An experimental study has been made to compare the frictional resistance of several ship hull coatings in the unfouled, fouled, and cleaned conditions. Hydrodynamic tests were completed in a towing tank using a flat plate test fixture towed at a Reynolds number ReL range of 2.8×106-5.5×106 based on the plate length and towing velocity. The results indicate little difference in frictional resistance coefficient CF among the coatings in the unfouled condition. Significant differences were observed after 287 days of marine exposure, with the silicone antifouling coatings showing the largest increases in CF. While several of the surfaces returned to near their unfouled resistance after cleaning, coating damage led to significant increases in CF for other coatings. The roughness function ΔU+ for the unfouled coatings showed reasonable collapse to a Colebrook-type roughness function when the centerline average height k=0.17Ra was used as the roughness length scale. Excellent collapse of the roughness function for the barnacle fouled surfaces was obtained using a new roughness length scale based on the barnacle height and percent coverage.

Keywords:
friction, protective coatings, hydrodynamics, surface roughness, paints, boundary layer turbulence
Topics:
Coatings, Friction, Reynolds number, Skin friction (Fluid dynamics), Surface roughness, Uncertainty, Silicones, Ships
1.
Kempf
,
G.
,
1937
, “
On the Effect of Roughness on the Resistance of Ships
,”
Trans. Institution of Naval Architects
79
, pp.
109
–
119
.
2.
Benson, J. M., Ebert, J. W., and Beery, T. D., 1938, “Investigation in the NACA Tank of the Effect of Immersion in Salt Water on the Resistance of Plates Coated With Different Shipbottom Paints,” N.A.C.A. Memorandum Report C&R C-S19-1(3).
3.
Denny
,
M. E.
,
1951
, “
B.S.R.A. Resistance Experiments on the Lucy Ashton: Part I—Full-Scale Measurements
,”
Trans. Institution of Naval Architects
93
, pp.
40
–
57
.
4.
Lewthwaite
,
J. C.
,
Molland
,
A. F.
, and
Thomas
,
K. W.
,
1985
, “
An Investigation Into the Variation of Ship Skin Frictional Resistance With Fouling
,”
Trans. Royal Institute of Naval Architect.
,
127
, pp.
269
–
284
.
5.
Watanabe
,
S.
,
Nagamatsu
,
N.
,
Yokoo
,
K.
, and
Kawakami
,
Y.
,
1969
, “
The Augmentation in Frictional Resistance Due to Slime
,”
J. Kansai Society of Naval Architects
,
131
, pp.
45
–
51
.
6.
Leer-Andersen
,
M.
, and
Larsson
,
L.
,
2003
, “
An Experimental/Numerical Approach for Evaluating Skin Friction on Full-Scale Ships With Surface Roughness
,”
J. Marine Sci. Technol.
,
8
, pp.
26
–
36
.
7.
Townsin
,
R. L.
,
2003
, “
The Ship Hull Fouling Penalty
,”
Biofouling
,
19
(
Supplement
), pp.
9
–
16
.
8.
Swain, G., 1998, “Biofouling Control: A Critical Component of Drag Reduction,” Proceedings of the International Symposium on Seawater Drag Reduction, Newport, RI, pp. 155–161.
9.
Champ
,
M. A.
,
2003
, “
Economic and Environmental Impacts on Port and Harbors From the Convention to Ban Harmful Marine Anti-Fouling Systems
,”
Mar. Pollution Bull.
,
46
, pp.
935
–
940
.
10.
Swain
,
G. W.
, and
Schultz
,
M. P.
,
1996
, “
The Testing and Evaluation of Non-Toxic Antifouling Coatings
,”
Biofouling
,
10
, pp.
187
–
197
.
11.
Candries, M., Atlar, M., and Anderson, C. D., 2000, “Considering the Use of Alternative Antifoulings: the Advantages of Foul-Release Systems,” Proceedings ENSUS 2000, Newcastle, UK, pp. 88–95.
12.
Brady
,
R. F.
, and
Singer
,
I. L.
,
2000
, “
Mechanical Factors Favoring Release From Fouling Release Coatings
,”
Biofouling
,
15
, pp.
73
–
81
.
13.
Schultz
,
M. P.
,
Finlay
,
J. A.
,
Callow
,
M. E.
, and
Callow
,
J. A.
,
2003
, “
Three Models to Relate Detachment of Low Form Fouling at Laboratory and Ship Scale
,”
Biofouling
,
19
(
Supplement
), pp.
17
–
26
.
14.
Swain
,
G. W.
,
Nelson
,
W. G.
, and
Preedeekanit
,
S.
,
1998
, “
The Influence of Biofouling and Biotic Disturbance on the Development of Fouling Communities on Non-Toxic Surfaces
,”
Biofouling
,
12
, pp.
257
–
269
.
15.
Kavanagh
,
C. J.
,
Schultz
,
M. P.
,
Swain
,
G. W.
,
Stein
,
J.
,
Truby
,
K.
, and
Darkangelo Wood
,
C.
,
2001
, “
Variation in Adhesion Strength of Balanus Eburneus, Crassotrea Virginica and Hydroides Dianthus to Fouling-Release Coatings
,”
Biofouling
,
17
, pp.
155
–
167
.
16.
Kovach, B. S., and Swain, G. W., 1998, “A Boat-Mounted Foil to Measure the Drag Properties of Antifouling Coatings Applied to Static Immersion Panels,” Proceedings of the International Symposium on Seawater Drag Reduction, Newport, RI, pp. 169–173.
17.
