The frictional resistance characteristics of a Foul Release coating have been compared with those of a Tin-free Self-polishing Co-Polymer,
which is an IMO-compliant but toxic antifouling
system. Measurements of the roughness characteristics have been correlated
with drag measurements obtained from towing tank and water tunnel experiments.
The two-component two-beam LDV equipment measures
the turbulent boundary layer over a sand-roughened surface.
Water tunnel experiments have been carried out to measure the turbulent
boundary-layer characteristics of the different coatings with laser-doppler
velocimetry (LDV). The LDV equipment measures the boundary-layer velocity
profile over a flat plate set-up and allows the indirect calculation of
the roughness functions over the different painted surfaces using the Clauser
method (as modified by Perry et al.), the Hama method and the Reynolds-stress
method. Five test plates have been tested: steel (smooth), SPC, Foul-release
(sprayed and rollered) and Sand-grit. The roughness functions have been
correlated with a combination of roughness parameters. The roughness parameters
have been measured with both a stylus instrument (the standard BMT Hull
Roughness Analyser for ship hulls) and a non-intrusive optical instrument.
1. A 2.55m long plate was used for the experiments in the 40m long towing
tank of the University of Newcastle-upon-Tyne (1998).
plane experiments in Newcastle University Towing Tank
2. A 1/35-scale model of a narrow hull 115m wavepiercing catamaran was
used for the experiments in the 65m long towing tank of the University
of Strathclyde in collaboration with the University of Newcastle-upon-Tyne
(1999 - 2000).
The flat plate experiments have shown that the foul-release coating
system is hydrodynamically smoother than the SPC system.
The prospect of combining the foul-release coating with a drag
reduction technique seems interesting in terms of long-term marine application.
Particular attention is paid to passive techniques such as riblets and
compliant coatings; both of which are also encountered in nature as shark
scales and dolphin skin respectively.
My PhD research under the surpervision of Prof. Mehmet Atlar was sponsored by EPSRC, EDC and International
Coatings Ltd. The research project is ongoing and now focuses on the effect of coating propellers and the effect of slime films on the boundary-layer characteristics of coated surfaces.
Candries M., Atlar, M. and Anderson, C.D. (2003), Estimating the impact of new-generation antifoulings on ship performance: the presence of slime, Proceedings of the Institute of Marine Engineering, Science and Technology, Part A: Journal of Marine Engineering and Technology, No. A2, pp. 13-22, IMarEst Publications, London.
Anderson, C.D., Atlar, M., Candries, C., Callow, M.E., Milne, A. and Townsin, R.J. (2003) The development of Foul Release coatings for seagoing vessels, A Submission for IMarEST Marine Environment Award Queen�s Golden Jubilee Medal.
Candries, M., Atlar, M., Mesbahi, E. and Pazouki, K. (2003), The measurement of the drag characteristics of Tin-free Self-Polishing Co-polymers and Fouling Release coatings using a rotor apparatus. Biofouling,Vol. 19 Supplement: Papers of the 11th International Conference on Marine Corrosion and Fouling, San Diego, Cal., 21-26 July 2002, pp. 27-37.
Atlar M., Glover, E.J., Candries, M., Mutton, R.J. and Anderson C.D. (2002), The Effect of a Foul Release Coating on Propeller Performance, ENSUS 2002: International Conference on Marine Science and Technology for Environmental Sustainability, University of Newcastle-upon-Tyne, 16-18 December 2002, Newcastle-upon-Tyne.(PDF,
Candries, M and Atlar, M. (2002), Experimental investigation of the turbulent
boundary layer of surfaces coated with marine antifoulings, submitted
to ASME Journal of Fluids Engineering.
Candries, M. (2001), Drag, Boundary-Layer and Roughness Characteristics
of Marine Surfaces Coated with Antifoulings, PhD Thesis, December
2001, Department of Marine Technology, University of Newcastle-upon-Tyne,
M. Candries, M.Atlar, A. Guerrero and C.D. Anderson (2001), Lower frictional
resistance characteristics of Foul Release systems, Proceedings of the
Eight International Symposium on the Practical Design of Ships and Other
Floating Structures, Volume 1, pp. 517-523, Elsevier, Amsterdam.
M. Candries, C.D. Anderson and M. Atlar (2001), Low-energy surfaces on
high-speed craft. Proceedings HIPER '01, Hamburg, 3 May 2001. (PDF,
M. Candries, C.D. Anderson and M. Atlar (2001), Foul release systems and
drag. Proceedings PCE 2001, Antwerp, 28 March 2001. (PDF,
M. Candries (1998), Recent developments in surface technology and
the effect on roughness and drag, MSc Dissertation, University of
Ghent (Completed at the University of Newcastle-upon-Tyne under the Erasmus/Socrates
European Exchange Programme), Belgium. (1007 KB, available on request)
M. Atlar, E.J. Glover and M. Candries, Calculation of the effects of blade roughness on the performance of the propeller of M/T Guardian, Department of Marine Technology
Report No. MT-2002-003, University of Newcastle-upon-Tyne, February
M. Candries and M. Atlar, Experiments with a wavepiercing catamaran model
: the effect of three different paints, Department of Marine Technology
Report No. MT-2000-067, University of Newcastle-upon-Tyne, November
M. Candries and M. Atlar (2000), Influence of two different antifoulings
on the resistance and roughness of a flat plate, Department of Marine
Technology Report No. MT-2000-012, University of Newcastle-upon-Tyne,
M. Atlar, M. Candries and I. Paterson (1999), Coating performance tests
with model propeller no. ECT101, Department of Marine Technology Report
No. MT-1999-021, University of Newcastle-upon-Tyne, July 1999.
M. Candries, M. Atlar, G.H.G. Mitchell and D. Lamb (1998), Flat plane towing
experiments with two coatings. Department of Marine TechnologyReport
No. MT-1998-034, University of Newcastle-upon-Tyne, October 1998.
M. Candries and M. Atlar (1999), Review of drag reduction techniques for
long-term marine application: considering the combination with novel anti-fouling
systems. In: Z. Chara and J. Pollert (Eds.), Proceedings of the
11th European Drag Reduction Working Meeting, Institute of Hydrodynamics,
Prague, September 15-17, 1999.
M. Candries (1999), Recent Developments in Surface Technology and the
Effects on Roughness and Drag. Joint Winner of the 1999 KBUSI/URBIN
Price for Final Year Dissertations in Marine Technology, presented at the
Sofitel Hotel, Antwerp, 27 April 1999.
Because of my research I am particularly interested in flow control,
coherent motions and the effect of roughness on near-wall turbulence. In
a desire to learn more, make contacts with colleagues and keep up-to-date,
I created a maillist
devoted to turbulence on 15 March 1999