Drag reduction using a self-adaptive flexible coating

Abstract

We investigated the drag-reducing capabilities of a flexible coating on a rigid bluff body. Conducted in a wind tunnel, our experiments employed a rigid plate coated with a polyethylene membrane of various widths. The results indicated that the drag reduction, contingent on the membrane width, could reach up to 22.2%. Smoke-wire visualization corroborated the delay in flow separation and the emergence of narrower wake structures. This effect is ascribed to the self-adaptation of the flexible membrane to the fluid dynamics. Our study reveals that such passive flow control mechanisms are highly effective in complex, turbulent, three-dimensional flow conditions.