Experimental Investigation of Marangoni Effect in Aqueous LiBr Solution With Additives

Abstract

Abstract The objective of this paper is to establish a model for inducement of Marangoni convection in aqueous LiBr solution with heat transfer additives. Basic mechanism of Marangoni convection was introduced from the viewpoints of the surface tension and the interfacial tension gradients. The Wilhelmy plate method was used to measure the surface tension and the interfacial tension of various heat transfer additives such as n-Octanol, 2-Octanol, 3-Octanol, 4-Octanol, n-Decanol, 2-Decanol, 3-Decanol and 2-ethly-1-hexanol. It was found that the salting-out model can not be a general criterion for inducement of Marangoni convection. The salting-out effect is a trigger for inducement of Marangoni convection before the additive solubility while the imbalance of the surface tension and the interfacial tension is a trigger for inducement of Marangoni convection after the solubility. The surface tension gradients by the solution temperature is not a trigger for inducement of Marangoni convection. The interfacial tension gradients by the LiBr concentration and the solution temperature can not be an initial cause for inducement of Marangoni convection. However, the magnitude of the interfacial tension plays an important role for inducement of Marangoni convection.