EP3544885B1 - Underwater craft less likely to be detected across great distances - Google Patents

Description

The invention relates to an underwater vehicle, in particular a submarine, with an external shape, the shape being optimized to reduce the detectability by means of active sonar. As a result, the distance from which the underwater vehicle can probably be detected can be significantly reduced.

Underwater vehicles, in particular military submarines, currently have a roughly simplified cylindrical basic shape in the central nave with a hemispherical bow and a conical stern. This shape is aerodynamically favorable and can be easily manufactured as a single-hull or two-hull boat.

Sonar, in particular, is used today for the detection of submarines, the detection preferably being carried out over large distances, for example 100 km. This means that the sound waves of the sonar hit an underwater vehicle at a very flat angle parallel to the water surface. In order to avoid detection, the reflection of the sound waves must be avoided, especially towards the transmitter, where the receiver is usually located. This geometrical consideration shows that the detectability of an underwater vehicle at a great distance depends in particular on the reflection of sound at an angle of ± 20 °, in particular at an angle of ± 10 °.

At short distances, other locating options, in particular heat, sound emission, magnetic behavior and many others, are relevant, so that the detectability here is regularly determined by other parameters.

However, a cylindrical body has the property of reflecting a wave practically vertically isotropically and thus emitting practically the same energy in all vertical spatial directions. This means that the detection in the critical flat angle range is not particularly low.

From the U.S. 1,500,997 a plate-shaped cladding of a submarine for reducing the signature is known.

From the GB 531 892 A an electrically powered micro-submarine is known.

From the DE 196 23 127 C1 a sound absorber for reducing the target size is known.

From the DE 197 54 333 A1 a catamaran submarine is known.

From the DE 1 196 531 A a curved surface underwater vehicle is known.

From the US 2005/0145159 A1 a ship hull construction is known which has a curvature.

From the U.S. 4,577,583 A an underwater vehicle with a streamlined hull is known.

From the EP 0 850 830 A2 a submarine with three push bodies is known.

The object of the invention is to create an underwater vehicle which, under the conditions of location over a distance, has a significantly reduced detection probability.

This object is achieved by an underwater vehicle with the features specified in claim 1. Advantageous further developments result from the subclaims, the following description and the drawings.

The underwater vehicle according to the invention with a reduced probability of detection has an outer shell. The underwater vehicle has a bow section, a stern section and a central ship section. The outer shell of the central ship section has a polygonal cross section transversely to the longitudinal direction of the underwater vehicle. Furthermore, the outer shell of the central ship section has a curvature along the longitudinal direction of the underwater vehicle over the entire length of the central ship section.

The polygonal cross section is known per se for the targeted reflection of a detection wave in a direction deviating from the transmitter. This is known in principle in aircraft construction or shipbuilding, for example the Sea Shadow. Here, large, flat and tilted surfaces are used as reflectors.

This alone has the disadvantage that reflections of a higher order also occur in other angles and thus detectability can also take place in the critical flat angle range. Furthermore, such an arrangement alone is not as effective for a submarine as it is for an airplane, for example, since a submarine is surrounded by several boundary surfaces at which a reflection to the transmitter can take place. Such interfaces are, for example, above all the sea bed and the water surface, but also areas that can result from the stratification of the sea water and represent planes of reflection.

In order to minimize this disadvantage, according to the invention, the outer shell of the central ship section has a curvature along the longitudinal direction of the underwater vehicle. This results in both effects, reflection and dispersion. The effect is that the energy of the detection wave can be significantly minimized in the critical flat angle range. The curvature of the outer shell of the central nave section extends over the entire length of the central nave section. The curvature can have a variable radius of curvature over the length, but the radius of curvature must not become infinite. This would create a flat surface at least at one point, which would reflect an incoming beam without dispersion.

The central ship section is arranged between the bow section and the stern section. The bow section has a length of 5% to 40%, preferably 5% to 30%, particularly preferably 5% to 20% of the total length of the underwater vehicle, the bow section beginning at the bow of the underwater vehicle. The stern section has a length of 5% to 40%, preferably 5% to 30%, particularly preferably 5% to 20% of the total length of the underwater vehicle, the stern section beginning at the stern of the underwater vehicle. The central ship section thus has a length of 20% to 90%, preferably from 40% to 90%, particularly preferably from 60% to 90% of the total length of the underwater vehicle.

As a result, the power of the wave reflected in the transmitter direction can be reduced by a factor of 10,000, for example, compared to a conventional cylindrical underwater vehicle. This reduces the distance at which detection is probable by up to an order of magnitude. This significantly increases the freedom of movement of an underwater vehicle.

A triangle or a square, for example, can occur as a polygonal cross-section, these two polygons being rather less preferred due to the low adaptability. In contrast, polygons with 5 to 10 corners or sides are preferred, the lengths of the sides further preferably differing. Opposing sides are particularly preferably of the same length in pairs.

In a further embodiment of the invention, the polygonal cross section has rounded corner areas. This is advantageous in terms of production engineering and hydrodynamics.

In a further embodiment of the invention, the polygonal cross section has a mirror plane perpendicular to the longitudinal axis. This means that the outer contour of the port side and the starboard side are the same.

According to the invention, the outer shell of the central ship section has a curvature across the longitudinal direction of the underwater vehicle over the entire cross section along the longitudinal direction of the underwater vehicle.

In a further embodiment of the invention, the outer casing has at least one first segment, the first segment forming a first conic section in the longitudinal direction of the underwater vehicle or being composed of two or more conic sections. A segment is defined as an area which is bounded above and below by the edges of the polygonal cross section. In the longitudinal direction, the extension of the segment is limited by the extension of the central nave section. A conic section is a portion of the mantle of a cone. Particularly preferably, a first segment and a corresponding second segment lying on the opposite side of the ship have mirror-image conical sections. A cone or cone is a geometric figure that is defined by height and radius. In the case of a conical section, the radius of curvature thus changes continuously transversely to the longitudinal direction of the underwater vehicle. Of course, it can also be a conical section of an oblique cone, in which the height axis is not centered on the circular base area.

In a further embodiment of the invention, the outer shell has at least a third segment, the third segment in the longitudinal direction of the underwater vehicle at least partially, preferably completely, forming a third conic section, with height and / or Radius of the third conic section are different from the height and / or radius of the first conic section.

In a further embodiment of the invention, the cone of the conic section has a height, the ratio of height to length of the underwater vehicle being between 0.5 and 1,000, preferably between 3.5 and 130, particularly preferably between 8.0 and 35.

In a further embodiment of the invention, the cone of the conic section has a diameter, the ratio of cone diameter to length of the underwater vehicle being between 2 and 100, preferably between 6 and 50, particularly preferably between 10 and 20.

In a further embodiment of the invention, the underwater vehicle has a tower in the central ship section. The tower particularly preferably has outer walls inclined by at least 10 °, particularly preferably by at least 20 °, with respect to the vertical.

The tower particularly preferably has the same angle as the side of the polygonal cross section adjoining below the tower.

In a further embodiment of the invention, the curvature of the central ship section has a radius of curvature, the ratio of the radius of curvature to the length of the underwater vehicle being between 5 and 1,000, preferably between 10 and 250, particularly preferably between 25 and 100.

The curvature of the central nave section does not have to be constant over the entire length. The curvature of the central ship section can in particular increase towards the sections adjacent to the bow section and / or stern section, for example in order to create a transition. The curvature is preferably increasing in the transition from the central nave to the bow section and decreasing in the transition from the central nave to the area of the stern section.

For example, for an underwater vehicle with a length of 80 m, the result is a curvature of the central nave section which increases the cross-section of an imaginary circle encompassing the central nave compared to an uncurved, straight cylinder shape of approximately 0.5 m 2 m, whereby the tower or other structures or extensions are not considered here.

In a further embodiment of the invention, the polygonal cross section has a widest point, the widest point of the polygonal cross section being arranged below or above the center, the center being defined as half the height of the polygonal cross section.

The deviation from a symmetrical design makes it possible to specifically deflect a larger part of the incoming detection wave in the same direction. If the widest point is below the middle, the larger part is reflected upwards and thus towards the surface of the water. If the widest point is above the middle, the larger part is reflected downwards and thus to the seabed. For boat stability, the first variant is preferred for reducing the target size.

In a further embodiment of the invention, the widest point of the polygonal cross section is arranged at least 10%, preferably at least 20% of half the height of the polygonal cross section below or above the center.

In a further embodiment of the invention, all planes of the polygonal cross section have an inclination of at least 10 °, preferably of at least 20 °, with respect to the vertical.

In a further embodiment of the invention, all planes of the polygonal cross section have an inclination of 10 ° to 40 ° or 50 ° to 80 ° with respect to the vertical. The angle of 45 ° should also be avoided, since the incoming wave is reflected, for example, to the surface of the water, reflected back from it and then reflected back directly to the transmitter. Although the intensity is lower due to the multiple reflection, it is nevertheless significantly higher than at other angles.

In a further embodiment of the invention, the outer shell has a sound-absorbing property. In addition to the optimized geometry, the outer shell can consist of a sound-absorbing material, have it or be coated with it. Since the absorption can never be complete, the two effects combine positively.

In a further embodiment of the invention, the outer shell is essentially reflective and / or absorbent for sound waves in the frequency range from 100 Hz to 100 kHz, in particular in the range from 1 kHz to 25 kHz. Since other, non-optimized structures can be arranged under the outer shell, the transmission through the outer shell must be kept as low as possible. The sum of the degree of reflection, degree of absorption and degree of transmission is by definition 1. It is regarded as essentially reflective and / or absorbent if the degree of reflection and / or the degree of transmission is at least 0.75, preferably at least 0.9, particularly preferably at least 0.95.

According to the invention, the underwater vehicle has a substantially cylindrical pressure body under the outer shell.

In a further embodiment of the invention, the outer shell does not completely encompass the cylindrical pressure body. The pressure body thus forms the outer shell in some areas. This can be the case, for example, at rather uncritical points, for example on the underside.

In a further embodiment of the invention, sensors, in particular passive sonar sensors and / or fuel reservoirs, are arranged between the outer shell and the pressure body.

Fuel stores include all forms of storage goods that are required to operate the submarine, for example these are gasoline or diesel tanks, hydrogen stores, for example in the form of compressed gas stores, liquid hydrogen stores or metal hydride stores, oxygen stores, for example in the form of compressed gas stores or liquid oxygen stores , Methanol storage, ethanol storage, batteries, accumulators and compressed gas storage for gas turbines but also autonomous or remote-controlled underwater vehicles, weapons, such as torpedoes or missiles, or decoys.

In a further embodiment of the invention, a propeller is arranged at the level of the widest point of the outer skin.

In a further embodiment of the invention the underwater vehicle is a submarine. The underwater vehicle is preferably a military underwater vehicle, particularly preferably a military submarine.

Fig. 1

Aufsicht auf ein erfindungsgemäßes Unterwasserfahrzeug

Fig. 2

Querschnitt eines ersten beispielhaften Unterwasserfahrzeugs

Fig. 3

Querschnitt eines zweiten beispielhaften Unterwasserfahrzeugs

Fig. 4

Querschnitt eines dritten beispielhaften Unterwasserfahrzeugs

Fig. 5

Querschnitt eines vierten beispielhaften Unterwasserfahrzeugs

The underwater vehicle according to the invention is explained in more detail below with reference to the exemplary embodiments shown in the drawings.

Fig. 1

Top view of an underwater vehicle according to the invention

Fig. 2

Cross-section of a first exemplary underwater vehicle

Fig. 3

Cross-section of a second exemplary underwater vehicle

Fig. 4

Cross-section of a third exemplary underwater vehicle

Fig. 5

Cross-section of a fourth exemplary underwater vehicle

In Fig. 1 the top view of an underwater vehicle 10 with a bow section 20, a midship section 30 and a stern section 40 is shown, the underwater vehicle having a rudder 60, here in the form of a cross rudder, and a propeller 70 in the stern section 40. The underwater vehicle 10 has an outer shell 50 which, in the longitudinal direction of the underwater vehicle 10, has a curvature of the central ship section, as can be seen in comparison to a pressure body 80 shown in simplified form as a cylinder. In practice, the pressure body 80 will also have rounded ends, preferably hemispherical ends, at the bow and at the stern, which has been neglected here for the sake of simplification. The pressure body 80 does not have to take up the full length either. In particular, gun barrels can be arranged in the bow.

Fig. 2 shows a first exemplary cross section. The outer shell 80 has a hexagonal cross section; the widest point 100 lies exactly at the level of the center 90, which is formed by the center point of the cylindrical pressure body 80. This point is used here and in the following as the center according to half the height of the polygonal cross-section, since these practically coincide, but the center point is easier to visualize. All surfaces of the outer shell 50 have an angle of 30 ° or 90 ° with respect to the vertical.

