The present disclosure relates to a device and a method for swinging power generation and vibration suppression by using arc-shaped wing plates with rough surfaces. The device consists of two parts, namely, a rotary swinging system and a collector system. The rotary swinging system includes a collector riser, steering bearings, nanometer material arc-shaped power generation wing plates, and flexible tail plates. The collector system includes telescopic power generation cylinders, a waterproof electric slip ring, and a waterproof power transmission line. The suppression of energy-consumption-free vortex-induced vibration is realized under the combined action that the nanometer material arc-shaped power generation wing plates divide a flowing space and adjust a flow direction, the nanometer material arc-shaped power generation wing plates drive the flexible tail plates to swing to destroy a tail vortex street, and hemispherical bulges and trumpet-shaped deflector holes disturb a boundary layer around flow.

A system and a method for reducing drag on the aft-fuselage of an aircraft are provided, which system and method utilize at least one finlet provided on each side of the aft-fuselage of an aircraft for reducing drag—on the aft-fuselage, which finlets are (i) positioned at the rear half of an upswept portion of the aft-fuselage starting at a breakline, (ii) positioned in the path of the vortices generated by the aft-fuselage, and (iii) oriented at 1 to 9 degrees angle relative to the local airflow about the aft-fuselage of the aircraft to straighten the airflow about the aft-fuselage. In addition, the finlets generate an induced secondary vortex having an opposite rotation direction relative to the rotation direction of the vortices generated by the aft-fuselage, thereby counteracting the vortices generated by the aft-fuselage.

An article that includes a vortex-generator device may include various features. For example, the article may include a material layer and one or more elongate members coupled to the material layer. In addition, the one or more elongate members interconnect two or more vortex generators.

A coating apparatus for the reduction of aerodynamic noise and vibrations. The coating apparatus is configured to include a group of fibrillar structures, wherein each fibrillar structure is configured with a diverging tip so that the coating reduces the size of and shifts downstream, a separation bubble, and modulates large-scale recirculating motion. Each fibrillar structure can be configured as a cylindrical micropillar. The group of fibrillar structures can be configured as a group of uniformly distributed cylindrical micropillars (e.g., one or more micropillar arrays). The surface coating is effective in reducing the separation bubble and displacing the separation bubble downstream. The coating facilitates a reduction in noise (e.g., aerodynamic noise) and vibrations due to the reduction in the size of the separation bubble.

Provided are: an adhesive sheet-shaped member for airflow, in an optimum form that can improve fuel efficiency and travel performance as a result of more effectively suppressing a large airflow separation phenomenon that becomes air resistance; and a travel vehicle using the same. A sheet-shaped member that is: provided thinly so as to prevent, as far as possible, the thickness thereof providing air resistance; adhered to a surface in contact with an airflow provided by a material that charges negative static electricity; formed in a long sheet shape in a flow direction of airflow, compared to the width direction of the airflow, so as to be adhered along the direction of the airflow; and provided using a material that charges a negative static electricity and has a different ease of static electrical charge than the surface in contact with the airflow.

Body provided with a superficial area adapted to reduce drag when the body is moving relative to a gaseous or watery medium, comprising depressions in said superficial area, wherein the depressions have a greater length than width and are provided in the superficial area so as to collectively shape a curvature provided in a length direction of said depressions in the superficial area, and/or said depressions themselves are provided with a curvature in their length direction. The depressions are thus adapted to provide that a turbulent boundary layer of the gaseous or watery medium adjacent to the superficial area of the body is exposed to lateral excitation with reference to a movement direction of the body in the gaseous or watery medium or with reference to a flow direction of said turbulent boundary layer along said superficial area of the body. Said lateral excitation results in a reduction of drag.

An aerodynamic or hydrodynamic wall surface has an array of fibrillar structures disposed on and extending from the wall surface, wherein each fibrillar structure comprises a stalk and a tip. The stalk has a first end and a second end, wherein the first end is attached to the wall surface, and the stalk is oriented with respect to the wall surface at a stalk angle between approximately 1 degrees and 179 degrees. The tip has a first side and a second side, wherein the first side is attached proximate to the second end of the stalk, the tip has a larger cross-sectional area than the stalk, and the second side comprises a substantially planar surface that is oriented with respect to the stalk at a tip angle between approximately 0 degrees and 90 degrees.

A phononic material and a method of using a phononic material for use in interacting with a fluid or solid flow are provided. The phononic material includes an interface surface and a subsurface feature. The interface surface is adapted to move in response to a pressure, and/or velocity gradients, associated with complex motion of a turbulent flow exhibiting a polarity of frequencies exerted on the interface surface. The subsurface feature extends from the interface surface. The subsurface feature comprises a phononic crystal or locally resonant metamaterial adapted to receive the pressure, and/or velocity gradients, from the turbulent flow via the interface surface and alter the phase and amplitude of a polarity of frequency components of the turbulent flow in order to reduce or increase the kinetic energy of the turbulent flow. The interface surface is adapted to vibrate at a polarity of frequencies, phases and amplitudes in response to the frequency, phase and amplitude of at least one component of the turbulent flow.

Pressure oscillations or acoustic loads over an open type cavity having a front face an upper edge of which constitutes a leading edge and having a rear face an upper edge of which constitutes a trailing edge are reduced by applying curvature to the rear face so as to present a convex curved surface internal to the cavity. In one embodiment, a cross-section through a longitudinal axis of the convex curved surface describes part of an ellipse.

A layer system having a metallic substrate, in particular made of a >=9% by weight chromium steel, in particular with roughness of the substrate <=2 m and optionally an intervening chromium layer directly on the substrate, in particular made of Cr/CrN, an underlayer or middle layer of AlCr, and an outer layer, in particular outermost layer, of AlCrO, where the AlCr and AlCrO layers in particular are PVD coatings wherein a shark skin effect is achieved with a simple geometric arrangement, and can be used particularly for compressor blades.