A Note on the Efficiency Potential of Semi-Submerged Ships. Revision 1,
Abstract
The 'lift/drag' ratio (L/D) which could be achieved with semi-submerged ships (s3) was studied. Given that the motion in a seaway can be very small, then L/D is by far the most important factor in any comparison with other forms of vehicle. That motions can be less than for conventional ships has been clearly shown by a number of eminent workers over the last thirty years. We suggest here, in fact, that motions could be essentially zero, if one is prepared to accept a form which has negligible hydrostatic pitch and roll stiffness when underway, relying on dynamic pressure forces on stabilizer foils for stability. We conclude that in medium and large sizes, S3 offers the possibility of very high L/D ratios in the intermediate speed range around 60 knots, and large S3 may be competitive at 100 knots. The poor showing to date seems to be principally due to designs which have the submerged hull to close the surface, struts which are very thick and/or have large wetted area, and insufficient development work on reducing interference drag.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1976
- Accession Number
- ADA081474
Entities
People
- Peter R. Payne