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Published on: February 17, 2019
Evaluation of hydrodynamic drag on experimental fouling-release surfaces, using rotating disks
Eric R Holm1, Michael P Schultz, Elizabeth G Haslbeck
1Naval Surface Warfare Center, Carderock Division, Code 641, Bldg 60, Rm 334, MacArthur Blvd, West Bethesda, MD 20817 5700, USA. holmer@nswccd.navy.mil
Abstract:
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.
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