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Authors
Abstract(s)
Este estudo pretende caraterizar o espetro de ondulação do Tanque do Laboratório
de Arquitetura Naval, utilizando um sensor e um flutuador concebido com o objetivo de
ser sensível à influência das ondas geradas, determinando a aceleração da superfície livre
derivada da variação da sua elevação provocada por essas ondas.
Esta dissertação começa por ter a teoria linear das ondas como base, uma vez que
vão ser geradas ondas no tanque, e dada a interferência destas com o objeto concebido, vai
ser notado o efeito de arfagem nesse mesmo objeto. Dada a sua sensibilidade para notar a
aceleração proporcionada pelas ondas, e com o auxílio de um acelerómetro, um
amplificador de carga e um osciloscópio, vamos obter o gráfico correspondente a essa
aceleração num certo período de tempo, cuidadosamente definido por forma a evitar as
ondas estacionárias originadas devido às dimensões e restantes condicionantes do tanque.
Recolhidos estes dados, e com o uso do
, vai-se proceder à integração
dos gráficos resultantes das medições, por forma a passar o gráfico correspondente à
aceleração medida para um gráfico de posição. Para obter o espetro de ondulação
correspondente ao tanque, torna-se necessária a criação de um código respetivo às
Transformadas Rápidas de Fourier utilizando diferentes regimes de rotações do gerador de
ondas. Para confirmar a tendência dos valores a obter relativamente à frequência e à
amplitude com a variação do regime de rotações do motor, os gráficos resultantes vão ser
comparados com os valores obtidos com base nas fórmulas da teoria linear das ondas.
This study aims to characterize the wave spectrum of the Tank of the Laboratory of Naval Architecture, using a sensor and a float designed with the objective of being sensitive to the influence of the generated waves, determining the acceleration of the free surface variation derived from his elevation caused by these waves. This dissertation is based on the linear theory of waves, since waves are going to be generated in the tank and, as these interfere with the object designed, the heave effect will be perceived in that same object. Due to its sensitivity to detect the acceleration caused by the waves, and with the help of an accelerometer, a charge accelerator and an oscilloscope, we will obtain the graph corresponding to that acceleration in a certain period of time, carefully defined to avoid the stationary waves originated due to the dimensions and constraints of the tank. After these data are collected and using the we will carry out the integration of the graphs corresponding to the measurements in order to transform the graph corresponding to the measured acceleration into a displacement graph. For the corresponding wave spectrum of the tank, it is necessary to create a code relating to the Fast Fourier Transform using different rotation regimes of the wave generator. To confirm the trend of values to obtain for the frequency and amplitude variation of the rotation speed of the motor, the resulting graphics will be compared with the values obtained using the linear wave theory.
This study aims to characterize the wave spectrum of the Tank of the Laboratory of Naval Architecture, using a sensor and a float designed with the objective of being sensitive to the influence of the generated waves, determining the acceleration of the free surface variation derived from his elevation caused by these waves. This dissertation is based on the linear theory of waves, since waves are going to be generated in the tank and, as these interfere with the object designed, the heave effect will be perceived in that same object. Due to its sensitivity to detect the acceleration caused by the waves, and with the help of an accelerometer, a charge accelerator and an oscilloscope, we will obtain the graph corresponding to that acceleration in a certain period of time, carefully defined to avoid the stationary waves originated due to the dimensions and constraints of the tank. After these data are collected and using the we will carry out the integration of the graphs corresponding to the measurements in order to transform the graph corresponding to the measured acceleration into a displacement graph. For the corresponding wave spectrum of the tank, it is necessary to create a code relating to the Fast Fourier Transform using different rotation regimes of the wave generator. To confirm the trend of values to obtain for the frequency and amplitude variation of the rotation speed of the motor, the resulting graphics will be compared with the values obtained using the linear wave theory.
Description
Keywords
Sensibilidade; Ondas estacionárias; Espetro de ondulação; Frequência; Teoria Linear das ondas. Sensivity; Stationary waves; Wave spectrum; Frequency; Linear wave theory.