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Abstract(s)
Previsão de comportamento no mar de navios : Desenvolvimento de uma ferramenta de cálculo de Response Amplitude Operators (RAOs)
O seakeeping é uma área de estudo essencial na engenharia naval, esta concentra-se na análise e previsão do comportamento de navios em resposta a determinadas condições de mar. Compreender e avaliar o desempenho de um navio é crucial para garantir a segurança, o conforto da guarnição e a eficiência das operações navais.
Os Response Amplitude Operators (RAOs) são parâmetros fundamentais no estudo do seakeeping. Estes representam a resposta de um navio à excitação causada pelas ondas em termos de amplitude de movimento e fase. Os RAOs são usados para prever a resposta dinâmica do navio nos movimentos de avanço, deriva, arfagem, balanço e cabeceio, sob diferentes estados de mar e direção das ondas relativamente ao navio para diferentes velocidades.
O objetivo deste trabalho consiste na resolução, no domínio da frequência, da equação dinâmica do corpo livre de uma forma matricial. Este trabalho surge na sequência dos trabalhos realizados por Ferreira, S. (2018) e Ramujane, M. (2019), nas suas dissertações de mestrado os autores determinaram os coeficientes de massa acrescentada e de amortecimento recorrendo à Transformação de Lewis e ao Método de Mapeamento Conforme Multiparâmetro, respetivamente. O trabalho do autor Balixa, C. (2021) consistiu na determinação das forças de excitação de Froude-Krylov e forças de Difração que são responsáveis pela excitação externa do sistema navio em ondas. Para a determinação dos RAOs recorreu-se aos estudos acima mencionados. De entre os métodos existentes, neste trabalho são utilizados como suporte teórico a Teoria das faixas e o método de Transformação Conforme Multiparâmetro.
Este trabalho para além de contribuir para a construção e retenção de conhecimento na área de Comportamento no Mar de navios, na Escola Naval e na Marinha, permitiu obter uma ferramenta computacional que determina RAO’s para navios da Marinha recorrendo aos métodos acima mencionados.
Ship behavior at sea : Development of a Response Amplitude Operators (RAOs) calculation tool Seakeeping is an essential area of study in Naval architecture, which focuses on analyzing and predicting the behavior of ships to certain sea conditions. Understanding a ship’s performance is crucial to ensuring safety, crew comfort and the efficiency of naval operations. The Response Amplitude Operators (RAOs) are fundamental parameters in the study of seakeeping. These represent a ship’s response to excitation caused by waves in terms of amplitude of motion and phase. RAOs are used to predict the ships’s dynamic response, such as surge, sway, heave, roll, pitch and yaw motions, under different sea states and wave direction relative to the ship for different speeds. The objective of this work is to solve the problem, in the frequency domain, of the free-body dynamic equation in a matrix form. This work follows on from the works carried out by Ferreira, S. (2018) and Ramujane, M. (2019) the authors, in their master’s dissertations, determined the added mass and damping coefficients using the Lewis Transformation and the Method of Conformal Multiparameter Mapping, respectively. Other work on this subject by Balixa, C. (2021) consisted in the determination of the Froude-Krylov excitation forces and Diffraction forces that are responsible for the external excitation of the ship system in waves. To determine the RAOs, the mentioned studies were used. Among the existing methods, these approach the Strip Theory and the Conformal Multiparameter Mapping. This work, in addition to contributing to the construction and retention of knowledge in the area of Seakeeping, at the Naval School and the Navy, made it possible to obtain a computational tool that determines RAO’s for Navy ships using the methods mentioned above.
Ship behavior at sea : Development of a Response Amplitude Operators (RAOs) calculation tool Seakeeping is an essential area of study in Naval architecture, which focuses on analyzing and predicting the behavior of ships to certain sea conditions. Understanding a ship’s performance is crucial to ensuring safety, crew comfort and the efficiency of naval operations. The Response Amplitude Operators (RAOs) are fundamental parameters in the study of seakeeping. These represent a ship’s response to excitation caused by waves in terms of amplitude of motion and phase. RAOs are used to predict the ships’s dynamic response, such as surge, sway, heave, roll, pitch and yaw motions, under different sea states and wave direction relative to the ship for different speeds. The objective of this work is to solve the problem, in the frequency domain, of the free-body dynamic equation in a matrix form. This work follows on from the works carried out by Ferreira, S. (2018) and Ramujane, M. (2019) the authors, in their master’s dissertations, determined the added mass and damping coefficients using the Lewis Transformation and the Method of Conformal Multiparameter Mapping, respectively. Other work on this subject by Balixa, C. (2021) consisted in the determination of the Froude-Krylov excitation forces and Diffraction forces that are responsible for the external excitation of the ship system in waves. To determine the RAOs, the mentioned studies were used. Among the existing methods, these approach the Strip Theory and the Conformal Multiparameter Mapping. This work, in addition to contributing to the construction and retention of knowledge in the area of Seakeeping, at the Naval School and the Navy, made it possible to obtain a computational tool that determines RAO’s for Navy ships using the methods mentioned above.
Description
Keywords
Arquitetura Naval Comportamento no mar de navios Response Amplitude Operators Mapeamento Conforme Multiparâmetro Teoria das Faixas