The Small Froude Number Paradoxes and Wave Resistance at Low Speeds.

Abstract

Two basic asymptotic expansions of the equations of two-dimensional free-surface gravity flow past a body are first discussed: (i) the thin body, and (ii) the naive small Froude number expansions. It is shown that different solutions are obtained for small Froude number and thin body from (i) and (ii) (the first paradox), because (ii) is not uniform in the downstream region of the flow domain, where waves are concentrated. Moreover, the thin body expansion, which leads at first order to the usual linearized wavemaking approximation, is not uniform as the Froude number tends to zero (the second paradox). By using the exact solution of a model problem, linearized free-surface conditions leading to uniform small Froude number solutions have been derived. (Author)

Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1972
Accession Number
AD0746191

Entities

People

  • Gedeon Dagan

Tags

DTIC Thesaurus Topics

  • Asymptotic Series
  • Equations
  • Froude Number
  • Mathematics
  • Physical Properties
  • Resistance
  • Surface Properties
  • Two Dimensional

Fields of Study

  • Mathematics

Readers

  • Fluid Dynamics.
  • Marine Hydrodynamics