An experimental/numerical approach for evaluating skin friction on full-scale ships with surface roughness

Leer-Andersen, Michael; Larsson, Lars

doi:10.1007/s10773-003-0150-y

Cited by 36 publications

(18 citation statements)

References 2 publications

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“…These tests have been performed in cavitation tunnels, for instance measuring the forces on a floating element at the wall [6], or velocity profiles and Reynolds stresses using laser Doppler velocimetry [4,42]. However, a more accurate means to measure ∆U + is through the measure of the streamwise pressure gradient and the flow rate in a fully-developed channel flow facility [23,43]. In fact, indirect methods for the determination of frictional resistance from velocity measurements are highly sensible to scatter in the data [44].…”

Section: Recommended Experimental Setupmentioning

confidence: 99%

“…Every surface must be treated separately and its frictional properties tested experimentally [22]. This approach was followed by Leer-Andersen and Larsson [23], who suggested an experimental-numerical procedure to include experimental results into a commercial boundaryelement software. Following this approach, in the present paper the experimental data are fed to ad hoc wall-functions for a RANS code.…”

Section: Introductionmentioning

confidence: 99%

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Modelling of hull roughness

et al. 2019

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In this paper we present a practical guideline on how to estimate the frictional resistance of ship hulls due to different fouling control coatings. Most of the current methods rely on empirical formulations based on an equivalent sand grain roughness height. These correlations are not universal and cannot be applied to every marine surface. Conversely, the shear stress of a specific coating can be measured in an experimental facility at the same Reynolds roughness number as at full scale. The results can be used to inform the boundary conditions of computational fluid dynamics, where the complex flow around the ship can be computed for any sailing condition. Hence, this methodology allows the estimation of the frictional resistance due to a specific surface in a specific sailing condition. Representative antifouling coating products by AkzoNobel, and wall functions for the open-source code OpenFOAM, are used to illustrate the methodology. Similarities and differences with other methods are discussed.

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Section: Recommended Experimental Setupmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modelling of hull roughness

et al. 2019

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“…In the early 2000, Dubigneau el al [1] also applied the full-scale CFD method to optimize hull form and found significant difference on design results. At the same time, Leer-Andersen and Larsson [2] performed experimental and numerical investigation on full-scale ship to evaluate the effect of different surface topographies on skin friction. As a result, a modification on friction resistance calculations were added to the CFD code SHIPFLOW.…”

Section: Introductionmentioning

confidence: 99%

Numerical Analysis of Full-scale Ship Self-Propulsion Performance with direct Comparison to Statistical Sea Trail Results

Sun¹,

Hu²,

Hu³

et al. 2019

Preprint

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Accurate prediction of the self-propulsion performance is one of the most important factors for energy-efficient design of a ship. In general, the hydrodynamic performance of a full-scale ship could be achieved by model-scale simulation or towing tank test with extrapolations. With the development of CFD methods and computing power, directly predict ship performance with full-scale CFD is an important approach. In this article, a numerical study on the full-scale self-propulsion performance with propeller operating behind ship at model- and full-scale is presented. The study includes numerical simulations using RANS method with double-model and VOF model respectively and scale effect analysis based on overall performance, local flow fields and detailed vortex identification. Verification study on grid convergence is also performed for full-scale simulation with global and local mesh refinements. And a series of sea trail tests were performed to collect reliable data for the validation of CFD predictions. The analysis of scale effect on hull-propeller interaction shows that the difference on hull boundary layer and flow separation is the main source of scale effect on ship wake. And the results of the fluctuations of propeller thrust and torque along with circulation distribution and local flow field show that propeller’s loading is significantly higher for model-scale ship. It is suggested that the difference on vortex evolution and interaction is more pronounced and have larger effects on ship’s powering performance at model-scale than full-scale according to the simulation results. From the study on self-propulsion prediction, it could be concluded that the simplification on free surface treatment does not only affect the wave-making resistance for bare hull but also the propeller performance and propeller induced ship resistance which can produced up to 5% uncertainty to the power prediction. Roughness is another important factor in full-scale simulation because it has up to approximately 7% effect on the delivery power. As a result of validation study, the numerical simulations of full-scale ship self-propulsion shows good agreement with the sea trail data especially for cases that have considered both roughness and free surface effects. This result will largely enhance our confidence to apply full-scale simulation in the prediction of ship’s self-propulsion performance in the future ship designs.

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“…Marine fouling organisms, such as barnacles, mussels, hydroids and ascidians cause serious problems by settling on ship hulls, and other water-borne structures such as hydroelectric power plants, cooling systems, off-shore platforms and fishing equipment. [2][3][4] Biofouling represents a major nuisance for maritime industries, especially for shipping, as biofouling on ship hulls may increase boat weight, subsequently inducing over-consumption of fuel and increased maintenance costs. [5] To protect these marine structures from such settlement, paints containing biocidal compounds such as organotin and copper compounds have been widely used as the most effective antifouling agents.…”

Section: Introductionmentioning

confidence: 99%

Isolation and Antimacrofouling Activity of Indole and Furoquinoline Alkaloids from ‘Guatambú’ Trees (Aspidosperma australe and Balfourodendron riedelianum)

Pérez

Diez

Valdez

et al. 2019

Chemistry & Biodiversity

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In this work, the antifouling activity of five alkaloids, isolated from trees of the Atlantic rainforest, was studied. The tested alkaloids were olivacine (1), uleine (2) and N‐methyltetrahydroellipticine (3) from Aspidosperma australe (‘yellow guatambú’) and the furoquinoline alkaloids kokusaginine (4) and flindersiamine (5) from Balfourodendron riedelianum (‘white guatambú’). All these compounds can be isolated from their natural sources in high yields in a sustainable way. The five compounds were subjected to laboratory tests (attachment test of the mussel Mytilus edulis platensis) and field trials, by incorporation into soluble matrix paints, and 45 days of exposure of the painted panels in the sea. The results show that compound 3 is a very potent antifoulant, and that compounds 4 and 5 are also very active, while compounds 1 and 2 did not show any significant antifouling activity. These results open the way for the development of environmentally friendly antifouling agents, based on abundant and easy‐to‐purify compounds that can be obtained in a sustainable way.

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An experimental/numerical approach for evaluating skin friction on full-scale ships with surface roughness

Cited by 36 publications

References 2 publications

Modelling of hull roughness

Modelling of hull roughness

Numerical Analysis of Full-scale Ship Self-Propulsion Performance with direct Comparison to Statistical Sea Trail Results

Isolation and Antimacrofouling Activity of Indole and Furoquinoline Alkaloids from ‘Guatambú’ Trees (Aspidosperma australe and Balfourodendron riedelianum)

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