Session: 06-03-06 Fluid-Structure, Multi-body and Wave-body Interaction - VI

Submission Number: 181348

A Review of Methodologies, Standards, and Uncertainties in the Hydrodynamic Modelling of Marine Growth 

Coastal and offshore structures such as vessels, offshore wind turbines or subsea cables, are exposed to an environment of rich biodiversity. Such structures serve as surfaces for the settlement of marine organisms, forming biofilms and marine growth (MG) communities. In general, MG may be characterized as hard, soft, or long flapping with seven specific groups identified in previous literature: (i) mussels; (ii) kelps; (iii) algae (other than kelps); (iv) barnacles, tubeworms, limpets, etc.; (v) rock borers; (vi) hydroids and bryozoans; and (vii) sponges, anemones, sea squirts, and alcyonium. The specific composition of the MG community may vary depending on the timing of installation, time since installation, colour, orientation, geographic location, depth as well as the surface material and texture of the marine structure and is subject to succession dynamics. Settlement can also be influenced by variations in metocean conditions such as storminess, seasonality, and the influence of adjacent communities of epibenthic biota.

The resulting effects of MG on coastal and offshore structures are ample. Amongst others, the surface roughness and effective diameter of structures increases, flow dynamics around the structures are altered, and structural mass often increases. As a result, vessels may sail at reduced fuel efficiency, offshore wind turbine foundations / hulls and moorings may experience increased hydrodynamic loading, and subsea cables may suffer from reduced fatigue life.

Using anti-fouling coatings or performing frequent (manual) cleaning of surfaces can mitigate the negative effects of MG; however, such methods may not always be practicable, too costly or time consuming. Thus, an understanding of the effects of MG on marine structure is crucial to support the design of such structures and cater for detrimental MG-related effects throughout the life-cycle already during the design phase. Modelling MG during hydrodynamic investigations in experimental or numerical campaigns can provide improved understanding. However, methodologies for such testing are inconsistent, available standards may suffer from over-simplifications, and uncertainties concerning the characteristics of MG are still significant.

This study aims at supporting efforts to provide more consistent means for the hydrodynamic analysis of MG by reviewing existing methodologies, standards, and uncertainties. To that end, this study screens and collates the existing literature on the hydrodynamic modelling of MG in a systematic manner. Combing the exiting knowledge on MG modelling in a comprehensive study together with identifying existing knowledge gaps and shortcomings of existing methodologies will help to improve modelling capabilities and serves as a call for future research.

Presenting Author: Christian Windt Technische Universität Braunschweig

Presenting Author Biography: Christian Windt graduated from the Hamburg University of Technology with a B.Sc in Mechanical Engineering (2013) and a M.Sc. in Energy Systems (2016). In 2020, Christian received a PhD from Maynooth University, with a thesis focused on high-fidelity numerical hydrodynamic modelling of wave energy converters in the CFD framework. In 2020 Christian then joined the Leichtweiss-Institute for Hydraulic Engineering and Water Resources as the project coordinator of the ERAnet Co-Fund project NuLIMAS. Currently, Christian is the research group leader “Sustainable Ocean Engineering”, which embraces various projects related to marine renewable energies and aquaculture.

Authors:

Christian Windt Technische Universität Braunschweig
Henri Busch Technische Universität Braunschweig
Rodrigo Ezeta MARIN
Nils Goseberg Technische Universität Braunschweig
Terry Griffiths Aurora Offshore Engineering
Henrik Neufeldt Technische Universität Braunschweig
Marie-Lise Schläppy Aurora Offshre Engineering
Franck Schoefs Nantes Université
Krish Sharman University of Massachusetts Amherst
Bryan Thurstan Aurora Offshore Engineering
Gael Verao Technische Universität Braunschweig