Abstract
Heat convection in water can be suppressed by adding a small amount of highly thermophilic nanoparticles. We show that such suppression is not effective when a suspension with uniform concentration of nanoparticles is suddenly heated from below. At Rayleigh numbers smaller than a sample dependent threshold we observe transient oscillatory convection. Unexpectedly, the duration of convection diverges at . Above oscillatory convection becomes permanent and the heat transferred exhibits bistability. Our results are explained only partially and qualitatively by existing theories.
- Received 18 November 2008
DOI:https://doi.org/10.1103/PhysRevLett.102.104503
©2009 American Physical Society