Distributions of temperature and heat flux around bubbles of flow boiling in narrow channel

Boiling and Two-phase flow in narrow channel has been recently proposed for cooling the heat sources directly in application of thermal management for electronic devices. Many researches were carried out to investigate the mechanism of heat transfer in the narrow channel. In this study, the boiling heat transfer and gas-liquid behavior on the heated surface in narrow channel is investigated experimentally by using Temperature-Sensitive Paint (TSP). Experiments are performed in a single rectangular narrow channel having 10 mm width, 35 mm heated length and 0.5 mm height and using FC-72 as a test fluid. TSP coated on the heated wall located at upper side of the channel is used to obtain the local temperature and subsequently local heat flux distribution. In addition, simultaneous flow visualizations are conducted to observe and explore the flow boiling in narrow channel. Flow rate of FC-72 is 24-30 ml/min and heated water at 45-50 ^◦C is used as a heat source for boiling of the test fluid. Pressure at the inlet of the test section is about 50 kPa. As a result, the heat flux in the thin liquid film region that is located around bubbles is 4-5 times higher than that of other region.