EXPERIMENTAL STUDY ON HEAT TRANSFER CHARACTERISTICS OF DIMPLED SURFACE THERMOSYPHON WITH Al2O3 NANOFLUID.

The current research on boiling in heat transfer applications has been increased due to the effective heat dissipation rate in solar applications, cooling of new generation electronic chips with the goal of improving performance by controlling physical factors. Thermosyphons are one among the phase change medium which has the higher critical heat flux to accelerate the heat transfer. Current work in Thermosyphon focuses on the design, fabrication, and performance analysis of dimpled thermosyphon with certain variables like surface area of heat exchange, composition of working fluid and setup angle. Due to the impact of nanotechnology, the investigation is carried out by using Al₂O₃ nanofluid as working fluid. The experiments are conducted initially with plain thermosyphons, later with surface modifications (dimple) by changing the orientation of the thermosyphons. The performance results of the plain thermosyphon filled with water, plain thermosyphon filled with nanofluid is compared with dimpled thermosyphon with nanofluid at different angles such as 0°, 45°, and 90°. Evaporator side dimple and condenser side dimple also designed and investigated. It is observed that thermal resistance for dimple thermosyphon-nanofluid is very low in the range of 0.06-0.20 °C/W when compared with plain thermosyphon-water varies from 0.1-0.45 °C/W, for plain thermosyphon-nanofluid is 0.1-0.31 °C/W. It is also observed that the efficiency of dimpled tube Thermosyphon with Nanofluid is estimated as 50.66%, 69.7%, and 74.23% at 0°, 45°, and 90°, respectively, which is the maximum value when compared with plain thermosyphon with water and nanofluid. [ABSTRACT FROM AUTHOR]