An apparatus is for attaching an aerodynamically functional film to a surface of a body around which flow passes. The apparatus includes: a self-adhesive, redetachable positioning film having positioning aids for the exact positioning of the positioning film on the surface of the body around which flow passes and having at least one application area for the aerodynamically functional film that is to be applied.

A contamination protection is for edges of a riblet film, which is adhesively bonded to a surface. The riblet film has riblets formed on an upper side of a film layer, and an adhesive layer at a lower side of the film layer. The contamination protection has: an edge protection. The edge protection is formed directly on the riblet film that is adhesively bonded to the surface in such a manner that the edge protection covers the adhesive layer of the riblet film, but does not protrude over the upper side of the riblet film.

An airflow profile structure having a leading and/or trailing edge profiled with a serrated profile having a succession of teeth and depressions. Along the leading and/or trailing edge, from a first location to a second location, the teeth of the serrated profile are individually inclined towards the second location.

Disclosed is a deflector disc of a disc tube membrane module, including a deflector disc body, radial water distribution ribs, an inner support ring and an outer support ring. Bulges are arranged on the front and back sides of the deflector disc body; first and second ends of the radial water distribution rib are respectively fixedly connected with an inner edge of the deflector disc body and an outer edge of the inner support ring, an annular boss is arranged on the front side of the inner support ring, a seal ring groove is respectively arranged at corresponding positions of the front and back sides of the inner support ring, multiple yielding water collecting grooves are annularly and uniformly distributed on the inner surface of the inner support ring; an inner edge of the outer support ring is fixedly connected with an outer edge of the deflector disc body.

A front fan turbomachine includes an annular separating wall having a slat for separating an air flow between a primary flow and a secondary flow, the slat having a leading edge; inlet guide vanes (IGV) for guiding the primary flow and outlet guide vanes (OGV) blades for guiding the secondary flow. The leading edge of the slat has a serrated profile having a succession of teeth and depressions.

Described herein is a process for producing a structured article (A1M1) in which a material (M1) including at least one micro- and/or nanostructured surface (SU1) containing a plurality of micro-scale and/or nano-scale surface elements is covered with an at least partially cured coating layer (C2) to provide a composite (M1C2), said composite (M1C2) is attached to an object (A1) and the coating layer (C2) is at least partially peeled off to provide the structured article (A1M1). Also described herein is a composite (M1C2) in which the surface elements of the material (M1) are covered by a protective coating layer (C2).

A method for producing an object with riblets on and/or in the surface, around which object a fluid flows during use. A frictional resistance acting on a surface region along a flow direction during a flow around the object in the fluid is calculated and added up to a cumulative frictional resistance over a length of the surface region in the flow direction, after which the riblets are provided on and/or in a partial region of the surface in which an increase in the cumulative frictional resistance is at least 0.9, in particular greater than 1.0 to 0.9. Moreover, a method is provided for modifying a surface of an object around which a fluid flows during use, such as a foil. A structure having riblets is created on and/or in the surface, which structure reduces flow resistance of the object. Furthermore, a fluid flows around an object during use.

An airflow profile structure having a leading and/or trailing edge profiled with a serrated profile. The serrated profile has a succession of teeth and depressions, characterized in that, along the leading and/or trailing edge, from a first location to a second location, the teeth of the serrated profile are individually inclined towards the second location.

Surface elements, such as protrusions, are provided for use on the surface of flow-following apparatuses, such as surface drifters or subsurface drogues, to enhance the hydrodynamic properties of the apparatus and enhance their capabilities to follow fluid motion. The protrusions may comprise helical strakes or splitter plates for optimizing the drag-to-inertia ratio of the flow-following apparatus, with the goal to enhance their flow-following capabilities. In some embodiments, the flow-following apparatus has a generally axisymmetric body shape, such as having a cylindrical, spherical or oblong shape. The flow-following apparatus may further comprise a position tracking device to track flow motion such as ocean currents.

Provided is the film that can reduce aerodynamic drag and enhance aerodynamic performance. The film according to an embodiment is a film (1) to be attached to a moving body that moves in a predetermined moving direction, extends along a second direction (D2) being the moving direction, and includes recesses and protrusions (2A) configured to enhance aerodynamic performance of the moving body on a surface of the film.