Accession Number:

ADA063326

Title:

A General Method for Calculating Three-Dimensional Laminar and Turbulent Boundary Layers on Ship Hulls.

Descriptive Note:

Final technical rept. Jul 76-Oct 78,

Corporate Author:

DOUGLAS AIRCRAFT CO LONG BEACH CALIF

Personal Author(s):

Report Date:

1978-10-01

Pagination or Media Count:

73.0

Abstract:

A general method for representing the flow properties in the three-dimensional boundary layers around ship hulls of arbitrary shape is described. It makes use of an efficient two-point finite-difference scheme to solve the boundary-layer equations and includes an algebraic eddy-viscosity representation of the Reynolds-stress tensor. The numerical method contains novel and desirable features and allows the calculation of flows in which the circumferential velocity component contains regions of flow reversal across the boundary layer. The inviscid pressure distribution is determined with the Douglas-Neumann method which, if necessary, can conveniently allow for the boundary-layer displacement surface. To allow its application to ships, and particularly to those with double-elliptic and flat-bottomed hulls, a nonorthogonal coordinate system has been developed and is shown to be economical, precise and comparatively easy to use. Present calculations relate to zero Froude number but they can be extended to include the effects of a water wave and local regions of flow separation which may stem from bulbous-bow geometries. Author

Subject Categories:

  • Marine Engineering
  • Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE