Basics of lava-lamp convection
Abstract
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.
- Publication:
-
Physical Review E
- Pub Date:
- October 2009
- DOI:
- 10.1103/PhysRevE.80.046307
- Bibcode:
- 2009PhRvE..80d6307G
- Keywords:
-
- 47.55.pb;
- 44.25.+f;
- 91.45.Fj;
- Thermal convection;
- Natural convection;
- Convection currents and mantle plumes