| The high level of maturity reached in many computational disciplines, prompts for the study of new multidisciplinary applications, of great importance for engineering purposes. Such is the case of fluid-structure interaction, where deformable solids interact with surrounding fluids. The deformation of the solid due to the fluid loads is such that the flow field is altered, making it necessary to solve the coupled problem simultaneously.; The loose coupling approach is based on the assumption that the fluid and structural solvers need not to be re-written, they can be combined in order to solve the coupled problem. This allows an efficient re-use of existing solvers, which are specialized for different fluid and structural models.; The ability to deal with arbitrarily complex fluid and structural models, geometries and discretization techniques, introduces a number of problems associated to the transfer of information between the coupled programs. All of them are the consequence of the possibility of different discretizations and geometric modeling of the fluid-structure interface. The focus of this work is in the development of the necessary algorithms for the information transfer, which allows the accurate simulation of fluid-structure problems with loose coupling algorithms.; The three major issues studied here are: (1) the transfer of loads from the fluid to the solid (load projection), (2) the transfer of the interface deformations from the solid to the fluid (surface tracking), and (3) the synchronization of the fluid and solid solutions to account for possible different time-step sizes.; The solution of these problems are closely related to search and interpolation algorithms for unstructured grids.; The main contributions of this work are new, accurate and conservative load transfer and surface tracking schemes, based on adaptive Gaussian quadrature and monotonicity preserving algorithms. These contributions open the possibility of accurately simulating new fluid-structure interaction problems, that are of great importance for engineering problems. In particular, they extend the range of applicability of CFD and CSD, and introduce new methods for transmitting data between general unstructured grids which can be used in other computational sciences as well.; Although the discussions are centered on fluid-structure interaction problems, and in particular in the area of Aeroelasticity, the techniques presented are of a general character. Therefore, other multidisciplinary fields can benefit from them. |
