FLOWS GENERATED BY THE PERIODIC HORIZONTAL OSCILLATIONS OF A SPHERE IN A LINEARLY STRATIFIED FLUID

Citation
Q. Lin et al., FLOWS GENERATED BY THE PERIODIC HORIZONTAL OSCILLATIONS OF A SPHERE IN A LINEARLY STRATIFIED FLUID, Journal of Fluid Mechanics, 263, 1994, pp. 245-270
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanics,"Phsycs, Fluid & Plasmas
Journal title
ISSN journal
0022-1120
Volume
263
Year of publication
1994
Pages
245 - 270
Database
ISI
SICI code
0022-1120(1994)263:<245:FGBTPH>2.0.ZU;2-F
Abstract
The flow field induced by a sphere oscillating horizontally in a linea rly stratified fluid is studied using a series of laboratory experimen ts. The resulting flows are shown to depend on the Stokes number beta, the Keulegan-Carpenter number KC and the internal Froude number Fr. F or Fr less than or similar to 0.2, it is shown that the nature of the resulting flow field is approximately independent of Fr and, based on this observation, a flow regime diagram is developed in the (beta, KC) -plane. The flow regimes include: (i) fully-attached flow; (ii) attach ed vortices; (iii) local vortex shedding; and (iv) standing eddy pair. An internal-wave flow regime is also identified but, for such flows, the motion field is a function of Fr as well. Some quantitative measur es are given to allow for future comparisons of the present results wi th analytical and/or numerical models. Wherever possible, the results are compared with the experiments of Tatsuno & Bearman (1990) on right circular cylinders oscillating in homogeneous fluids.