An adaptive air pressure regulating system, air film drag reduction ventilation device and application

Abstract

This invention discloses an adaptive air pressure regulation system, an air film drag reduction ventilation device, and its application, belonging to the field of air film drag reduction technology. It includes a sealed housing with an air inlet and an air outlet, and a pressure reducing valve unit and a check valve unit are installed inside the housing. The valve port of the pressure reducing valve unit is connected to the air inlet, and the valve port of the check valve unit is connected to the air outlet. When the air pressure inside the housing is lower than the water pressure outside the air outlet, the valve port of the check valve unit is normally closed, shutting off the air outlet. When the air pressure inside the housing is higher than the water pressure outside the air outlet, the valve port of the check valve unit is opened. The opening degree of the valve ports of the check valve unit and the pressure reducing valve unit is adaptively adjusted according to the pressure difference between the internal air pressure and the external water pressure, allowing airflow adapted to the existing water pressure environment to be discharged from the air outlet. This invention is entirely a mechanical device, without any electronic components, resulting in high reliability, ease of operation, and significantly reducing the design and manufacturing costs of air-draft-reducing vessels and underwater vehicles.

Description

Technical Field

[0001] This invention belongs to the field of air film drag reduction technology, specifically relating to an adaptive air pressure regulation system, an air film drag reduction ventilation device, and its application. Background Technology

[0002] With the International Maritime Organization's increasingly stringent requirements for energy conservation and emission reduction, improving ship energy efficiency and reducing ship energy consumption have become industry trends. Superhydrophobic surfaces, due to their aerophilic properties, can form an air film layer underwater, significantly reducing the drag of underwater vehicles and ships by changing solid-liquid friction to gas-liquid friction. However, during navigation, the continuous scouring of the air film by the water causes its loss, necessitating external ventilation to replenish the lost air film and maintain the drag reduction effect. Ventilation drag reduction technology itself is an important drag reduction technology. In recent years, ventilation drag reduction technology has been widely promoted and applied to ships and other vehicles, producing significant drag reduction effects. However, changes in the attitude of the vehicle during navigation pose a serious challenge to uniform air supply.

[0003] Ventilation drag reduction technology involves introducing air into the hull or underwater vehicle's surface through openings in the vents. This creates a continuous air film on the surface, changing the solid-liquid contact between the hull (or underwater vehicle) and seawater to an air-liquid contact, thereby reducing friction and thus drag. In this operation, the vents are distributed at different locations on the surface due to operational requirements. The height difference between each vent creates a pressure difference, resulting in variations in ventilation pressure at each vent. Furthermore, as the vehicle navigates in water, environmental factors often cause changes in attitude and depth. Therefore, the water pressure corresponding to each vent also changes in real time, necessitating real-time adjustment of the air pressure at each vent to meet specific operational requirements. Currently, the air layer drag reduction technology for ships discloses the use of branch pipelines to regulate air volume. This technology regulates the stability of the air volume in the air supply pipelines at different locations on the hull by installing regulating valves, pressure detection devices, and controllers on the air supply pipelines of each vent, thereby achieving optimal air volume distribution. This method can effectively ensure that each vent can achieve optimal air volume distribution. However, each air path requires a sensor, controller, and dynamic regulating valve to work together to regulate the air volume. For ships with a large number of vents, this design is more complex, requiring a large number of controllers, sensors, and regulating devices, making implementation difficult and costly. To address the aforementioned issues, existing technologies have achieved effective airflow rectification through structural design and proposed a marine ventilation drag reduction system. This system utilizes the coordination of pipelines, branch pipelines, shut-off valves, and throttle valves to supply air. However, this invention only solves the airflow rectification problem through structural design. When seawater conditions change, i.e., when the direction and velocity of the water flow change, the opening of the throttle valve still needs to be manually adjusted to regulate the total amount of air supplied, thus matching the ventilation volume with the ship's navigation status. This method of manual adjustment by operators requires a certain level of professional skill and places high demands on the operators. Furthermore, it is not suitable for underwater unmanned vehicles.

[0004] Therefore, a solution is urgently needed to address the challenge of individually adjusting and rectifying the pressure and flow of each vent during the flight of an aircraft. Summary of the Invention

[0005] The technical problem to be solved:

[0006] To overcome the shortcomings of existing technologies, this invention provides an adaptive air pressure regulation system, an air film drag-reducing ventilation device, and its application. This system senses external pressure through the outlet gas flow rate and adaptively adjusts the output gas pressure based on the relationship between internal air pressure and external water pressure. This ensures the ventilation pressure remains adaptable to different depths and navigation conditions, and also features rectification, backflow prevention, and overload protection. The device is entirely mechanical, without any electronic components, resulting in high reliability, ease of operation, and significantly reduced design and manufacturing costs for drag-reducing vessels and underwater vehicles.

[0007] The technical solution of the present invention is: an adaptive air pressure regulation system, comprising a sealed housing with an airflow inlet and an airflow outlet, wherein a pressure reducing valve unit and a check valve unit are disposed within the housing; the valve port of the pressure reducing valve unit is connected to the airflow inlet, and the valve port of the check valve unit is connected to the airflow outlet;

[0008] When the internal air pressure of the housing is less than the water pressure outside the air outlet, the valve port of the check valve unit is normally closed, thus closing the air outlet.

[0009] When the internal air pressure of the housing is greater than the external water pressure of the air outlet, the valve port of the check valve unit is opened. The valve opening degree of the check valve unit and the pressure reducing valve unit is adaptively adjusted according to the pressure difference between the internal air pressure and the external water pressure, and the airflow adapted to the water pressure environment is discharged from the air outlet.

[0010] A further technical solution of the present invention is as follows: the pressure reducing valve unit includes a pressure reducing valve core, a pressure reducing valve control chamber, a pressure reducing valve drive end, and a pressure reducing valve port; the pressure reducing valve drive end is located in the pressure reducing valve control chamber, its output end is connected to the pressure reducing valve core, and the end of the pressure reducing valve core cooperates with the pressure reducing valve port; the pressure reducing valve drive end is activated by the air pressure in the pressure reducing valve control chamber, and the pressure reducing valve drive end converts the received air pressure into axial displacement of the pressure reducing valve core, changing the positional relationship between the end of the pressure reducing valve core and the pressure reducing valve port, thereby completing the control of the opening degree of the pressure reducing valve port.

[0011] A further technical solution of the present invention is: the valve core of the pressure reducing valve is in a normally open state, and its opening degree h satisfies

[0012] h=(P2V2T1)(vP1St1T2) -1

[0013] Where P1 and P2 are the pressure inside the air outlet and the external pressure, respectively; T1 and T2 are the temperature inside the air outlet and the external temperature, respectively; V2 is the volume of gas discharged from the air outlet outside the vehicle; v is the gas velocity flowing through the pressure reducing valve port; S is the effective circumference of the pressure reducing valve port; and t1 is the characteristic time.

[0014] A further technical solution of the present invention is as follows: the check valve unit includes a check valve core, a check valve control chamber, a check valve drive end, and a check valve port; the check valve drive end is located in the check valve control chamber, its output end is connected to the check valve core, and the end of the check valve core cooperates with the check valve port; the check valve drive end is activated by the air pressure in the check valve control chamber, and the check valve drive end converts the received air pressure into axial displacement of the check valve core, changing the positional relationship between the end of the check valve core and the pressure reducing valve port, thereby completing the control of the opening degree of the check valve port.

[0015] A further technical solution of the present invention is: the valve core of the check valve is normally closed, and its opening degree h range satisfies

[0016] h = Q(stv) -1

[0017] Where Q is the flow rate required under actual working conditions, s is the effective perimeter of the valve opening of the check valve, t is the characteristic time, and v is the airflow velocity at the valve core of the check valve.

[0018] A further technical solution of the present invention is: the pressure reducing valve drive end includes a pressure reducing valve spring and a pressure reducing valve diaphragm, one end of the pressure reducing valve spring is fixed to the inner wall of the pressure reducing valve control cavity, and the other end is connected to the pressure reducing valve diaphragm, the pressure reducing valve diaphragm is in sliding sealing contact with the inner circumferential surface of the pressure reducing valve control cavity, and the pressure reducing valve spring is coaxially arranged with the pressure reducing valve core;

[0019] The check valve drive end and the pressure reducing valve drive end have the same structural principle.

[0020] An air film drag reduction ventilation device includes the adaptive air pressure regulation system, whose air inlet is connected to an air source through a pipeline, and whose air outlet is connected to the surface to be drag-reduced. A rectifier core is provided at the channels of the air inlet and the air outlet, and they are connected through an airflow connection channel.

[0021] The pressure reducing valve unit and check valve unit of the adaptive air pressure regulation system are arranged in parallel within the housing. Connection channels are respectively provided between the pressure reducing valve control chamber of the pressure reducing valve unit and the airflow connection channel, and between the check valve control chamber of the check valve unit and the airflow connection channel, so that the airflow entering from the airflow inlet acts on the pressure reducing valve unit and the check valve unit in real time. Based on the relationship between the water-air pressure difference at the airflow outlet and the output airflow, the internal air pressure and the pressure reducing valve unit and the check valve unit are adaptively adjusted according to the water-air pressure difference at the outlet to complete the control of the valve opening and output the required drag-reducing air film.

[0022] A further technical solution of the present invention is: the pressure reducing valve core of the pressure reducing valve unit is provided with two plugs along the moving direction. The two plugs are located on both sides of the pressure reducing valve port. When the pressure inside the housing is too low or too high, the pressure reducing valve port is blocked by the two plugs to prevent water from entering the gas source.

[0023] An underwater vehicle includes an air source and multiple air film drag reduction ventilation devices. The output end of the air source is connected to the input end of a main pipeline. The output end of the main pipeline is connected to multiple air film drag reduction ventilation devices through multiple branch pipelines. A main shut-off valve is installed on the main pipeline to control the air flow. The air outlets of the air film drag reduction ventilation devices are all located on the outer circumferential surface of the underwater vehicle.

[0024] A vessel includes an air source and multiple air-film drag-reducing ventilation devices. The output end of the air source is connected to the input end of a main pipeline. The output end of the main pipeline is connected to multiple air-film drag-reducing ventilation devices through multiple branch pipelines. A main shut-off valve is installed on the main pipeline to control the airflow interruption. The airflow outlets of the air-film drag-reducing ventilation devices are all located on the bottom surface or the side of the bottom of the vessel.

[0025] Beneficial effects

[0026] The beneficial effects of this invention are as follows:

[0027] 1. This invention, through the integrated design of an adaptive air pressure regulation system, can realize adaptive pressure regulation of the air film drag reduction ventilation device. Compared with the current pressure regulation system that uses pressure sensors and solenoid valves, this invention greatly reduces the cost and difficulty of ventilation pressure control for drag reduction in ships and underwater vehicles, and can greatly promote the industrial application of drag reduction.

[0028] 2. This invention cleverly combines a pressure regulating device and a rectification device. Based on the relationship between the outlet water-air pressure difference and the output airflow (the larger the ratio of air pressure to water pressure, the more airflow is output; the smaller the ratio of air pressure to water pressure, the less airflow is output), the internal air pressure and the pressure reducing valve unit and check valve unit adaptively adjust according to the outlet water-air pressure difference (the larger the internal air pressure, the greater the pressure on the pressure reducing valve unit and check valve unit, and the larger the valve opening), thus controlling the valve opening and outputting the required drag-reducing air film. Therefore, this invention can achieve stable rectification of the output airflow while realizing adaptive pressure regulation.

[0029] 3. The pressure reducing valve unit of the present invention has two plugs at the end of the valve core. When the pressure inside the housing is too low or too high, the pressure reducing valve port is sealed by the two plugs to block the water flow into the air source. The function of preventing backflow under ultra-high pressure can be achieved without the use of a one-way valve. The device has high integration and can effectively prevent damage to the aircraft when the external pressure is too high without manual intervention. This design can be automatically triggered when the pressure is too high without external control, and the reliability is greatly improved. Attached Figure Description

[0030] Figure 1 This is a schematic diagram illustrating the principle of the present invention;

[0031] Figure 2 This is a schematic diagram and explanation of the working principle of the present invention;

[0032] Figure 3 This is a schematic diagram of the working process of the present invention;

[0033] Figure 4 Schematic diagram of rectifier core;

[0034] Figure 5 Example 1: Schematic diagram of the design components;

[0035] Figure 6 Example 1: Schematic diagram of the cavity design structure;

[0036] Figure 7 Example 1: Schematic diagram of pressure reducing valve core structure;

[0037] Figure 8 Example 1: Outlet airflow rate versus external pressure;

[0038] Figure 9 Example 2: Application of underwater vehicles;

[0039] Figure 10 Example 3: Ship Application Case;

[0040] Explanation of reference numerals in the attached drawings: 1-Check valve diaphragm; 2-Check valve spring; 3-Pressure reducing valve core; 4-Pressure reducing valve spring; 5-Pressure reducing valve diaphragm; 6-Check valve core; 7-Outlet airflow rectifier chamber; 8-Inlet airflow rectifier chamber; 9-Airflow inlet; 10-Pressure reducing valve port; 11-Check valve cavity passage; 12-Pressure reducing valve cavity passage; 13-Airflow outlet; 14-Check valve control chamber; 15-Pressure reducing valve control chamber; 16-Outlet chamber; 17-Inlet chamber; 18-Shell; 19-Inlet rectifier core; 20-Outer shell structure of the device; 21-Pressure reducing valve rectifier core; 22-Pressure reducing valve core; 23-Pressure reducing valve spring; 24-Pressure reducing valve cover plate; 25-Check valve cover plate; 26-Check valve spring; 27-Check valve core; 28-Outlet rectifier core; 29-Airflow inlet channel; 30-Pressure reducing valve port; 31-Airflow connection channel; 32-Pressure reducing valve control chamber; 33-Pressure reducing valve spring chamber; 34-Pressure reducing valve control chamber connection channel; 35-Check valve spring chamber; 36-Check valve control chamber connection channel; 37-Check valve control chamber; 38-Airflow outlet; 39, 44-Air source; 40, 45-Main pipeline; 41, 46-Main shut-off valve; 42, 47-Branch pipeline; 43, 48-Air film drag reduction ventilation device;

[0041] 7-1- First rectifier layer of the outlet rectifier core; 7-2- Second rectifier layer of the outlet rectifier core; 7-3- Third rectifier layer of the outlet rectifier core; 8-1- First rectifier layer of the inlet rectifier core; 8-2- Second rectifier layer of the inlet rectifier core; 8-3- Third rectifier layer of the inlet rectifier core;

[0042] A1 - Diaphragm working area of ​​check valve; A2 - Valve core working area of ​​check valve; A3 - Diaphragm working area of ​​pressure reducing valve; Q - Airflow. Detailed Implementation

[0043] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0045] Addressing the shortcomings of existing ship hull drag reduction technologies, which cannot automatically adjust and rectify the pressure and flow rate of each vent individually, this invention provides an adaptive air pressure regulation system. The system includes a sealed housing with an airflow inlet and an airflow outlet. A pressure-reducing valve unit and a check valve unit are installed within the housing. The valve port of the pressure-reducing valve unit is connected to the airflow inlet, and the valve port of the check valve unit is connected to the airflow outlet. When the internal air pressure is lower than the external water pressure at the airflow outlet, the valve port of the check valve unit is normally closed, shutting off the airflow outlet. When the internal air pressure is higher than the external water pressure, the valve port of the check valve unit is opened. The opening degree of the check valve unit and the pressure-reducing valve unit is adaptively adjusted according to the pressure difference between the internal air pressure and the external water pressure, allowing airflow adapted to the local water pressure environment to be discharged from the airflow outlet.

[0046] Specifically, the pressure reducing valve unit includes a pressure reducing valve core, a pressure reducing valve control chamber, a pressure reducing valve drive end, and a pressure reducing valve port. The pressure reducing valve drive end is located inside the pressure reducing valve control chamber, and its output end is connected to the pressure reducing valve core. The end of the pressure reducing valve core cooperates with the pressure reducing valve port. The pressure reducing valve drive end is activated by the air pressure in the pressure reducing valve control chamber. The pressure reducing valve drive end converts the received air pressure into axial displacement of the pressure reducing valve core, changing the positional relationship between the end of the pressure reducing valve core and the pressure reducing valve port, thereby controlling the opening degree of the pressure reducing valve port.

[0047] Specifically, the check valve unit includes a check valve core, a check valve control chamber, a check valve drive end, and a check valve port. The check valve drive end is located inside the check valve control chamber, and its output end is connected to the check valve core. The end of the check valve core mates with the check valve port. The check valve drive end is activated by the air pressure inside the check valve control chamber. The check valve drive end converts the received air pressure into axial displacement of the check valve core, changing the positional relationship between the end of the check valve core and the pressure reducing valve port, thereby controlling the opening degree of the check valve port.

[0048] Specifically, the pressure reducing valve drive end includes a pressure reducing valve spring and a pressure reducing valve diaphragm. One end of the pressure reducing valve spring is fixed to the inner wall of the pressure reducing valve control chamber, and the other end is connected to the pressure reducing valve diaphragm. The pressure reducing valve diaphragm and the inner circumferential surface of the pressure reducing valve control chamber are in sliding sealing contact, and the pressure reducing valve spring and the pressure reducing valve core are coaxially arranged. The check valve drive end and the pressure reducing valve drive end have the same structural principle.

[0049] This invention discloses an air-film drag-reducing ventilation device employing an adaptive air pressure regulation system. The system includes an airflow inlet connected to an air source via a pipeline, and an airflow outlet leading to the surface to be drag-reduced. A rectifier core is installed at both the airflow inlet and outlet channels, and they are connected via an airflow connection channel. The pressure-reducing valve unit and check valve unit of the adaptive air pressure regulation system are arranged in parallel within the housing. Connection channels are provided between the pressure-reducing valve control chamber of the pressure-reducing valve unit and the airflow connection channel, and between the check valve control chamber of the check valve unit and the airflow connection channel, respectively, so that the airflow entering from the airflow inlet acts on the pressure-reducing valve unit and the check valve unit in real time. Based on the relationship between the water-air pressure difference at the airflow outlet and the output airflow, the internal air pressure and the pressure-reducing valve unit and check valve unit adaptively adjust according to the outlet water-air pressure difference to control the valve opening and output the required drag-reducing air film.

[0050] The above technical solution will be further explained below with reference to the accompanying drawings:

[0051] Reference Figure 1As shown, this embodiment provides an adaptive air pressure regulation system, including a check valve diaphragm 1, a check valve spring 2, a check valve core 6, a pressure reducing valve core 3, a pressure reducing valve spring 4, a pressure reducing valve diaphragm 5, an outlet airflow rectifier chamber 7, an inlet airflow rectifier chamber pipe 8, a ventilation airflow inlet 9, a pressure reducing valve port 10, a check valve cavity channel 11, a pressure reducing valve cavity channel 12, a ventilation airflow outlet 13, a check valve control chamber 14, a pressure reducing valve control chamber 15, an outlet chamber 16, an inlet chamber 17, and a housing 18. The airflow inlet 9 is the inlet for gas to enter the automatic pressure regulation system; the inlet airflow rectifier chamber 8 is located at the airflow inlet and can rectify the gas source before it enters the device; the air intake chamber 17 is the first cavity through which the airflow enters the device after passing through the inlet airflow rectifier chamber 8 from the airflow inlet 9; the pressure reducing valve port 10 is the inlet through which the airflow flows from the air intake chamber 17 into the air outlet chamber 16; the pressure reducing valve core 3 is the valve core that reduces pressure when the airflow flows from the air intake chamber 17 into the air outlet chamber 16 and passes through the pressure reducing valve port 10; the pressure reducing valve spring 4 is the spring that pushes the pressure reducing valve core 3 to reset; the pressure reducing valve diaphragm 5 is the diaphragm that isolates the airflow inside the device from the cavity where the pressure reducing valve spring 4 is located; the pressure reducing valve cavity channel 12 connects the air outlet chamber 16 and the pressure reducing valve diaphragm. The pressure reducing valve control chamber 15 is the chamber where the pressure reducing valve diaphragm 5 is located. Gas in this chamber can act on the pressure reducing valve diaphragm 5 to control the opening of the pressure reducing valve port 10. The airflow outlet 13 is the outlet where gas is discharged into the water after passing through the device. The outlet airflow rectifier chamber 7 is located at the airflow outlet and is used to rectify the discharged gas. The check valve core 6 is a valve core that prevents external water from flowing into the device. The check valve spring 2 is a spring that pushes the check valve core 6 to reset. The check valve diaphragm 1 is a diaphragm that separates the check valve spring 2 from the working area. The check valve control chamber 14 is a chamber where gas can act on the check valve diaphragm 1 to control the opening of the check valve core 6. The check valve chamber channel 11 is a channel connecting the check valve control chamber 14 and the air outlet chamber 16.

[0052] Reference Figure 2As shown, the air supply equipment inside the aircraft is connected to the ventilation inlet 9 of the system, and the system of the present invention is further connected to the vent of the aircraft; the introduced gas enters the intake chamber 17 from the ventilation inlet 9, flows through the pressure reducing valve port 10 and then enters the outlet chamber 16. At this time, since the check valve core 6 is in a normally closed state, and the outlet chamber 16 is connected to the pressure reducing valve control chamber 15 through the check valve chamber channel 11, the pressure reducing valve chamber channel 12 and the check valve control chamber 14, the introduced gas can act on the check valve diaphragm 1 and the pressure reducing valve diaphragm 5; as the introduced gas continues to increase, the pressure reducing valve core 3 begins to be in a normally open state, and the gas enters the intake chamber 16 and is reduced in pressure. When the pressure valve port 10 enters the exhaust chamber, the gas entering the exhaust chamber 16 cannot be discharged in time because the check valve core 6 is initially closed. At this time, the pressure in the exhaust chamber 16 begins to increase. Therefore, the gas pressure acting on the check valve diaphragm 1 and the pressure reducing valve diaphragm 5 also begins to increase. Under the action of the pressure P inside the valve chamber, the check valve core 6 and the pressure reducing valve core 3 should satisfy (5~10)(pA1-K1x1)=pA2-K2x2. Therefore, under the action of the pressure inside the chamber, the check valve core 6 is opened first. At this time, the gas in the exhaust chamber 16 is introduced into the outside of the ship through the airflow outlet 13, realizing ventilation and drag reduction.

[0053] Reference Figure 3As shown, the adaptive air pressure regulation system operates as follows: when the external water pressure at the air outlet 13 is high, the amount of gas discharged from the outlet chamber 16 decreases under the action of external pressure. At this time, the air source continues to enter the inlet chamber 17 from the air inlet 9 and further enters the outlet chamber 16 through the pressure reducing valve port 10. As the gas inside the outlet chamber increases continuously, the gas pressure in the outlet chamber 16 begins to rise. At the same time, the force acting on the pressure reducing valve diaphragm 5 and the check valve diaphragm 1 also begins to increase, which in turn causes the check valve spring 2 to be further compressed, the check valve core 6 to open further, and the pressure reducing valve core 3 to move upward. At this time, the pressure reduction effect through the pressure reducing valve port 10 weakens, and the gas entering the outlet chamber 16 increases faster and with greater pressure, thereby further increasing the pressure in the outlet chamber 16. When the gas pressure in the outlet chamber 16 increases to be greater than the external water pressure, the gas in the outlet chamber 16 can be vented to the outside of the aircraft to achieve ventilation and drag reduction. As the external pressure of the aircraft gradually decreases, the pressure inside the exhaust chamber 16, connected to the outside by the exhaust port 13, also begins to decrease according to the principle of communication. This causes the pressure acting on the pressure reducing valve diaphragm 5 and the check valve diaphragm 1 to gradually decrease. At this time, the pressure reducing valve spring 4 and the check valve spring 2 extend, the pressure reducing valve port 10 decreases, and the pressure reducing effect is enhanced, resulting in a decrease in the air pressure inside the exhaust chamber 16, thereby achieving the reduction and regulation of exhaust pressure. However, when the external pressure of the aircraft (ship, etc.) continues to increase due to navigation factors, until the pressure exceeds the pressure inside the intake chamber 17, under the action of the communication principle, the pressure reducing valve diaphragm 5 begins to be compressed under the huge pressure in the exhaust chamber 16, causing the pressure reducing valve core 3 to further retract until the pressure reducing valve core blocks the pressure reducing valve port 10, preventing backflow of water into the ventilation chamber 17 and thus into the exhaust system, which could damage the aircraft.

[0054] Specifically, the area A1 of the check valve diaphragm 1, the elastic coefficient K1 of the check valve spring 2, the stroke x1 of the check valve spring 2, the working area A2 of the pressure reducing valve diaphragm 5, the elastic coefficient K2 of the pressure reducing valve spring 4, and the stroke x2 of the pressure reducing valve spring 4 are all determined by the pressure reducing valve core 3 and the check valve core 6. Under the pressure P inside the valve cavity, the pressure reducing valve core 3 and the check valve core 6 should satisfy (5~10)(pA1-K1x1)=pA2-K2x2. Therefore, the check valve core 6 will move before the pressure reducing valve core 3 under the gas pressure inside the outlet chamber 16. The pressure-reducing effect of valve core 3 is greatest at the beginning and gradually weakens as the pressure inside the vent chamber 16 increases. Check valve core 6 also has a certain pressure-reducing effect, but it is smaller; its main function is to isolate the vent chamber 16 from the external water environment before the vehicle is initially placed in water for ventilation. The force exerted by check valve spring 2 on check valve 6 should be greater than the force exerted by the external water environment on surface A2 of check valve 6 when the vehicle is not navigating on the water surface. The opening range h of check valve core 6 should satisfy h = Q(stv). -1Where Q is the flow rate required under actual working conditions, s is the effective circumference of the valve opening of the check valve, t is the characteristic time, v is the airflow velocity at valve core 6 of the check valve; the opening degree h of valve core 3 of the pressure reducing valve should satisfy h=(P2V2T1)(vP1St1T2). -1 Where P1 and P2 are the pressure in the outlet chamber 16 and the external pressure, respectively; T1 and T2 are the temperature in the outlet chamber 16 and the external temperature, respectively; V2 is the volume of gas discharged from the air outlet 13 to the outside of the vessel; v is the gas flow velocity through the pressure reducing valve port 10; S is the effective circumference of the pressure reducing valve port 10; and t1 is the characteristic time. The valve port opening range can be adjusted according to the navigation depth and marine environment of the installed vessel and vessel. When the working depth range is less than 30m, the adjustment range generally does not exceed 500 micrometers; when the working depth range is between 30-200m, the adjustment range generally does not exceed 200 micrometers; and when the working depth range is between 200-600m, the adjustment range generally does not exceed 100 micrometers. The pressure reducing valve spring 4 and the check valve spring 2 are adjustable. The prestress provided by the check valve spring 2 should be greater than or equal to the pressure exerted on the area A2 by the working water pressure. The pressure reducing valve spring 4 should be sensitive enough to respond to small pressure changes inside the outlet chamber 16.

[0055] The pressure reducing valve core 3 and the check valve core 6 can generally be cylindrical, elliptical, polygonal, etc. The overall size of the device can also be designed according to the size and dimensions of the carrier ship and aircraft. Generally, the shape of the outlet airflow rectifier 7 and the inlet airflow rectifier 8 depends on the shape of the inlet and outlet channels.

[0056] Reference Figure 4 As shown, the inlet airflow rectifying chamber has a three-layer rectifying structure. The first layer, facing the airflow, is a porous material with a porosity of 70%–75% and a thickness of (0.5–1)d1 (where d1 is the characteristic diameter of the inlet flow channel), used to break up the vortices of the high-speed airflow. The second layer, facing the airflow, is a porous material with a porosity of 80%–85% used to rectify the incoming airflow, with a thickness of (1–2)d1. The third layer, facing the airflow, is a rectifying layer with a porosity of 85%–95%, used to further rectify the outgoing airflow, with a thickness of (1–2)d1. The rectifying chambers at the airflow inlet and outlet have the same structure, but the outlet rectifying chamber is thinner (its corresponding thicknesses are generally (0.5–1)d2, (1–2)d2, and (1–2)d2, where d2 is the characteristic diameter of the outlet flow channel). This design can maintain a good rectification effect while making it sufficiently sensitive to external pressure.

[0057] Example 1:

[0058] Reference Figure 5-8 As shown, this embodiment is a ship air film drag reduction ventilation device.

[0059] Reference Figure 5 The device in this embodiment mainly consists of an inlet rectifier core 19, a device housing structure 20, a pressure reducing valve rectifier core 21, a pressure reducing valve core 22, a pressure reducing valve spring 23, a pressure reducing valve cover plate 24, a check valve cover plate 25, a check valve spring 26, a check valve core 27, an outlet rectifier core 28, an airflow inlet channel 29, a pressure reducing valve port 30, an airflow connection channel 31, a pressure reducing valve control chamber 32, a pressure reducing valve spring chamber 33, a pressure reducing valve control chamber connection channel 34, a check valve spring chamber 35, a check valve control chamber connection channel 36, a check valve control chamber 37, and an airflow outlet 38. The pressure reducing valve core structure is shown in the figure. Figure 7 The device operates as follows:

[0060] Step 1: Gas enters the device through the air inlet channel 29 via the air inlet rectifier core 19, at which time the check valve core 27 is in the closed state;

[0061] Step 2: Since the pressure reducing valve core 22 is in the normally open state, gas can enter the gas flow connection channel 31 from the pressure reducing valve port 30 through the pressure reducing valve rectifier core 21, and then enter the pressure reducing valve control chamber 32 and the check valve control chamber 37 through the pressure reducing valve control chamber connection channel 34 and the check valve control chamber connection channel 36.

[0062] Step 3: As the internal pressure of the cavity increases, the check valve begins to open under the action of the internal pressure of the check valve control chamber 37, which allows gas to be discharged from the air outlet 38 into the water environment outside the ship to achieve ventilation.

[0063] Step 4: When the pressure in the external water environment changes and decreases, the pressure inside the check valve control chamber 37 decreases, which causes the check valve opening to decrease, and the discharged air flow rate decreases.

[0064] Step 5: When the pressure in the external water environment increases, it becomes more difficult for the airflow inside the device cavity to escape. The airflow accumulates inside the cavity, causing the internal pressure to increase. At this time, the internal pressure of the pressure reducing valve control cavity 32 and the check valve control cavity 37 both increase, which makes the pressure reducing valve port 30 larger and reduces the pressure reducing effect. As a result, the pressure inside the airflow connection channel 31 and the airflow outlet 38 gradually increases, which enables the airflow discharge device to ventilate the outside of the vehicle.

[0065] Step Six: When the external pressure suddenly increases and exceeds the maximum pressure of the discharged gas, the pressure inside the control chamber 31 of the pressure reducing valve rises, causing the pressure reducing valve core to move upward to its maximum displacement. The bottom of the pressure reducing valve core directly seals the valve port of the pressure reducing valve, preventing water from entering the exhaust system.

[0066] In this embodiment, the changes in external pressure and exhaust gas flow rate in the aquatic environment are as follows: Figure 8As shown, the gas flow rate is stable before the set pressure of 25 Pa. When the pressure exceeds the set pressure, the pressure reducing valve core actuates to cut off the gas flow, thus closing the valve port. It should be noted that in this embodiment, the pressure reducing valve core contains an airflow rectifying core, which is mainly composed of two materials, 7-2 and 7-3, with a total thickness of half the cross-sectional width of the pressure reducing valve core. The two layers are of the same thickness and are used to rectify the vortex airflow discharged from the valve port.

