THE EFFECT OF ENTRAPPED AIR UPON THE SLAMMING OF SHIPS' BOTTOMS
The effect of entrapped air on the slamming of ships' bottoms is examined with regard to dry cargo merchant ships. Experimental results, contrasted with the predictions of Ogilvie's theory, are presented along with outlines of new theoretical work based on them. Both one-dimensional and two-dimensional theories are advanced. The two-dimensional theory provides reasonable estimates for the duration and magnitude of peak centerline pressure during water impact. Further experimental work is desirable, especially to check some of the theoretical predictions of water and air movement. A more detailed analysis of the initial conditions is also required. A significant feature of the new theory is that, whereas both compressible and incompressible movement of the water is assumed to take place, the time scale of events is so long that the compressibility of the water is of less importance. Therefore flat impact is largely a hydrodynamic phenomenon. The magnitude of the peak pressure is dependent primarily upon the hydrodynamic added mass and the velocity of the water surface at coalescence.
- This document is available for review at the Department of Commerce Library, Main Commerce Building, Washington, D.C., under reference number UCB-NA-66-5.
University of California, BerkeleyCollege of Engineering
Berkeley, CA USA 94720
- Lewison, G
- Maclean, W M
- Publication Date: 1966-3
- Features: Appendices; Figures; Photos; References;
- Pagination: 62 p.
- TRT Terms: Hulls; Ships; Slamming; Vehicle design
- Uncontrolled Terms: Ship design
- Old TRIS Terms: Hull damage
- Subject Areas: Design; Marine Transportation; Vehicles and Equipment;
- Accession Number: 00026991
- Record Type: Publication
- Source Agency: Maritime Administration
- Report/Paper Numbers: NA-66-5
- Contract Numbers: MA-2620
- Files: TRIS, USDOT
- Created Date: Jun 15 1973 12:00AM