Accession Number : AD0649159

Title :   A STUDY OF FLOW PAST A SHIP-LIKE BODY,

Corporate Author : CONNECTICUT UNIV STORRS DEPT OF CIVIL ENGINEERING

Personal Author(s) : Lin,J. D. ; Hall,R. S. , Jr

Report Date : NOV 1966

Pagination or Media Count : 140

Abstract : A method is presented for calculating the flow about ship-like bodies in the presence of a linearized free surface and also for determining the interaction effect of potential flow and boundary layer on wave-making resistance. The complete velocity potential for a vertical line source and its image system is derived and the expressions for the velocity components obtained. A computer program was written to evaluate these components and the potential at any field point. Several numerical methods for predicting the value of oscillating integrals were evolved to greatly reduce computer calculation time. To obtain a ship-like body whose wave system satisfied the linearization assumptions, many source lines with varying strengths and positions are required. This large number of source lines makes it prohibitively time consuming to calculate body streamlines. The zero Froude number condition corresponding to a planar free surface has a simple image system and the streamlines on the body are obtained directly by numerical integration. At selected points on the waterline of this body the velocities due to the complete potential are calculated from which the wave profile is determined. In the second part of the study a revised method is presented for the calculation of the three dimensional boundary layer characteristics in streamline coordinates, having the potential flow solution of the first part available. (Author)

Descriptors :   (*FLOATING BODIES, *FLUID FLOW), SHIPS, BOUNDARY LAYER, WATER WAVES, INTERACTIONS, COMPUTER PROGRAMS, DRAG, POTENTIAL THEORY, MATHEMATICAL ANALYSIS

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE