Interaction Analyses of Three Dimensional Multiphase Fluids and Flexible Solids
| Autor: | Chih-Jung Huang, 黃致榮 |
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| Rok vydání: | 2013 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 101 Three dimensional fluid-structure dynamic interaction behaviors contain fruitful and complex physical phenomena and are interested to engineers for their design and analysis works. Computational mechanics is an effective way to assist engineers obtaining more detail information for this type of problem. This dissertation presents a newly developed fluid-solid interaction analysis algorithm. This algorithm can be used to investigate the motions of discrete deformable bodies in multi-phase viscous fluid. The CFD analysis in this computation algorithm uses the Truchas developed by the Los Alamos National Laboratory (LANL) and the motions of the solids are computed by a algorithm developed based on the vector form intrinsic finite element (VFIFE) method. A two-way coupled moving solid algorithm is developed. The motions of solids are based on the surface pressure obtained from solving the Navier-Stokes equations. The free-surface kinematic is tracked by the volume-of-fluid (VOF) method. The modified projection method is used to decouple and solve the pressure and velocity field. The two-way coupled moving solid method is developed to bridge the VFIFE model and VOF model. With this newly developed moving-solid method, the trajectory of the solid motion is no longer needed to be prescribed. The VFIFE method analyzes the motion of the solids and structures by modeling the individual object as a group of representative finite particles. The motion of each particle subjected to external and internal forces is used to simulate the large displacements and failures of the whole structure. The VFIFE method based on the intrinsic theories of mechanics avoids the difficulties such as the iterative and perturbation procedures in solving partial differential equations in the traditional nonlinear structural analyses. The key concepts in the analysis of the VFIFE method are: (1) the point value description (PVD), (2) the path element, and (3) the convected material frame (CMF). With these features, the VFIFE method can analyze the motion of a body from continuous states to discontinuous states with load control or displacement control easily and adaptively. Hence, the multi-hazard and failure analyses of infrastructures under the excitations of earthquake, debris flow, wind and flood can be conducted by this newly proposed computational fluid-structure interaction analysis method. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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