Date of Award

4-2017

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Ocean Engineering and Marine Sciences

First Advisor

Prasanta K. Sahoo

Second Advisor

Chelakara Subramanian

Third Advisor

Geoffrey Swain

Fourth Advisor

Ronnal Reichard

Abstract

Marine fouling on the hull of surface vessels is a topic of increasing importance in the maritime field for its environmental and financial impacts. Recent research developments have introduced mathematical models dealing with the frictional resistance associated with fouling, thus enabling to single out their impact on ship hydrodynamics. Herein, two implementations of these models are presented. The first implementation used Computational Fluid Dynamics to assess the additional drag induced by fouling for a specific ship model. With the software STAR CCM+, Reynolds Averaged Navier-Stokes equations have been used to model turbulence, wall laws parameters have been adapted to suit a Colebrook-type engineering roughness function, and a hybrid wall treatment captures the flow near the wall. Full details of the simulation set-up are given. The second implementation used turbulent flow similarity scaling laws in a MATLAB code to predict the added resistance of ships due to biofouling and the associated costs. With flexibility in mind, the code has been designed to account for the singularity of each context based on at least one in-situ observation of the fouling condition. Through a hypothetical, yet realistic scenario, it is shown that it enables proactive management by indicating when the cumulative penalty of fouling is no longer tolerable from a financial standpoint. The results of both implementations were validated against experimental data found in the literature. Prediction of the additional drag caused by fouling on a frigate showed excellent agreement of both methods.

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