Definition of an Artificial Reef Unit through Hydrodynamic and Structural (CFD and FEM) Models—Application to the Ares-Betanzos Estuary

María Isabel Lamas Galdo,Ricardo Veira Lorenzo,Javier Lamas Vigo,Ismael Ameneiros Rodriguez,Juan Carlos Carral Couce,Luis Carral Couce,María Jesús Rodríguez Guerreiro

doi:10.3390/jmse10020230

María Isabel Lamas Galdo, Ricardo Veira Lorenzo + Show 5 more

Open Access

https://doi.org/10.3390/jmse10020230

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Abstract

The application of hydrodynamics to the definition of artificial reefs is of great interest since the positioning of the artificial reef modules on the sea floor alters the water velocity field, causing an appropriate circulation of nutrients and promoting a habitat for settling desired species. Nevertheless, the designs must be subjected to a structural calculation that will condition the constructive process to be applied. The present research proposes a methodology to determine the geometry of an artificial reef in terms of hydrodynamic and structural criteria. The solution proposed was analyzed through Computational Fluid Dynamics (CFD) and the Finite Element Method (FEM). Using concrete as base material for artificial reefs, four different dosages were proposed with different proportions of cement and water, leading to different mechanical properties, which determine different constructive strategies, such as dwell time in the mold. From the hydrodynamic point of view, it was found that the solution proposed provides a proper replacement of nutrients. From the structural point of view, it was found that the solution proposed does not need steel reinforcements in concrete, which improves the sustainability of the artificial reef. The four different concrete dosages will condition the constructive strategy through the dwelling time in the mold and, for any established production, the necessary number of molds (formworks).

Highlights

Published: 9 February 2022Oceans embrace more than 90% of life in the biosphere [1] and produce half of the oxygen we employ to breathe and burn fossil fuels [2]
The present work proposes a methodology for designing an artificial reef according to hydrodynamic-structural calculation-construction criteria
Since artificial reefs alter the water velocity field, promoting an appropriate habitat for settling desired species, it is very important to analyze the geometry of the artificial reef carefully

Summary

Introduction

Published: 9 February 2022Oceans embrace more than 90% of life in the biosphere [1] and produce half of the oxygen we employ to breathe and burn fossil fuels [2]. Oceans regulate the global climate since they act as a thermal mass to store heat and CO2 generated by human activities [3]. The conditions of oceans present direct implications to life on our planet [4]. The risk of overexploitation is too high unless the extractive activities start effective regulation [6]. The consequences of human activities on oceans manifest through reductions of fish populations, a threat with the extinction of others, destruction of habitats, pollution, the introduction of non-native species, ocean warming and acidification, and so on [8,9]. According to FAO (Food and Agriculture Organization of United Nations), 25% of the worldwide fisheries were overexploited, depleted or in the depletion process in

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