Drag reduction in ultrahydrophobic channels with micro-nano structured surfaces  

作　　者：LU Si YAO ZhaoHui HAO PengFei FU ChengSong 

机构地区：[1]School of Aerospace,Tsinghua University,Beijing 100084,China

出　　处：《Science China(Physics,Mechanics & Astronomy)》2010年第7期1298-1305,共8页中国科学:物理学、力学、天文学(英文版)

基　　金：supported by the National Natural Science Foundation of China (Grant No. 10872106)

摘　　要：A series of experiments have been performed to demonstrate the significant drag reduction of the laminar flow in the ultrahydrophobic channels with dual-scale micro-nano structured surfaces.However,in previous experiments,the ultrahydrophobic surfaces were fabricated with micro-structures or nano-structures and the channels were on the microscale.For the drag reduction in macro-scale channels few reports are available.Here a new method was developed to fabricate ultrahydrophobic surfaces with micro-nano hierarchical structures made from carbon nanotubes.The drag reductions up to 36.3% were observed in the macro-channels with ultrahydrophobic surfaces.The micro-PIV was used to measure the flow velocity in channels.Compared with the traditional no-slip theory at walls,a significant slip velocity was observed on the ultrahydrophobic surfaces.A series of experiments have been performed to demonstrate the significant drag reduction of the laminar flow in the ultrahydrophobic channels with dual-scale micro-nano structured surfaces.However,in previous experiments,the ultrahydrophobic surfaces were fabricated with micro-structures or nano-structures and the channels were on the microscale.For the drag reduction in macro-scale channels few reports are available.Here a new method was developed to fabricate ultrahydrophobic surfaces with micro-nano hierarchical structures made from carbon nanotubes.The drag reductions up to 36.3% were observed in the macro-channels with ultrahydrophobic surfaces.The micro-PIV was used to measure the flow velocity in channels.Compared with the traditional no-slip theory at walls,a significant slip velocity was observed on the ultrahydrophobic surfaces.

关 键 词：ultrahydrophobic surfaces hierarchical structure laminar flow drag reduction velocity slip 

分 类 号：O357.4[理学—流体力学]