KR102182067B1 - Underwater surface structure with feather structure of cormorant and underwater structure comprising thereof - Google Patents

Abstract

The underwater surface structure according to an embodiment includes a base plate; Partition partition walls arranged to be spaced apart from each other at a first regular interval on the base plate; Fine partitions connected between the partition partitions and arranged to be spaced apart from each other at a predetermined second interval; And a cavity formed between the partition partition wall and the fine partition wall on the base plate, and the second interval may be smaller than the first interval.

Description

An underwater surface structure having a cormorant's feather structure, and an underwater structure including the same {UNDERWATER SURFACE STRUCTURE WITH FEATHER STRUCTURE OF CORMORANT AND UNDERWATER STRUCTURE COMPRISING THEREOF}

The following description relates to an underwater surface structure having a cormorant feather structure and an underwater structure including the same.

In the case of underwater vehicles moving underwater such as ships, submarines and torpedoes, a lot of energy is consumed to overcome the resistance of water. In particular, since the fuel cost is known to account for about 60 to 80% of the operating cost of the ship, it is important to reduce the frictional resistance acting on the surface of the underwater vehicle in order to reduce this.

In order to reduce the frictional resistance acting on an underwater vehicle, a superhydrophobic surface technology having a low friction function has been developed. However, as time passes, the air layer formed in the cavity inside the superhydrophobic surface is gradually destroyed and the function is deteriorated. Therefore, the practical use of the superhydrophobic surface is not properly achieved.

On the other hand, in the case of the technology of spraying air along the hull surface underwater to restore the destroyed air layer, it is difficult to commercialize it due to the problem that it is not efficient due to the consumption of additional energy consumed in air spraying.

Therefore, while implementing superhydrophobic surface technology that can achieve the effect of drag reduction and stability of the air layer, research and development on underwater surface structures that can satisfy both socio-economic and environmental cost aspects are actively progressing. .

The above-described background technology is possessed or acquired by the inventor in the process of deriving the present invention, and is not necessarily a known technology disclosed to the general public prior to filing the present invention.

An object of an embodiment is to provide an underwater surface structure having a feather structure of a cormorant and an underwater structure including the same.

The underwater surface structure according to an embodiment includes a base plate; Partition partition walls arranged to be spaced apart from each other at a first regular interval on the base plate; Fine partitions connected between the partition partitions and arranged to be spaced apart from each other at a predetermined second interval; And a cavity formed between the partition partition wall and the fine partition wall on the base plate, and the second interval may be smaller than the first interval.

The partition partition wall and the fine partition wall may be disposed perpendicular to each other.

The partition partition wall, the fine partition wall, and the base plate may be formed of a superhydrophobic material.

The partition partition wall, the fine partition wall, and the base plate may be surface-treated with a superhydrophobic material.

The partition partition wall may include a first protrusion protruding from an upper end of the partition partition wall toward the cavity.

The fine partition wall may include a second protrusion formed from an upper end of the fine partition wall to protrude in a lateral direction toward the cavity.

The first protrusion may have a shape in which an end protruding laterally from an upper end of the partition partition is bent downward.

The second protrusion may have a shape in which an end protruding laterally from an upper end of the fine partition wall is bent downward.

The first and second intervals may be designed in inverse proportion to the size of the pressure gradient based on the magnitude of the pressure gradient that changes along the horizontal direction of the underwater surface structure.

The first and second intervals may be designed within a range satisfying the following equation.

(Equation)

(Where "L" is the first interval between partition partitions, "w" is the second interval between fine partitions, " dP _c / dx " is the magnitude of the pressure gradient on the surface of the underwater surface structure, and "b" is the proportional constant )

The partition partition wall naturally simulates a barb of a cormorant feather structure, and the fine partition wall may be a natural simulation of a barbule of a cormorant feather structure.

The partition partition wall and the micro partition wall may have a linear shape, and the minute partition wall may have a ridge shape recessed toward the inside of the surface of the underwater surface structure between a pair of adjacent partition partition walls.

The underwater structure according to an embodiment may include a first underwater surface structure having a cormorant feather structure, and a second underwater surface structure, wherein the first underwater surface structure includes a first base plate, and on the first base plate. A first partition partition wall arranged to be spaced apart from each other at a first constant interval, a first fine partition wall connected between the first partition partition walls and arranged to be spaced apart from each other at a constant second interval, and the first on the first base plate It may include a first cavity formed between the partition partition wall and the first fine partition wall, the second gap is smaller than the first gap, the second underwater surface structure, a second base plate, the second base A second partition partition wall arranged to be spaced apart from each other at a predetermined third interval on the plate, a second fine partition wall connected between the second partition partition walls and arranged to be spaced apart from each other at a constant fourth interval, and the second base plate It may include a second cavity formed between the second partition and the second fine partition, the fourth interval is smaller than the third interval, the third interval is smaller than the first interval, the fourth interval May be smaller than the second interval.

The underwater structure may be a water surface or an underwater vehicle that moves underwater, the second underwater surface structure may be disposed in front of the underwater vehicle, and the first underwater surface structure may be a side of the underwater vehicle or Can be placed in the rear.

Based on the direction of gravity, the second underwater surface structure may be disposed below the first underwater surface structure.

According to the underwater structure of an embodiment, the cavity can be stably maintained through the configuration of the cavity that simulates the feather structure of a cormorant, so that hydraulic drag acting on the surface of the underwater structure can be effectively reduced.

1 is a side view of a ship having an underwater surface structure according to an embodiment.
2 is a view showing the structure of the cormorant's wing.
3 is a perspective view of an underwater surface structure according to an embodiment.
4 is a plan view of an underwater surface structure according to an embodiment.
5 is a cross-sectional view of an underwater surface structure according to an embodiment taken along line II of FIG. 4.
6 is a cross-sectional view of an underwater surface structure according to an embodiment taken along line II-II of FIG. 4.
7 is a cross-sectional view of an underwater surface structure according to another embodiment taken along line II of FIG. 4.
8 is a cross-sectional view of an underwater surface structure according to another embodiment taken along line II-II of FIG. 4.

Hereinafter, embodiments will be described in detail through exemplary drawings. In adding reference numerals to elements of each drawing, it should be noted that the same elements are assigned the same numerals as possible even if they are indicated on different drawings. In addition, in describing the embodiment, if it is determined that a detailed description of a related known configuration or function interferes with the understanding of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the constituent elements of the embodiment, terms such as first, second, A, B, (a) and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, order, or order of the component is not limited by the term. When a component is described as being "connected", "coupled" or "connected" to another component, that component may be directly connected or connected to that other component, but another component between each component It should be understood that may be “connected”, “coupled” or “connected”.

Components included in one embodiment and components including common functions will be described using the same name in other embodiments. Unless otherwise stated, descriptions in one embodiment may be applied to other embodiments, and detailed descriptions in the overlapping range will be omitted.

1 is a side view of a ship having an underwater surface structure according to an embodiment, FIG. 2 is a view showing a wing structure of a cormorant, FIG. 3 is a perspective view of an underwater surface structure according to an embodiment, and FIG. 4 is an embodiment A plan view of the underwater surface structure according to the example, FIG. 5 is a cross-sectional view of the underwater surface structure according to an embodiment taken along line II of FIG. 4, and FIG. 6 is a plan view taken along line II-II of FIG. 4. Is a cross-sectional view of the underwater surface structure.

First, referring to FIG. 1, the appearance of the underwater structure 8 formed of the underwater surface structure 1 according to an embodiment of the hull surface can be confirmed. Here, the "underwater structure" may be understood as a concept including all of a moving body that moves on the surface or underwater, such as a ship or a submarine, or a fixed body fixedly installed in the water such as a conduit for fluid transport. Hereinafter, a case where the underwater structure 8 is a ship will be exemplarily described, but it should be noted that the present invention is not necessarily limited thereto. In addition, it is found that it can be used not only in macroscale but also in the field of microfluidics. The underwater surface structure 1 according to an embodiment is installed on the hull surface of an underwater vehicle such as a ship 8 or Since it can be formed integrally with the outside of the hull, it is possible to greatly improve fuel efficiency and operational stability by reducing the frictional resistance acting along the hull surface and reducing the movement resistance according to the operation of the underwater vehicle.

Referring to FIG. 2, an image of an enlarged image of a cormorant feather and a structure of a feather by an X-ray imaging technique can be confirmed.

The structure of the cormorant's feathers, which not only swims freely in the water, but also keeps the feathers dry while diving up to 30 meters underwater, is well known as an effective waterproofing system.

Looking at the enlarged image of the cormorant feather structure, a barbule (fine feather structure) with a diameter of about 10 μm is arranged in parallel with a spacing of about 15 μm, and about 100 to support the parallel barbules. It can be seen that a structure in which a partition wall structure made of μm-thick barbs (thick feathers) is arranged spaced apart by about 200 μm intervals therebetween.

According to the above feather structure, when a cormorant swims in the water, it can play a role of preventing water from flowing into the inside, and a cavity structure formed between the fine feathers when the feather enters the water. By forming an air plastron in the air, it is possible to reduce the drag acting on the cormorant, and the thick feathers forming the bulkhead structure have the effect of continuously maintaining this air layer.

Accordingly, an object of the present invention is to propose an underwater surface structure (1) that simulates the microstructure of such a cormorant feather, thereby applying it to the surface of a ship, a submarine, an underwater vehicle such as a torpedo, a conduit for transporting fluid, or an offshore structure. This is to implement a superhydrophobic surface.

3 to 6, a specific structure of the underwater surface structure 1 according to an embodiment can be confirmed.

The underwater surface structure 1 according to an embodiment includes a plate-shaped base plate 11, a partition partition 12 arranged to be spaced apart from each other at regular intervals on the base plate 11, and a partition partition wall on the base plate 11 (12) Including a micro-barrier 13 connected to each other and spaced apart from each other at regular intervals, and a cavity 14 formed between the partitioning and micro-barrier 13 to form an air layer therein. can do.

The base plate 11 may be a plate-shaped member installed on a target surface on which the underwater surface structure 1 is installed. As another example, the base plate 11 may be integrally formed with the target surface.

The partition wall 12 is a natural simulation of a barb having a cormorant feather structure, and may support a plurality of fine partition walls 13. The partition partition walls 12 may be arranged to be spaced apart from each other at a first interval L on the base plate 11. For example, the partition wall 12 may be formed to protrude from the surface of the base plate 11 by a protruding height H.

For example, the partition partition wall 12 may include a first protrusion 121 protruding from an upper end toward the cavity 14 in a lateral direction.

The first protrusion 121 may reduce a cross-sectional area of an inlet portion connected to the cavity 14 from the surface of the underwater surface structure 1. For example, the first protrusion 121 has a structure formed to protrude vertically toward the other adjacent partition partition 12 on a side cross section cut along a direction perpendicular to the length direction of the partition partition wall 12 as shown in FIG. 5. Can have.

According to the first protrusion 121, when a fluid flows on the surface of the underwater surface structure 1, external flow by increasing the pinning force of the fluid due to the surface tension at the inlet portion of the cavity 14 It is possible to effectively protect the air layer formed inside the cavity 14, and at the same time, it is possible to prevent the air layer from being lost out of the cavity.

The fine partition wall 13 naturally simulates a barb of a cormorant feather structure, and by maintaining an air layer, it is possible to prevent water from flowing into the interior of the underwater structure 8 through the underwater surface structure 1. have. The base plate 11 may be arranged to be spaced apart from each other at a constant second interval w, and the second interval w may be smaller than the first interval L. For example, the thickness of the fine partition wall 13 may be smaller than the thickness of the partition wall 12.

For example, the fine partition wall 13 may be formed to protrude from the surface of the base plate 11 along a direction perpendicular to the length direction of the partition partition wall 12. For example, the protruding height of the fine partition wall 13 may be equal to or smaller than the protruding height H of the partition partition wall 12.

On the other hand, unlike FIG. 3, the fine partition wall 13 may have a shape of a ridge recessed from the surface of the underwater surface structure 1 toward the inside, like the barb of the cormorant feather shown in FIG. 2. . In other words, both ends of the fine partition wall 13 may be formed higher than the central portion. In other words, when viewed in the y-axis direction with reference to FIG. 4, the central portion of the fine partition wall 13 may have a shape recessed in the negative direction of the z-axis.

For example, the fine partition wall 13 may include a second protrusion 131 protruding in a lateral direction from the upper end of the fine partition wall 13 toward the cavity 14.

The second protrusion 131 may reduce a cross-sectional area of an inlet portion connected to the cavity 14 from the surface of the underwater surface structure 1. For example, the second protrusion 131 has a structure in which the second protrusion 131 protrudes vertically toward the other adjacent fine partitions 13 on a side cross section cut along a direction perpendicular to the length direction of the fine partition 13 as shown in FIG. 6. Can have.

According to the above structure, the edge of the entrance of the cavity 14 has a structure that is narrowed by the first protrusion 121 and the second protrusion 131, so that the cavity from the external flow like the above-described first protrusion 121 (14) It is possible to effectively protect the air layer formed inside, and at the same time, it is possible to more effectively prevent the air layer from being lost out of the cavity 14.

For example, the partition partition wall 12, the fine partition wall 13, and the base plate 11 may be formed of a hydrophobic material, so that the air layer inside the cavity 14 can be more effectively protected by the flowing fluid, It can reduce the frictional resistance of the fluid.

For example, the underwater surface structure 1 may be formed of SPC (Self Polishing Copolymer) or a silicon-based hydrophobic material.

As another example, the partition partition wall, the fine partition wall, and the base plate may increase the hydrophobicity while increasing the surface durability of the underwater surface structure 1 by additionally applying a surface treatment using a hydrophobic chemical substance.

The cavity 14 is a space defined by the partition partition 12 and the fine partition wall 13 protruding from the base plate 11, and traps air inside even if the surface of the underwater surface structure 1 contacts the fluid. It is possible to form an air layer that maintains the state.

According to the air layer formed in the cavity 14, the hydraulic drag force can be reduced by reducing the frictional resistance acting on the surface of the underwater surface structure 1.

For example, the size of the cavity 14, the spacing of the partition walls 12, and the like may be designed differently according to the flow conditions of the fluid flowing on the surface of the underwater surface structure 1. For example, the size of the cavity 14 may be determined based on the amount of pressure formed by the fluid flowing on the surface of the underwater surface structure 1.

In the case of the ship 8, as the flow conditions are determined differently based on the position of the hull surface or the size of the curvature of the surface, the magnitude of the hydraulic pressure applied to the underwater surface structure 1 may be formed differently.

Therefore, when the underwater surface structure (1) is applied to an underwater vehicle or offshore structure such as a ship (8), the underwater surface structure (1) is based on the flow conditions of the surface portion on which the underwater surface structure (1) is installed. As the degree of influence on the drag reduction effect and the stability of the air layer can be formed differently, the size, shape, or spacing of the cavity 14 of the underwater surface structure 1 can be designed to suit the flow conditions. .

In this case, the first gap L between the partition walls 12 and the second gap w between the fine bulkheads 13 may be in inverse proportion to the magnitude of the pressure acting on the surface of the underwater surface structure 1.

For example, a plurality of underwater surface structures 1 having different shapes for each location of the underwater structure 8 may be installed. Specifically, each of the first interval (L) and the second interval (w) in the plurality of underwater surface structures 1 may be set within a range that satisfies Equation 1 below.

(Here, "L" is the first interval between partition partitions, "w" is the second interval between fine partitions, " P _c "is the magnitude of pressure applied to the surface of the underwater surface structure, and "a" is a proportional constant)

In another example, the size of the cavity 14 of the underwater surface structure 1, that is, the first gap L between the partition walls 12 and the second gap w between the fine bulkheads 13 are along the flow direction of the fluid. It can also be determined by the magnitude of the pressure gradient, which represents the non-uniformity of the applied pressure.

When a plurality of underwater surface structures (1) having different shapes for each location of the underwater structure (8) are installed, each of the first interval (L) and the second interval (w) in the plurality of underwater surface structures (1) May be set within a range that satisfies Equation 2 below.

(Here, "L" is the first interval [μm] between partition partitions, "w" is the second interval [μm] between fine partitions, " dP _c / dx " is the size of the pressure gradient at the surface of the underwater surface structure, "b" is a proportional constant)

According to the above structure, the first interval L based on the value of the pressure gradient indicating the degree of change in the magnitude of the pressure along the flow direction on each surface of the underwater surface structure 1 installed for each position of the underwater structure 8 And the size of the second interval w may be set.

For example, the size of the cavity 14 can be made compact and compact at a point where the pressure begins to rapidly change along the surface of the underwater structure 8, and the cavity 14 at a point where the pressure change is relatively small. The size of the can be formed relatively large and less dense, it is possible to more effectively respond to changes in the flow of the fluid on the surface of the underwater structure (8).

As a result, as the size of the underwater surface structure 1 can be adjusted and applied according to the flow conditions acting on the underwater surface structure 1, the drag force according to the different flow conditions for each installation location of the underwater surface structure 1 By optimizing the reduction effect and the preservation effect of the air layer, the hydrophobicity of the underwater surface structure 1 can be greatly improved.

For example, the first gap (L), the second gap (w), and the thickness of the fine partition wall 13 may be formed in micrometers, and the size of the pressure gradient applied to the underwater surface structure 1 It may be a relationship inversely proportional to.

For example, the structure of the cavity 14 of the underwater surface structure 1, that is, the shape of the partition partition wall 12 and the fine partition wall 13 may be formed through a photolithography process.

Meanwhile, as described above, the underwater structure 8 according to an embodiment may include a plurality of underwater surface structures 1 formed in different sizes from each other.

For example, when the underwater structure 8 is an underwater vehicle such as a ship, a submarine, or a torpedo, the size of the partition bulkhead 12 and the fine bulkhead 13 is small and compact in the front where the pressure applied to the surface is large. The underwater surface structure 1 may be installed, and at the side or rear where the pressure applied to the surface is formed less than the front, the size of the interval between the partition partition 12 and the fine partition 13 is relatively large and less dense. Can be formed.

Here, the underwater surface structure (1) installed at the rear of the underwater structure (8) may be referred to as the first underwater surface structure (1), and the underwater surface structure (1) installed in front of the underwater structure (8) is prepared. 2 It can be called an underwater surface structure (1).

The first underwater surface structure (1) is arranged to be spaced apart from each other by a first base plate (11) and a constant first distance (L) on the first base plate 11 and the same structure as the structure of the underwater surface structure (1). On the first fine partition wall 13 and the first base plate 11 are connected between the first partition wall 12 and the first partition wall 12 and are spaced apart from each other at a constant second interval (w). A first cavity 14 formed between the first partition wall 12 and the first fine partition wall 13 may be included.

The second underwater surface structure 1 is also spaced apart from each other by a constant third distance L on the second base plate 11 and the second base plate 11 similar to the structure of the first underwater surface structure 1. The arranged second partition partition walls 12 and the second fine partition walls 13 connected between the second partition partition walls 12 and arranged to be spaced apart from each other at a constant fourth interval w, and the second base plate 11 ) May include a second cavity 14 formed between the second partition wall 12 and the second fine partition wall 13.

For example, the fourth interval w may be smaller than the third interval L, and the thickness of the second fine partition wall 13 may be smaller than the thickness of the second partition partition wall 12.

The third interval L may be smaller than the first interval L, and the fourth interval w may be smaller than the second interval w. In other words, the distance between the partition walls 12 of the first underwater surface structure 1 is larger than the distance between the partition walls 12 of the second underwater surface structure 1, and the first underwater surface structure 1 The spacing between the fine partition walls 13 may be formed larger than the spacing of the fine partition walls 13 of the second underwater surface structure 1.

In addition, the second underwater surface structure 1 having a relatively small size of the cavity 14 based on the direction of gravity may be disposed below the first underwater surface structure 1. For example, when the underwater structure 8 is an underwater vehicle 8 such as a ship, a submarine, or a torpedo, or a fixed body 8 fixed in the water, the water pressure increases downward along the direction of gravity. As the direction goes, the submerged surface structure 1 may be installed in which the spacing between the partition walls 12 and the spacing between the fine bulkheads 13 are small.

Meanwhile, the underwater structure 8 may further include a third underwater surface structure 1 disposed between the first underwater surface structure 1 and the second underwater surface structure 1. Similarly, the third underwater surface structure (1) is also spaced apart from each other by a constant fifth interval (L) on the third base plate 11 and the third base plate 11 similar to the structure of the first underwater surface structure 1 The third partition partition wall 12 and the third base plate are connected between the third partition partition wall 12 and the third partition partition wall 12 are arranged and are spaced apart from each other at a constant sixth interval w. 11) A third cavity 14 formed between the third partition wall 12 and the third fine partition wall 13 may be included.

For example, the product of the fifth interval (L) and the sixth interval (w) is inversely proportional to the magnitude of the pressure gradient between the first underwater surface structure 1 and the second underwater surface structure 1 according to Equation 2 Can be set.

7 is a cross-sectional view of the underwater surface structure cut along the cut line I-I of FIG. 4, and FIG. 8 is a cross-sectional view of the underwater surface structure according to another embodiment cut along the cut line II-II of FIG. 4.

7 and 8, the construction of the underwater surface structure 2 having the protrusions 121 and 131 of the underwater surface structure 1 shown in FIGS. 5 and 6 and the protrusions 221 and 231 of a different shape can confirm.

The first protrusion 221 has a shape formed to protrude vertically toward the other adjacent partition partition 22 on a side cross section cut along a direction perpendicular to the length direction of the partition partition wall 22 as shown in FIG. 7. The protruding end may have a shape that is bent downward.

For example, the second protrusion 231 is formed to protrude vertically toward the other adjacent fine partition wall 23 on a side section cut along a direction perpendicular to the length direction of the fine partition wall 23 as shown in FIG. 8, The protruding end may have a shape that is bent downward.

