Accession Number : AD0710767

Title :   SECOND-ORDER THEORY OF OSCILLATING CYLINDERS,

Corporate Author : CALIFORNIA UNIV BERKELEY COLL OF ENGINEERING

Personal Author(s) : Potash,Roger L.

Report Date : JUN 1970

Pagination or Media Count : 167

Abstract : Two-dimensional cylinders of arbitrary shape undergo small-amplitude forced sinusoidal motion in sway, heave and roll in (or near) the free surface of an infinitely deep ideal fluid. Equations for the theoretical fluid response to 'second-order' are derived and their solution formulated in terms of Fredholm integral equations. A numerical procedure is developed and applied to three surface-piercing cylinder sections. Graphs of added mass, damping coefficient, pressure distribution, force and asymptotic wave amplitude as functions of non-dimensional wave number k are presented for the pure motions and for combined sway and heave, sway and roll, and heave and roll. The results indicate the significance of second-order coupling forces which result in the later motion cases. Additionally, second-order response coefficients are shown to be important in the higher frequency range. (Author)

Descriptors :   (*HYDRODYNAMICS, CYLINDRICAL BODIES), (*CYLINDRICAL BODIES, OSCILLATION), (*SHIPS, MOTION), FLOATING BODIES, POTENTIAL THEORY, BOUNDARY VALUE PROBLEMS, INTEGRAL EQUATIONS, NUMERICAL METHODS AND PROCEDURES, WATER WAVES, HARMONIC GENERATORS, SHIP HULLS, RESPONSE

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE