A propulsion device with outboard waterjet for high-speed marine vehicles, the propulsion device comprising:
- a nacelle comprising a housing with hydrodynamic shape, wherein said housing is extended axially according to an extension direction (X) between a front end and a rear end, and is provided with a conveyance channel, which is extended along said extension direction (X) between an inlet section, arranged at said front end, and an opposite outlet section arranged at said rear end;
- said nacelle being intended to be connected to the exterior of a bottom of a ship in order to be immersed within a fluid in which said ship is intended to advance;
- a propeller arranged within the conveyance channel of said housing and actuatable in order to determine a propulsion in a specific advancement direction (V1) substantially transverse to the inlet section of said housing;
- wherein:
- said propeller comprises a pump actuatable for generating a flow of said fluid through said conveyance channel according to an outflow sense (VF) which goes from said inlet section to said outlet section;
- wherein said pump is provided with at least one impeller having a radius and a rotation axis (Y) parallel to the extension direction (X) of said housing;
- said nacelle comprises:
- a dynamic intake, which comprises a front section of said housing;
- wherein said front section is extended axially along said extension direction (X) between said inlet section and said pump, and has passage sections, transverse to said extension direction (X), increasing according to said outflow sense (VF), in a manner such to cause, in said dynamic intake, a slowing of local speed of said fluid and a pressure rise of said fluid;
- a discharge nozzle, which comprises a substantially axially-symmetric rear section of said housing;
- wherein said rear section is extended axially along said extension direction (X) between said pump and said outlet section, and has passage sections, transverse to said extension direction (X), decreasing in said outflow sense (VF), in a manner such to cause, in said discharge nozzle, an increase of the local speed of said fluid and a pressure decrease of said fluid, creating a propulsive thrust jet exiting from said outlet section;
- a central body comprising an intermediate section of said housing;
- wherein said intermediate section is extended along said extension direction (X) between said dynamic intake and said discharge nozzle, at its interior houses said pump and has passage sections, transverse to said extension direction (X), having constant area along said extension direction (X);
- wherein the front section of said dynamic intake is connected to an external surface of the housing of said nacelle by means of a lip of rounded shape, which delimits an edge of the inlet section of said nacelle;
- and
- wherein the at least one impeller of said pump is provided with blades having airfoil with chord increasing, which increases as a function of the radius of said at least one impeller.