Accession Number : AD0690945

Title :   DEVELOPMENT AND EVALUATION OF A SECOND-ORDER WAVE-RESISTANCE THEORY.

Descriptive Note : Final rept.,

Corporate Author : STEVENS INST OF TECH HOBOKEN N J DAVIDSON LAB

Personal Author(s) : Eng,King

Report Date : AUG 1969

Pagination or Media Count : 79

Abstract : A new second-order wave-resistance theory for floating bodies is developed, and then assessed by application to a parabolic strut. The problem is treated as a potential flow problem with a centerplane distribution of sources to represent the body. However, the kinematical boundary condition is satisfied on the surface of the body. It is supposed that the beam-length ratio , t , is small and that the square of the disturbance velocities which appeared in Bernoulli's equation on the free surface is given in terms of the components of the first-order potential. It is also assumed that the solution of the source density, sigma, is in the form of an asymptotic series in t , and the solution for sigma is obtained up to the order of t sq. The wave resistance is then computed on the basis of the improved source density and the correction arising from the improved representation of the free surface. It is found that at low Froude number the expansion scheme used by Sisov, by Maruo, by Yim, and by Eggers, can give negative resistance if the beam-length ratio is not small enough. Therefore, a new definition is adopted; that is, the second-order wave resistance is based on the improved disturbance potential without expansion of the amplitude function of the wave-resistance integral. (Author)

Descriptors :   (*FLOATING BODIES, *DRAG), HYDRODYNAMICS, SHIP STRUCTURAL COMPONENTS, SUPPORTS, PARABOLIC BODIES, THEORY, MATHEMATICAL ANALYSIS, THESES

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE