Correlation of Theoretical Predictions of Propeller-Induced Hull Pressures with Available Data.

Abstract

A method has been developed to calculate the blade frequency point pressure on a hull surface in the presence of a propeller and a free water surface. The approach is based on that previously employed in calculating the propeller-induced hull forces in which the hull is represented by a source distribution smeared over the hull surface whose strength is determined through the solution of a Fredholm integral equation of the 2nd kind in terms of specified propeller-induced velocities. Point pressures are determined by superposing the free-space pressure emanating from the propeller through its fanning action on the pressure due to the diffraction potential. A series of calculations was performed for the case of a model tanker tested extensively at the Norwegian Experimental Tank (Ship and Ocean Labroatory, Norwegian Hydrodynamic Laboratories. The agreement between experimental and predicted values varies from point to point; in general, the maximum deviation of amplitude is between + or - 30%, but the phases are in poor agreement. A new method is suggested in which the hull is represented by a doublet distribution rather than a source distribution. This approach which reduces computing time considerably permits improved accuracy and results in much better correlation between experimental and calculated values.

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1980
Accession Number
ADA110836

Entities

People

  • J. P. Breslin
  • J. Teeters
  • S. Tsakonas

Organizations

  • Stevens Institute of Technology

Tags

Communities of Interest

  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Accuracy
  • Bessel Functions
  • Cartesian Coordinates
  • Computer Programs
  • Coordinate Systems
  • Froude Number
  • Integral Equations
  • Lifting Surfaces
  • Marine Propellers
  • Measurement
  • Pressure Distribution
  • Propeller Blades
  • Ship Hulls
  • Ship Models
  • Steady State
  • Stratified Fluids
  • Two Dimensional

Readers

  • Aerodynamics.
  • Calculus or Mathematical Analysis
  • Naval Architecture and Marine Engineering.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster