Banca de QUALIFICAÇÃO: PAOLA ANDREA DEL PILAR FONSECA FLÓREZ

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : PAOLA ANDREA DEL PILAR FONSECA FLÓREZ
DATE: 11/10/2023
TIME: 18:30
LOCAL: Sala 406 do Bloco B do Campus de Santo André da Universidade Federal do ABC
TITLE:

Experimental Identification of the Hydrodynamic Parameters for an Open Frame ROV Used in the Stock Assessment of Scallops

PAGES: 95
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUBÁREA: Projetos de Máquinas
SPECIALTY: Máquinas, Motores e Equipamentos
SUMMARY:

This work addresses the experimental identification of the main hydrodynamic parameters of a ROV (remotely operated vehicle) used for the stock assessment of scallops on the north coast of Peru. This vehicle contains eight thrusters, which allows it to move in six degrees of freedom. It is a high-resolution camera that, with a detection algorithm of scallops, can estimate the quantity and size of this benthonic animal per square meter on the ocean floor. The present work is divided into two parts.

 Firstly, the mechanical design, where both the propulsion system and structural configuration are described, as well as the instrumentation and communication system.

The second part of the work, which contains three papers in the process of being published, presents the procedures and results of the experimental tests to determine the drag coefficients and added masses. These tests were classified into three types described below,

The first type consisted of moving the ROV through a water channel with the vehicle attached to a towing carriage at constant velocities in surge, sway, and heave directions, considering one direction at a time. The drag force was measured by a load cell. Then, using the velocity and drag force data, the linear and quadratic drag coefficients were determined by the least square method.

In the second type of test, the vehicle moved through a pool using its propulsion system. The ROV had velocity sensors and gyroscopes to measure the linear and angular velocities, respectively. The vehicle individually moved in each of its degrees of freedom, surge, sway, heave, roll, pitch, and yaw at constant velocities. Afterward, the linear and quadratic drag coefficients were also determined by the least square method using the velocity, force, and torque data collected for each DOF tested.

Finally, the third type of test determined the added masses in surge, sway, and heave directions through damped free oscillation tests in a water tank. The tests consisted of supporting the ROV model reduced on a scale of 1:3 in a fixed structure through springs and made it oscillate free and damply in still water in 1-DOF from different initial amplitudes and equivalent stiffnesses. The acceleration during the oscillations was measured by an accelerometer coupled to the reduced model to know the natural frequency of the system. Then, the added mass was determined using the damped natural frequency equation for a 1-DOF mass-spring-damper system.

The results of drag coefficients and added masses were compared with those obtained by other researchers available in the literature that used ROVs with similar shapes to the vehicle used in this work. The results obtained demonstrated to be coherent. There was a difference in the thrust curve obtained between the tests using the towing tank and those made using the propulsion system because, in this last, the thrust curve of the thrusters was not determined with them installed in the ROV, so the loss of force caused by the vehicle's motion and interactions thruster-thruster and thruster-frame was not included in the curve.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1761050 - JUAN PABLO JULCA AVILA
Membro Titular - Examinador(a) Externo à Instituição - ANDREA PIGA CARBONI
Membro Titular - Examinador(a) Externo à Instituição - JOSEPH ARTHUR MELENDEZ VASQUEZ
Membro Suplente - Examinador(a) Interno ao Programa - 2249350 - DIEGO PAOLO FERRUZZO CORREA