Hidrodinamica dos movimentos e esforcos induzidos em navios por ondas de grande amplitude.

The objective of the thesis is to develop a method to predict the vertical responses of ships advancing in large amplitude waves. The vertical responses include the heave and pitch motions and the vertical sectional structural loads. The method must account for the dominant nonlinear hydrodynamic contributions. On the other hand, the numerical solution of the theoretical model must be possible to implement in a computer program, and run with a relatively small computational effort. In this way it can be used for practical engineering applications. The thesis work follows several steps, beginning with a review of the state of art in the area of sea keeping, and of the methods presently available, together with an analysis of the advantages and disadvantages of each. Afterwards one is ready to firstly decide upon the general characteristics of the method to be developed (given the objectives), secondly to develop the formulations, and thirdly to implement the solution in a computer code in order to obtain the numerical solution. Finally it is necessary to validate the theoretical and numerical solution, for which the numerical results are compared with experimental data. Since the amount of experimental data which is published and available with emphasis and complete information on the nonlinear vertical responses of ships is very sparse, it was decided to carry out an experimental program. A model of a container ship advancing in regular and irregular large amplitude waves is used, and the measured responses are the heave and pitch motions, relative motions, vertical accelerations, and sectional loads. The numerical procedure is assessed by comparing its results with the experiments.Available from Fundacao para a Ciencia e a Tecnologia, Servico de Informacao e Documentacao, Av. D. Carlos I, 126, 1249-074 Lisboa, Portugal / FCT - Fundação para o Ciência e a TecnologiaSIGLEPTPortuga