Condensation on a horizontal surface with periodic asymmetrical structures - transient film growth

详细信息    查看全文

• 作者：Shashank Natesh^a ; Eric Truong^a ; Vinod Narayanan^a ; ^{vnarayanan@ucdavis.edu} ; Sushil Bhavnani^b
• 关键词：Filmwise condensation ; Asymmetric microstructures ; Passive directional motion ; Phase change ; Numerical modeling
• 刊名：International Journal of Heat and Mass Transfer
• 出版年：2017
• 出版时间：May 2017
• 年：2017
• 卷：108
• 期：part_PA
• 页码：1126-1139
• 全文大小：1965 K
• 卷排序：108

文摘

Filmwise condensation on horizontal surface with asymmetric structures is studied. A transient film rise within an asymmetric structure (ratchet) is characterized. Film growth on an asymmetric ratchet is compared against a symmetric ratchet. Numerical results are validated by visualization experiments of condensate growth. Condensate rises preferentially towards the steeper slope of the ratchet. Condensate rise rate increases with an increase in ratchet surface asymmetry. Condensate growth is a function of capillary number. Condensate growth rate is independent of Bond number for ratchet pitches < 2.4 mm. Surface heat transfer coefficient increases with increase in surface asymmetry. Surface heat transfer coefficient increases fourfold from pitch of 2.4 mm to 80 µm.