The invention pertains to the use of an easy-to-clean soft fiber-coated material on the underwater surface of structures to mimic mammal pelage and as such reducing residual drag, wherein said material comprises or consists of fibers having an average fiber length between 0.3 and 4 mm, and an average fiber thickness between 5 and 80 μm. The underwater surface of structure is preferably the hull of a movable or moving vessel, or the underwater part of a static structure such as offshore wind monopiles and off-shore rigs. In some embodiments, the invention pertains to the reduction of fuel consumption of a nautical vessel passing through water.

In one aspect of the present disclosure, a streamlined body for passing through a fluid is provided. The streamlined body includes an outer surface defining a leading edge and a trailing edge. The leading edge is oriented to pass through the fluid before the trailing edge during movement of the body through the fluid. The streamlined body further includes a plurality of fibers coupled to the outer surface. Each fiber of the plurality of fibers projects away from the outer surface.

An antenna apparatus is provided. The antenna apparatus in embodiments of this application includes a radome. An interference structure is disposed on a surface of the radome, and the interference structure is configured to change an airflow at a surface boundary layer when the airflow passes through the surface of the radome. The interference structure is disposed on the antenna apparatus to change the airflow at the surface boundary layer.

A reduced drag surface involves a perforated or porous surface exposed to a flowing fluid and a slip interface disposed between the surface and the flowing fluid, wherein the slip interface is formed from an entrapped fluid trapped at the surface. A method for modifying a drag coefficient on a reduced drag surface involves the steps of supplying a fluid to a perforated or porous surface exposed to a flowing fluid, wherein the surface traps the fluid at the surface to form an entrapped fluid and forming a slip interface between the surface and the flowing fluid, wherein the slip interface is formed from the entrapped fluid. An apparatus for a reduced drag surface includes the reduced drag surface described above and a source of fluid fluidically coupled to the surface such that the source supplied fluid to the surface to form the entrapped fluid.

The present disclosure is directed to a rotatable fairing panel at a rear end of a sleeper cab. The rotatable fairing panel covers an opening between a trailer attached to a vehicle and the sleeper cab of the vehicle. The rotatable fairing panel has a closed position and an opened position. At least one locking assembly locks the rotatable fairing panel in place when in the closed position. The at least one locking assembly is configured to be unlocked by a user such that the rotatable fairing panel may be rotated from the closed position to the opened position such that a user may access the opening between the trailer attached to the vehicle and the sleeper cab of the vehicle. The at least one locking assembly automatically locks when the user rotates the rotatable fairing panel into the closed position.

A fluidic oscillator having independent frequency and amplitude control includes a fluidic-oscillator main flow channel having a main flow inlet, a main flow outlet, and first and second control ports disposed at opposing sides thereof. A fluidic-oscillator controller has an inlet and outlet. A volume defined by the main flow channel is greater than the volume defined by the controller. A flow diverter coupled to the outlet of the controller defines a first fluid flow path from the controller's outlet to the first control port and defines a second fluid flow path from the controller's outlet to the second control port.

Waveguide or flow guide surfaces can improve the efficiency of fluid flow through tubes or over surfaces. When incorporated in a tube, the waveguides improve flow and function as sound absorbers making them useful in engine mufflers, firearm silencer/suppressors and jet engine exhaust attenuators. On surfaces, the waveguides can reduce fluid drag and find use on projectiles (e.g., bullets), airfoils for aircraft, and land borne vehicles. The waveguide array in either a tubular chamber or on a surface comprises a plurality of successive wave-like undulations inclined generally in the direction of flow and when employed in tubes extending inwardly to permit an unobstructed path for the fluid gas from entry to exit. The waves define annular wave cavities between their successive inwardly extending edges and the wall of the chamber with each cavity having a cavity mouth open to the unobstructed path. The waveguides are sized and spaced so that gas vortices are created within the cavities when gas flow occurs which vortices create a fluid boundary layer that assists the gas flow.

A magnetic insertion meter is disclosed herein. Disclosed insertion meters include in some examples, a sensor head tube cylinder having a textured front surface and at least two electrodes. Disclosed insertion meters include a textured front surface adapted to move the separation point of a fluid flowing over the sensor head tube towards the upstream surface as compared to the same sensor head tube without the textured front surface. Methods of measuring flow are also disclosed herein using example magnetic insertion meters.

A novel mechanism for reducing boundary layer friction and inhibiting the effects of uncontrolled fluid turbulence and turbulent layer separation, thus reducing the body drag, kinetic energy losses and lowering engine and pump fuel consumption is proposed. It steps on the type of turbulence observed in the so-called in fluid dynamics “drag crisis”. Plurality of device shapes and plurality of devices producing the wanted pure form of even plurality of counter-rotating vortices extending into the flow, i.e. tubes, are presented and discussed in detail, contrasting with the prior art. Configurations of multiple devices for the purposes of drag and fuel reduction, including their simulations and experimental results are put forward. Additional embodiments of the resulting tubes disclose use on aircraft or vessel control surfaces as stall inhibitors, use in wind turbines as dynamic range extenders, as well as use in turbines in efficient cooling mechanisms.

A flow modification device connectable to a generally cylindrical element adapted for immersion in a fluid medium is provided. The device comprises an elongate body having a length and a generally circular cross-section; a plurality of raised body portions disposed about and extending along the length of the elongate body, the raised body portions having a height between 2% and 10% of a diameter of the body; and an aperture extending through the length of the elongate body, the aperture being adapted to receive the generally cylindrical element such that the flow modification device is arranged about the cylindrical element. The plurality of raised body portions are helically arranged or twisted about a longitudinal axis of the elongate body and are adapted to reduce vortex-induced vibration and/or drag on the cylindrical element when the device is connected to the cylindrical element and the connected device and cylindrical element are immersed in the fluid medium and there is relative movement between the connected device and cylindrical element and the fluid medium.