FIELD OF THE INVENTION
[0001] The invention relates to a hydrofoil water vehicle used in the field of water sports.
BACKGROUND OF THE INVENTION
[0002] There are various solutions for implementing stabilization of a hydrofoil, such as
in patent
WO2019091437A1, where additional driven units are used, which create a lifting force in a certain
direction, depending on the angle of rotation, the height of the hydrofoil above the
water surface changes accordingly. Variants of this solution have poor lateral stability
(longitudinal and transverse direction), the vehicle is difficult to control, and
requires skills and experience of the surfer to ride it, making it unsuitable for
learners.
[0003] Patents
JPH1120775A and
JPH1120785A disclose a watercraft with a two-wing hydrofoil, which are arranged parallel to each
other and are used to prevent lateral rocking of the hull and to increase the load
capacity (increase the weight it can carry) of the vehicle. This design is complex
and includes controllable movable elements, such as ailerons, which require complex
mechanics and control. This way of arranging the stabilizers leads to an increase
in the area, but also to a decrease in the efficiency of the two-wing system. When
moving in an aquatic environment, the double hydrofoil does not protrude above the
water surface.
[0004] Moreover, document
US 10 358 194 B1 discloses a water vehicle comprising the features of the preamble in claim 1.
SUMMARY OF THE INVENTION
[0005] It is an aim of the present invention to provide an additional stabilization of a
water vehicle with a hydrofoil and a correction of the angle of attack of the bearing
wing without the need for additional movable controllable parts or high driving power.
Within this aim, an additional task is to provide a water vehicle with low manufacturing
costs.
[0006] This aim is achieved by creating a water vehicle with a hydrofoil with an additional
second horizontal stabilizer, which creates additional lifting force while in the
water, which leads to a longitudinal change in the angle of attack of the front wing.
In this way a change in the height of the platform above the water surface is achieved
- it rises above the water surface. Upon reaching a height at which the additional
second horizontal stabilizer rises above the water surface, the lifting force created
by it is eliminated (the stabilizer no longer creates lifting force) and the hydrofoil
again changes the longitudinal angle to the water surface - the nose of the platform
above the water points down and it descends towards the water surface. The additional
second horizontal stabilizer works on a passive principle, i.e., it is not connected
to an energy source.
[0007] In particular, the water vehicle according to the invention includes:
- an above-water platform,
- hydrofoil, including a fuselage with front wing and a first horizontal stabilizer,
- a supporting mast connecting the above-water platform to the hydrofoil,
- an underwater drive means for creating a horizontal thrust,
and
- a second horizontal stabilizer located vertically both between the fuselage and the
above-water platform and between the underwater drive means (6) and the above-water
platform (1), wherein, longitudinally, the second horizontal stabilizer is located
behind the front wing.
[0008] Preferably, the second horizontal stabilizer is mounted to the water vehicle with
the possibility of changing the vertical position of the second horizontal stabilizer.
[0009] In one embodiment, the second horizontal stabilizer is mounted directly or indirectly
to the supporting mast, preferably by means of a supporting element.
[0010] The supporting element of the second horizontal stabilizer can be a supporting beam,
which is attached to the supporting mast with the possibility of changing the vertical
position of the supporting element.
[0011] Preferably, the second horizontal stabilizer is mounted at a distance of at least
10 cm below the above-water platform.
[0012] In a preferred embodiment, the second horizontal stabilizer in the longitudinal direction
is located between the front wing and the first horizontal stabilizer.
[0013] In one embodiment the underwater drive means for creating a horizontal thrust is
at least one electric motor with a water propeller, which electric motor is connected
to a power source.
[0014] Advantages of the water vehicle according to the invention are:
- improves the longitudinal stability of the hydrofoil by changing the pitching moment
of the hydrofoil;
- prevents the uncontrolled emerging out of the water of the hydrofoil wing;
- restricts the rise (flight) of the above-water platform above the water surface;
- improves the flight stability of the hydrofoil;
- mounting of an additional horizontal stabilizer to the supporting mast is a simple
and cost-effective design.
BREIF DESCRIPTION OF THE FIGURES
[0015] Further in the description of the water vehicle that is the object of the invention,
it is explained via a preferred embodiment, given as a non-limiting the scope of the
invention example, with a reference to the attached figures, where:
FIG. 1 is a schematic side view of a water vehicle according to the invention;
FIG. 2 is a diagram of a force analysis of a hydrofoil according to the invention.
EXAMPLES OF EMBODIMENT AND OPERATION OF THE INVENTION
[0016] The terms "below", "above", "in front", "front", "behind", "rear" in the present
description and in the claims reflect the relative position of the structural elements,
as shown in the figures and in the usual operating position of the device.
[0017] The water vehicle according to the invention comprises an above-water platform 1,
a hydrofoil and a supporting mast 2 connecting the above-water platform 1 and the
hydrofoil (Fig. 1) and supporting the above-water platform 1 during the above-water
flight.
[0018] The proposed structural scheme of a hydrofoil, as shown in figure 1, complements
the standard scheme of a hydrofoil, which includes a fuselage 5, a bearing (front)
wing 7 and a rear located first horizontal stabilizer 8, with an additional second
horizontal stabilizer 4 located between the above-water platform 1 and the fuselage
5 in height. For the purposes of this description the front part of the fuselage is
the part where the bearing (front) wing 7 is located and the rear part of the fuselage
is the part where the first horizontal stabilizer 8 is located, so in the fuselage
5 the first horizontal stabilizer 8 is located behind the bearing (front) wing 7 with
respect to the movement direction of the vehicle. The hydrofoil may or may not (as
shown on the figures) have a vertical stabiliser in the rear part of the fuselage.
[0019] As shown in Figures 1 and 2, the water vehicle has a drive means 6. Typically, the
drive means 6 generates thrust in the direction of movement and includes, for example,
at least one electric motor with a water screw propeller, which electric motor is
connected to a source of electricity, such as rechargeable batteries. The drive means
6 can be located both on the fuselage (figure 1) or be mounted directly to the supporting
mast 3 above the fuselage, wherein in the second variant the second horizontal stabilizer
4 is mounted above the drive means 6.
[0020] It is possible to combine the water vehicle in a known way with a windfoil as means
of propulsion.
[0021] The additional second horizontal stabilizer 4 in the longitudinal direction is located
behind the front wing 7 with respect to the movement direction of the vehicle. By
"longitudinal direction" is meant a direction parallel to the longitudinal axis of
the fuselage 5. In the embodiment shown in Figures 1 and 2 the second horizontal stabilizer
4 in the longitudinal direction is between the front wing 7 and the first horizontal
stabilizer 8. This arrangement allows the overall design of the water vehicle to be
more compact. In addition, the optimum action of the second horizontal stabilizer
and the best stabilization effect are achieved.
[0022] Variants are also possible in which the second horizontal stabilizer 4 is located
immediately above or behind the first horizontal stabilizer 8.
[0023] It will be apparent to those skilled in the art that the location, configuration,
dimensions and fastening of the front wing 7 and the first horizontal stabilizer 8
to the fuselage 5 may be different as long as the above condition is met that the
second horizontal stabilizer 4 is located longitudinally behind the front wing 7.
For example, the front wing 7 and the first horizontal stabilizer 8 may be located
in one plane or the first horizontal stabilizer 8 may be located lower than the front
wing 7.
[0024] The second horizontal stabilizer 4 may have the shape and dimensions of the first
horizontal stabilizer 8, but may have another shape that must meet the following criteria:
- to have a streamlined profile, which can be dense (solid) or hollow, and waterproof;
- have a hydrodynamic shape with low hydrodynamic resistance;
- to generate a downward force that creates a stabilizing moment.
[0025] The elements of the hydrofoil are made of the usual, known from the prior art, suitable
materials. The second horizontal stabilizer 4, as well as the front wing 7 and the
first horizontal stabilizer 8, for example, may be made of expanded polystyrene (EPS),
expanded polypropylene (EPP), impregnated plywood and the like. The listed materials
may also be in combination with a carbon coating applied via a known method.
[0026] Preferably, the second horizontal stabilizer 4 is mounted at a distance ℓ
3 below the above-water platform 1 not less than 10 cm (figure 1). It is also recommended
that the second horizontal stabilizer 4 is not mounted directly above the fuselage
5.
[0027] In a preferred embodiment, the second horizontal stabilizer 4 is mounted directly
or indirectly to the supporting mast 2.
[0028] As shown in Figures 1 and 2, the second horizontal stabilizer 4 may be located on
a supporting element 3. For example, the second horizontal stabilizer 4 may be attached
to the rear of a support beam, which with its front part is mounted with fastening
means to the supporting mast 2 with the possibility of vertical relocation and fastening
in a different vertical position. This can be done, for example, by providing mounting
holes in the supporting mast 2 at different heights, in which the fastening means
of the supporting beam, such as a screw, a bolt with a nut or other suitable known
detachable fastening means, are arranged. The detachable fastening of the support
element 3 to the supporting mast 2 can also be achieved in other ways known to those
skilled in the art. The beam can be mounted perpendicular to the supporting mast 2
or at another angle from 1 to 179 °. The support element may consist of two arms located
at different angles to each other. It is also possible for the support means to be
telescopic, for example a telescopic extension beam.
