Mechanical fluid dynamic device for the propulsion and flow control in the water-jet propelled boats

Abstract

The device includes conveying ducts of the fluid ( 2, 9 ), a tubular mean ( 1 ) with variable internal volume ( 1 ′), a tapered onion-shaped body ( 17 ) centred ( 18 ) inside the tubular mean, a nozzle ( 16 ) for the ejection of the fluid adjustable in position and opening for the variation of said internal volume ( 11 ), one or more gas injectors ( 21 ), and means to change the direction of the jet ( 6 ). In this way a fluid with variable characteristics can be obtained which allows the adjustment of the intensity, flow, direction and slant of the jet ( 6 ), moreover releasable also above the water surface ( 10 ), in view of the optimisation of the increased performances and consumption reduction. Unlike the devices of the known technique suitable only to convey the fluid and give the flow a single direction, the jet ( 6 ) is not diverted by other members, but is oriented through the joint ( 8 ) which allows its displacement in all the directions, in fact thanks to this said jet ( 6 ) can be directed without damping. It finds peculiar application in the propulsion and control of the hydrodynamic flow in the water-jet propelled boats or craft, besides as retrofit of easy embodiment to be installed also on the boats that have a traditional water-jet.

1 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, including conveying ducts of the fluid ( 2 ,  9 ), a tubular mean ( 1 ) with variable geometry and variable internal volume, a body ( 17 ) centred inside said tubular mean by means of a wing-shaped ring or support nut ( 18 ) with spokes or fluid dynamic blades, an adjustable nozzle ( 16 ) to eject the fluid, one or more gas injectors ( 21 ), and means ( 8 ,  22 ) to change the direction and the slant of the jet ( 6 ), characterised by the fact that the change of the volume of the chamber ( 1 ′) inside the tubular mean ( 1 ) for the control of the flow is obtained by displacement and opening of the adjustable nozzle ( 16 ) to change said internal volume ( 1 ′), without the need to change the shape and geometry of said nozzle ( 16 ) ( FIG. 3 ). 
   
   
       2 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according the  claim 1 , characterised by the fact that the movement of the nozzle ( 16 ) for the adjustment of the volume of the chamber ( 1 ′) inside the tubular mean ( 1 ) is carried out by a motorised system including a motor ( 12 ,  14 ,  24 ), like an electrical stepper motor, and by a gearbox, pinion and cogwheel ( 13 ,  15 ), suitable to displace, adjust and restrict said nozzle ( 16 ) from a minimum to a maximum opening position for the variation of the kinetic energy of the jet ( 6 ) itself. ( FIG. 3 ). 
   
   
       3 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to  claim 1  or  2 , characterised by the fact that the tapered pinecone or onion-shaped body ( 17 ) to drive and control the flow is made of deformable plastic material and has a hole ( 17 ′) linked to a hydraulic circuit ( 17 ″) to be filled by a fluid to change its volume and obtain a further adjustable element to control the hydrodynamic flow ( FIG. 4 ). 
   
   
       4 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to any one of the previous claims, characterised by the fact the ring or nut ( 18 ), on which the pinecone or onion-shaped body is mounted and centred ( 19 ,  20 ,  23 ) for guidance and control of the hydrodynamic flow inside the tubular mean ( 1 ), has a wing section or an aerodynamic profile ( 18 ″) and can move ( 18 ′) along the axis of the said body ( 17 ) from a minimum to a maximum point, to guarantee a depression at its centre and to direct the gas or air on the said onion-shaped tubular element, to determine a further adjustable element to change the parameters of the flow ( FIG. 5 ). 
   
   
       5 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to any one of the previous claims, characterised by the fact that the injectors ( 21 ) are placed and arranged at the centre of the ring ( 18 ) with wing section ( 18 ″) to force the gas to lap only on the surface of the pinecone ( 17 ) without disperse on the chamber ( 1 ′). 
   
   
       6 ) Mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to any one of the previous claims, characterised by the fact that the jet ( 6 ), besides the possibility of a release underwater like the traditional water-jets, can be also released outside the water above the water surface ( 10 ), like a jet engine or water-jet, said option resulting more effective and more appreciable in terms of better performances. 
   
   
       7 ) Use of the mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to any one of the previous claims, characterised by the fact that it ( 1 ) is symmetrically arranged in a determined number of couples on the lateral walls of the hull to optimise the auxiliary manoeuvres in harbour, said water-jets ( 1 ) being fed by hydraulic pumps ( 29 ,  29 ′) through ducts ( 30 ,  30 ′) and shutters ( 27 ,  27 ′) driven by electrovalves ( 28 ,  28 ′) and controlled by joystick ( FIGS. 6 ,  7 ). 
   
   
       8 ) Use of the mechanical fluid dynamic jet device, according to any one of the previous claims, for the control of the hydrodynamic flow in the propulsion and in the manoeuvre of the water-jet propelled boats or crafts. 
   
   
       9 ) Use of the mechanical fluid dynamic jet device for the propulsion and control of the hydrodynamic flow in the water-jet propelled boats, according to any one of the previous claims, for the control of the hydrodynamic flow in the propulsion and in the manoeuvre of the water-jet propelled boats or crafts, as a retrofit of easy embodiment to be installed also on the boats that have a water-jet or manoeuvring propellers of traditional type.