Effects of microstructured surface and mixed surfactants on the heat transfer performance of pulsed spray cooling

Pulsed spray cooling is a highly promising method for efficiently cooling high heat flux electronic components. In this study, the factors affecting the heat transfer performance of pulsed spray cooling were investigated on a closed pulsed spray cooling experimental system. It was found that a straight fin microstructured surface has a higher heat transfer performance than a smooth surface, but it decreases the surface temperature uniformity. Based on this, the effects of binary mixed surfactants, DuPont Capstone FS-31:Tween 20, FS-31:sodium dodecyl sulfate (SDS), and FS-31:cetyltrimethylammonium bromide (CTAB), on the heat transfer performance and surface temperature uniformity of pulsed spray cooling with a microstructured surface were investigated. The results show that the surface tension and contact angle of 75% FS-31:25% CTAB were the lowest and the heat transfer performance was the highest. The mean surface temperature was 47.26 degrees C and the heat transfer coefficient was 2.02 W/(cm(2)K). Compared with the results without surfactants on microstructured surface, the mean surface temperature was lower by 8.43 degrees C and the heat transfer coefficient was higher by 35.57%. The mixed surfactants greatly improved the temperature uniformity of the microstructured surface, and the maximum surface temperature difference decreased from 1.587 degrees C to 0.471 degrees C.