[0029] Attaching the supporting beam with the additional second horizontal stabilizer 4
allows to change the position of the whole unit along the height of the supporting
mast 2. This allows the second horizontal stabilizer 4 to be at a variable distance
from the fuselage 5 and to have a different effect on the longitudinal stability of
the entire hydrofoil, resulting in a greater or lesser pitching moment, which raises
or lowers the nose of the hydrofoil.
[0030] In addition, it is possible that the second horizontal stabilizer 4 is mounted to
the above-water platform 1, to the additional structurally supporting details, to
the details that serve to change the angle of attachment of the main horizontal stabilizer,
to the fuselage 5 or to the drive means 6 by means of a support element 3 with a possibility
to change the vertical position.
[0031] There are additional details that constructively support the attaching of the supporting
mast to the above-water platform (such as mounting plates or those that change the
profile at one end of the mounting between the supporting mast and the above-water
platform), as well as such additional details that allow changing the angle on the
mounting of the front wing or the first (main) horizontal stabilizer (such are the
so-called shims).
[0032] Figure 4 shows schematically the following alternatives for attaching the second
horizontal stabilizer 4 to the water vehicle:
- mounting by means of a support element 3 to the above-water platform 1, the support
element being a beam or other suitable mechanical part which descends vertically to
the fuselage 5 at an angle of 90 degrees to the above-water platform or at another
angle (or a combination of vertical arm and arm at an angle of 1 to 89 degrees);
- mounting by means of a supporting element or directly to the additional structurally
supporting details (at an angle), located between the above-water platform 1 and the
supporting mast 2;
- mounting by means of a support element or directly to the additional details, which
usually serve to change the angle of the first horizontal stabilizer 8; in such an
installation of the second horizontal stabilizer, the supporting element, for example
a beam, may be located both parallel to the supporting mast and at an angle to the
supporting mast or to the longitudinal axis of the fuselage;
- mounting by a support element to the fuselage 5 of the hydrofoil, wherein the support
element, for example a beam, may be attached vertically or at an acute angle to the
longitudinal axis of the fuselage 5;
- mounting by means of a support element to the housing of the drive means 6, the support
element, for example a beam, being able to be located vertically or at an acute angle
to the longitudinal axis of the drive means 6.
[0033] Mounting of a second horizontal stabilizer 4 to the hydrofoil of the water vehicle
is intended to provide variable behaviour of the hydrofoil during above-water flight,
which is expressed in a continuous (cyclic) transition from floating at a certain
height to subsequent diving to prevent uncontrolled emerging out of the water of the
underwater part, leading to loss of control and falling of the surfer. In other words,
a system is created to support stabilization along a longitudinal angle of inclination.
[0034] The principle of operation of the additional second horizontal stabilizer 4 is as
follows: during the initial acceleration of the hydrofoil, the second horizontal stabilizer
4 is under water together with the other structural elements of the underwater part.
Thus, it acts as the rear first horizontal stabilizer 8, generating a downward force,
which in turn creates a stabilizing moment, assisting the first horizontal stabilizer
8 in balancing the hydrofoil system. When take-off speed is reached (separation of
the above-water platform from the water surface), the hydrofoil begins to rise, which
continues until the second horizontal stabilizer 4 rises above the water. At this
point, it loses its lift power, and the stabilizing moment created by it disappears.
Thus, the total moment balancing the hydrofoil system is reduced and a tendency is
created to reduce the angle of attack of the wing 7, provided that the surfer's position
is maintained invariably relative to the longitudinal axis of the hydrofoil. Reducing
the angle of attack of the wing leads to a subsequent dive down and re-entry of the
second horizontal stabilizer 4 in the water, which in turn leads to a tendency to
increase the angle of attack. This is followed by a new rise above the water of the
second horizontal stabilizer 4 and so diving and rising are repeated cyclically in
order to maintain a certain altitude above the water (flight is maintaining a certain
distance between the water surface and the above-water platform), without significant
intervention of the surfer. The immersion depth of the underwater part of the hydrofoil
can be adjusted by changing the vertical position of the second horizontal stabilizer
4 on the supporting mast 2, for example by changing the place of attachment of the
supporting beam in the vertical direction. The closer the support beam and the second
horizontal stabilizer 4 are to the fuselage 5, the higher will be the surfacing of
the above-water platform 1 and vice versa - the farther the second horizontal stabilizer
4 is from the fuselage 5, the lower will be the surfacing of the above-water platform
1.
