Onset and Stability of Convection in Porous Media: Visualization by Magnetic Resonance Imaging
Journal Article
·
· Physical Review Letters
- Department of Physics and Center for Nonlinear and Complex Systems, Duke University, Durham, North Carolina 27708-0305 (United States)
- Center for In-Vivo Microscopy, Duke University Medical Center, Durham, North Carolina 27710 (United States)
- Mechanical and Industrial Engineering Department, University of Illinois, Urbana-Champaign, Urbana, Illinois 61801 (United States)
Using magnetic resonance imaging, we examine the onset and stability of porous media convection (PMC) in packings of solid spheres. Nominally, PMC resembles Rayleigh-Benard convection, except that there should be no vertical vorticity. We find pinned defects in convection patterns for disordered sphere packings. Roll-like structures form in regularly packed media, with rapid relaxation to stable patterns within the expected stable range. The size of up flow regions decreases relative to down flow regions with increasing Rayleigh number, producing a novel time dependent state for Ra/Ra{sub {ital c}}{gt}6.
- DOE Contract Number:
- FG05-90ER14141
- OSTI ID:
- 253246
- Journal Information:
- Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 10 Vol. 75; ISSN 0031-9007; ISSN PRLTAO
- Country of Publication:
- United States
- Language:
- English
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