Bistable Heat Transfer in a Nanofluid

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 Ra* we observe transient oscillatory convection. Unexpectedly, the duration of convection diverges at Ra*. Above Ra* oscillatory convection becomes permanent and the heat transferred exhibits bistability. Our results are explained only partially and qualitatively by existing theories.

Roberto Cerbino

Professor of Experimental Soft Matter Physics

My research interests include Soft matter physics, living matter, cell biophysics and quantitative microscopy.