Accession Number : ADA299197

Title :   Droplet-Turbulence Interactions Over a Wide Spectral Range.

Descriptive Note : Annual technical rept. 1 Nov 93-31 Oct 94,

Corporate Author : CALIFORNIA UNIV IRVINE DEPT OF MECHANICAL AND AEROSPACE ENGINEERING

Personal Author(s) : Sirignano, W. A. ; Elghobashi, S. E. ; Kim, I. ; Masoudi, M.

PDF Url : ADA299197

Report Date : 30 NOV 1994

Pagination or Media Count : 100

Abstract : In the last year, the unsteady, three-dimensional, incompressible, viscous flow interactions between a single vortex tube advected by a uniform free stream and a spherical particle held fixed in space was investigated numerically for a range of particle Reynolds numbers between 20 and 100. Useful correlations of lift coefficient, moment coefficient, and drag coefficient with velocity fluctuation, Reynolds number, offset distance, and initial vortex size have been obtained and reported. A new mechanism based upon droplet lift has been suggested for the dispersion of sprays. Since the beginning of this year, the interactions between a pair of vortex tubes and a rigid sphere have been studied in order to generalize the findings from the previous investigation. Similar correlations for the force and moment coefficients have been found and are being reported. These correlations will be useful in predicting droplet trajectories. The investigation for the heat and mass transfer of a droplet interacting with vortex tubes is also under way. This should lead to useful correlations to predict droplet heating and vaporization in a flow with vortical fluctuations.

Descriptors :   *INTERACTIONS, *TURBULENCE, *DROPS, VELOCITY, DISPERSING, SIZES(DIMENSIONS), MOMENTS, VORTICES, SPHERES, VARIATIONS, SPECTRA, CORRELATION, PARTICLES, COEFFICIENTS, HEATING, MASS TRANSFER, UNSTEADY FLOW, RANGE(EXTREMES), RANGE(DISTANCE), DRAG, LIFT, FREE STREAM, VISCOUS FLOW, TRAJECTORIES, RIGIDITY, SPRAYS, REYNOLDS NUMBER, INCOMPRESSIBLE FLOW, VAPORIZATION, TUBES, THREE DIMENSIONAL FLOW.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE