Accession Number : AD0779844

Title :   Divergence Analysis of Swept Hydrofoils-Computer Program (SWDIVRG).

Descriptive Note : Final rept.,

Corporate Author : NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD

Personal Author(s) : Caspar,John R.

Report Date : APR 1974

Pagination or Media Count : 79

Abstract : A systematic approach is described by which divergence characteristics of swept or unswept hydrofoils may be calculated. The computer program, called SWDIVRG, developed to do the calculations makes use of a lumped-parameter approach, resulting in a matrix solution of the system. The bending and torsional displacements any of N stations along the hydrofoil span can be calculated at speeds less than divergence. Bending and torsional moments can be calculated for the condition of cantilever-beam constraints. The divergence spe d is principally computed by an eigenvector iteration scheme. A convenient formulation and a plot are provided for estimating the hydrodynamic loading parameters for finite-span, surface-piercing hydrofoils. Also, a useful closed-form divergence formulation, which considers submergence level, has been derived for the special case of a uniform cantilever strut or foil. Test calculations of airfoil models and one hydrofoil model, using both SWDIVRG and the closed-form solution, show good agreement with experimental model-divergence speeds. (Author)

Descriptors :   *Hydrofoil craft, *Hydrofoils, FORTRAN, Bending moments, Torsion, Lifting surfaces, Hydrodynamics, Mathematical models, Computer programs

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE