DRAG ENHANCEMENT OF MICROBIAL SLIME FILMS ON ROTATING DISCS
Recent advances in anti-fouling technology have made control of macroscopic fouling organisms (barnacles, bryozoans and tubeworms) feasible. Among the limiting factors in fast ship performance in the absence of macrofouling are the hydrodynamic drag of hull coatings themselves, the drag increment caused by microbial fouling of hull coatings, and losses in propulsion efficiency resulting from microbial colonization of propellers. This work assesses the significance of microbial colonization of organic and metal surfaces for hydrodynamic drag over a wide range of flow velocities. Measurements made with a rotating disc apparatus at disc peripheral speeds from 9.5 to 33 Kn (17 to 61 Km/hr) showed that (a) microbial slime films can be grown which withstand testing at these velocities and (b) drag increments in excess of 10% are often observed. Therefore, because they are not eliminated by current antifoulants, microbial fouling films and their effects on ship performance warrant serious consideration.
Naval Research Laboratory4555 Overlook Avenue, SW
Washington, DC United States 20375-5320
- Loeb, G I
- Publication Date: 1981-3-27
- Features: References;
- Pagination: 19 p.
- TRT Terms: Biodeterioration; Drag forces; Fouling (Naval architecture); Fouling organisms; Hulls; Propellers; Roughness; Skin resistance
- Old TRIS Terms: Hull roughness; Propeller efficiency
- Subject Areas: Marine Transportation; Vehicles and Equipment;
- Accession Number: 00331658
- Record Type: Publication
- Report/Paper Numbers: NLR Memo 4412 Final Rpt.
- Files: TRIS
- Created Date: Jun 12 1981 12:00AM