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 ca...

Full description

Saved in:
Bibliographic Details
Main Author: Loeb,George I
Format: Report
Language:English
Subjects:
ANTIFOULING
ANTIFOULING COATINGS
BACTERIA
BARNACLES
CHLORELLA
Coatings, Colorants and Finishes
COLONIES(BIOLOGY)
DRAG
FOULING ORGANISMS
HYDRODYNAMIC CONTROL SURFACES
HYDRODYNAMICS
Marine Engineering
MARINE PROPELLERS
METALS
MICROORGANISMS
ORGANIC MATERIALS
PE64561N
POLYCHAETA
SHIP HULLS
SLIME
SURFACES
THICKNESS
WU1144
Online Access:Request full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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. (Author)