Accession Number : AD0701368

Title :   IRROTATIONAL FLOW ABOUT SHIP FORMS,

Descriptive Note : Interim rept.,

Corporate Author : IOWA UNIV IOWA CITY IOWA INST OF HYDRAULIC RESEARCH

Personal Author(s) : Landweber,Louis ; Macagno ,Matilde

Report Date : DEC 1969

Pagination or Media Count : 35

Abstract : A method of computing the potential flow about a ship model in terms of a source distribution on the hull surface is described. After a formulation and discussion of the flow with wavemaking, the zero-Froude number, double-ship-model case is treated in detail. The Fredholm singular integral equation of the second kind for the source distribution is solved numerically by removing the singularity, replacing the integral by a quadrature formula, and solving the resulting high-order set of linear equations by an iteration formula for which convergence is proved. The corresponding velocity potential on the hull surface, the evaluation of which from the source distribution also requires the calculation of a singular integral, is obtained by first solving the equipotential problem for the hull form (which employs the same kernel as the original integral equation). The solution of this Dirichlet problem is then used to remove the singularity from the velocity-potential integral, and then the latter is computed by means of a quadrature formula. The method is applied to an ellipsoid, results from which are compared with the exact solution. A FORTRAN program is included. (Author)

Descriptors :   (*SHIP HULLS, *HYDRODYNAMICS), INCOMPRESSIBLE FLOW, SHIP MODELS, POTENTIAL THEORY, SHIPS, INTEGRAL EQUATIONS, THREE DIMENSIONAL FLOW, DISTRIBUTION, SOURCES

Subject Categories : Marine Engineering
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE