IT202100016967A1 - Variable geometry hull for boats - Google Patents

Description

DESCRIPTION of the Industrial Invention entitled: ?Variable geometry hull for boats?

DESCRIPTION

The present invention relates to a variable geometry hull for boats, comprising a back wall, to which back wall ? fixed at the bottom at least one hull element through a post.

Also provided are two wing surfaces located laterally and below the hull element, which wing surfaces are connected to the bottom wall through corresponding supports.

The hull object of the present invention refers, preferably, but not exclusively, to hulls which can be used in small boats operating in canals or lagoon waters, such as for example boats for private service and "Taxi", but which can, at the same time, also tackle crossings in the open sea, at high speed.

Currently, hulls equipped with wing surfaces are known, such as for example hydrofoils, which can be used according to different configurations, or for various types of uses.

One of these uses is, for example, the so-called ?water taxi?, that is, the transport of people along water basins, but also in open waters, at high speeds, to reduce journey times.

The boats used for this type of use therefore need to: travel within protected areas, at maximum speed? possible and resulting in reduced wave formation.

Wave formation? a fundamental requirement as it is directly linked to the efficiency of the vessel in terms of energy consumption while the vessel is running.

As ? known, there are different types of naval hulls and hulls that differ from each other in the type of sustenance, which can? be of the hydrostatic type, due to the thrust of the immersed hull volume, or of the hydrodynamic type, due to the lift of the hull surface that slides on the water.

Traditional boats, in principle, are divided between displacement boats, those that primarily exploit hydrostatic thrust, and planing boats, those that exploit hydrodynamic lift. The resistance of the former? strongly related to waterline length. It gradually increases with the speed up to a speed critical, function of said length, to then increase strongly, making any increase in power to significantly increase speed inefficient and uneconomical. The incidence of the displacement? not relevant.

In the case of a water taxi or a small vessel, the length? usually contained, and therefore the speed? criticism turns out to be very low, a few knots, and therefore, however efficient, in terms of strength / weight ratio, the displacement hull cannot? be adopted for small boats where you need a speed? operational usually higher than the critical one of the displacement.

For planing hulls in all their variations, the resistance? instead strongly linked to the displacement. In these cases the lightness? essential to drastically reduce consumption.

However, both configurations have the disadvantage of consistent waveforming and low sensitivity. to wave motion.

A solution known to the state of the art that allows you to reduce the sensitivity? to wave motion and resistance ? the S.W.A.T.H. type boat In one of its most widespread configurations, hydrostatic support ? provided by two completely immersed bodies, similar to torpedoes, connected to the main boat, which is completely out of the water, by means of vertical supports having a section that is as thin as possible. because the vertical supports have thin sections, the resistance to their progress ? minimal, what? such as wave formation. For the same reason, the state of the sea does not influence the movements of the main vessel, which is almost transparent when a wave passes by.

However, SWATH-type boats have a high draft, as well as limited capacity? to bear load variations, often compensated with ballast tanks, and therefore a useless increase in weight.

Another type of hull for high speed? ? the hydrofoil, in which the hydrodynamic sustenance ? made by means of wing surfaces called wings or hydrofoils or foils, completely or partially submerged, which at a speed? greater than the take-off height, lift the boat completely out of the water. The advantages are the reduced drag, essentially due to the drag/lift ratio of the wings and the vertical supports that connect them to the boat.

The disadvantages of this solution are related to speed? minimum necessary to keep the hydrofoil in flight, which can only be maintained for a limited time of the operational profile of boats of the water taxi or similar type.

At low speeds, the hydrofoil behaves, from the point of view of resistance and seaworthiness, worse than the hull without wings, as the resistance of the hull is added to that of the wings.

Another disadvantage of this vehicle? often the limited excursion of the capacity? load, as for strong displacement excursions, the wings would become too loaded and would begin to lose efficiency, not allowing the flight of a too heavy hydrofoil.

Another disadvantage is the excessive draft when the boat is stationary which restricts access to some ports.

Finally, the hydrofoil, before taking off, must reach high speeds? in displacement conditions and therefore navigate, albeit for a limited time, with high wave formation.

So is there a need? not satisfied by the systems known to the state of the art, of realizing a hull which presents a limited wave formation, a high stability? platform and finally present the possibility? to take off even at low speeds, maintaining a limited draft.

A further object of the present invention ? the creation of a variable geometry hull which can be used substantially on any type of vessel, in particular in vessels such as hydrofoils, SWATH or the like, which can be used by way of example, but not exclusively, as a "water taxi".

The present invention achieves the above aims, realizing a hull with variable geometry as previously described, in which the hull element is? mounted translatable along said upright, in such a way that the hull element moves along an approach/away direction from the bottom wall.

Also, the displacement of the hull element ? adjusted on the basis of the speed? of running of the boat.

In accordance with this configuration, the hull element allows part of the buoyancy to be provided, while the wing surfaces, in a vessel traveling at speed high enough, they are configured to provide the remainder of the vertical thrust necessary to keep the boat above the water surface at a predetermined altitude.

According to a possible embodiment, at least two floating elements are provided located in correspondence with said supports, in such a way that the floating elements are mounted in a translatable manner with respect to the bottom wall and in such a way that the floating elements move along a direction of approach/departure from the back wall.

Also in this case, the displacement of the floating elements ? adjusted on the basis of the speed? of running of the boat.

The displacement of the floating elements allows their immersion to increase as the speed decreases. of the boat and, therefore, to provide the vertical thrust to maintain or regulate the distance of the boat from the water, in an optimal and functional way at the service of the boat, even at speed? reduced or at rest.

Therefore, advantageously, the present variable geometry hull allows to overcome the problems of high draft typical of some known solutions, to obtain a reduced wave formation and furthermore to obtain a reduced resistance to forward movement.

The hull object of the present invention ? therefore able to reduce the draft, or in any case maintain a pre-established height with respect to the floating surface, to allow passengers to be embarked and disembarked, with the ship stationary or maneuvering, by modifying its geometry, in a short time and with simple operations and carried out safely.

Furthermore, the hull object of the present invention allows to modify the capacity? load with the boat stationary maintaining the same height of the part of the boat outside the surface of the sea, with respect to the waterline.

In fact, when the boat is stationary, is the hydrostatic support ? given, by? element of scada and the portion of the immersed volume of the floating elements placed at the extremities? of the wing surfaces. As the load increases, moving the wing surfaces and immersing the floating elements, or watertight volumes more, the boat's altitude with respect to the waterline does not change. Obviously this allows you to adjust the height of the boat with respect to the height of the embarkation platform, and to keep this height constant during all embarkation operations.

Also due to the fact that the submerged portion of the watertight volumes to determine the share of the boat, the draft of the same pu? be kept within the limits required to reach the quay even in the case of shallow waters.

Furthermore, by immersing one or the other of the watertight volumes placed at the ends? of the wing surfaces, a possible asymmetry of the load pu? be compensated without using ballast tanks, and therefore increase the weight of the boat unnecessarily.

Another advantage of the hull object of the present invention? relating to take-off operations, i.e. the transition between hydrostatic support of the watertight volumes and hydrodynamic support of the wing surfaces, which takes place in practice without variation of the vessel's altitude.

During the acceleration phase of the boat, the partially immersed watertight volumes not only contribute to hydrostatic support, but also contribute to stability? transversal of the boat also acting as a stabilization system for ship motion.

When the speed? ? such that the wing surfaces are able to compensate for the hydrostatic thrust of the floating elements, a movement mechanism moves the wing surfaces to which they are connected, until they are completely out of the water. In these conditions the boat? fully supported by the immersed volume and the lift of the wing surfaces.

From this moment the dynamic behavior of the boat allows you to have a high capacity? of load in virtue? of the high hydrostatic thrust of the hull element, a high stability? of platform, a reduced resistance to? Advancement and a reduced wave formation, in virtue? of the reduced waterline section of the vertical structure of the hull element and of the wing surfaces.

During this phase of flight the stability? to ship motions? provided by the presence of the wing surfaces which, moving controlled by an automatic system, react to a change in attitude by modifying its lift. To control ship motion, the wing surfaces can be equipped with independent flaps for trim control and regulation.

Finally, the submerged bodies can be brought into contact with the emerged part of the boat by transmitting to them a portion of the vertical thrust, and unloading the central structure. In this way the wing surfaces are loaded more? balanced, like a beam on two supports, instead of a beam wedged on one side only, reducing the dynamic stresses to which they are subjected during the flight phase, and increasing their resistance to fatigue and the average life of the structure.

What about navigability? in protected areas with stringent requirements on wave formation, at low speeds, when the boat is? in hydrostatic support on the hull element and on the partially submerged floating elements, the wave formation would still be limited like that of a traditional multi-hull.

Think, for example, of a catamaran or a trimaran.

The floating elements could have very narrow and streamlined sections, while the connection between the hull element and the boat, which in itself has a very narrow section, it could conveniently be designed in its upper connection to the topsides to take the shape of the central hull of a trimaran.

This geometry would therefore allow the hull object of the present invention to reach the speed? take-off with reduced wave formation, and continue navigation on the wing surfaces, lifting the floating elements, with further reduced wave formation, but at high speeds?, even in areas where other boats would be limited in speed? due to high wave formation.

Furthermore, the possibility to move, on the basis of the speed?, the element of the hull, allows that such element of the hull can be lifted in the emerged condition, avoiding the generation of a resistance of form and, consequently, the speed is not limited? maximum.

In this case, the speed? ? such that only the wing surfaces are able to support the whole weight of the boat through the hydrodynamic thrust. The boat can continue browsing at speed? high, supported only by the wing surfaces, like a hydrofoil with immersed wings.

According to a possible embodiment, the wing surfaces can have different profiles, each of which has a maximum efficiency in a given speed range. In particular, from the speed? at which the take-off takes place, up to the speed? for which the element of the hull can? be raised, and beyond up to a limit value, the best profile for the wings ? the one defined as sub cavitating or the NACA type profile.

However, does this profile also have a maximum speed limit? beyond which it becomes inefficient.

Beyond this limit the wing surfaces, to be efficient, should have a trans cavitating or sub cavitating profile.

For this reason, the hull object of the present invention foresees that, in addition to a given speed, the only part of the immersed wing surface is that with the profile suitable for such speeds. really high.

The boat which has a variable geometry hull which is the object of the present invention? therefore able to increase its speed? until reaching a new physical limit represented by the profile of the wing surfaces. the wing surfaces of a hydrofoil have airfoils of the NACA or Sub cavitating series, which should never cavitate. actually? these profiles accept a level of cavitation up to 10-15% of the surface of the wing, but as the speed increases? of the boat, the cavitation exceeds this limit and these profiles become inefficient. To overcome this new limit, the NACA profiles should be replaced with a trans cavitating profile, i.e. profiles where the back of the wing? completely enveloped by the cavitation, and the thrust ? generated by a single face, or super cavitating, or rather profiles for which the wing to be efficient must work in totally cavitating regimes.

At speed? higher than this limit the vessel lifts off the surface of the sea also uncovering a portion of the wing surfaces, the one with sub-cavitating profiles, and leaving only that portion of the wing surfaces submerged with a trans-cavitating or super-cavitating profile.

This further characteristic therefore allows the hull object of the present invention to reach speeds very high.

The set of characteristics of the invention therefore allow it to reach the speed take-off with reduced wave formation, continue navigation in the channels with the submerged body and on the wings with a sub cavitating profile or NACA, lifting the floating elements, then go out into the open sea and also lift the submerged body in the shape of a torpedo and fly supported only on the wings, and finally reach speed? higher than those reachable by a traditional hydrofoil, uncovering the sub cavitating portion of wings and leaving only the sub cavitating portion immersed.

The combination of all the characteristics makes the invention further advantageous, also compared to the hydrofoil with immersed wings, not only in the canals, where the latter must in any case cross the area in displacement and at low speeds, but also in the open sea where it is in fact equivalent to it up to the speed? limit at which the transition between sub cavitating and super cavitating takes place, making it finally much more? efficient of? hydrofoil immersed wings for speed? above this transition.

These and further objects of the present invention are achieved by means of a bottling device according to the attached independent claim and the subclaims.

Optional characteristics of the device of the invention are contained in the attached dependent claims, which form an integral part of the present description.

These and other features and advantages of the present invention will be more clearly from the following description of some executive examples illustrated in the attached drawings in which:

figure 1 ? a schematic side view of an embodiment of the present variable geometry hull stationary or at speed? very low, in particular with the wing surfaces or wings in the position in which the floating elements or watertight volumes disposed at their extremities? are lifted, a condition in which the boat is in the most? low, that of maximum draft;

the fig. 2 ? a side view of the hull of fig.

1 stopped or at speed? very low with the wing surfaces or wings in the position in which the floating elements or watertight volumes disposed at their extremities? are lowered, a condition in which the boat is in the most? high, the one with minimum draft;

figure 3 ? a side view of the hull of figure 1 moving at speed? intermediate with the wing surfaces in the position in which the floating elements or watertight volumes arranged at their ends? are completely emerged, a condition in which the boat? supported by the hydrodynamic thrust of the wings and hydrostatic thrust of the submerged volume;

figure 4 ? a side view of the hull of figure 1 moving at speed? elevated with the wing surfaces or wings in the position in which the watertight bodies or volumes disposed at their extremities? have completely emerged and also the element of the hull, or immersed volume, is? been lifted, condition in which the boat? sustained only by the hydrodynamic thrust of the wing surfaces;

figure 5 ? a side view of the hull of figure 1 moving at speed? elevated motion with the wing surfaces or wings in the position in which the floating elements or watertight volumes arranged at their ends? have completely emerged, the immersed volume ? in its position low, but the whole boat is supported on tan-cavitating or super-cavitating wings;

figure 6 ? a schematic cross-sectional view of the hull in the configuration of figure 1;

figure 7 ? a schematic cross-sectional view of the hull in the configuration of figure 2;

the figure 8 ? a schematic cross-sectional view of the hull in the configuration of figure 4;

figure 9 ? a schematic cross-sectional view of the hull in the configuration of figure 4;

figure 10 ? a schematic cross-sectional view of the hull in the configuration of figure 5;

figure 11 ? a top view of the hull of figure 1;

figure 12 ? a schematic side view according to a further embodiment of the present variable geometry hull stationary or at speed? very low, particularly in the configuration in which the watertight bodies or volumes arranged at the ends? of the wings are lifted, condition in which? boat is found in the most? low, that of maximum draft;

figure 13 ? a side view of the hull of figure 1 stationary or at speed? very low in the configuration in which the bodies or watertight volumes arranged at the ends? of the wings are lowered, condition in which the boat is in the most? high, the one with minimum draft;

figure 14 ? a side view of the hull of figure 1 moving at speed? intermediate in the configuration in which the watertight bodies or volumes arranged at the ends? of the wings have completely emerged, condition in which the boat? supported by the hydrodynamic thrust of the wings and hydrostatic thrust of the submerged volume;

figure 15 ? a side view of the hull of figure 1 moving at speed? elevated in the configuration in which the watertight bodies or volumes arranged at their ends? have completely emerged, and also the immersed volume ? been lifted, condition in which the boat? sustained only by the hydrodynamic thrust of the wings;

figure 16 ? a side view of the hull of figure 1 moving at speed? high motion, configuration in which the bodies or watertight volumes arranged at their ends? I'm in the best position low, while the immersed volume ? lifted, and the whole boat is supported on the trans cavitating or super cavitating wings;

figure 17 ? a schematic cross-sectional view of the hull in the configuration of figure 12;

figure 18 ? a schematic cross-sectional view of the hull in the configuration of figure 13;

figure 19 ? a schematic cross-sectional view of the hull in the configuration of figure 14;

figure 20 ? a schematic cross-sectional view of the hull in the configuration of figure 15;

figure 21 ? a schematic cross-sectional view of the hull in the configuration of figure 16.

It is specified that the figures annexed to the present patent application illustrate only some possible embodiments of the variable geometry hull object of the present invention, in order to better understand the advantages and characteristics described.

These embodiments are therefore to be understood for purely illustrative purposes and not as a limitation to the inventive concept of the present invention, i.e. that of realizing a hull which has a limited draft, which allows to obtain a reduced wave formation and furthermore to obtain a reduced resistance to water. advancement.

With particular reference to the accompanying drawings, in figures 1 to 11 ? illustrated is a boat 11 comprising a hull 10a with variable geometry according to a first embodiment of the present invention.

This hull 10a comprises a hull with a bottom wall 13 and a hull element 12a, configured to provide part of the buoyancy force, fixed to the bottom wall 13 through one or more? uprights 14.

The hull also includes one or more? immersed wing surfaces 15 having a sub cavitating or NACA type profile, which, in a situation of boat 11 traveling at speed? sufficiently high, but lower than a certain limit, they are configured to provide the remaining part of the vertical thrust necessary to keep the boat 11 above the water surface at a predetermined height.

The hull element 12a, or even the part 12a, can? be a torpedo-shaped element, or an airfoil or a set of airfoils, a support structure or other.

Advantageously, part 12a pu? translate along the upright 14 and in certain speed conditions? progress of the boat, get out of the water.

Advantageously part 12a ? equipped with secondary wing surfaces, or movable wings 42, having a trans cavitating or super cavitating profile suitable for operating at high speeds. The surface of the wings 42 ? such that these wings are able to produce, at speed? very high, a hydrodynamic thrust which alone supports all the weight of the boat.

Furthermore, these secondary wing surfaces 42 can rotate around hinges 44 to pass from a lower positioning, in which the wings 42 extend below the part 12a and in which they generate lift, to a higher positioning, in which they extend above said part 12a, in which they do not generate added drag, reducing the efficiency of other livelihoods.

The hull 10a includes one or more? supports 16a connected to the wing surfaces 15 and associated with floating elements 17a, movable with respect to said part 12a. Said floating elements 17a are fixed to said supports 16a or movable with respect to said supports 16a. These floating elements 17a are so? substantially associated with said fully immersed part 12a and with said wing surfaces 15. These wing surfaces 15 are configured to move with respect to said completely immersed part 12a or remain fixed with respect to the same and said mobile floating elements 17a are configured to increase their immersion as the of the speed? of the boat 11 and therefore provide the vertical thrust to maintain or adjust the distance of the boat 11 from the water in an optimal and functional manner at the service of the boat 11 also at speed? reduced or with vessel 11 stationary.

The part 12a, in completely immersed condition, generates only a part of the total hydrostatic thrust necessary to maintain the weight of the boat 11. This part 12a ? connected to the boat by means of said one or more? masts 14a having a very thin section spanning the surface of the sea. There are also at least one pair of said wing surfaces 15 each connected by means of a hinge 30 to the immersed part 12.

? it is also possible to provide that the wing surfaces 15 are joined to the part 12a by means of two hinges, one longitudinal, i.e. the hinge 30, to vary the height and one horizontal or transversal to vary the angle of incidence of the wing surfaces 15 or the longitudinal attitude of the floating elements 17a in the vertical plane in order to modify the trim angle of the boat.

The joint between the wing surfaces 15 and the part 12a could also consist of two hinges, one longitudinal, i.e. the hinge 30, to vary the height, and a vertical one, to vary the angle of incidence of the wing surfaces 15 or the longitudinal arrangement of the floating elements 17a in the horizontal plane, in order to change the direction of the boat.

In further embodiments, the joint between the wing surfaces 15 and the part 12a could be constituted by a sliding block which, by sliding, varies the height of the floating elements 17a at the end? of the bearing surfaces.

The masts 14a could also be of the telescopic and adjustable type, so as to increase or decrease the distance of the submerged part 12, wing surfaces 15 and floating elements 17a from the emerged part 13 as a function of what is convenient for navigation.

The wing surfaces 15 are preferably placed in pairs in a symmetrical position on the sides of the torpedo-shaped hull. The wing surfaces 15 are characterized by a load-bearing wing profile, i.e. provided with a curvature with respect to a joining straight line X2 which passes through the leading edge and the trailing edge of said wing surfaces. This profile also? positioned so that the above straight line X2 has an angle ?1 with respect to the incident flow, and ? equipped with a flap which moves by varying the angle ?1 between the above indicated straight line and the line joining the leading and trailing edge of a flap 29 of which it can? be equipped with this wing surface 15, see also figure 2.

The curved profile and the fixed angle of attack ?1 generate a constant lift, while varying the angle of the flap ?1 ? It is possible to vary this lift to modify the trim of the boat in flight. Once you reach and exceed the speed? take-off, the wing surfaces 15 generate a hydrodynamic thrust, which together with the hydrostatic thrust of the part 12 are able to maintain the weight of the boat 11. The pair of floating elements 17a placed at the ends? of the wing surfaces 15, due to the relative movement of the latter with respect to the immersed part 12, can be partially submerged or completely out of the water. When the boat is stationary, when the wing surfaces 15 do not generate lift, the immersed portion of floating element 17a generates a hydrostatic thrust capable of supporting, together with the hydrostatic thrust of the immersed part 12, the weight of the boat.

The wing surfaces 15 and the floating elements 17a can be moved with respect to the fully immersed part 12 by means of the hinges 30, see also figures 6 to 10. These hinges 30 allow the transition movement of the floating elements 17a from partially immersed to fully emerged above the surface of the sea.

To pass from the position of figure 6 to the position of figure 7 and vice versa, the present hull 10a can? be equipped with a hydraulic actuator 32 which allows the correct movement of the wing surfaces 15 and therefore the correct opening or closing of the floating elements 17a.

To pass from the configuration of figure 8 to the configuration of figure 9 and vice versa, the present hull 10a ? equipped for example with a hydraulic actuator 41 which allows the correct movement of the immersed body 12a and of the trans cavitating or super cavitating wings 42.

During the movement from figure 8 to figure 9, the wings 42 are also rotated by means of a rotation system which includes a hydraulic actuator and a lever system 43, around hinges 44.

To pass from figure 9 to figure 10 and vice versa, does the present hull 10a ? equipped for example with a hydraulic actuator 41 which allows the correct movement of the immersed body 12a and of the trans cavitating or super cavitating wings 42.

During handling from fig. 9 to fig.

10 also the wings 42 are rotated by means of a rotation system which includes a hydraulic actuator and a lever system 43, around hinges 44.

The hull 10a pu? furthermore, it can be equipped with a propulsion system 34, for example equipped with a pair of propellers 35 mounted on wing surfaces 36, which can be equipped with flaps 37, see again figures 1 and figures 2. be equipped with a steering control system, in this case a rudder 38.

During the transition from the configuration of figure 9 to the configuration of figure 10, the propulsion system 34 is also rotated around a longitudinal hinge to lower and keep the propellers 35 immersed or even only partially immersed.

When the boat is stationary or maneuvering at low speed, it is the two propellers 35 located at a certain distance from the boat?s centreline axis X3 which, by rotating in the opposite direction, allow the boat to turn on itself? itself. To improve maneuverability? of the boat, a transverse thruster could be installed at the bow of part 12a, or the propellers, including the bow one, could be placed in special thrusters able to rotate around a vertical axis.

The wing surfaces 36 help to control the attitude of the boat in flight. In this regard with ?2 ? indicated the angle of incidence of the wing surface 36, while with ?2 ? indicated the angle of incidence of the flap 37 of the independent wing.

The wing surfaces 15, in the position of figure 3, can bring the floating elements 17a into contact with the boat 11, transmitting to it part of the vertical and horizontal thrusts due to the actions of the sea and therefore reducing the structural stresses on the uprights 14. In particular , these floating elements 17a could be housed in seats 28 obtained on the bottom of the boat 11.

The wing surfaces 15, as a function of their relative position with respect to the part 12, in addition to the possible immersion variation of the floating elements 17a, vary their surface or the angle of incidence, or, by means of the flap 29, vary their profile consequently varying the lift in order to control and reduce the ship motions in all operating conditions of the boat 11: stationary boat, take-off and flight, the above in combination with the hydrostatic and hydrodynamic thrust of the part 12 and possibly of the wing surfaces 36 , fixed or mobile, but independent of the wing surfaces 15 associated with the floating elements 17a.

In figure 11 ? therefore shown is a top view of the immersed part 12a, for example a torpedo-shaped one, and of the wing surfaces 15 and 36. In particular, it can be seen that a portion of the wing surface is? dedicated to the flaps 29 and 37, which increase or reduce the lift in order to regulate trim and reduce ship motion in flight conditions, by modifying the angles of attack ?1 and ?2, see also figures from 1 to 5.

Figures 1 to 10 also ideally indicate the waterline L1 of the boat during the displacement operations, i.e. with the floating elements 17a immersed and the line L2 representing the surface of the water when the boat 11 is ? in flight, in the configuration in which both the wings and the immersed body participate in the maintenance of the boat, and in the configuration in which only the wings support the weight of the boat. With L3 ? indicated the baseline of the boat 11. And finally with L4 ? indicated the waterline at speed? higher than that relating to the transition from sub cavitating to super cavitating.

With the boat stationary or manoeuvring, see figures 2 and 7, the floating elements 17a are partially immersed and keep the boat at a predetermined height H, equal to the flight height, without modifying the immersion D. Without floating elements 17a immersed , the immersion of the boat would increase up to depth D1 making it impossible to dock in many unequipped landing places, figures 1 and 6.

Furthermore, the movement of the floating elements 17a with the boat stationary counteracts the ship's motions, keeping the boat stable despite a rough sea.

In the transition phase, the portion of the vertical thrust not supplied by the immersed part 12a ? partly compensated for by the hydrostatic thrust of the partially immersed floating elements 17a and partly by the hydrodynamic lift of the wing surfaces 15 and the floating elements 17a behave like real hulls and, for this reason, their shape must be optimized in order to reduce the resistance and wave formation. These floating elements 17a can for example be torpedo-shaped, as illustrated.

In figures 12 to 21 ? a further embodiment of the present hull 10b is illustrated which comprises rigid supports 16c along which the floating elements 17c can slide.

? It is possible to provide on each side of the hull 10c at least one pair of supports 16c along which the floating elements 17c are positioned.

These supports 16c are connected on one side to the wing surfaces 15 and on the other side to a lower part of the hull 10c.

These supports 16c are also directed substantially along a vertical or slightly inclined direction, see figure 9, in particular inclined towards the inside of the hull 10c.

The wing surfaces 15 are connected to each other. These supports 16c can be, for example , thin rigid rods, or profiles of another shape, for example rounded, elliptical or other. ? It is possible to provide actuation systems suitable for raising or lowering the floating elements 17c with respect to said supports 16c, for example actuators associated on one side with the floating element 17c and on the other side with the hull 10c, or other.

Furthermore, in embodiments, these floating elements 17c can have a substantially "V" shape, as illustrated by way of example .

The upright 14c and the immersed body 12c can slide vertically in a linear guide 45 located inside the hull 11, lifting the immersed body at a speed superior to that for which only the wings with sub cavitating profile or NACA are able to support the hull 10a in flight.

The wings with trans cavitating or super cavitating profile 42c are connected to the floating element 17c, and are immersed in water when this is? slid along the supports 16c. At speeds higher than the transition speed, these 42c wings are able to support the entire weight of the boat.

Also the supports 16c and the wings 15 can slide inside guides placed in the hull 11 in order to reduce the total height of the boat during the flight on the wings 42c.

The present hull, see for example hull 10a fig. 12, can include a control system 27 equipped with inertial sensors and altitude detectors configured to manage the movement of the wing surfaces for the active control of the ship's motions in the two main conditions of use, i.e. in maneuvering by exploiting the increase or reduction in the immersed volume of said floating elements and in flight at the speed? cruising by varying the lift of said wing surfaces.

While the invention? susceptible to various modifications and alternative constructions, some preferred embodiments have been shown in the drawings and described in detail.

It must be understood, however, that there is no no intention of limiting the invention to the specific embodiment illustrated, but, on the contrary, it is intended to cover all modifications, alternative constructions, and equivalents which fall within the scope of the invention as defined in the claims.

The use of ?for example?, ?etc.?, ?or? indicates non-exclusive alternatives without limitation unless otherwise indicated.

Using ?include? means ?includes, but not limited to? unless otherwise indicated.

Claims (10)

1. Variable geometry hull for boats (11), comprising a back wall (13) to which back wall (13) ? at least one hull element (12, 12a, 12c) is fixed at the bottom through a post (14a), two wing surfaces (15) being provided laterally and below said hull element (12, 12a, 12c), which wing surfaces (15) are connected to said bottom wall (13) through corresponding supports (16a, 16b, 16c), characterized in that the said hull element (12, 12a, 12c) ? mounted translatable along said post (14), in such a way that said hull element (12, 12a, 12c) moves along an approach/removal direction from said bottom wall (13), being the displacement of said hull element (12, 12a, 12c) regulated on the basis of the speed? of running of the boat. 2. Hull according to claim 1, wherein at least two floating elements (17a, 17b, 17c) are provided located in correspondence with said supports (16a, 16b, 16c), being said floating elements (17a, 17b, 17c) mounted in a translatable manner with respect to the bottom wall (13) in such a way that said floating elements (17a, 17b, 17c) move along an approach/away direction from said back wall (13), since the displacement of said floating elements (17a, 17b, 17c) is regulated on the basis of the speed? of running of the boat. 3. A hull according to claim 1 or claim 2, wherein said wing surfaces (15) have a sub-cavitating or NACA type profile. 4. Hull according to one or more? of the preceding claims, wherein said wing surfaces (15) are mounted in oscillation with respect to said hull element (12, 12a, 12c). 5. Hull according to one or more? of the preceding claims, wherein said hull element (12, 12a, 12c) comprises two secondary wing surfaces (42) which two secondary wing surfaces (42) extend below said hull element (12, 12a, 12c) beyond said wing surfaces (15). 6. Hull according to claim 5, wherein said secondary wing surfaces (42) are oscillatingly mounted on said hull element (12, 12a, 12c), the movement of said secondary wing surfaces (42) being regulated on the basis of speed ? of running of the boat. 7. Hull according to one or more? of the preceding claims, wherein said secondary wing surfaces (42) have a trans cavitating or super cavitating profile. 8. Hull according to one or more? of the previous claims, in which ? Is there a propulsion system (37) comprising one or more? propulsion propellers (34), which propulsion propellers (34) are fixed to mounted support elements translatable along an approach/removal direction from said bottom wall (13). 9. Hull according to one or more? of the preceding claims, wherein said upright (14) and/or said supports (16a, 16b, 16c) consist of telescopic elements. 10. Hull according to one or more? of the preceding claims, wherein the floating elements (17a, 17b, 17c) are fixed to said bottom wall (13) through actuator elements (32).