[Problem] To provide a method for further reducing the friction resistance of a friction resistance reduced ship. [Solution] Rolling and pitching vary greatly depending on variations in climate, etc.; however, when limited to an extremely short time, the rolling and pitching repeat in an almost identical or similar pattern. Therefore, if the pattern of the immediately preceding rolling and pitching is understood, the subsequent pattern can also be predicted. This is similar for vertical position variation patterns of minute bubble generation units calculated from the angle of the rolling and pitching. Furthermore, the vertical position variation also differs depending on the installation position of each minute bubble generation unit, so the present invention measures the vertical position variation for each minute bubble generation unit, while also predicting the vertical position variation at and after the current time. The predicted vertical position variation is compared with the waterline height, while the time at which the minute bubble generation units below the sea surface will be above the sea surface or the time at which the minute bubble generation units above the sea surface will be below the sea surface are predicted, and an ON/OFF valve 8 is switched at that time.

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 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.

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.

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 drainage device may include a channel body mountable on the surface proximate to an outlet on the surface and extendable away from the surface. A drainage device may include a groove formed along at least a partial length of the channel body. A drainage device may include a lip protruding from a bottom edge of the channel body at an end of the channel body that is distal from the surface when the drainage device is mounted thereon, wherein when the drainage device is mounted on the surface proximate to the outlet, fluid from the outlet is directed by the drainage device away from the surface.

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 (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 (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).