par Queeckers, Patrick 
;Dupin, Jean-Charles ;Legros, Jean Claude
Référence Heat transfer in convective flows: presented at the 1989 National Heat Transfer Conference(6-9 august 1989: Philadelphia, Pennsylvania,USA), national heat transfer conference 1989, Amer Society of Mechanical, Vol. 107, page (405)
Publication Publié, 1989-08-01
;Dupin, Jean-Charles ;Legros, Jean Claude Référence Heat transfer in convective flows: presented at the 1989 National Heat Transfer Conference(6-9 august 1989: Philadelphia, Pennsylvania,USA), national heat transfer conference 1989, Amer Society of Mechanical, Vol. 107, page (405)
Publication Publié, 1989-08-01
Publication dans des actes
| Résumé : | We studied the influence of the surface viscosity on the Marangoni-Bénard Instabilities (MBI) when heating from top, layers of aqueous solutions of long chain alcohols (C7 - Cl0 - C12). These solutions have surface tension variations with temperature which presents a minimum. We worked at temperature for which the temperature coefficient of surface tension is positive. The linear stability analysis performed leads to the definition of. a modified critical Marangoni number in which the surface viscosity appears. We have measured the surface tension and the surface viscosity of these solutions. By heating from the top, we observed Marangoni Bénard convection in heptanol and decanol. For the dodecanol solution, no convection has been detected due to surface viscosity effect. For increasing values of the imposed heat flux at the lower plate, at the onset of convection, we observed an abrupt decrease of the resulting temperature difference. This is explained by the existence of an inverse bifurcation at the critical point. This demonstrates the important role played by the surface viscosity in the Marangoni-Bénard instability problem. |
