THE DYNAMICS OF CONTAINED OIL SLICKS
Numerous papers are written describing devices which solve the problem of oil spill clean-up but which in fact have only been tested in sheltered laboratory flumes or at best in confined and protected waterways. At present there is no known means of removing an oil film as such from a water surface other than by the natural processes of evaporation and biological degradation. The efficiency of man devised removal techniques increases rapidly as the thickness of the slick itself increases so that confinement of the slick is usually the first step in the clean-up procedure. Wind and currents will cause oil to accumulate on the upstream side of any partially submerged barrier which impedes the flow of oil on the water surface. Unfortunately oil slicks cannot always be contained in this way. Wind and waves can splash oil under and over an oil boom which itself may fail structurally due to the drag forces of currents and waves. However these faults are basically design failings and it is foreseeable that in the future they can be rectified to some extent. But there is another more basic limitation to oil booms and this is dynamic instability of the slick itself over which the boom designer has no control. This instability can occur in any slick contained in water of finite depth and develops when the slick thickness is approximately one third of the flow depth. Fortunately its occurrence can also be predicted when a dimensionless number based on the stream velocity upstream of the slick, the stream depth and the density of the oil attains a critical value. The criteria for the dynamic stability of an oil slick are examined so that regions of a channel, river or tidal estuary where containment of oil slicks is possible, may be determined in advance. Attempts to contain oil in areas when the slick would be dynamically unstable are bound to fail.
- Appeared in DME/NAE Quarterly Bulletin No. 1972 (1).
National Research Council of CanadaDivision of Mechanical Engineering, Montreal Road
Ottawa, ONo K1A 0R6, Canada
- Wilkinson, D L
- Publication Date: 1972-4
- Features: References;
- Pagination: 39 p.
- TRT Terms: Oil booms; Oil spill cleanup; Oil spills
- Old TRIS Terms: Oil containment; Oil spill behavior; Oil spill control
- Subject Areas: Environment; Marine Transportation;
- Accession Number: 00054205
- Record Type: Publication
- Source Agency: National Research Council of Canada
- Files: TRIS
- Created Date: May 7 1974 12:00AM