EP3943377A1 - Underwater craft less likely to be detected across great distances - Google Patents

Abstract

The present invention relates to an underwater vehicle 10 with a reduced probability of detection, the underwater vehicle 10 having an outer hull 50, the underwater vehicle 10 having a bow section 20, a stern section 40 and a midship section 30, the outer hull 50 of the midship section 30 transverse to the longitudinal direction of the underwater vehicle 10 has a polygonal cross section, wherein the outer shell 50 of the midship section 30 has a curvature of the midship section along the longitudinal direction of the underwater vehicle 10 .

Description

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

Underwater vehicles, in particular military submarines, currently have, in a roughly simplified manner, a basic cylindrical shape in the central nave with a hemispherical bow and a conical stern. This shape is streamlined and easy to manufacture as a single-hull or double-hull boat.

Sonar, in particular, is used today to detect submarines, with detection preferably taking place over large distances, for example 100 km. This means that the sound waves from 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 geometric 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 localization options are relevant, in particular heat, noise emissions, magnetic behavior and many others, so that detectability 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. As a result, detection in the critical flat angle range is not particularly low.

From the U.S. 1,500,997 is a plate-shaped paneling of a submarine known to reduce the signature.

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 U.S. 2005/0145159 A1 a ship hull construction is known which has a curvature.

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

This problem is solved by an underwater vehicle with the features specified in claim 1 . Advantageous developments result from the dependent claims, 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 midship section. The outer shell of the central ship section has a polygonal cross section transverse to the longitudinal direction of the underwater vehicle. Furthermore, the outer hull of the midship section has a curvature along the longitudinal direction of the underwater vehicle over the entire length of the midship section.

The polygonal cross section per se is known for the targeted reflection of a detection wave in a direction deviating from the transmitter. This is known in principle in aircraft construction or ship construction, 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, so that it can also be detected 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 a number of interfaces is where a reflection to the transmitter can occur. Such boundary surfaces are, for example, above all the seabed and the water surface, but also areas that can result from the stratification of the seawater and represent reflection levels.

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. As a result, both effects, reflection and dispersion, occur. 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 hull of the midship section extends the full length of the midship section. The curvature can have a variable radius of curvature over the length, but the radius of curvature must not become infinite. This would form a flat surface at least at one point, which would reflect an incoming beam without dispersion.

The midship section is located between the bow section and the stern section. The length of the bow section is 5% to 40%, preferably 5% to 30%, particularly preferably 5% to 20% of the total length of the underwater vehicle, with 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 center ship section thus has a length of 20% to 90%, preferably 40% to 90%, particularly preferably 60% to 90% of the total length of the underwater vehicle.

As a result, the power of the wave reflected in the direction of the transmitter 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 likely by up to an order of magnitude. This significantly increases the freedom of movement of an underwater vehicle.

For example, a triangle or a square can occur as a polygonal cross-section, these two polygons being less preferred due to the limited possibility of adjustment. However, preference is given to polygons with 5 to 10 corners or sides, the Length of the sides differ more preferred. Opposite sides are particularly preferably of equal length in pairs.

In a further embodiment of the invention, the polygonal cross section has rounded corner areas. This is advantageous in terms of manufacturing technology 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 contours of the port side and the starboard side are the same.

In a further embodiment of the invention, the outer shell of the center ship section has a curvature across the entire cross section along the longitudinal direction of the underwater vehicle, transversely to the longitudinal direction of the underwater vehicle.

In a further embodiment of the invention, the outer shell 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 bounded at the top and bottom by the edges of the polygonal cross-section. In the longitudinal direction, the expansion of the segment is limited by the expansion of the midship 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 cutouts. A cone or cone is a geometric figure that is defined by its height and radius. In the case of a cone section, the radius of curvature changes continuously transversely to the longitudinal direction of the underwater vehicle. Of course, it can also be a cone section of an oblique cone in which the vertical axis is not in the center of the circular base area.

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

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 1000, 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 the cone diameter to the 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 center ship section. The tower particularly preferably has outer walls inclined by at least 10°, particularly preferably by at least 20°, relative to the vertical.

Particularly preferably, the tower has the same angle as the side of the polygonal cross-section adjacent 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 midship section need not be constant over the entire length. The curvature of the midships section can, in particular, increase towards the sections adjacent to the bow section and/or the stern section, for example in order to create a transition. Preferably, the curvature increases in the transition from the central nave to the bow section and decreases in the transition from the central nave to the region of the stern section.

For example, for an underwater vehicle with a length of 80 m, there is a curvature in the midship section which causes an increase in the cross section of an imaginary circle encompassing the midship compared to an uncurved, straight cylindrical shape of around 0.5 m to 2 m, with the tower or other top or Extensions are not considered here.

In another embodiment of the invention, the polygonal cross-section has a widest point, the widest point of the polygonal cross-section being located below or above the center, the center defining half the height of the polygonal cross-section.

The deviation from a symmetrical design makes it possible to 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 to the water surface. If the widest point is above the middle, the larger part is reflected downwards and thus to the seabed. The first option is preferred for boat stability, and the second option is preferred for target size reduction.

In a further embodiment of the invention, the widest point of the polygonal cross-section is 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 at least 20°, relative 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, on the water surface, is reflected back from it and is then reflected back directly to the transmitter. Although the intensity is lower due to the multiple reflections, it is still significantly higher compared to 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 for sound waves in the frequency range from 100 Hz to 100 kHz, in particular in the range from 1 kHz to 25 kHz im Is substantially reflective and / or absorbent. 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, according to definition, 1. It is regarded as essentially reflecting and/or absorbing 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.

In a further embodiment of the invention, the underwater vehicle has an essentially cylindrical pressure body under the outer shell.

In a further embodiment of the invention, the outer shell does not completely enclose 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 stores, are arranged between the outer shell and the pressure hull.

Fuel storage includes all forms of stored goods that are required to operate the submarine, for example, these are petrol or diesel tanks, hydrogen storage, for example in the form of compressed gas storage, liquid hydrogen storage or metal hydride storage, oxygen storage, for example in the form of compressed gas storage or liquid oxygen storage , 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 exemplary embodiments illustrated in the drawings.

1

Top view of an underwater vehicle according to the invention

2

Cross section of a first exemplary underwater vehicle

3

Cross-section of a second exemplary underwater vehicle

4

Cross-section of a third exemplary underwater vehicle

figure 5

Cross-section of a fourth exemplary underwater vehicle

In 1 is the plan view of an underwater vehicle 10 with a bow section 20, a midship section 30 and a stern section 40, 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 has a curvature of the central ship section in the longitudinal direction of the underwater vehicle 10, as can be seen in comparison to a pressure body 80 shown in simplified form as a cylinder. In practice, the pressure hull 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 simplicity. Also, the pressure body 80 does not have to take up the full length. In particular, weapon barrels can be arranged in the bow.

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

3 shows a second exemplary cross section. The outer shell 80 has an irregular hexagonal cross-section with the widest point 100 being located well above the center 90. FIG. As a result, a large part of the incoming waves are reflected to the seabed, which further minimizes the probability of detection.

4 shows a third exemplary cross-section. The outer shell 80 has an irregular hexagonal cross-section with the widest point 100 being located well below the center 90. FIG. As a result, although a large part of the incident waves are reflected to the water surface, 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 Figures 2 to 4 indicates figure 5 a cross-section with rounded corners otherwise principally the same as the second exemplary cross-section 3 is. In addition, fuel reservoirs 110 and sonar sensors 120 are arranged between the outer shell 50 and the pressure hull 80 .

Alone Figures 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 sign

10

underwater vehicle

20

bow section

30

midship 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 (15)

Submersible (10) with a reduced probability of detection, the underwater vehicle (10) having an outer hull (50), the underwater vehicle (10) having a bow section (20), a stern section (40) and a midship section (30), the outer hull ( 50) of the midship section (30) transverse to the longitudinal direction of the underwater vehicle (10) has a polygonal cross-section, characterized in that the outer shell (50) of the midship section (30) has a curvature along the longitudinal direction of the underwater vehicle (10) over the entire length of the midship section (30). Underwater vehicle (10) according to Claim 1, characterized in that the polygonal cross section has rounded corner areas. Underwater vehicle (10) according to one of the preceding claims, characterized in that the polygonal cross section has a mirror plane perpendicular to the longitudinal axis. Submersible (10) according to one of the preceding claims, characterized in that the outer shell (50) of the midship section (30) transverse to the longitudinal direction of the underwater vehicle (10) has a curvature over the entire cross section along the longitudinal direction of the underwater vehicle (10). Underwater vehicle (10) according to Claim 4, characterized in that the outer shell (50) forms a conic section in the longitudinal direction of the underwater vehicle (10) or is composed of two or more conic sections. Submersible (10) according to one of the preceding claims, characterized in that the submersible (10) has a tower in the midship section (30). Underwater vehicle (10) according to any one of the preceding claims, characterized in that 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 (10) being between 5 and 1,000, preferably between 10 and 250, particularly preferably between 25 and 100, lies. Underwater vehicle (10) according to one of the preceding claims, characterized in that the polygonal cross section has a widest point (100), the widest point (100) of the polygonal cross section being arranged below or above the center (90), the center ( 90) is defined as half the height of the polygonal cross-section. Underwater vehicle (10) according to claim 8, characterized in that the widest point (100) of the polygonal cross-section is located at least 10%, preferably at least 20% of half the height of the polygonal cross-section below or above the center (90). Underwater vehicle (10) according to one of the preceding claims, characterized in that all planes of the polygonal cross section have an inclination of at least 10°, preferably at least 20°, relative to the vertical. Underwater vehicle (10) according to one of the preceding claims, characterized in that all planes of the polygonal cross-section have an inclination of 10° to 40° or 50° to 80° with respect to the vertical. Underwater vehicle (10) according to one of the preceding claims, characterized in that the outer shell (50) has a sound-absorbing property. Underwater vehicle (10) according to one of the preceding claims, characterized in that the outer shell (50) for sound waves in the frequency range from 100 Hz to 100 kHz, in particular in the range from 1 kHz to 25 kHz is essentially reflecting and / or absorbing. Underwater vehicle (10) according to one of the preceding claims, characterized in that the underwater vehicle (10) has a substantially cylindrical pressure body (80) under the outer shell (50). Underwater vehicle (10) according to Claim 14, characterized in that sensors, in particular passive sonar sensors (120), and/or fuel storage (110) are arranged between the outer shell (50) and pressure hull (80).

Images