A Systematic Approach to the Bow Problem.

Abstract

The wave making effectiveness of a ship is an important feature that must be fully recognized in developing a uniformly valid slender-ship theory for the wave resistance problem. The usual results of ordinary slender-ship theory are invalid near the bow of a slender ship because the theory fails to take into account the dominant effects of the divergent wave system in this region. A new approach based on the matched asymptotic expansions technique is used to solve the bow problem. The general solution of the far-field problem includes the well-known wave-free potentials plus the potential due to a line distribution of wave sources that extends outside the limits of the ship to guarantee the proper description of the far-field flow. The bow-near-field problem and the general form of its solution are derived. In order to match the two solutions in their overlap domain near the bow, the far-field source function is decomposed into two parts that include a 'slowly' varying source function and a 'rapidly' varying source function. The slowly varying sources can be determined from the solution of the bow-near-field problem. However, the rapidly varying sources, which are associated with the disturbances ahead of the bow and consequently needed to obtain the solution of the bow-near-field problem, cannot be determined unless we match the bow flow to the middle-body flow. The next step in the analysis will concern this problem. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Jul 01, 1978
Accession Number
ADA062560

Entities

People

  • Nabil Daoud

Organizations

  • University of Michigan

Tags

Communities of Interest

  • Air Platforms
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Applied Mathematics
  • Asymptotic Series
  • Computational Science
  • Engineering
  • Engineers
  • Equations
  • Far Field
  • Fluid Mechanics
  • Hulls (Marine)
  • Marine Engineering
  • Naval Architecture
  • Near Field
  • Physics Laboratories
  • Radiation
  • Ship Hulls
  • Standing Waves
  • Surface Properties

Readers

  • Calculus or Mathematical Analysis
  • Marine Hydrodynamics