According to the structure of the first protrusion 221 or the second protrusion 231 having a shape bent downward, the air layer collected in the cavity 24 from the fluid flowing on the surface of the underwater surface structure 2 is more stably While protecting, it is possible to more effectively prevent the air layer from being lost out of the cavity.

As described above, although the embodiments have been described by the limited drawings, various modifications and variations are possible from the above description to those of ordinary skill in the art. For example, the described techniques are performed in a different order from the described method, and/or components such as the described structure, device, etc. are combined or combined in a form different from the described method, or in other components or equivalents. Even if substituted or substituted by, an appropriate result can be achieved.

Claims (8)

Base plate;
Partition partition walls arranged to be spaced apart from each other at a first interval on the base plate;
Fine partitions connected between the partition partitions and arranged to be spaced apart from each other at a predetermined second interval; And
On the base plate, including a cavity formed between the partition partition wall and the fine partition wall,
The partition partition wall and the fine partition wall are disposed perpendicular to each other,
The partition partition wall,
And a first protrusion formed vertically protruding in a lateral direction from an upper end of the partition partition wall toward the cavity,
The fine partition wall,
And a second protrusion formed to protrude vertically in a lateral direction toward the cavity from an upper end of the fine partition,
When the fluid flows on the base plate, the first protrusion and the second protrusion increase the pinning force due to surface tension at the inlet of the cavity to effectively prevent the air layer formed inside the cavity from external flow. Protect,
An underwater surface structure in which the first and second intervals are designed in inverse proportion to the size of the pressure gradient, as shown in the following equation, based on the magnitude of the pressure gradient that changes along the horizontal direction of the base plate.
(Equation)

(Here, "L" is the first interval [μm] between partition partitions, "w" is the second interval [μm] between fine partitions, " dP _c / dx " is the size of the pressure gradient at the surface of the underwater surface structure, "b" is a proportional constant)
delete The method of claim 1,
Ends protruding in the lateral direction from the first protrusion and the second protrusion are each bent downwardly.
delete The method of claim 1,
The partition partition wall naturally simulates a barb of a cormorant feather structure, and the fine partition wall naturally simulates a barbule of a cormorant feather structure.
In an underwater structure comprising a first underwater surface structure having a cormorant feather structure and a second underwater surface structure,
The first underwater surface structure,
A first base plate, a first partition partition wall arranged to be spaced apart from each other at a constant first interval on the first base plate, and a first fine particle connected between the first partition partition wall and arranged spaced apart from each other at a constant second interval A partition wall, and a first cavity formed between the first partition partition wall and the first fine partition wall on the first base plate,
The second underwater surface structure,
A second base plate, a second partition partition wall arranged to be spaced apart from each other at a constant third interval on the second base plate, and a second fine particle connected between the second partition partition wall and arranged spaced apart from each other at a constant fourth interval A partition wall, and a second cavity formed between the second partition partition wall and the second fine partition wall on the second base plate,
The first partition partition wall and the first fine partition wall each include a first protrusion formed vertically protruding in a lateral direction toward the first cavity from an upper end of each of the first partition partition wall and the first minute partition wall,
The second partition partition wall and the second fine partition wall each include a second protrusion formed vertically protruding in a lateral direction toward the second cavity from an upper end of each of the second partition partition wall and the second minute partition wall,
When the fluid flows on the underwater structure, the first protrusion and the second protrusion increase the pinning force due to surface tension at the inlet portion of the cavity, so that the inside of the first cavity and the second cavity Effectively protects the formed air layer,
Based on the magnitude of the pressure gradient that changes along the horizontal direction of the underwater structure, the first and second intervals or the third and fourth intervals are designed in inverse proportion to the size of the pressure gradient as shown in the following equation. Underwater structures.
(Equation)

(Here, "L" is the first interval [μm] or the third interval [μm] between the partition partitions, "w" is the second interval [μm] or the fourth interval [μm] between the fine partition walls, " dP _c / dx "Is the magnitude of the pressure gradient at the surface of the first underwater surface structure or the second underwater surface structure, "b" is a proportional constant)
The method of claim 6,
The underwater structure is an underwater vehicle that moves on the water surface or underwater, and the first underwater surface structure and the second underwater surface structure are selectively arranged according to the position of the underwater vehicle.
The method of claim 7,
The first underwater structure and the second underwater structure is an underwater structure, characterized in that coated with a hydrophobic material.

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