A transverse hydro-laminar flow system is a system that improves laminar flow across a watercraft's hull as the watercraft is moving through a body of water. The system may include air dispersal units, a first base anchor, a second base anchor, an air supply system, a controller, and a power system. The air dispersal units enable the creation of an air layer between the watercraft's hull and the surrounding water. The first base anchor and the second base anchor facilitate the fastening of the air dispersal units about the watercraft's hull without the need to dry dock the watercraft. The air supply system provides a constant air flow to each of the air dispersal units to enable the creation of the air layer that reaches most of the watercraft's hull. The controller enables the configuration of the system, while the power system supplies the necessary power for the system operation.

Device mountable on a surface (10), the device comprising a spacer system (12, 16, 20, 22) and a grid structure (2) which grid structure (2) is attached in spaced relation to the surface (10) by means of the spacer system (12, 16, 20, 22), wherein the distance between the surface (10) and the grid structure (2) is in a range from >0.1 m to <10 mm, wherein the grid structure (2) forms meshes of a mesh size in a range from >0.5 m to <8 mm, and wherein the surface of the grid structure (2) is at least partially amphiphobic. Method of maintaining a gas or air layer on a surface when the surface is immersed in a liquid or water comprising such device, and uses thereof.

A low-cost viscous-drag-reducing cladding for a ship's hull comprising airbags whose outer surfaces are adapted to be water repelling. Each airbag comprises a plenum that comprises substantially open space, which does not obstruct the flow of air through it. The airbags are inflated with compressed air to a pressure higher than the adjoining hydrostatic pressure. The airbag material comprises a reinforcing fabric, which is adapted to withstand the forces encountered during operation, and is sealed with a sealant so as to be made substantially impermeable to air. The outer water-repelling surface of each airbag is connected to a plenum by means of restrictor holes. Air flows from the plenum through the restrictor holes into the water-repelling layer.

Disclosed are a frictional resistance reducing device that effectively reduces the frictional resistance of a ship, and a ship including same. The frictional resistance reducing device comprises: a first air discharge part formed on the leading undersurface of a ship and discharging air into water, a second air discharge part formed behind the first air discharge part and discharging air into water; and an air supplying source supplying air to the first air discharge part and the second air discharge part, wherein the first air discharge part and the second air discharge part are disposed in-line along the lengthwise direction of the ship, and at least a portion of a first air discharge duration of the first air discharge part and at least a portion of a second air discharge duration of the second air discharge part overlap each other.

A microstructured surface with microfeatures formed thereon and defining spaces between the microfeatures includes least one electrode of an electrode pair in the spaces, wherein electrodes of the pair are electrically connected to one another. The at least one electrode located in the space is configured to generate a gas in between the microfeatures when an electrolyte solution penetrates into the microfeatures. Importantly, the electrodes are not connected to any external power source. Because the microstructured surface is self-powered in replenishing the gas lost in a submerged condition, no additional provision to supply energy or regulate the replenishment is necessary for implementation and use.

Disclosed is a vessel including a hull and a system providing an air lubricating layer between the bottom and water, including a cavity defined by sidewalls, a top wall and an interface plane, in which water mixes with air due the Kelvin Helmholtz effect. The sidewalls extend from a dagger-shaped nose section at the front end to the rear end of the cavity and diverge so a distance between the sidewalls increases along the length of the cavity when going in a rearward direction. The diverging cavities provide a stable air lubrication layer that covers a relatively large area of the bottom, so the number of cavities can be reduced. The alignment of the diverging cavities with the streamlines has relatively large tolerances so construction is simplified and can be carried out in a cost-effective manner. The diverging sidewalls lead to reduced formation of vortices and reduced drag.

The present invention seeks to reduce the frictional resistance of a vessel through enhanced air lubrication by creating and sustaining a superaerophilic surface underneath the vessel. Air is supplied by two different means: through vents near the bow of the vessel and through the perforated superaerophilic surface underneath the vessel. The air delivered through the perforations in the superaerophilic surface prohibits wetting of microscopic structures on the surface, maintaining the superaerophilic properties of it. Since the superaerophilic surface attracts air close to the hull surface, this invention greatly increases the ratio of air from the bow vents within the boundary layer, improving the efficiency and effectiveness of the air lubrication system. Aerophilic effects are enhanced by carbon, which is captured, filtered, and mixed in with the air supplied to the plastron.

Systems, methods and apparatuses are provided for the reduction of hydrodynamic frictional drag. These systems, methods and apparatuses can include a vessel surface having an external layer and a plurality of dimples, wherein the external layer comprises a hydrophilic material, and wherein each of the dimples includes an inner surface having a superhydrophobic coating. The dimples can be configured to maintain an air-water interface as one or more fluids flow over the vessel surface. In some embodiments, a pressure reservoir can be coupled with the dimples, and can include an acoustic speaker to vibrate the air-water interface.

A method for reducing marine growth on a vessel, includes providing an air lubrication system and covering at least a part of the hull with air bubbles. Also described is a vessel having an air lubricating system with releasable connection of the deflectors across the cavity, a closeable outlet valve in the air outlet duct, connection of a compressor to each cavity or pair of cavities and an air inlet opening in the top of the cavity.

The invention provides a solution for inadequate boundary layer testing methods. The invention includes a uniquely configured multi-module concentric loop cycling water past a testing module to obtain real-time values and variables to use in CFD calculations. The invention is comprised of various sections, specifically designed to support the entire system. The system includes: one or more water reservoirs/degassing tanks, high-capacity water pumps, water stream straightener(s), stable flow section, air induction ports, viewing ports, test modules containing test surfaces designed to measure friction and pressure of a passing water or air/water stream. The present invention includes one or more sensors on the test surface(s) that convey conditions to one or more computers that may receive, store, process and send interpretations to one or more visual monitors on or near the invention in real time.