APPLICATION OF LIFTING-SURFACE THEORY TO THE PREDICTION OF HYDROELASTIC RESPONSE OF HYDROFOIL BOATS.

Abstract

A theoretical procedure is developed for the prediction of the dynamic response, elastic or rigid body, of a hydrofoil-supported vehicle in the flying condition -- to any prescribed transient or periodic disturbance. The procedure also yields the stability indices of the response, so that dynamic instabilities such as flutter can also be predicted. The unsteady hydrodynamic forces are introduced in the equations of motion for the elastic vehicle in terms of the indicial-pressure-response functions, which are derived from lifting-surface theory. Thus, the predicted vehicle-response includes the effects of three-dimensional unsteady flow conditions at specified forward speed. The natural frequencies and elastic modes of vibration of the vehicle and foil system in the absence of hydrodynamic effects are presumed known. A numerical procedure is presented for the solution of the downwash integral equations relating the unknown indicial pressure distributions to the specified elastic-mode shapes. The procedure is based on use of the generalized-lift-operator technique together with the collocation method. (Author)

Document Details

Document Type
Technical Report
Publication Date
May 01, 1967
Accession Number
AD0653751

Entities

People

  • Charles J. Henry

Organizations

  • Stevens Institute of Technology

Tags

DTIC Thesaurus Topics

  • Dynamic Response
  • Equations
  • Equations Of Motion
  • Flow
  • Frequency
  • Hydrofoils
  • Integral Equations
  • Lifting Surfaces
  • Modal Analysis
  • Pressure Distribution
  • Resonant Frequency
  • Surfaces
  • Three Dimensional
  • Unsteady Flow
  • Vibration

Fields of Study

  • Physics

Readers

  • Aerodynamics/Aeronautics.
  • Control Systems Engineering.
  • Marine Hydrodynamics