Lackenby, H., 1962, “Resistance of Ships, With Special Reference to Skin Friction and Hull Surface Condition,” Proceedings of the Institution of Mechanical Engineers, 176, pp. 981–1014.
18.
Musker
,
A. J.
,
1980
–1981, “
Universal Roughness Functions for Naturally-Occurring Surfaces
,”
Trans. Can. Soc. Mech. Eng.
,
1
, pp.
1
–
6
.
19.
Townsin
,
R. L.
,
Byrne
,
D.
,
Svensen
,
T. E.
, and
Milne
,
A.
,
1981
, “
Estimating the Technical and Economic Penalties of Hull and Propeller Roughness
,”
Trans. SNAME
,
89
, pp.
295
–
318
.
20.
Granville
,
P. S.
,
1987
, “
Three Indirect Methods for the Drag Characterization of Arbitrarily Rough Surfaces on Flat Plates
,”
J. Ship Res.
,
31
, pp.
70
–
77
.
21.
Medhurst, J. S., 1989, “The Systematic Measurement and Correlation of the Frictional Resistance and Topography of Ship Hull Coatings, With Particular Reference to Ablative Antifoulings,” Ph.D. Thesis, University of Newcastle-upon-Tyne, Newcastle, UK.
22.
Grigson
,
C. W. B.
,
1992
, “
Drag Losses of New Ships Caused by Hull Finish
,”
J. Ship Res.
,
36
, pp.
182
–
196
.
23.
Anon, 1952, Marine Fouling and Its Prevention, Woods Hole Oceanographic Institution.
24.
McEntee
,
W.
,
1915
, “
Variation of Frictional Resistance of Ships With Condition of Wetted Surface
,”
Trans. SNAME
,
24
, pp.
37
–
42
.
25.
Picologlou
,
B. F.
,
Zelver
,
N.
, and
Characklis
,
W. G.
,
1980
, “
Biofilm Growth and Hydraulic Performance
,”
J. Hydraul. Div., Am. Soc. Civ. Eng.
,
HY5
, pp.
733
–
746
.
26.
Haslbeck, E. G., and Bohlander, G., 1992, “Microbial Biofilm Effects on Drag—Lab and Field,” Proceedings 1992 SNAME Ship Production Symposium.
27.
Schultz
,
M. P.
, and
Swain
,
G. W.
,
1999
, “
The Effect of Biofilms on Turbulent Boundary Layers
,”
ASME J. Fluids Eng.
,
121
, pp.
733
–
746
.
28.
Schultz
,
M. P.
,
2000
, “
Turbulent Boundary Layers on Surfaces Covered With Filamentous Algae
,”
ASME J. Fluids Eng.
,
122
, pp.
357
–
363
.
29.
Clauser
,
F. H.
,
1954
, “
Turbulent Boundary Layers in Adverse Pressure Gradients
,”
J. Aeromaut. Sci.
,
21
, pp.
91
–
108
.
30.
Hama
,
F. R.
,
1954
, “
Boundary-Layer Characteristics for Rough and Smooth Surfaces
,”
Trans. SNAME
,
62
, pp.
333
–
351
.
31.
Krogstad
,
P. A˚.
, and
Antonia
,
R. A˚.
,
1999
, “
Surface Roughness Effects in Turbulent Boundary Layers
,”
Exp. Fluids
,
27
, pp.
450
–
460
.
32.
Schultz
,
M. P.
, and
Flack
,
K. A.
,
2003
, “
Turbulent Boundary Layers Over Surfaces Smoothed by Sanding
,”
ASME J. Fluids Eng.
,
125
, pp.
863
–
870
.
33.
Schultz
,
M. P.
, and
Myers
,
A.
,
2003
, “
Comparison of Three Roughness Function Determination Methods
,”
Exp. Fluids
,
35
, pp.
372
–
379
.
34.
Granville
,
P. S.
,
1958
, “
The Frictional Resistance and Turbulent Boundary Layer of Rough Surfaces
,”
J. Ship Res.
,
2
, pp.
52
–
74
.
35.
Schultz
,
M. P.
,
2002
, “
The Relationship Between Frictional Resistance and Roughness for Surfaces Smoothed by Sanding
,”
ASME J. Fluids Eng.
,
124
, pp.
492
–
499
.
36.
ASTM D3623, 1994, “Standard Test Method for Testing Antifouling Panels in Shallow Submergence,” Vol. 6.02.
37.
Moffat
,
R. J.
,
1988
, “
Describing the Uncertainties in Experimental Results
,”
Exp. Therm. Fluid Sci.
,
1
, pp.
3
–
17
.
38.
Coleman
,
H. W.
, and
Steele
,
W. G.
,
1995
, “
Engineering Application of Experimental Uncertainty Analysis
,”
AIAA J.
,
33
(
10
), pp.
1888
–
1896
.
39.
Schoenherr
,
K. E.
,
1932
, “
Resistances of Flat Surfaces Moving Through a Fluid
,”
Trans. SNAME
,
40
, pp.
279
–
313
.
40.
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
,
19
(
Supplement
), pp.
27
–
36
.
41.
Schlichting, H., 1979, Boundary-Layer Theory, 7th ed., McGraw-Hill, New York.
42.
Nikuradse, J., 1933, “Laws of Flow in Rough Pipes,” NACA Technical Memorandum 1292.
43.
Bradshaw
,
P.
,
2000
, “
A Note on “Critical Roughness Height” and “Transitional Roughness”
,”
Phys. Fluids
,
12
, pp.
1611
–
1614
.
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