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 moveable exhaust trim tab for a motorized boat directs exhaust gas and cooling liquid into the water, changing the size and shape of the wake and reducing engine noise. The device comprises a trim tab base having a lip and a cap attached to the trim tab base to form a cavity between the lip and the cap into which the boat's exhaust is directed. The cavity has various apertures that permit the exhaust to exit the cavity and, in some embodiments, permit water to enter the cavity from below. The device may comprise baffles, outlets, inlets, and directional collars to change the flow of the exhaust. The trim tab is attached to the boat with an actuator that lets the trim tab to be adjusted at an angle relative to the boat.

A method for exhaust gas treatment in vessels/installations located in a body of water is disclosed. The method comprises admixing ambient air to exhaust gas in a dilution unit (3) resulting in diluted exhaust gas, drawing water and diluted exhaust gas into bubble generator (4) and generating bubbles containing diluted exhaust gas in the water, and releasing the bubble-containing water into the body of water. A corresponding system is also disclosed.

Disclosed is an air supply system for supplying air to an outside of a hull of a vessel, the vessel holding a combustion engine. The air supply system comprises one or more air discharge units (ADUs) for releasing compressed air to an outside of the hull below a waterline of the vessel. The air supply system comprises a plurality of turbocharger(s) for supplying a compressed air flow to the combustion engine of the vessel via a first flow path. The plurality of turbochargers each comprises a turbine configured to be driven by an exhaust gas flow of the combustion engine and a compressor connected to the turbine and comprising an inlet for receiving air and an outlet for providing the compressed air flow to the first flow path. The plurality of turbochargers comprises a first turbocharger and a second turbocharger arranged in series with the compressor of the second turbocharger being downstream of the compressor of the first turbocharger in the first flow path. The air supply system comprises a first sub-path and a second sub-path branching off the first flow path and supplying the sub-flow of air to the ADUs. The first sub-path branches off from the first flow path downstream of the first turbocharger and upstream of the second turbocharger and wherein the second sub-path branches off from the first flow path downstream of both the first turbocharger and the second turbocharger.

Disclosed is an air supply system (100) for supplying air to an outside of a hull (201) of a vessel (200). The vessel comprises an engine. The air supply system comprises one or more turbocharger(s) (10) for supplying a compressed main air flow to the engine of the vessel via a respective first flow path (11A). The air supply system comprises an exhaust gas recirculation (EGR) system for recirculating exhaust gas into the compressed main airflow supplied to the engine via a second flow path (11B). The air supply system comprises a third flow path (11C) for supplying a sub-flow of compressed air to one or more Air Discharge Units (ADUs). The EGR system comprises a blower (31) arranged in the second flow path (11B) for supplying exhaust gas to the engine. The first flow path and the second flow path have a first connecting path (11AB) upstream of the blower (31) and a second connecting path (11BA) downstream of the blower. The third flow path is in fluid connection with the first flow path and the second flow path downstream of the blower, such that the sub-flow of compressed air can be extracted from the first flow path and/or the second flow path.

Disclosed is an air supply system (100) for supplying air to an outside of a hull of a vessel. The air supply system (100) comprises a plurality of air discharge units, ADUs, (20) for releasing a compressed air flow to the outside of the hull below a waterline of the vessel, wherein the plurality of ADUs (20) are configured to be arranged around a longitudinal centre line (202) of the hull of the vessel. The air supply system (100) comprises a first flow path (11A) for providing the compressed air flow to the ADUs (20). The air supply system (100) comprises one or more pressure control device(s) (30) arranged in the first flow path (11A) for feeding the compressed air flow to the ADUs (20) at pressure larger than a discharge pressure at the ADUs (20). Each pressure control device (30) comprises an inlet (34) for receiving an inlet air flow, a first outlet (35A) and a second outlet (35B) for feeding the air flow to a subset of the plurality of ADUs (20AB, 20BA; 20CD, 20DC). The first outlet (35A) is connected to a first subset of ADUs (20AB; 20CD) arranged on a first side of the longitudinal centre line (202) of the hull (201) of the vessel (200) and the second outlet (35B) is connected to a second subset of ADUs (20BA; 20DC) arranged on a second, opposite, side of the longitudinal centre line (202) of the hull of the vessel. The one or more pressure control device(s) (30) is/are configured to compensate for a difference in discharge pressure between the first subset of ADUs (20AB; 20CD) and the second subset of ADUs (20BA; 20DC).

Disclosed is an air supply system for supplying air to an outside of a hull of a vessel holding a combustion engine. The air supply system comprises one or more air discharge units, ADUs, for releasing compressed air to an outside of the hull below a waterline of the vessel. The air supply system comprises a pump for generating a first flow of sea water. The airs supply system comprises an injector comprising a first inlet for receiving the first flow of sea water from the pump, a second inlet for receiving a second flow of gas from the combustion engine, an outlet for discharging a third flow of gas to the ARUs, and an expansion portion arranged downstream of the first inlet and the second inlet and upstream of the outlet. The injector is configured to mix the first flow of sea water and the second flow of gas into the third flow of gas and the expansion portion is configured to expand the third flow of gas to increase the pressure of the third flow of gas discharged from the injector through the outlet. The air supply system is configured to evaporate the first flow of sea water using thermal energy from the combustion engine so that the third flow of gas is enriched with steam from the first flow of sea water.

An air supply apparatus for a ship is described. The air supply apparatus includes a fuel cell and an air lubrication device for resistance reduction of the ship. An exhaust gas outlet of the fuel cell is connected with the air lubrication device via an exhaust gas line for supplying exhaust gas to the air lubrication device. Further, a ship comprising an air supply apparatus according to any embodiments described herein as well as a method of supplying air to an air lubrication device of a ship are described.

A rudder assembly, including a steering engine; an axial hollow rudder stock; a rudder blade; a gas release unit; and a tiller. The steering engine is disposed in a vessel stern. The tiller is connected to the steering engine. The axial hollow rudder stock includes a through hole. The through hole is small and disposed along the axis of the axial hollow rudder stock. The gas release unit is disposed in the vessel stern, and includes a control cabinet. The control cabinet includes a reagent storage tank, a reagent conveying hose connected to the reagent storage tank, a compressed air bottle, a pressure hose connected to the compressed air bottle, and a console. The pressure hose and the reagent conveying hose pass through the through hole of the axial hollow rudder stock, and then communicate with the cavity of the rudder blade.