Accession Number : AD0474568

Title :   ANALYSES OF SPHERICAL BULBS ON A SHIP BOW.

Descriptive Note : Technical rept.,

Corporate Author : HYDRONAUTICS INC LAUREL MD

Personal Author(s) : Yim, B.

Report Date : OCT 1965

Pagination or Media Count : 42

Abstract : A bulb at a ship bow has long been known to be effective in reducing the ship wave resistance. The mechanism of bulbs is in cancelling sine waves from a ship bow consequently decreasing the bow wave resistance. The reduction of wave resistance is a function of Froude number, the ship shape, and the form, the size and the location of the bulb. The bulb has been generally expressed by a point doublet or a doublet line. There are two methods of obtaining the optimum bulb: one is by matching the amplitude functions of the ship bow waves and the bulb waves; the other is by minimizing the resistance due to the waves starting from the bulbous bow. It is shown that the reduction of the ship wave resistance due to a point doublet is almost as good as the distributed one. (Author)

Descriptors :   (*SHIP HULLS, SPHERES), FRICTION, DRAG, INCOMPRESSIBLE FLOW, WATER WAVES.

Subject Categories : Marine Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE