Accession Number : ADA131909

Title :   Water Waves Generated by a Slowly Moving Two-Dimensional Body. Part 1.

Descriptive Note : Final rept.,

Corporate Author : MICHIGAN UNIV ANN ARBOR DEPT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING

Personal Author(s) : Ogilvie,T Francis ; Chen,Si-Xiong

PDF Url : ADA131909

Report Date : May 1982

Pagination or Media Count : 31

Abstract : Low-speed motion of a ship leads to a singular perturbation problem as speed approaches zero, since waves occur only in a boundary layers of vanishing thickness at the free surface. The complete solution consists of the singular expansion superposed on a regular expansion. The latter (the naive expansion ) by itself satisfies all conditions in the lower half-space below the undisturbed free surface, but it does not represent the boundary layer. For the case of a two-dimensional surface-piercing body, it is shown that the regular perturbation series fails to satisfy the body boundary condition in a small wetted region just above the level of the undisturbed free surface. This fact leads to a nonhomogeneous body boundary condition that must be satisfied by the singular expansion. Without such a condition, the singular part of the solution (which represents the real wave motion) would satisfy purely homogeneous conditions and thus would be indeterminate. (Author)

Descriptors :   *Water waves, *Ship motion, Ship hulls, Two dimensional, Perturbations, Equations of motion, Boundary layer flow, Flow fields

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE