0

Full Content is available to subscribers

Subscribe/Learn More  >

Interfacial Dynamics of Two Layer Couette Flow: Gravity Enhanced Kelvin-Helmholtz Instability

[+] Author Affiliations
Joshua H. Colistra, Mahesh V. Panchagnula, Alparslan Öztekin, Sudhakar Neti, John Chen

Lehigh University, Bethlehem, PA

Paper No. FEDSM2005-77459, pp. 287-292; 6 pages
doi:10.1115/FEDSM2005-77459
From:
  • ASME 2005 Fluids Engineering Division Summer Meeting
  • Volume 2: Fora
  • Houston, Texas, USA, June 19–23, 2005
  • Conference Sponsors: Fluids Engineering Division
  • ISBN: 0-7918-4199-5 | eISBN: 0-7918-3760-2
  • Copyright © 2005 by ASME

abstract

The Couette flow of two immiscible liquids is examined using flow visualization techniques. The flow dynamics are studied as a function of several independent parameters including gravity. The two fluids are initially separated by a sheet of aluminum sufficient in length to ensure that fully developed flow conditions are achieved for both fluids before they come in contact with each other. The experiments are performed for various flowrates of Canola Oil and Polyethylene Glycol (PEG) corresponding Reynolds numbers for Oil and PEG of 0 to 20 and 0.01 to 0.2 respectively. Photographic images of the flow field are recorded and analyzed with the aid of image analysis software to illustrate interfacial dynamics of the flow. A qualitative and quantitative analysis of the flow instability is performed for various inclinations of the test apparatus, including the extreme cases of upward vertical and downward vertical with the horizontal being the baseline test case. Neutral stability curves are identified for the range of variables studied in the experiments. The long wave instability is observed to be very periodic. At the onset of instability, the flow structure is three-dimensional and exhibits wave growth in the flow direction. The wave growth ultimately results in droplet pinch off from the crest of a folded wave. At a constant relative velocity, the wave length is at a minimum when the flow is oriented in the upward vertical direction, opposing gravity. For a given PEG flowrate, the critical Oil flowrate for the onset of interfacial instability decreases as the angle increases. These results indicate gravity enhanced Kelvin-Helmholtz interfacial instability even for low Reynolds numbers. Through a course of systematic variation of flow angles we have been able to separate the effects of inertia, gravity (buoyancy) and viscous shear forces on the wavelength of instability.

Copyright © 2005 by ASME

Figures

Tables

Interactive Graphics

Video

Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

NOTE:
Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In