Fig. 3 shows a second exemplary cross section. The outer shell 80 has an irregular hexagonal cross section, the widest point 100 being arranged well above the center 90. As a result, a large part of the incident waves is reflected to the sea floor, which further minimizes the detection probability.

Fig. 4 shows a third exemplary cross section. The outer shell 80 has an irregular hexagonal cross section, the widest point 100 being arranged well below the center 90. As a result, a large part of the incident waves are reflected to the surface of the water, but the center of gravity of the underwater vehicle 10 can be arranged lower. This is advantageous for the stability of the underwater vehicle 10.

In contrast to FIGS. 2 to 4 shows Fig. 5 a cross-section with rounded corners, which is otherwise basically the same as the second exemplary cross-section Fig. 3 is. In addition, fuel storage 110 and sonar sensors 120 are arranged between the outer shell 50 and the pressure body 80.

Alone FIGS. 2 to 5 The cross-sections shown are mirror-symmetrical. This is not necessary, but preferred.

10

Unterwasserfahrzeug

20

Bugsektion

30

Mittelschiffsektion

40

Hecksektion

50

Außenhülle

60

Ruder

70

Propeller

80

Druckkörper

90

Mitte

100

breiteste Stelle

110

Treibstoffspeicher

120

Sonarsensoren

Reference number

10

Underwater vehicle

20th

Bow section

30th

Central nave section

40

Rear section

50

Outer shell

60

Rudder

70

propeller

80

Pressure hull

90

center

100

widest point

110

Fuel storage

120

Sonar sensors

Claims (11)

1. Underwater craft (10) less likely to be detected, wherein the underwater craft (10) comprises an outer hull (50), wherein the underwater craft (10) comprises a bow section (20), a stern section (40) and a midship section (30), wherein the underwater craft (10) comprises a substantially cylindrical pressure vessel (80) under the outer hull (50), wherein the outer hull (50) of the midship section (30) has a polygonal cross section transversely with respect to the longitudinal direction of the underwater craft (10), wherein the polygonal cross section has three to 10 corners, wherein the outer hull (50) of the midship section (30) comprises a curvature along the longitudinal direction of the underwater craft (10) over the entire length of the midship section (30), characterized in that the outer hull (50) of the midship section (40) comprises a curvature along the longitudinal direction of the underwater craft (10) over the entire cross section transversely with respect to the longitudinal direction of the underwater craft (10).
2. Underwater craft (10) according to Claim Fehler! Verweisquelle konnte nicht gefunden werden., characterized in that the polygonal cross section comprises a mirror plane perpendicularly to the longitudinal axis.
3. Underwater craft (10) according to either of the preceding claims, characterized in that the outer hull (50) forms a conical section in the longitudinal direction of the underwater craft (10) or is composed of two or more conical sections.
4. Underwater craft (10) according to one of the preceding claims, characterized in that the underwater craft (10) comprises a tower in the midship section (30).
5. Underwater craft (10) according to one of the preceding claims, characterized in that the curvature of the midship section comprises a radius of curvature, wherein the ratio of the radius of curvature to the length of the underwater craft (10) is between 5 and 1000, preferably between 10 and 250, particularly preferably between 25 and 100.
6. Underwater craft (10) according to one of the preceding claims, characterized in that the polygonal cross section comprises a widest point (100), wherein the widest point (100) of the polygonal cross section is arranged below or above the centre (90), wherein the centre (90) is defined as half the height of the polygonal cross section.
7. Underwater craft (10) according to Claim Fehler! Verweisquelle konnte nicht gefunden werden., characterized in that the widest point (100) of the polygonal cross section is arranged at least 10%, preferably at least 20% of half the height of the polygonal cross section below or above the centre (90) .
8. Underwater craft (10) according to one of the preceding claims, characterized in that all of the planes of the polygonal cross section comprise an inclination of at least 10°, preferably of at least 20°, in relation to the perpendicular.
9. Underwater craft (10) according to one of the preceding claims, characterized in that all of the planes of the polygonal cross section comprise an inclination of 10° to 40° or 50° to 80° in relation to the perpendicular.
10. Underwater craft (10) according to one of the preceding claims, characterized in that the outer hull (50) comprises a sound-absorbing property.
11. Underwater craft (10) according to one of the preceding claims, characterized in that sensors, in particular passive sonar sensors (120), and/or fuel stores (110) are arranged between the outer hull (50) and the pressure vessel (80).

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