Accession Number : AD0624508

Title :   COMPLIANT WATER WAVE ABSORBERS.

Descriptive Note : Annual rept.,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF NAVAL ARCHITECTURE AND MARINE ENGINEERING

Personal Author(s) : Milgram,Jerome H.

Report Date : AUG 1965

Pagination or Media Count : 266

Abstract : This report comprises a detailed theoretical and experimental study of the problem of absorbing plane water waves by means of a moving boundary at one end of a channel. The non-linear problem is formulated as a sequence of linear problems by means of perturbation techniques. This formulation is carried out first for a general moving boundary and then for the specific case where the boundary is a hinged paddle above a solid wall. In order to avoid the parameter of the channel length in the theoretical work, this work is carried out for a semiinfinite tank. Solutions for the necessary wave absorber characteristics are determined by the first order (linear) theory. Second order solutions are determined when the incident wave is a plane, periodic, progressive wave. The theoretical developments are done with the neglect of surface tension, but these effects are considered in a separate chapter and they are accounted for in the computer programs used for the design of a wave absorbing system. The problem of synthesizing a wave absorbing system whose characteristics closely approximate an ideal absorber and which can be constructed readily is solved. The solution of this problem requires a computeraided design procedure for electric filters which may be of general interest for its own sake, apart from the remainder of this work.

Descriptors :   (*WATER WAVES, ABSORPTION), (*ABSORPTION, WATER WAVES), PERTURBATION THEORY, ELECTRIC FILTERS, HYDRODYNAMICS, WATER TANKS, EXPERIMENTAL DATA, THEORY

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE