Session: 13-01-02 Blue Economy II

Paper Number: 104425

104425 - A Comparative Study Between Morison Equation and Screen-Type Method for Net Cages Under Waves and Currents 

Fish cage nets are important components in a marine aquaculture system. Because the complexity of the net-type structure leads to difficulty in modelling fluid dynamics, empirical methods are often applied in engineering practice. However, the accurate assessment of hydrodynamic loads is still an issue that has received considerable attention in engineering. At present, the two main approaches to the empirical evaluation of hydrodynamic loads on fish cage nets include the Morrison equation and the screen-type method. This paper will discuss the selection of key hydrodynamic parameters and the main differences between the two empirical formulations for cylindrical net chambers under wave and current actions. The finite element method (FEM) based dynamic solver AquaSim is adopted to simulate the hydroelastic behaviour of the net-type structure. A comparative study using these two hydrodynamic models performed a comprehensive investigation of the dynamic behavioural characteristics of net cages under different hydrodynamic conditions (incident wave angle, wave period, flow angle of attack, and incoming current velocity) and structural parameters (net solidity ratio, twine stiffness). The key hydrodynamic characteristics that determine these two methods, such as wake interaction, fluid inertia effects, fluid-structure interaction, etc., will be discussed. These studies may provide a reference for the selection of suitable hydrodynamic models in the design of practical marine aquaculture systems.

Presenting Author: Mingyuan Ma Griffith University

Presenting Author Biography: Mingyuan Ma is currently a PhD student at Griffith University, Australia. His research interests are mainly in the fields of offshore floating structures, wave dynamics, and fluid-structure interaction.

Authors:

Mingyuan Ma Griffith University
Hong Zhang Griffith University
Dong-Sheng Jeng Griffith University
Chien Ming Wang The University of Queensland