Heat Transfer Enhancement in Subcooled Flow Boiling by Using Grooved and Thermal Spray Coated Surface

Abstract

The purpose of this research is to enhance heat transfer of subcooled boiling flows in a horizontal narrow channel by using grooved and thermal spray coated surface. The V-grooves with an opening of 0.5 mm was fabricated perpendicular to the flow direction in order to supply liquid from the side walls to the middle of the channel by capillary force. Then, thermal spray coating was formed on the V-grooved surface to increase nucleation sites density. The results on heat transfer coefficient (HTC) for these surfaces were compared with those on the smooth surface. It was found that the HTC of the V-grooved surface with thermal spray coating could be drastically enhanced by the synergy effect of the V-groove and thermal spray coating.