[0035] In the embodiment in which the second horizontal stabilizer 4 in the longitudinal
direction is located between the front wing 7 and the first horizontal stabilizer
8, optimal stabilization is achieved, wherein the distance of the above-water platform
to the water surface varies within small limits - with minimal oscillations of movement
as to facilitate the management of the surfboard along the longitudinal axis.
[0036] The proposed design with two horizontal stabilizers achieves, with appropriate adjustment,
stable maintenance of a certain flight height of the above-water platform above the
water.
[0037] The force analysis shown in Figure 2 of a hydrofoil with an additional horizontal
stabilizer shows the main forces acting on the underwater elements of the hydrofoil.
Description of reference positions:
[0038]
M - pitching moment of the wing;
G - total weight of the hydrofoil;
L1 - lifting force of the first horizontal stabilizer;
L2 - lifting force of the second horizontal stabilizer;
ℓ1 - arm of the first horizontal stabilizer;
t2 - arm of the second horizontal stabilizer;
ℓG - arm of the total weight;
Equation (1)

represents the moment equation about the 25% point of the mean aerodynamic chord
of the wing, i.e. the application point of the lifting force of the wing. It describes
the balance in the longitudinal direction and helps to understand the principle of
operation of the second horizontal stabilizer 4
[0039] When all the elements of the hydrofoil, including the second horizontal stabilizer
4, are under water, the complete scheme of figure 2 is valid and the equilibrium is
determined by equation (1). When the take-off speed is reached, a process of emerging
up at an angle of attack of the wing set by the position of the surfer is performed,
as the surfer is the largest single mass in the system. In the case when the second
horizontal stabilizer 4 emerges above water, and the force L2 becomes zero, then the
system tends to dive into the water, reducing its angle of attack. This behaviour
is best described by inequality (2):

[0040] The reference numbers of the technical features are included in the claims only for
the purpose of increasing the comprehensibility of the claims and, therefore, these
reference numbers have no restrictive effect on the interpretation of the elements
indicated by these reference numbers.
1. A water vehicle comprising:
- an above-water platform (1),
- a hydrofoil comprising a fuselage (5) with a front wing (7) and a first horizontal
stabilizer (8), and
- a supporting mast (2) connecting the above-water platform (1) with the fuselage
(5) of the hydrofoil,
- an underwater drive means (6) for creating of horizontal thrust,
characterized in that the water vehicle comprises a second horizontal stabilizer (4) located in the vertical
direction both between the fuselage (5) and the above-water platform (1) and between
the underwater drive means (6) and the above-water platform (1), wherein the second
horizontal stabilizer (4), in the longitudinal direction, is located behind the front
wing (7).
2. Water vehicle according to Claim 1, characterized in that the second horizontal stabilizer (4) is mounted to the water vehicle with the possibility
of changing of the vertical position.
3. Water vehicle according to Claim 1 or 2, characterized in that the second horizontal stabilizer (4) is mounted directly or indirectly to the supporting
mast (2).
4. Water vehicle according to Claim 3, characterized in that the second horizontal stabilizer (4) is mounted to the supporting mast (2) by means
of a support element (3).
5. Water vehicle according to Claim 4, characterized in that the support element (3) of the second horizontal stabilizer (4) is a support beam
which is attached to the supporting mast (2) with the possibility of changing its
vertical position.
6. Water vehicle according to one of the preceding claims, characterized in that the second horizontal stabilizer (4) is mounted at a distance of at least 10 cm below
the above-water platform (1).
7. Water vehicle according to one of the preceding claims, characterized in that the second horizontal stabilizer (4) is located in the longitudinal direction between
the front wing (7) and the first horizontal stabilizer (8).
8. Water vehicle according to one of the preceding claims, characterized in that the drive means (6) comprises at least one electric motor with a water screw propeller,
which electric motor is connected to a source of electricity.
1. Ein Wasserfahrzeug umfassend:
- eine Überwasserplattform (1),
- ein Tragflügelboot, der einen Rumpf (5) mit einem Vorderflügel (7) und einem ersten
horizontalen Stabilisator (8) umfasst, und
- einen Tragmast (2), der die Überwasserplattform (1) mit dem Rumpf (5) des Tragflügels
verbindet,
- ein Unterwasser-Antriebsmittel (6) zur Erzeugung eines horizontalen Schubs, dadurch gekennzeichnet, dass das Wasserfahrzeug einen zweiten Horizontalstabilisator (4) umfasst, der in vertikaler
Richtung sowohl zwischen dem Rumpf (5) und der Überwasserplattform (1) als auch zwischen
dem Unterwasser-Antriebsmittel (6) und der Überwasserplattform (1) angeordnet ist,
wobei der zweite Horizontalstabilisator (4) in Längsrichtung hinter dem Vorderflügel
(7) angeordnet ist.
