Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-19T09:06:10.055Z Has data issue: false hasContentIssue false

Drag on a sphere moving horizontally through a stratified liquid

Published online by Cambridge University Press:  20 April 2006

Karl E. B. Lofquist
Affiliation:
National Bureau of Standards, Gaithersburg, MD 20899
L. Patrick Purtell
Affiliation:
National Bureau of Standards, Gaithersburg, MD 20899

Abstract

The drag on a sphere moving horizontally through stably stratified salt water is measured in laboratory experiments. The increment ΔCD in drag coefficient due to the stratification is obtained as a function of a stratification parameter κ and, in principle, the usual Reynolds number R. In these experiments, where R ranges from 150 to 5000, ΔCD is insensitive to R. But, as a function of κ, ΔCD has both positive and negative values attributable respectively to lee-wave drag and to suppression of turbulence in the wake. An observed delay in flow separation also apparently results from the lee-wave drag.

Type
Research Article
Copyright
© 1984 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Achenbach, E. 1972 Experiments on the flow past spheres at very high Reynolds numbers. J. Fluid Mech. 54, 565575.Google Scholar
Achenbach, E. 1974 Vortex shedding from spheres. J. Fluid Mech. 62, 209221.Google Scholar
Debler, W. & Fitzgerald, P. 1971 Shadowgraph observations of the flow past a sphere and a vertical cylinder in a density stratified liquid. Tech. Rep. EM-71-3, Dept Engng Mech., Fluid Mech. Sect., Univ. Mich.Google Scholar
Lin, J. T. & Pao, Y. H. 1979 Wakes in stratified fluids. Ann. Rev. Fluid Mech. 11, 317338.Google Scholar
Pao, H. P. & Kao, T. W. 1977 Vortex structure in the wake of a sphere. Phys. Fluids 20, 187191.Google Scholar
Schlichting, H. 1968 Boundary-Layer Theory, 6th edn. McGraw-Hill.