Accession Number : ADP002253

Title :   Separation and Vortical-Type Flow Around a Prolate Spheroid - Evaluation of Relevant Parameters,

Corporate Author : DEUTSCHE FORSCHUNGS- UND VERSUCHSANSTALT FUER LUFT- UND RAUMFAHRT E V GOETTINGEN (GERMANY F R)

Personal Author(s) : Vollmers,H. ; Kreplin,H. P. ; Meier,H. U.

Report Date : JUL 1983

Pagination or Media Count : 14

Abstract : The definition of some special lines in a flow field is discussed and a criterion for the identification of axes of local rotation is given. A preferred direction is introduced in space using the local direction of the velocity. A surface is constructed locally such that at any point the surface is normal to the velocity field. For a (normalized) direction field of the velocity, the components of the gradient tensor on this surface can be regarded as being equivalent to the curvature tensor of the surface. The behaviour of the curvature is discussed. The surface is partitioned into hyperbolic and elliptic regions by the sign of the Gaussian curvature. It is found that the special points are associated with regions of extremely steep variations of the Gaussian curvature. Experimental evidence to this effect if provided by measurements of wall shear stress vectors and velocity vectors in the flow field around an inclined prolate spheroid. The above procedure is shown to be a tool for revealing some properties of th vortex skelton of a flow field. Several other parameters of the measured flow field are also evaluated and presented. (Author)

Descriptors :   *Vortices, *Flow separation, Flow fields, Shear stresses, Walls, Spheres, Rotation, West Germany

Distribution Statement : APPROVED FOR PUBLIC RELEASE