2. Ein Wasserfahrzeug gemäß Anspruch 1, dadurch gekennzeichnet, dass der zweite Horizontalstabilisator (4) mit der Möglichkeit der Veränderung der vertikalen
Position am Wasserfahrzeug angebracht ist.
3. Ein Wasserfahrzeug gemäß Anspruch 1 oder 2, dadurch gekennzeichnet, dass der zweite Horizontalstabilisator (4) direkt oder indirekt an dem Tragmast (2) angebracht
ist.
4. Ein Wasserfahrzeug gemäß Anspruch 3, dadurch gekennzeichnet, dass der zweite Horizontalstabilisator (4) mittels eines Trägerelements (3) am Tragmast
(2) befestigt ist.
5. Ein Wasserfahrzeug gemäß Anspruch 4, dadurch gekennzeichnet, dass das Trägerelement (3) des zweiten Horizontalstabilisators (4) ein Tragbalken ist,
der am Tragmast (2) mit der Möglichkeit zur Veränderung seiner vertikalen Position
befestigt ist.
6. Ein Wasserfahrzeug gemäß einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der zweite Horizontalstabilisator (4) in einem Abstand von mindestens 10 cm unterhalb
der Überwasserplattform (1) angebracht ist.
7. Ein Wasserfahrzeug gemäß einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass der zweite Horizontalstabilisator (4) in Längsrichtung zwischen dem Vorderflügel
(7) und dem ersten Horizontalstabilisator (8) angeordnet ist.
8. Ein Wasserfahrzeug gemäß einem der vorhergehenden Ansprüche, dadurch gekennzeichnet, dass die Antriebseinrichtung (6) mindestens einen Elektromotor mit Wasserschraubenpropeller
umfasst, wobei der Elektromotor an eine Stromquelle angeschlossen ist.
1. Un véhicule nautique comprenant :
- une plateforme émergée (1),
- un hydroptère comprenant un fuselage (5) avec une aile avant (7) et un premier stabilisateur
horizontal (8), et
- un mât porteur (2) reliant la plateforme émergée (1) avec le fuselage (5) de l'hydroptère,
- un moyen propulseur immergé (6) pour créer une poussée horizontale,
caractérisé en ce que le véhicule nautique comprend une second stabilisateur horizontal (4) situé suivant
la direction verticale à la fois entre le fuselage (5) et la plateforme émergée (1),
et entre le moyen propulseur immergé (6) et la plateforme émergée (1), dans lequel
le second stabilisateur horizontal (4), suivant la direction longitudinale, est situé
à l'arrière de l'aile avant (7).
2. Véhicule nautique selon la revendication 1, caractérisé en ce que le second stabilisateur horizontal (4) est monté sur le véhicule nautique avec la
possibilité de changer de position verticale.
3. Véhicule nautique selon l'une quelconque des revendications 1 et 2, caractérisé en ce que le second stabilisateur horizontal (4) est monté directement ou indirectement sur
le mât porteur (2).
4. Véhicule nautique selon la revendication 3, caractérisé en ce que le second stabilisateur horizontal (4) est monté sur le mât porteur (2) au moyen
d'un élément support (3).
5. Véhicule nautique selon la revendication 4, caractérisé en ce que l'élément support (3) du second stabilisateur horizontal (4) est une poutre support
qui est fixée au mât de support (2) avec la possibilité de changer sa position verticale.
6. Véhicule nautique selon l'une quelconque des revendications précédentes, caractérisé en ce que le second stabilisateur horizontal (4) est monté à une distance d'au moins 10 cm
sous la plateforme émergée (1).
7. Véhicule nautique selon l'une quelconque des revendications précédentes, caractérisé en ce que le second stabilisateur horizontal (4) est situé suivant la direction longitudinale
entre l'aile avant (7) et le premier stabilisateur horizontal (8).
8. Véhicule nautique selon l'une quelconque des revendications précédentes, caractérisé en ce que le moyen propulseur (6) comprend au moins un moteur électrique avec une hélice de
propulsion à eau, dont le moteur électrique est connecté à une source d'électricité.