An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

An arrangement for reducing resistance to the advance of a vessel its navigation includes:

at least one rotating body of revolution attached to the vessel by support and draft control means associated with its longitudinal rotation axis which is arranged perpendicular to the direction of advance of said vessel, and associated with driving means, the at least one rotating body of revolution located in front of the bow or behind the stern of said vessel. The rotation of rotating body of revolution is synchronized with the vessel’s forward speed. The rotating body of revolution closest to the hull of the vessel is separated from the hull by a clearance of approximately 5% or less of its maximum diameter. The support and draft control means are forks associated with pistons and maintain the rotating body of revolution submerged in the order of 30% of its maximum diameter during navigation.

The present invention relates to the design of seagoing vessels and can be used for most hull types from slow-moving ships and barges to high-speed ships and boats that are operated up to planing speed, and also for sailing boats. The invention relates to the design of the vessel's forepart and relates to a device that reduces the vessel's wave resistance within a wide speed range, and also reduces or eliminates spray and wave-breaking resistance. The device comprises a body that is fully or partly submerged in a mass of water and positioned at the bow area, the body working in interaction with the hull behind. The body is designed and positioned such that it essentially displaces oncoming water mass in the vertical plane and then leads the water mass that passes on the top surface of the body away from and/or essentially parallel to the bow area, such the hull itself, behind the body, displaces oncoming water masses to the least possible extent. A reduced resistance to forward movement from the vessel is thus obtained.

An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

An intentional fluid manipulation apparatus (IFMA) assembly with a first thrust apparatus that imparts a first induced velocity to a local free stream flow during a nominal operation requirement. The first thrust apparatus creates a streamtube. A second thrust apparatus is located in a downstream portion of the streamtube. The second thrust apparatus imparts a second induced velocity to the local free stream flow. The second induced velocity at the location of the second thrust apparatus has a component in a direction opposite to the direction of the first induced velocity at the location of the second thrust apparatus.

Ships for navigating in icy waters having improved propulsion performance in open water and at the same time good maneuverability forward in icy waters are provided. Such ships include those having a bow area with a bulb adapted to generate a bow wave in phase opposition with respect to that generated by the ship's hull.

A personal watercraft hull has a bow, a keel, starboard and port upper edges, a starboard portion extending between the keel and the starboard upper edge, a port portion extending between the keel and the starboard upper edge, and a transom. The starboard portion has a starboard row of grooves. The port portion has a port row of grooves. The rows of grooves extend in a longitudinal direction and are laterally offset from the longitudinal centerline and from their corresponding upper edge. The grooves of the rows of grooves define recesses in an outer surface of the hull. A personal watercraft having the personal watercraft hull is also disclosed.

Vessel equipped with a hydrodynamic duct of flow management at the bow composed by a horizontal wall portion (2) extending at each side of the centerline (CL) of the bow of the vessel (8), at least one additional horizontal wall portion (1) positioned above the horizontal wall portion (2) at the region of the waterline adapted to managing surface waves and a pair of lateral wall portions (5) connected at each end of the horizontal wall portions (1) and (2) and extending upwardly at each side of the bow thereby forming in conjunction with the horizontal wall portions (1) and (2) a circumferentially closed duct, inside which, the flow is entirely differentiated from the flow outside the duct, such differentiation resulting at a reduction of the wave making resistances and of the required rated horsepower and fuel consumed for the navigation of the vessel. Proposed variations with one additional horizontal wall portion (3) or two wall portions (3,4) between the horizontal wall portions (1) and (2) operating complementarily or alternately in an unloaded and loaded condition of the vessel.

Vessel equipped with a hydrodynamic duct of flow management at the bow composed by a horizontal wall portion (2) extending at each side of the centerline (CL) of the bow of the vessel (8), at least one additional horizontal wall portion (1) positioned above the horizontal wall portion (2) at the region of the waterline adapted to managing surface waves and a pair of lateral wall portions (5) connected at each end of the horizontal wall portions (1) and (2) and extending upwardly at each side of the bow thereby forming in conjunction with the horizontal wall portions (1) and (2) a circumferentially closed duct, inside which, the flow is entirely differentiated from the flow outside the duct, such differentiation resulting at a reduction of the wave making resistances and of the required rated horsepower and fuel consumed for the navigation of the vessel. Proposed variations with one additional horizontal wall portion (3) or two wall portions (3,4) between the horizontal wall portions (1) and (2) operating complementarily or alternately in an unloaded and loaded condition of the vessel.