A pressure stabilizing cavum includes multiple PE pipes and a backing plate. The multiple PE pipes are inserted through a longitudinal keel of the ship. Each PE pipe is provided with a first opening. Both two sides of the each PE pipe in the width direction of the first opening are connected to a hull bottom plate of the ship to form a pressure stabilizing cavum. The backing plate is located between the each PE pipe and the hull bottom plate and is sealingly connected to the each PE pipe and the hull bottom plate. The backing plate is provided with a first through hole, and the hull bottom plate is provided with a second through hole communicating with the first through hole, and the pressure stabilizing cavum communicates with the outside of the ship through the first through hole and the second through hole.

This invention introduces a unique two-piece nozzle used to provide air to the hull bottom of a ship, reducing the drag of water friction while in motion. The unique base assembly will mount flush in the bottom portion of a hull of a ship, creating no additional drag when closed. The unique interchangeable and modular nozzle design will allow for maintenance and or development of various designs in the water, without requiring a drydock visit. A flap portion of the nozzle insert will open when air is supplied, releasing small air bubbles to a ship's hull. The flap portion of the nozzle insert may incorporate various materials and passive closing schemes to adjust the air plastron. The present invention creates and maintains an air curtain, called plastron, delivering air underneath a ship hull through an array of nozzles.

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.

Disclosed is a dual cavity air lubrication system including an air flow splitter with an air inlet pipe branching into a first branch pipe and a second branch pipe, wherein a first passive valve is arranged in the first branch pipe and a second passive valve is arranged in the second branch pipe, wherein the branch pipes are in fluid communication with each other upstream from their respective valves, and wherein the valves are adapted for regulating the flow of air to respective air cavities to compensate for difference in air pressure in the cavities caused by a relative change in level of the cavities due to roll or heel of the vessel.

The invention relates to a system for providing an air lubricating layer between the hull of a vessel and the water flowing under the hull as said vessel is moving through the water, comprising an air cavity and a wave deflector having a planar bottom surface which faces said interface plane and extends parallel thereto and is arranged in an air cavity of said air lubrication system at a distance of 2-15 cm from the interface plane, wherein said bottom surface has a peripheral edge that is spaced apart from said sidewalls by a gap having a width of 0.5-15 cm, wherein, when viewed in projection onto a plane wherein said planar bottom surface extends, at least 85% of the area of said opening is covered by said wave deflector and/or said planar bottom surface thereof, more preferably at least 90%, and most preferably at least 95%.

A marine vessel hull, and marine vessels comprising at least one such hue, comprising a non-entrapment hull having at least one longitudinally vented transverse step, each longitudinally vented transverse step comprising a transverse step, and one or.sup.- more longitudinal steps extending forward therefrom. Each longitudinal step portion has a cross-sectional profile defining a cutout into the hull relative to a line defined by a deadrise angle of the hull. The cutout defines a vertical rise starting from the line defined by the deadrise angle and a run tilted outwardly upward at a non-horizontal angle less than the deadrise angle and that extends to an intersection with the line defined by the deadrise angle.

A system for reducing drag on a marine vessel (2) comprising a plurality of outlets (4) provided in the hull of the vessel (2) for delivering a layer of air bubbles between at least a portion of the hull and the water: at least one venturi tube (6) adapted to supply air and water to one or more of said plurality of air outlets (4): at least one seawater inlet (8) located in the bow region of the vessel (2) adapted to supply seawater to the at least one venturi tube (6) as the vessel (2) moves through the water: at least one seawater pump (10) adapted to supply seawater to the at least one venturi tube (6): at least one ambient air inlet port (16) adapted to supply ambient air to the at least one venturi tube (6) such that ambient air is entrained into sea water flowing through the at least one venturi tube (6): a compressor (18) supplying compressed air to the at least one venturi tube (6): a controller adapted to regulate the flow rate of sea water supplied from the at least one seawater pump and to regulate the supply of compressed air from the compressor to optimise the delivery of air bubbles through the plurality of outlets in the hull and thereby optimise drag reduction of the vessel.

An air supply system applicable to an air layer drag reduction ship includes an air tank and a cooling assembly. The air tank is provided with an air outlet pipeline and multiple air inlet pipelines. The air outlet pipeline and the air inlet pipelines are each provided with a first monitoring assembly and a first remote control valve. The cooling assembly is disposed inside the air tank and includes a liquid inlet pipe and a liquid outlet pipe, where the liquid outlet pipe is provided with a second monitoring assembly, the liquid inlet pipe is provided with a second remote control valve, and the second monitoring assembly and the first monitoring assembly are communicatively connected to the second remote control valve. The air supply system is capable of supplying stable and low-temperature air.

A frictional resistance-reducing device and a ship including the same are disclosed. The ship comprises: an outer panel including and air outlet; a plurality of reinforcement members provided on the inner surface of the outer panel so as to be spaced from each other; and a frictional resistance-reducing device formed on the inner surface of the out panel between immediately neighboring reinforcement members among the plurality of reinforcement members, so as to cover the air outlet, wherein the frictional resistance-reducing device includes: a hollow housing of which one surface is opened; and an air inlet formed in the housing, and the opened one surface faces the air outlet.

A marine vessel hull, and marine vessels comprising at least one such hull, comprising a non-entrapment hull having at least one longitudinally vented transverse step, each longitudinally vented transverse step comprising a transverse step extending from starboard to port, and one or more longitudinal steps extending forward therefrom. One or more longitudinal steps may also extend aft of an aft-most longitudinally vented transverse step, and may converge to a relatively lesser depth at the stern than a maximum depth at a location fore of the stern. The one or more longitudinal steps may gradually transition to a maximum depth aft of a discontinuity introduced by a forward transverse step. The hull may also have one or more longitudinal step tunnels.