The present invention relates to a surface cover for a body which can be brought into contact with a liquid, comprising: a layer which at least partly contains gas and which is designed and arranged such that at least some sections of a layer face facing the liquid contacts the liquid; a gas-permeable layer which is arranged on the gas-containing layer on a face that faces the body and is opposite the face facing the liquid or which is integrally formed with the gas-containing layer; and a gas-supplying device which is connected to the gas-permeable layer such that gas can flow from the gas-supplying device to the gas-containing layer through the gas-permeable layer. The invention also relates to an arrangement and a use.

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.

Disclosed are a method and a device for reducing the wave-making resistance and friction force during ship navigation. The device includes a gas-liquid mixing device and a control device that are connected. The gas-liquid mixing device is provided with a water inlet, a gas inlet, a water outlet, and a gas-liquid mixing cavity arranged between the water inlet and the water outlet. Water and gas enter the gas-liquid mixing cavity via the water inlet and the gas inlet respectively, the control device controls gas intake at the gas inlet, and in this process, the water inlet is controlled to intermittently suspend water intake or intermittently implement low-speed water intake or implement continuous low-speed water intake, so that more gas enters the gas-liquid mixing cavity.

An air supply apparatus for a ship is described. The air supply apparatus includes a first turbocharger having a first compressor and a first turbine being drivable by exhaust gas provided from one or more engines. The first compressor is coupled to the first turbine via a transmission configured for changing a speed of the first compressor. Additionally, the air supply apparatus includes an air lubrication device for resistance reduction of the ship. The first compressor is connected with the air lubrication device for supplying air to the air lubrication device.

A belt for reducing the drag of a hull of a floating vessel, whereby the belt includes a belt body extending in a length direction (L), whereby the belt has, a sequence of bubble generators which are embedded in the belt body, whereby the belt has an air channel for supplying pressurized air to the bubble generators, whereby the air channel extends in the length direction (L), whereby the bubble generators are connected to the air channel, whereby the belt body is made of a flexible material. Also disclosed is a device having such a belt and a method of reducing the drag of a hull of a floating vessel using such a belt.

An assembly in a marine vessel includes a unit arranged in a water tight chamber opening in a hull of a vessel, wherein the unit is adapted to extend into the water below the vessel when at a mounted position. A connection path between an inside and an outside of the vessel is provided with a sealing system and the sealing system divides the connection path into an outside connection path portion and an inside connection path portion. The assembly includes a gas inlet system opening to the outside connection path portion.

A flat-bottomed vessel for transporting persons or goods, the vessel including a drag reduction system attached to the bottom of the vessel. The drag reduction system includes: two or more turbulence members extending perpendicular to the longitudinal direction of the vessel for generating an area with turbulent flow downstream to the turbulence members at the bottom of the vessel during movement. Additionally, for each turbulence member an air injector can be used to inject an air flow at or near to the turbulence members.

Hull with variable geometry for a vessel (11), comprising a completely immersed part (12), configured to provide part of the buoyancy thrust and integral with an emerged part (13) of the hull by means of one or more uprights (14), and one or more immersed wing surfaces (15) which, in a situation in which the vessel travels at a sufficiently high speed, are configured to provide the remaining part of the vertical thrust required to keep the vessel (11) above the surface of the water at a predetermined height; the hull comprises one or more supports (16a, 16b, 16c) connected to the wing surfaces (15) and associated with floating elements (17a, 17b, 17c) which are mobile with respect to the completely immersed part (12); the floating elements (17a, 17b, 17c) are fixed to the supports (16a, 16b, 16c) or mobile with respect to the supports (16a, 16b, 16c), therefore the floating elements (17a, 17b, 17c) are substantially cooperating with the completely immersed part (12) and with the wing surfaces (15); the wing surfaces (15) are configured to move with respect to the completely immersed part (12) or to remain fixed with respect thereto and the floating elements (17a, 17b, 17c) are configured to increase their immersion as the speed of the vessel decreases, and therefore provide the vertical thrust to maintain or adjust the distance of the vessel from the water in a manner that is optimal and functional for the use of the vessel, even at reduced speeds or when the vessel is stationary.

A device for reducing frictional resistance includes: a chamber which is provided to a draft part of a hull and in which blowing holes blowing out air into the water of the outside of the hull from different positions to each other in a height direction of the hull are formed; a supply pipe supplying the air to an internal space of the chamber; and a distributor provided to each of the blowing holes, and guiding a part of the air, which was supplied inside the chamber from the supply pipe, to each of the blowing holes. The plurality of distributors has a flow-amount adjuster adjusting a flow amount of the air guided to the blowing hole corresponding to each of the distributors so that the flow amount of the air blown out from the plurality of blowing holes is equalized in each of the blowing holes.

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.