Accession Number : ADP003045

Title :   A Numerical Investigation of the Slender-Ship Wave Resistance Approximation,

Corporate Author : SCIENCE APPLICATIONS INC LA JOLLA CA

Personal Author(s) : Scragg,C. A.

Report Date : 17 NOV 1983

Pagination or Media Count : 18

Abstract : It would appear that the slender-ship approximation offers some promise for economical approximation of the wave resistance for some hull forms. We do not expect it to be as accurate as some of the more sophisticated numerical approaches, but its speed and simplicity can make it a valuable tool in the design process. For the two destroyer hulls examined in this study, this approach led to results which were in good agreement with experimental results although we note that the wave resistance is slightly over-predicted near the large hump in the curve at high Froude numbers (approximately 0.45). For the ATHENA, the agreement was not as good, especially near the wave resistance hump (Fn approximately 0.45). These results, although not as good as those obtained by Dawson or Chang, did agree reasonably well with experimental values at Froude numbers both below and above this Froude number. For the Wigley hull, the slender-ship approximation appears to yield significantly better agreement with experimentally determined values than was obtained by the thin-ship approximation, especially for high Froude numbers. As was the case with the ATHENA, the slender-ship results were somewhat lower than the thin-ship results at all Froude numbers. For the series 60 hull, the reduction in predicted wave resistance obtained by using the slender-ship approximation was very slight and the results did not agree with experimentally determined values to an acceptable degree. The submerged hull was the only case examined thus far in which thin-ship results agreed with experiment better than the slender-ship results. It was also the only case in which both theories under-predicted the wave resistance.

Descriptors :   *Ship hulls, *Water waves, Slender bodies, Resistance, Destroyers, Approximation(Mathematics), Computerized simulation

Distribution Statement : APPROVED FOR PUBLIC RELEASE