Amphibious vehicle body water sailing drag reduction device using supercavitation

Abstract

The invention provides an amphibious vehicle body water sailing drag reduction device using supercavitation. The device comprises a tail gas collecting device, a compressed gas storage device, an expansion unit, a constant temperature device, a gas conveying assembly and a supercavity emitting device. The tail gas collecting device collects and filters tail gas generated by an amphibious vehicle engine, and the tail gas is compressed and stored in the compressed gas storage device. During use, gas is subjected to pressure and temperature adjustment through the expansion unit and the constant temperature device, then the gas is conveyed to the supercavity launching device arranged on the bow of the amphibious vehicle body through the body conveying assembly, and the gas with the needed stable pressure and temperature is emitted outwards through holes in the supercavity launching device; and supercavities for reducing resistance are formed around the holes. By means of the amphibious vehicle, resistance borne by the amphibious vehicle in the water sailing process can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of underwater drag reduction of amphibious vehicles, and in particular to a drag reduction device for amphibious vehicles on water using supercavitation. Background Art

[0002] At present, when amphibious vehicles are sailing on water, they are usually affected by large water resistance, which leads to increased energy consumption and limited driving speed. Especially when amphibious vehicles pass through the water, water resistance becomes the main factor affecting driving efficiency. Therefore, how to effectively reduce the resistance during water navigation has always been a research hotspot in amphibious vehicle technology.

[0003] In many industrial applications, cavitation is generally considered a harmful phenomenon because it can cause performance degradation and structural damage to hydraulic machinery. However, when sailing underwater, when a cavity surrounds the vehicle body, the surface of the vehicle body contacts the cavity, such as gaseous fluids such as water vapor, air, and exhaust gas, rather than liquid water. Therefore, the resistance of the vehicle body in water travel can be greatly reduced. According to the mechanism of cavitation generation, cavitation can be divided into two types: natural cavitation and ventilated cavitation.

[0004] Natural cavitation is mainly formed by pressure changes in fluid dynamics, while ventilation cavitation is produced by artificial cavitation by injecting non-condensable gases such as air and exhaust gas into the liquid flow field. These two types of cavitation have broad application prospects in reducing drag of underwater vehicles, increasing speed and range, etc.

[0005] Supercavitation is the formation of a large continuous gas cavity around the surface of an underwater vehicle, which reduces the drag of the water flow on the object. Supercavitation can reduce the drag of a moving vehicle, allowing it to move steadily at high speed underwater. When the flow around the surface of an object is replaced by a layer of gas, both friction and pressure resistance can be significantly reduced. The gas layer causes a significant reduction in near-wall density and changes in fluid viscosity, similar to the supercavitation flow phenomenon around an underwater vehicle.

[0006] The use of supercavitation effect to reduce underwater resistance has not yet been applied to reducing the drag of amphibious vehicles on water. Summary of the invention

[0007] In view of this, the present invention provides an amphibious vehicle body water navigation drag reduction device using supercavitation, which can reduce the resistance encountered by the amphibious vehicle during the water navigation process.

[0008] In order to solve the above technical problems, the present invention is implemented as follows.

[0009] A drag reduction device for an amphibious vehicle body using supercavitation, comprising: an exhaust gas collection device, a compressed gas storage device, an expansion unit, a constant temperature device, a gas delivery component, and a supercavitation launch device;

[0010] The exhaust gas collecting device is used to collect and filter the exhaust gas generated by the engine of the amphibious vehicle;

[0011] The compressed gas storage device is used to pressurize and store the filtered exhaust gas collected by the exhaust gas collection device through a compressor;

[0012] The expansion unit is used to expand the gas in the compressed gas storage device to reduce the gas pressure and temperature when sailing on water;

[0013] The constant temperature device is used to cool the depressurized gas and maintain the gas temperature range;

[0014] The pressure- and temperature-regulated gas is sent to the supercavitation launch device through the gas delivery assembly;

[0015] The supercavitation launcher is arranged at the bow of the amphibious vehicle and has a hole, which emits the gas with adjusted pressure and temperature to the outside, forming a supercavitation around the hole for reducing drag.

[0016] Preferably, the exhaust gas collecting device is provided with a filtering device to remove impurities and harmful gases contained in the exhaust gas.

[0017] Preferably, the compressed gas storage device compresses the gas using a compression unit and stores the compressed gas in a compressed gas tank.

[0018] Preferably, the outlet of the compressed gas tank is connected via a pneumatic valve.

[0019] Preferably, when the expansion unit is sailing on water, the gas in the compressed gas storage device is expanded and heat-exchanged through an expander, so that the pressure is reduced to a target pressure.

[0020] Preferably, the supercavitation launch device includes an upper bow skateboard and a lower bow skateboard, and the two parts are not connected; the upper bow skateboard and the lower bow skateboard are controlled to have a folding state by a hydraulic strut, and the folding state includes an angle between the upper bow skateboard and the lower bow skateboard and covering the front surface of the amphibious vehicle body or unfolding in the same plane and docking; the upper bow skateboard is a solid structure; the lower bow skateboard is divided into two layers, the inner layer is a solid structure, and the outer layer is a hollow structure, and a hole is opened on the outer surface of the lower part of the space.

[0021] Preferably, the hydraulic strut is connected to the upper bow slide via a fixed structure to fix and limit the unfolding angles of the upper bow slide and the lower bow slide.

[0022] Preferably, the hydraulic strut includes a left hydraulic strut and a right hydraulic strut.

[0023] Preferably, the gas delivery assembly is connected to the ventilation pipes of the thermostat and the supercavitation launch device, and the ventilation pipes are multiple and evenly distributed at the bottom of the outer hollow structure of the lower bow slide, providing the hollow structure with gas with adjusted pressure and temperature.

[0024] Preferably, a pressure regulating valve and a temperature control valve are provided on the ventilation pipe to ensure that the introduced gas has the conditions to form supercavitation at the holes of the bow skateboard of the amphibious vehicle.

[0025] Beneficial effects:

[0026] (1) The present invention utilizes engine exhaust gas to generate supercavitation through treatment and pressure and temperature control, which can reduce the resistance encountered by an amphibious vehicle during navigation on water.

[0027] (2) Compressed gas is expanded and reused. Compared with general supercavitation application scenarios, the flow rate required to form supercavitation on the lower side of the bow skateboard of an amphibious vehicle is larger, so an expansion unit is required to increase the gas flow rate and control the exhaust gas pressure.

[0028] (3) The present invention uses a constant temperature device to help ensure the stability of gas flow and flow rate by maintaining the consistency of gas temperature, which helps to produce a more stable bubble layer and optimize the size and distribution of bubbles, thereby more effectively isolating water and the vehicle surface and reducing resistance.

[0029] (4) The supercavitation launch device is designed on the lower bow skateboard, which divides the lower bow skateboard into two layers, the outer layer is a cavity, and the lower part has a hole. The layered design can optimize the ratio of structural strength to weight, reduce the weight of the overall structure, and is beneficial to improving the maneuverability and navigation performance of the amphibious vehicle.

[0030] (5) The compressed gas tank is output through a pneumatic valve to control the flow of the exhaust gas to ensure that the gas pressure and flow meet the requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a schematic diagram of the drag reduction device for an amphibious vehicle body using supercavitation for water navigation.

[0032] Figure 2 It is a schematic diagram of the bow ski of an amphibious vehicle;

[0033] Figure 3 This is a schematic diagram of the bow ski support rod body.

[0034] Figure 4 It is a schematic diagram of the steps of the supercavitation drag reduction method of the present invention. DETAILED DESCRIPTION

[0035] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0036] The present invention provides an amphibious vehicle body water navigation drag reduction device using supercavitation. The device stores exhaust gas generated by an engine, and processes the exhaust gas into gas having supercavitation forming conditions through pressure and temperature control during water navigation. The exhaust gas is then emitted outward through holes in a supercavitation emission device, forming supercavitation around the holes for drag reduction during water navigation.

[0037] Figure 1 The schematic diagram of the amphibious vehicle body water navigation drag reduction device using supercavitation of the present invention is shown. As shown in the figure, the device includes an exhaust gas collection device, a compressed gas storage device, an expansion unit, a constant temperature device, a gas delivery component, and a supercavitation launch device.

[0038] The tail gas collecting device is used to collect and filter the high temperature tail gas generated by the engine of the amphibious vehicle. In a preferred embodiment, the tail gas collecting device is provided with a filtering device to remove impurities and harmful gases contained in the tail gas.

[0039] The compressed gas storage device is used to pressurize and store the filtered exhaust gas collected by the exhaust gas collection device through a compressor. In a preferred embodiment, the compressed gas storage device compresses the gas using a compression unit and stores it in a compressed gas tank to ensure that the gas can be used for subsequent regulation.

[0040] The expansion unit is used to expand the gas in the compressed gas storage device to reduce the gas pressure and temperature when sailing on the water. In a preferred embodiment, the expansion unit includes an expander, and the gas stored in the compressed gas storage device enters the expander through a regulating valve for expansion and heat exchange, thereby expanding the gas flow and reducing the gas pressure to the target pressure. At the same time, the temperature of the high-pressure gas can also be reduced to reduce the risk of supercavitation rupture.

[0041] The constant temperature device is used to cool the depressurized gas produced by the expansion unit to prevent the unevenness of the gas temperature and ensure that the gas temperature is stable within the range of 20 to 50°C.

[0042] The gas after pressure and temperature adjustment is sent to the supercavitation launcher through the gas delivery assembly. In a preferred embodiment, the gas delivery assembly is a plurality of ventilation pipes, for example, three ventilation pipes, which connect the amphibious vehicle body and the supercavitation launcher, and the gas treated by the constant temperature device will enter the supercavitation launcher through the three ventilation pipes.

[0043] The supercavitation launcher is arranged at the bow of the amphibious vehicle and has a hole, which emits the gas with adjusted pressure and temperature to the outside, forming a supercavitation around the hole for reducing drag.

[0044] Figure 2 and Figure 3 The schematic diagram of the structure of the supercavitation launcher of the present invention is shown. As shown in the figure, the supercavitation launcher includes an upper bow slide 1 and a lower bow slide 2, and the two parts are not connected; the upper bow slide 1 and the lower bow slide 2 are controlled to fold by a hydraulic strut, and the folding state includes that there is an angle between the upper bow slide 1 and the lower bow slide 2 and covers the front surface of the amphibious vehicle body or is unfolded in the same plane and docked. In this embodiment, there are two hydraulic struts, which are divided into a left hydraulic strut 7 and a right hydraulic strut 8, which respectively support the left and right sides of the upper bow slide 1 and the lower bow slide 2 to balance the force. When driving on land, the left hydraulic strut 7 and the right hydraulic strut 8 control the upper bow slide 1 and the lower bow slide 2 to form a certain angle, covering the front surface of the amphibious vehicle body; when driving on water, the left hydraulic strut 7 and the right hydraulic strut 8 extend, and the angle between the upper bow slide 1 and the lower bow slide 2 becomes larger, and finally becomes 180°, that is, the two bow slides are spliced ​​together and kept in the same plane. In order to fix and limit the angle between the two bow slides, the left hydraulic strut 7 is connected to the bow slide through the left fixed structure 9, and the right hydraulic strut 8 is connected to the upper bow slide through the right fixed structure 10.

[0045] The upper bow slide 1 is a solid structure; the lower bow slide 2 is divided into two layers, the inner layer 5 is a solid structure, the outer layer 4 is a hollow structure, and a hole 3 is provided on the outer surface of the lower part of the space. The amphibious vehicle body and the lower bow slide 2 are connected by a pipe 6, and the connecting pipe is made of high-strength sealing materials and high-temperature resistant pipes to ensure the airtightness and stability of the system. The injected gas is injected into the hole 3 of the lower bow slide 2 through the ventilation pipe 6 to form a supercavitation to reduce the resistance encountered by the amphibious vehicle when driving.

[0046] Furthermore, by providing a pressure regulating valve and a temperature control valve in front of the ventilation pipe connecting the bow skateboard and the vehicle body, it is ensured that the gas introduced has the conditions for forming supercavitation in the holes of the bow skateboard of the amphibious vehicle, thereby generating supercavitation and reducing the resistance encountered by the amphibious vehicle during underwater driving.

[0047] Cavitation flow is usually characterized by a dimensionless number, the cavitation number σ. The cavitation number is the ratio of the difference between the local and cavity absolute pressures to the kinetic energy per unit volume flow.

[0048]

[0049] Where P0 is the reference pressure, P c is the cavity pressure, U ∞ is the free stream velocity and ρ is the mass density of the fluid.

[0050] When the cavitation number σ is less than 0.1, supercavitation may occur. Therefore, it is necessary to control the pressure and flow rate of the injected gas so as to form supercavitation around the holes on the underside of the bow skateboard of the amphibious vehicle and reduce the resistance encountered by the vehicle when sailing underwater.

[0051] The present invention utilizes the working process of the supercavitation amphibious vehicle body water navigation drag reduction device, such as Figure 4 As shown:

[0052] Step 1: After the engine exhaust gas passes through a filtering device to remove impurities and harmful gases contained in the exhaust gas, it is collected through an exhaust gas collecting device.

[0053] Step 2, the compression unit in the compressed gas storage device compresses the processed gas and stores it in a compressed gas tank;

[0054] Step 3, when sailing on water, the gas in the compressed gas tank is expanded through the expansion heat exchange unit to expand the gas flow to reach the target pressure;

[0055] Step 4, passing the gas through a constant temperature device to reduce gas temperature fluctuations and keep the gas temperature stable;

[0056] Step 5, injecting gas into the cavity of the lower bow slide 2 through the ventilation pipe 6, and leading the gas through the cavity to the hole 3;

[0057] Step 6: Supercavitation is formed between the lower bow skid plate and the water body to reduce the resistance encountered by the amphibious vehicle when traveling underwater.

[0058] In step 1, the exhaust gas discharged by the engine enters the exhaust gas collection device through a pipeline, and harmful gases and impurities such as nitrogen oxides contained in the exhaust gas are removed by the filtering unit therein.

[0059] The compression unit in step 2 is mainly composed of a compressor. The compressor compresses the gas in the collection device and stores it in a compressed gas tank. The outlet of the compressed gas tank is connected through a pneumatic valve to control the flow of the exhaust gas to ensure that the gas pressure and flow meet the requirements.

[0060] The pressure released by the compressed gas tank in step 3 is controlled by a pneumatic regulating valve, and the released gas enters the expansion heat exchange unit through a pipeline. The expansion heat exchange unit is mainly composed of an expander. Compared with the general supercavitation application scenario, the flow rate required when the bow ski of an amphibious vehicle forms a supercavitation is larger, so the expansion heat exchange unit is required to increase the gas flow rate and control the discharged gas pressure.

[0061] The thermostatic device in step 4 helps ensure the stability of gas flow and flow rate by maintaining the consistency of gas temperature, which helps to produce a more stable bubble layer and optimize the size and distribution of bubbles, thereby more effectively isolating water and the vehicle surface and reducing resistance.

[0062] The above specific embodiments only describe the design principle of the present invention. The shapes and names of the components in the description may be different and are not limited. Therefore, those skilled in the art in the field of the present invention may modify or replace the technical solutions recorded in the above embodiments; and these modifications and replacements do not deviate from the creative purpose and technical solutions of the present invention and should all fall within the protection scope of the present invention.

Claims

1. A drag reduction device for an amphibious vehicle body using supercavitation, characterized in that: include: Exhaust gas collection device, compressed gas storage device, expansion unit, constant temperature device, gas delivery assembly, supercavitation launch device; The exhaust gas collecting device is used to collect and filter the exhaust gas generated by the engine of the amphibious vehicle; The compressed gas storage device is used to pressurize and store the filtered exhaust gas collected by the exhaust gas collection device through a compressor; The expansion unit is used to expand the gas in the compressed gas storage device to reduce the gas pressure and temperature when sailing on water; The constant temperature device is used to cool the depressurized gas and maintain the gas temperature range; The pressure- and temperature-regulated gas is sent to the supercavitation launch device through the gas delivery assembly; The supercavitation launcher is arranged at the bow of the amphibious vehicle and has a hole, which emits the gas with adjusted pressure and temperature to the outside, forming a supercavitation around the hole for reducing drag.

2. The amphibious vehicle body water navigation drag reduction device using supercavitation as claimed in claim 1, characterized in that: The tail gas collecting device is provided with a filtering device to remove impurities and harmful gases contained in the tail gas.

3. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 1, characterized in that: The compressed gas storage device compresses gas by using a compression unit and stores the compressed gas in a compressed gas tank.

4. The amphibious vehicle body water navigation drag reduction device using supercavitation as claimed in claim 3, characterized in that: The outlet of the compressed gas tank is connected via a pneumatic valve.

5. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 1, characterized in that: When the expansion unit is sailing on water, the gas in the compressed gas storage device is expanded and heat-exchanged through the expander, so that the pressure is reduced to the target pressure.

6. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 1, characterized in that: The supercavitation launch device comprises an upper bow slide (1) and a lower bow slide (2), the two parts are not connected; the upper bow slide (1) and the lower bow slide (2) are controlled to fold in a state by a hydraulic strut, the folding state comprising an angle between the upper bow slide (1) and the lower bow slide (2) and covering the front surface of the amphibious vehicle body or unfolding in the same plane and docking; the upper bow slide (1) is a solid structure; the lower bow slide (2) is divided into an inner and outer layer, the inner layer is a solid structure, the outer layer is a hollow structure, and a hole is provided on the outer surface of the lower part of the space.

7. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 6, characterized in that: The hydraulic strut is connected to the upper bow slide (1) via a fixed structure (9, 10) to fix and limit the unfolding angles of the upper bow slide (1) and the lower bow slide (2).

8. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 6, characterized in that: The hydraulic support rod comprises a left hydraulic support rod (7) and a right hydraulic support rod (8).

9. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 1, characterized in that: The gas delivery assembly is connected to the ventilation pipe of the thermostatic device and the supercavitation launch device. The ventilation pipe is a plurality of pipes evenly distributed at the bottom of the outer hollow structure of the lower bow slide plate (2) to provide the hollow structure with gas whose pressure and temperature are adjusted.

10. The drag reduction device for amphibious vehicles using supercavitation as claimed in claim 9, characterized in that: The ventilation pipeline is provided with a pressure regulating valve and a temperature controlling valve to ensure that the introduced gas has the conditions to form supercavitation at the hole of the bow skateboard of the amphibious vehicle.

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