Evaluation of hydrodynamic drag on experimental fouling-release surfaces, using rotating disks.
Fouling by biofilms significantly increases frictional drag on ships' hulls. A device, the friction disk machine, designed to measure torque on rotating disks, was used to examine differences among experimental fouling-release coatings in the drag penalty due to accumulated biofilms. Penalties were measured as the percentage change in the frictional resistance coefficient Cf. Drag penalties due to microfouling ranged from 9% to 29%, comparable to previously reported values. An antifouling control coating showed a smaller drag penalty than the fouling-release coatings. There were also significant differences among the fouling-release coatings in drag due to biofilm formation. These results indicate that the friction disk machine may serve as a valuable tool for investigating the effects of experimental coatings, both antifouling and fouling-release, on microfouling and associated drag penalties.
Holm
Eric R
ER
Naval Surface Warfare Center, Carderock Division, Code 641, Bldg 60, Rm 334, MacArthur Blvd, West Bethesda, MD 20817 5700, USA. holmer@nswccd.navy.mil
Schultz
Michael P
MP
Haslbeck
Elizabeth G
EG
Talbott
Walter J
WJ
Field
Andrew J
AJ
D000704:Analysis of Variance; D018441:Biofilms; D001703:Biophysics / Q000295:instrumentation* / Q000379:methods; D017276:Friction; D010150:Paint; D012767:Ships