Transient stability and convection in impulsively heated porous layers

M. J. Kohl, M. Kristofferson, F. A. Kulacki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Experiments are reported on initial instability and convection in a porous medium impulsively heated from below. The porous medium comprises either water or a water-glycerin solution and randomly stacked glass spheres in an insulated cylinder of height-to-diameter ratio of 1.9. Heating is accomplished with a constant flux lower surface and a constant temperature upper surface. Results include measurement of the initial transition to convection, overall heat transfer coefficient over a range of Rayleigh-Darcy numbers, and temperature profiles. Time-averaged temperature profiles suggest the existence of a unicellular flow over the range of Rayleigh numbers of the present experiments. The critical Rayleigh number for the onset of convection is obtained in terms of a length scale normalized to the thermal penetration depth as Rac = 83/(1.08η-0.08η2) for 0.02 < η < 0.18. Steady convection in terms of the Nusselt and Rayleigh numbers is represented by a new correlation form, Nu = 0.047 Ra0.91Pr0.11(μ/ μ0)0.72 where Ra is the Rayleigh-Darcy number, 400 < Ra < 5000, and the viscosity ratio is found sufficient to account for strongly temperature-dependent viscosity.

Original languageEnglish (US)
Title of host publicationProceedings of the ASME Summer Heat Transfer Conference, HT 2005
Pages235-242
Number of pages8
DOIs
StatePublished - Dec 1 2005
Event2005 ASME Summer Heat Transfer Conference, HT 2005 - San Francisco, CA, United States
Duration: Jul 17 2005Jul 22 2005

Publication series

NameProceedings of the ASME Summer Heat Transfer Conference
Volume1

Other

Other2005 ASME Summer Heat Transfer Conference, HT 2005
CountryUnited States
CitySan Francisco, CA
Period7/17/057/22/05

Fingerprint Dive into the research topics of 'Transient stability and convection in impulsively heated porous layers'. Together they form a unique fingerprint.

  • Cite this

    Kohl, M. J., Kristofferson, M., & Kulacki, F. A. (2005). Transient stability and convection in impulsively heated porous layers. In Proceedings of the ASME Summer Heat Transfer Conference, HT 2005 (pp. 235-242). [HT2005-72023] (Proceedings of the ASME Summer Heat Transfer Conference; Vol. 1). https://doi.org/10.1115/HT2005-72023