Enhanced boiling heat transfer performance on wettability-patterned surface

Abstract

As an efficient heat transfer method, boiling heat transfer (BHT) plays an important role in strengthening the thermal management of high-power electronics, etc. In this work, the wettability patterns are prepared on copper substrate by mask-assisted chemical processing method, which enhances the BHT performance. We firstly treat the copper surface into superhydrophilic by chemical immersion, and then it is modified by fluorosilane into superhydrophobic, and wettability patterns are formed with the assistance of mask. Then, the BHT performances and the corresponding bubble dynamics of the wettability-patterned surfaces are experimentally investigated. Finally, the optimal BHT performances of the wettability-patterned surface prepared by the proposed method are compared with other modified surfaces. The results show that the BHT is improved dramatically on the wettability-patterned surface, the critical heat flux (CHF) and the heat transfer coefficient (HTC) improve by 23% and 56%, respectively. Under high heat flux, the decrease of hydrophobic pattern size can significantly improve the BHT performances, while under low heat flux, reducing the hydrophobic pattern pitch can improve the BHT performances to a certain extent. The reduction of the hydrophobic area has a significant effect on the CHF and HTC.