Accession Number : ADA138795

Title :   Energetics of Vortex Ring Formation.

Descriptive Note : Interim rept.,

Corporate Author : GEORGE WASHINGTON UNIV WASHINGTON D C SCHOOL OF ENGINEERING

Personal Author(s) : Irdumsa,J Z ; Garris,C A

PDF Url : ADA138795

Report Date : Nov 1983

Pagination or Media Count : 7

Abstract : This paper presents an experimental investigation comparing the mass and energy content of fully formed laminar vortex rings in air with that of the original pulse which generated them for a variety of initial and boundary conditions. In particular, the fractional entrainment of mass and the partition of initial energy between kinetic energy of translation and kinetic energy of rotation is studied. It is found that a large degree of control can be exercised for the determination of the vortex energetics, as well as its final configuration. A technique is presented which enables calculation of kinetic energy of rotation from movie sequences. The ratio of characteristic translational speed to characteristic rotational speed is shown to be a useful parameter for correlation of data. Data on vortex size and speed are presented using this correlation and it is seen that all data, regardless of initial and boundary conditions, fall on a single curve. A theoretical curve is derived and it is seen that the data compare well with it. (Author)

Descriptors :   *Vortices, Laminar flow, Rings, Energy transfer, Mass, Entrainment, Air flow, Rotation, Energetic properties, Kinetic energy, Pulses, Mathematical models, Boundary value problems, Correlation, Chimneys, Thrust augmentation, Air ejectors, Motion pictures

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE