| Autor: |
Gyüre B; von Kármán Laboratory of Environmental Flows, Loránd Eötvös University, Budapest, Hungary., Jánosi IM |
| Jazyk: |
angličtina |
| Zdroj: |
Physical review. E, Statistical, nonlinear, and soft matter physics [Phys Rev E Stat Nonlin Soft Matter Phys] 2009 Oct; Vol. 80 (4 Pt 2), pp. 046307. Date of Electronic Publication: 2009 Oct 08. |
| DOI: |
10.1103/PhysRevE.80.046307 |
| Abstrakt: |
Laboratory experiments are reported in an immiscible two-fluid system, where thermal convection is initiated by heating at the bottom and cooling at the top. The lava-lamp regime is characterized by a robust periodic exchange process where warm blobs rise from the bottom, attach to the top surface for a while, then cold blobs sink down again. Immiscibility allows to reach real steady (dynamical equilibrium) states which can be sustained for several days. Two modes of lava-lamp convection could be identified by recording and evaluating temperature time series at the bottom and at the top of the container: a "slow" mode is determined by an effective heat transport speed at a given temperature gradient, while a second mode of constant periodicity is viscosity limited. Contrasting of laboratory and geophysical observations yields the conclusion that the frequently suggested lava-lamp analogy fails for the accepted models of mantle convection. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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