Title screen

[References: p. 163 (13 tit.)]

Bubbles collected on a local hydrophobic surface with nanocoating in a twophase flow in a minichannel havebeen detected experimentally. It has been proposed to use the effect of concentration of gas bubbles on hydrophobic segments of the surface of the channel with contrast wettability for ensuring drag reduction. A twodimensional flow model with the Navier slip condition in the region of the bubble layer gives criteria of dragreduction, depending on the slip length, dimension of bubbles, and dimension of the segment with nanocoating. The presence of the bubble layer on half of the surface of the channel can increase the flow rate of a liquidflowing through the channel by 40% at a fixed pressure gradient.