Spray cooling heat transfer on microstructured thin film enhanced surfaces

Experiments were performed with FC-72 (only for flow characteristics) and DI water to investigate heat transfer characteristics from enhanced surfaces through spray cooling. Three different enhanced microstructured surfaces of 50 μm SiC, 10 μm CNT and 50 μm diamond thin films were examined. Three full-cone spray nozzles were used with low mass flow rates of 2.92 × 10−4 kg/s to 17.85 × 10−4 kg/s. Three different nozzle-to-surface distances of 20 mm, 35 mm and 50 mm were tested. Both heat transfer data and spray flow characteristics visualization via a high-speed photographic image of droplet evolution impinging the heated surface were presented and discussed. Results indicate that significant cooling performance enhancement can be reached at about 610 W/cm2 with a 50 μm thin diamond film for the cases under study.