CLOSED CELL SURFACES WITH ENHANCED DRAG-REDUCTION PROPERTIES

摘要

An apparatus, comprising a plurality of closed cells disposed on a surface of a substrate. Each of the closed cells has at least one dimension that is less than about 1 millimeter and are configured to hold a medium therein. The apparatus also comprises a foam that contacts the closed cells. The foam has fluid walls that include a surfactant, and bubbles of the foam layer are filled with the medium.