
Accession Number : ADA115489
Title : Stern BoundaryLayer Flow on a ThreeDimensional Body of 3:1 Elliptic Cross Section.
Descriptive Note : Final rept.,
Corporate Author : DAVID W TAYLOR NAVAL SHIP RESEARCH AND DEVELOPMENT CENTER BETHESDA MD
Personal Author(s) : Groves,Nancy C ; Belt,Garnell S ; Huang,Thomas T
PDF Url : ADA115489
Report Date : May 1982
Pagination or Media Count : 122
Abstract : A comprehensive set of experimental pressure, velocity, and turbulence data are presented across the stern of a threedimensional model having 3:1 elliptic transverse cross sections. The axisymmetric displacement body concept is extended to threedimensions and the pressure and velocity data are compared with the predictions of existing threedimensional theoretical methods. The surface pressures for the displacement body are found to model, satisfactorily, the measured pressure coefficients in all regions except over the aft 7 percent of body length. In this tail region, the boundary layer is much thicker than the cross section dimensions and the theory overpredicts the measured distributions of the mean velocity. Agreement is particularly poor in the inner region of the tail boundary layer, indicating a need to examine the eddy viscosity model currently used in computing the thick stern boundary layer of threedimensional models. As was found in the axisymmetric case, the measured values of turbulence intensity, eddy viscosity, and mixinglength parameters in the stern region are much smaller than those of a thin boundary layer. (Author)
Descriptors : *Boundary layer flow, *Ship sterns, *Ellipses, *Cross sections, *Turbulent boundary layer, Wind tunnel tests, Three dimensional, Wind tunnel models, Ship models, Boundary layer, Thickness, Thinness, Eddy currents, Viscosity, Turbulence, Mathematical models
Subject Categories : Marine Engineering
Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE