Underwater vehicle with surface active microbubble drag reduction system

Abstract

The invention relates to an underwater vehicle with a surface active microbubble drag reduction system, the underwater vehicle has a double-layer shell, the inner-layer shell is a structural layer homogeneous shell, the outer-layer shell is a porous shell with a dense porous breathable structure, a middle pressure layer is formed between the inner-layer shell and the porous shell, and the surface active microbubble drag reduction system is arranged between the middle pressure layer and the porous shell. Densely attached microbubbles can be generated on the surface of the porous shell, and the microbubbles have the effect of reducing resistance in the running process of the underwater vehicle. The microbubbles are directly generated without depending on the head of the underwater vehicle, head noise in the sailing process can be reduced, reliable and stable work of head sonar is guaranteed while resistance is reduced, and the combat effectiveness of the underwater vehicle is improved.

Description

Technical Field

[0001] The invention relates to an underwater vehicle with a surface active microbubble drag reduction system, which is used for monitoring state information such as acceleration, temperature and humidity during cargo transportation. Background Art

[0002] The resistance encountered by underwater vehicles when moving underwater is much greater than the resistance encountered in the air. Excessive hydrodynamic resistance causes the vehicle to sail at a low speed underwater. Currently, the fastest conventional underwater vehicle has a speed of only 36m / s, which is far from meeting the requirements for fast navigation of underwater vehicles. Supercavitation technology is to build a large cavity on the surface of the underwater vehicle that can wrap the surface of the vehicle to reduce the navigation resistance of the underwater vehicle and increase the navigation speed. The Russian Buran underwater vehicle using supercavitation technology has a maximum speed of over 100-200m / s, which has great advantages and application prospects.

[0003] In the prior art, supercavitating underwater vehicles can be divided into ventilated supercavitating underwater vehicles and natural supercavitating underwater vehicles according to the different gas generation methods. Ventilated supercavitating underwater vehicles add a ventilation bowl to the head of the underwater vehicle, and send the gas carried by the underwater vehicle itself or generated by engine combustion to the ventilation bowl through the return air device and discharge it into the water, thereby wrapping the underwater vehicle. Natural supercavitating underwater vehicles use the high-speed movement of the underwater vehicle to evaporate the surrounding water to form water vapor, which wraps most or all of the surrounding water except the warhead, thereby achieving supercavitating navigation.

[0004] However, due to the poor sound propagation performance of the head gas and the huge noise of the supercavitating underwater vehicle itself, the guidance effect and performance of the torpedo using the above two methods are greatly damaged. The guidance can only rely on the tail wire guidance or short-range guidance device, and this type of underwater vehicle has poor maneuverability and short range, and still cannot fully meet the requirements.

[0005] Based on the above, a comprehensive analysis of conventional underwater vehicles and supercavitating underwater vehicles shows that the former has a low speed, but strong guidance capability and long range, while the latter has a fast speed, but its guidance capability is affected by supercavitation and its autonomous capability is insufficient. In summary, there is an urgent need for an underwater vehicle that simultaneously meets the requirements of low resistance, high speed, low head noise, and high guidance. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] In view of the above-mentioned deficiencies of the prior art, the present invention proposes an underwater vehicle with a surface active microbubble drag reduction system. The underwater vehicle adopts a double-layer shell and can simultaneously meet the requirements of low resistance, high speed, low head noise and high guidance.

[0008] (II) Technical solution

[0009] An underwater vehicle with a surface active microbubble drag reduction system, the underwater vehicle having a double-layer shell, the inner shell being a structural layer homogeneous shell having a main load-bearing structure and strict air tightness, and being used to support the force and navigation load of the underwater vehicle; the outer layer being a porous outer shell having a dense porous air-permeable structure, and being used to overflow dense microbubbles; an intermediate pressure layer is formed between the inner shell and the porous outer shell, and is provided with a plurality of supporting structures; the porous outer shell is non-homogeneous, and the microbubble generation speed of the surface active microbubble drag reduction system is controlled in different zones, the microbubble generation speed at the front end of the underwater vehicle is high, and the generated microbubbles are dense, while the microbubble generation speed at the middle and tail of the underwater vehicle is low, and the generated microbubbles are sparse.

[0010] Furthermore, when dense microbubbles are formed on the surface of the porous shell of the underwater vehicle, the cavitation number is less than the minimum surface pressure coefficient.

[0011] Furthermore, the pore size of the porous air-permeable structure in the porous shell is in the range of 100-200 microns, and no liquid leakage occurs when the internal and external pressures are equal.

[0012] Furthermore, the surface active microbubble drag reduction system has a pressure generating device, which is used to pressurize the gas medium in the pressure intermediate layer so that the gas medium passes through the porous outer shell to form a microbubble layer on the outer surface of the underwater vehicle. Some of the microbubbles in the microbubble layer pass through the gas-liquid boundary layer and overflow into the external liquid layer.

[0013] Furthermore, the surface active microbubble drag reduction system also has an air pressure sensitive device installed in the pressure intermediate layer, so that during underwater navigation, the surface active microbubble drag reduction system can pressurize the pressure intermediate layer in real time to maintain the pressure of the pressure intermediate layer not less than the pressure of the liquid layer, thereby preventing external liquid from excessively penetrating into the porous shell or entering the pressure intermediate layer.

[0014] Furthermore, the pressure generating device is an internal pressure gas cylinder or a chemical pressurizing device of the underwater vehicle, and is connected to the power system of the underwater vehicle through a pressure stabilizing control device in the surface active microbubble drag reduction system.

[0015] A method for reducing drag of an underwater vehicle having a surface active microbubble drag reduction system, comprising the following steps:

[0016] S1. The underwater vehicle is sent into the water by its launch device, the underwater vehicle is sent into the water by the launch device, the surface of the underwater vehicle is completely covered by water, the underwater vehicle is accelerated, and the intermediate pressure layer and the liquid layer are kept at the same pressure;

[0017] S2. During the speed-up process of the underwater vehicle, the pressure generating device increases the pressure, and the increase process is completed before the underwater vehicle reaches the maximum navigation speed without cavitation. After the pressure is increased to the maximum working pressure, the surface active microbubble drag reduction system maintains the maximum working pressure;

[0018] S3. After the maximum working pressure is maintained, the intermediate pressure layer begins to increase pressure until the pressure reaches the point where microbubbles occur. The microbubbles overflow through the porous shell and converge in the microbubble layer to form large cavitations. The large cavitations completely cover the entire outer surface of the underwater vehicle, thereby achieving drag reduction during its underwater navigation process.

[0019] S4. The surface active microbubble drag reduction system controls and regulates the density and frequency of microbubble generation, so that the microbubbles at the head of the underwater vehicle are denser, and the microbubbles in the middle and tail are sparser; when the microbubbles in the microbubble-dense area are reduced as they burst or overflow, the surface active microbubble drag reduction system will appropriately increase the amount of microbubbles generated in the microbubble-dense area; when the amount of microbubbles in the microbubble-sparse area is too much or too little, the surface active microbubble drag reduction system will appropriately adjust the amount of microbubbles in the microbubble-sparse area to balance the drag reduction effect and head noise of the underwater vehicle.

[0020] (III) Beneficial effects

[0021] The present invention proposes an underwater vehicle with a surface active microbubble drag reduction system. The underwater vehicle has a double-layer shell, and the outer porous shell is made of a breathable material. The surface of the shell can produce densely attached microbubbles, which can reduce the drag of the underwater vehicle during its travel. The generation of the microbubbles does not rely on the direct generation of the underwater vehicle head, which can reduce the head noise during navigation, reduce the resistance, and ensure the reliable and stable operation of the head sonar, thereby improving the combat effectiveness of the underwater vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 Double-layer hull structure diagram of the underwater vehicle of the present invention

[0023] Figure 2 Schematic diagram of the working process of the surface active microbubble drag reduction system of the present invention

[0024] Figure 3 Schematic diagram of automatic control of the surface active microbubble drag reduction system of the present invention DETAILED DESCRIPTION

[0025] See also Figure 1, an underwater vehicle with a surface active microbubble drag reduction system, the underwater vehicle having a double-layer shell, the inner shell 4 being a structural layer homogeneous shell, having a main load-bearing structure and strict air tightness, and being used to support the force and navigation load of the underwater vehicle; the outer layer being a porous outer shell 1 with a dense porous air-permeable structure, being used to overflow dense microbubbles; an intermediate pressure layer 3 is formed between the inner shell 4 and the porous outer shell 1, and is provided with a plurality of supporting structures 2; the porous outer shell 1 is non-homogeneous, and the microbubble generation speed of the surface active microbubble drag reduction system is controlled in a zoned manner, the microbubble generation speed at the front end of the underwater vehicle is high, and the generated microbubbles are dense, while the microbubble generation speed at the middle and tail of the underwater vehicle is low, and the generated microbubbles are sparse.

[0026] When dense microbubbles are formed on the surface of the porous shell 1 of the underwater vehicle, the cavitation number is less than the minimum surface pressure coefficient.

[0027] The pore size of the porous air-permeable structure in the porous shell 1 is in the range of 100-200 microns, and no liquid leakage occurs when the internal and external pressures are equal.

[0028] See also Figure 2 The surface active microbubble drag reduction system has a pressure generating device, which is used to pressurize the gas medium in the pressure intermediate layer 3 so that the gas medium passes through the porous shell 1 and forms a microbubble layer 5 on the outer surface of the underwater vehicle. Some microbubbles in the microbubble layer 5 pass through the gas-liquid boundary layer 7 and then overflow into the external liquid layer 6.

[0029] The surface active microbubble drag reduction system also has an air pressure sensitive device installed in the pressure intermediate layer 3, so that during underwater navigation, the surface active microbubble drag reduction system can pressurize the pressure intermediate layer 3 in real time to keep the pressure of the pressure intermediate layer 3 not less than the pressure of the liquid layer 6, thereby preventing external liquid from excessively penetrating into the porous shell 1 or entering the pressure intermediate layer 3.

[0030] The pressure generating device is an internal pressure gas cylinder or a chemical pressurizing device of the underwater vehicle, and is connected to the power system of the underwater vehicle through a pressure stabilizing control device in the surface active microbubble drag reduction system.

[0031] A method for reducing drag of an underwater vehicle having a surface active microbubble drag reduction system, comprising the following steps:

[0032] S1. The underwater vehicle is sent into the water by its launch device, the underwater vehicle is sent into the water by the launch device, the surface of the underwater vehicle is completely wrapped by water, the underwater vehicle is accelerated, and the intermediate pressure layer 3 and the liquid layer 6 are kept at the same pressure;

[0033] S2. During the speed-up process of the underwater vehicle, the pressure generating device increases the pressure, and the increase process is completed before the underwater vehicle reaches the maximum navigation speed without cavitation. After the pressure is increased to the maximum working pressure, the surface active microbubble drag reduction system maintains the maximum working pressure;

[0034] S3. After the maximum working pressure is maintained, the intermediate pressure layer 3 starts to increase the pressure until the pressure reaches the microbubble generation, the microbubble overflows outward through the porous shell 1, and the microbubble gathers in the microbubble layer 5 to form a large cavitation, which completely covers the entire outer surface of the underwater vehicle, thereby achieving drag reduction during its underwater navigation process;

[0035] S4. See Figure 3 The surface active microbubble drag reduction system controls and regulates the density and frequency of microbubble generation, so that the microbubbles at the head of the underwater vehicle are denser, and the microbubbles in the middle and tail are sparser; when the microbubbles in the microbubble dense area 8 decrease as they rupture or overflow, the surface active microbubble drag reduction system will appropriately increase the amount of microbubbles generated in the microbubble dense area 8; when the amount of microbubbles in the microbubble sparse area 7 is too much or too little, the surface active microbubble drag reduction system will appropriately adjust the amount of microbubbles in the microbubble sparse area 7 to balance the drag reduction effect and head noise of the underwater vehicle.

Claims

1. An underwater vehicle with a surface active microbubble drag reduction system, characterized in that: The underwater vehicle has a double-layer shell, the inner shell (4) is a structural layer homogeneous shell, has a main load-bearing structure and strict air tightness, and is used to support the force and navigation load of the underwater vehicle; the outer layer is a porous outer shell (1) with a dense porous air-permeable structure, which is used to overflow dense microbubbles; an intermediate pressure layer (3) is formed between the inner shell (4) and the porous outer shell (1), and a plurality of supporting structures (2) are provided; the porous outer shell (1) is non-homogeneous, and the microbubble generation speed of the surface active microbubble drag reduction system is controlled by partitioning, the microbubble generation speed at the front end of the underwater vehicle is high, and the generated microbubbles are dense, and the microbubble generation speed at the middle and tail of the underwater vehicle is low, and the generated microbubbles are sparse.

2. An underwater vehicle with a surface active microbubble drag reduction system as claimed in claim 1, characterized in that: When dense microbubbles are formed on the surface of the porous outer shell (1) of the underwater vehicle, the cavitation number is less than the minimum surface pressure coefficient.

3. An underwater vehicle with a surface active microbubble drag reduction system as claimed in claim 2, characterized in that: The pore size of the porous air-permeable structure in the porous outer shell (1) is in the range of 100-200 micrometers, and no liquid leakage occurs when the internal and external pressures are equal.

4. An underwater vehicle with a surface active microbubble drag reduction system as claimed in claim 3, characterized in that: The surface active microbubble drag reduction system has a pressure generating device, which is used to pressurize the gas medium in the pressure intermediate layer (3) so that the gas medium passes through the porous shell (1) to form a microbubble layer (5) on the outer surface of the underwater vehicle, and some microbubbles in the microbubble layer (5) pass through the gas-liquid boundary layer (7) and overflow to the external liquid layer (6).

5. An underwater vehicle with a surface active microbubble drag reduction system as claimed in claim 4, characterized in that: The surface active microbubble drag reduction system also has an air pressure sensitive device installed in the pressure intermediate layer (3), so that during underwater navigation, the surface active microbubble drag reduction system can pressurize the pressure intermediate layer (3) in real time to maintain the pressure of the pressure intermediate layer (3) not less than the pressure of the liquid layer (6), thereby preventing external liquid from excessively penetrating into the porous shell (1) or entering the pressure intermediate layer (3).

6. An underwater vehicle with a surface active microbubble drag reduction system as claimed in claim 5, characterized in that: The pressure generating device is an internal pressure gas cylinder or a chemical pressurizing device of the underwater vehicle, and is connected to the power system of the underwater vehicle through a pressure stabilizing control device in the surface active microbubble drag reduction system.

7. A method for reducing drag of an underwater vehicle using the surface active microbubble drag reduction system as claimed in claim 6, characterized in that: The following steps are involved: S1. The underwater vehicle is sent into the water by its launching device, the surface of the underwater vehicle is completely covered by water, and the underwater vehicle is accelerated to maintain the intermediate pressure layer (3) and the liquid layer (6) have the same pressure; S2. During the speed-up process of the underwater vehicle, the pressure generating device increases the pressure, and the increase process is completed before the underwater vehicle reaches the maximum navigation speed without cavitation. After the pressure is increased to the maximum working pressure, the surface active microbubble drag reduction system maintains the maximum working pressure; S3. After the maximum working pressure is maintained, the intermediate pressure layer (3) begins to increase the pressure until the pressure reaches the point where microbubbles occur. The microbubbles overflow outward through the porous outer shell (1) and converge in the microbubble layer (5) to form large cavities. The large cavities completely cover the entire outer surface of the underwater vehicle, thereby reducing the drag during its underwater navigation process. S4. The surface active microbubble drag reduction system controls and regulates the density and frequency of microbubble generation, so that the microbubbles at the head of the underwater vehicle are denser and the microbubbles at the middle and tail are sparser; when the microbubbles in the microbubble dense area (8) decrease as they rupture or overflow, the surface active microbubble drag reduction system will appropriately increase the amount of microbubbles generated in the microbubble dense area (8); when the amount of microbubbles in the microbubble sparse area (7) is too much or too little, the surface active microbubble drag reduction system will appropriately adjust the amount of microbubbles in the microbubble sparse area (7) to balance the drag reduction effect and head noise of the underwater vehicle.

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