2000 Volume 66 Issue 644 Pages 1085-1090
Drag reduction on highly water-repellent solid surfaces, characterized by its low surface energy and ultra small-scale concave-convex structure, has been investigated. The torque between brass cone and tested plain surface where water is confined was measured in the experiment. PTFE (polytetrafluoroethylene) membrane filter, which has water-repellence and porous structure with micrometer-order pores, was one of the surfaces that exhibited the drag reduction. 0.8 μm pore-size filter showed the reduction by maximally 8% at Reynolds number around 60000. Also tested was the ultra small-scale concave-convex surface made on 4inches silicon wafer by lithography and RIE (Reactive Ion Etching). The surface with high contact angle of 150 degrees for water droplet of 1.4 mm diameter showed the drag reduction by maximally 10% at Reynolds number around 65000.
Transactions of the Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers
Transactions of the Japan Society of Mechanical Engineers Series A
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B
TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series A
Transactions of the Japan Society of Mechanical Engineers Series C
