Heat transfer in liquid bridges surrounded by a heater/cooler ring*

Fluid flow and heat transfer due to Marangoni convection in a liquid-bridge suspended between two solid discs and surrounded by a heating/cooling ring is investigated in this work. The capillary bridge consists of water and the surrounding fluid is taken as a 10 cSt silicone oil. The flow and heat transfer are found to attain a quasi-steady state for most of the heater/cooler positions. In addition, heat transfer to the bridge in the heater configuration is found to be the maximum when the heater ring is closer to the bottom disc, whereas, this occurs for the cooler configuration when the cooling ring is near the top disc. Moreover, the heater configuration exhibits a transition in the heat transfer and interfacial velocity when the heater is placed midway between the two discs. There exists a range of heater locations for which such a jump in the heat transfer is observed. We examine the mechanism of this jump in this study and point out the importance of accounting for the interface deformation when dealing with Marangoni flows in liquid bridges. A similar investigation is performed for the cooler configuration, and the differences and similarities between the two configurations will be discussed.