Calculation of Two-Dimensional Nonlinear Fluid Flow Resulting from Large-Amplitude Forced Heave Motion of a U-Shaped Cylinder in a Free Surface.

Abstract

Progress in developing a tool to compute large amplitude ship motions is reported. In particular, a method to calculate transient two-dimensional potential flow about a body moving in a free surface is described. The flow problem is formulated as an initial-boundary value problem in which the velocity potential along the free surface and the positions of the moving boundaries are sought as solutions of a coupled system of differential equations. An implicit finite-difference method is used to advance the solution of the coupled system of equations in time. The auxiliary problem of computing the velocity potential inside the fluid region is solved by a method which is based on boundary-fitted coordinates and is directly extensible to three-dimensional flows. Results from calculating the potential flow about a body in forced heave motion are presented. The hydrodynamic force on the body has been obtained and compared with the hydrodynamic force predicted from second-order perturbation theory. Keywords: Free Surface Effects; Heaving Cylinder; Perturbation Theory; Ship Motions; Ship Hydrodynamics; Water Waves.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1985
Accession Number
ADA162969

Entities

People

  • John G. Telste

Tags

Communities of Interest

  • Ground and Sea Platforms
  • Space

DTIC Thesaurus Topics

  • Boundary Value Problems
  • Complex Variables
  • Computer Programs
  • Coordinate Systems
  • Difference Equations
  • Differential Equations
  • Engineering
  • Equations
  • Fluid Flow
  • Frequency
  • Hydrodynamics
  • Mathematical Filters
  • Perturbation Theory
  • Physics Laboratories
  • Security
  • Three Dimensional
  • Two Dimensional

Fields of Study

  • Physics

Readers

  • Finite Element Method (FEM) for solving Partial Differential Equations (PDEs)
  • Fluid Dynamics.
  • Marine Hydrodynamics