# Turbulent boundary layer measurements over flat surfaces coated by nanostructured marine antifoulings

Turbulent boundary layer measurements over flat surfaces coated by nanostructured marine... Whilst recent developments of nanotechnology are being exploited by chemists and marine biologists to understand how the completely environmentally friendly foul release coatings can control marine biofouling and how they can be developed further, the understanding of the hydrodynamic performances of these new generation coatings is being overlooked. This paper aims to investigate the relative boundary layer, roughness and drag characteristics of some novel nanostructured coatings, which were developed through a multi-European and multi-disciplined collaborative research project AMBIO (2010), within the framework of turbulent flows over rough surfaces. Zero-pressure-gradient, turbulent boundary layer flow measurements were conducted over flat surfaces coated with several newly developed nanostructured antifouling paints, along with some classic reference surfaces and a state-of-the-art commercial coating, in the Emerson Cavitation Tunnel (ECT) of Newcastle University. A large flat plane test bed that included interchangeable flat test sections was used for the experiments. The boundary layer data were collected with the aid of a two-dimensional DANTEC Laser Doppler Velocimetry (LDV) system. These measurements provided the main hydrodynamic properties of the newly developed nanostructured coatings including local skin friction coefficients, roughness functions and Reynolds stresses. The tests and subsequent analysis indicated the exceptionally good frictional properties of all coatings tested, in particular, the drag benefit of some new nanostructured coatings in the Reynolds number range investigated. The rapidly decreasing roughness function trends of AKZO19 and AKZO20 as the $$k_{s}^{ + }$$ increases were remarkable along with the dissimilar roughness function character of all tested coatings to the well-known correlation curves warranting further research at higher Reynolds numbers. The wall similarity concept for the Reynolds stresses was only validated for the transitionally rough surfaces from $$(y + \varepsilon)^{ + } \approx 100$$ up to the end of the boundary layer. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Experiments in Fluids Springer Journals

# Turbulent boundary layer measurements over flat surfaces coated by nanostructured marine antifoulings

, Volume 52 (6) – Jan 24, 2012
18 pages

/lp/springer_journal/turbulent-boundary-layer-measurements-over-flat-surfaces-coated-by-abae2u7ccx
Publisher
Springer-Verlag
Subject
Engineering; Engineering Fluid Dynamics; Engineering Thermodynamics, Heat and Mass Transfer; Fluid- and Aerodynamics
ISSN
0723-4864
eISSN
1432-1114
D.O.I.
10.1007/s00348-012-1262-z
Publisher site
See Article on Publisher Site

### Abstract

Whilst recent developments of nanotechnology are being exploited by chemists and marine biologists to understand how the completely environmentally friendly foul release coatings can control marine biofouling and how they can be developed further, the understanding of the hydrodynamic performances of these new generation coatings is being overlooked. This paper aims to investigate the relative boundary layer, roughness and drag characteristics of some novel nanostructured coatings, which were developed through a multi-European and multi-disciplined collaborative research project AMBIO (2010), within the framework of turbulent flows over rough surfaces. Zero-pressure-gradient, turbulent boundary layer flow measurements were conducted over flat surfaces coated with several newly developed nanostructured antifouling paints, along with some classic reference surfaces and a state-of-the-art commercial coating, in the Emerson Cavitation Tunnel (ECT) of Newcastle University. A large flat plane test bed that included interchangeable flat test sections was used for the experiments. The boundary layer data were collected with the aid of a two-dimensional DANTEC Laser Doppler Velocimetry (LDV) system. These measurements provided the main hydrodynamic properties of the newly developed nanostructured coatings including local skin friction coefficients, roughness functions and Reynolds stresses. The tests and subsequent analysis indicated the exceptionally good frictional properties of all coatings tested, in particular, the drag benefit of some new nanostructured coatings in the Reynolds number range investigated. The rapidly decreasing roughness function trends of AKZO19 and AKZO20 as the $$k_{s}^{ + }$$ increases were remarkable along with the dissimilar roughness function character of all tested coatings to the well-known correlation curves warranting further research at higher Reynolds numbers. The wall similarity concept for the Reynolds stresses was only validated for the transitionally rough surfaces from $$(y + \varepsilon)^{ + } \approx 100$$ up to the end of the boundary layer.

### Journal

Experiments in FluidsSpringer Journals

Published: Jan 24, 2012

## You’re reading a free preview. Subscribe to read the entire article.

### DeepDyve is your personal research library

It’s your single place to instantly
that matters to you.

over 18 million articles from more than
15,000 peer-reviewed journals.

All for just $49/month ### Explore the DeepDyve Library ### Search Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly ### Organize Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place. ### Access Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals. ### Your journals are on DeepDyve Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more. All the latest content is available, no embargo periods. DeepDyve ### Freelancer DeepDyve ### Pro Price FREE$49/month
\$360/year

Save searches from
PubMed

Create lists to

Export lists, citations