially challenging. As a consequence, for the sake of descriptive precision and conceptual clarity, a new formal framework using set theory concepts is developed. The fluid is discretized using a non body-conforming mesh and the boundaries of the bodies are embedded in this mesh. The force that the fluid exerts on a body is determined from the residual of the momentum equations. Conversely, the velocity of the body is imposed as a boundary condition in the fluid. In this context, two new approaches are proposed. To account for the fact that fluid nodes can become solid nodes and vice versa due to the rigid body movement, we have adopted the FMALE approach, which is based on the idea of a virtual movement of the fluid mesh at each time step. A new method of interpolation is adopted inside the FMALE implementation in order to improve the results. The physics of the fluid is described by the incompressible Navier-Stokes equations. These equations are stabilized using a variational multiscale finite element method and solved using a fractional step like scheme at the algebraic level. The incompressible Navier-Stokes solver is a parallel solver based on master-worker strategy. The bodies can have arbitrary shapes and their motions are determined by the Newton-Euler equations. The contacts between bodies are solved using impulses to avoid interpenetrations. The time of impact is determined implementing a dynamic collision detection algorithm. As far as the parallel implementation is concerned, the data of all the bodies are shared by all the subdomains. To track the boundary of the bodies in the fluid mesh, computational geometry tools have been used. |
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