THE PERIODIC HEAVING MOTION OF A HALF-IMMERSED SPHERE: THE ANALYTIC FORM OF THE VELOCITY POTENTIAL LONG-WAVE ASYMPTOTICS OF THE VIRTUAL-MASS COEFFICIENT

Abstract

The analytic form of the velocity potential of a heaving hemisphere is studied. The potential is expanded in terms of a wave source and of wave free potentials, and the coefficients in the expansion are studied (1) when the dimensionless wave number Ka is small, and (2) when Ka is arbitrary. A typical result is that the virtual mass coefficient is the real part of ( n Ka i ) A1*(Ka) A1**(Ka)/( n Ka - i )A2*(Ka) A2**(Ka), where the functions A(Ka) are entire functions of Ka, real for real Ka. The argument depends on the expansion of a surface source in powers of Kr and n Kr, given here for the first time. A similar theory, not given here, can be developed for two-dimensional moving cylinders. It is believed that investigations of this kind will be helpful in studying the damped motion of freely floating bodies on still water.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1962
Accession Number
AD0408465

Entities

People

  • F. Ursell

Organizations

  • University of Victoria

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Analytic Functions
  • Coefficients
  • Equations
  • Floating Bodies
  • Fluid Dynamics
  • Government Procurement
  • Governments
  • Integral Equations
  • Integrals
  • Legendre Functions
  • Mathematics
  • Military Research
  • Power Series
  • Surface Properties
  • Three Dimensional
  • Two Dimensional
  • Waves

Fields of Study

  • Physics

Readers

  • Calculus or Mathematical Analysis
  • Electromagnetic Wave Scattering and Antenna Radiation Engineering
  • Marine Hydrodynamics