[0067] The material and wall thickness of the air-film drag-reducing ventilation device can be selected and verified according to the navigation depth and ventilation pressure of the ship and aircraft; the check valve core shape can be cylindrical, conical, frustum-shaped, etc., and the valve core can fit well with the air outlet to prevent external water backflow; the check valve diaphragm can be made of suitable material according to specific working conditions, and it is mainly used to separate the check valve spring chamber and the check valve control chamber, preventing gas leakage from the check valve control chamber from entering the check valve spring chamber; the pressure reducing valve core is a double-headed valve core ( Figure 8 It can be used as one of the structures, and its movement in both directions can close the valve port of the pressure reducing valve. At the same time, the valve core of the pressure reducing valve can also be cylindrical, conical, frustum-shaped, etc., and its interaction with the valve port can create a pressure reducing effect.

[0068] Example 2:

[0069] Reference Figure 9 As shown, this embodiment is an application example of a ship's air film drag reduction ventilation device in an underwater vehicle. It includes an air source 39, a main pipeline 40, a main shut-off valve 41, branch pipelines 42, and an air film drag reduction ventilation device 43.

[0070] Step 1: When the vehicle needs to be aerated after entering the water environment, the main shut-off valve 41 is opened;

[0071] Step 2: Gas from gas source 39 enters the entire ventilation system through main pipe 40;

[0072] Step 3: After passing through the main pipeline 40, the airflow is diverted through multiple sets of branch pipelines 42 and enters the air film drag reduction ventilation device 43. Through the adaptive pressure regulation of the device 43, it is finally discharged at a suitable pressure to achieve external ventilation.

[0073] It should be noted that the air film drag reduction ventilation device 43 is distributed on the surface of the aircraft as needed in this system, with each branch pipeline corresponding to one air film drag reduction ventilation device 43, so as to achieve precise control of the exhaust air pressure and flow rate.

[0074] Example 3:

[0075] Reference Figure 10As shown, this embodiment is an application example of a ship air film drag reduction ventilation device in a surface vessel. It includes an air source 44, a main pipeline 45, a main shut-off valve 46, branch pipelines 47, and an air film drag reduction ventilation device 48.

[0076] Step 1: When the ship needs to be ventilated after entering the water environment, the main shut-off valve 46 is opened;

[0077] Step 2: Gas from gas source 44 enters the entire ventilation system through main pipe 45;

[0078] Step 3: After passing through the main pipeline 45, the airflow is diverted through multiple sets of branch pipelines 47 and enters the air film drag reduction ventilation device 48. Through the adaptive pressure regulation of the device 47, it is finally discharged at a suitable pressure to achieve external ventilation.

[0079] It should be noted that the air film drag reduction ventilation device 48 is distributed on the surface of the hull as needed in this system, with each branch pipeline corresponding to one air film drag reduction ventilation device 48, so as to achieve precise control of the pressure and flow rate of the exhaust airflow.

[0080] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. An adaptive air pressure regulation system, characterized in that: The device includes a sealed housing with an airflow inlet and an airflow outlet, and a pressure reducing valve unit and a check valve unit are provided inside the housing; the valve port of the pressure reducing valve unit is connected to the airflow inlet, and the valve port of the check valve unit is connected to the airflow outlet. The pressure reducing valve unit includes a pressure reducing valve core, a pressure reducing valve control chamber, a pressure reducing valve drive end, and a pressure reducing valve port. The pressure reducing valve drive end is located inside the pressure reducing valve control chamber, and its output end is connected to the pressure reducing valve core. The end of the pressure reducing valve core cooperates with the pressure reducing valve port. The pressure reducing valve drive end is activated by the air pressure in the pressure reducing valve control chamber. The pressure reducing valve drive end converts the received air pressure into axial displacement of the pressure reducing valve core, changes the positional relationship between the end of the pressure reducing valve core and the pressure reducing valve port, and thus completes the control of the opening degree of the pressure reducing valve port. The check valve unit includes a check valve core, a check valve control chamber, a check valve drive end, and a check valve port. The check valve drive end is located inside the check valve control chamber, and its output end is connected to the check valve core. The end of the check valve core mates with the check valve port. The check valve drive end is activated by the air pressure inside the check valve control chamber. The check valve drive end converts the received air pressure into axial displacement of the check valve core, changing the positional relationship between the end of the check valve core and the pressure reducing valve port, thereby controlling the opening degree of the check valve port. When the internal air pressure of the housing is less than the water pressure outside the air outlet, the valve port of the check valve unit is normally closed, thus closing the air outlet. When the internal air pressure of the housing is greater than the external water pressure of the air outlet, the valve port of the check valve unit is opened. The valve opening degree of the check valve unit and the pressure reducing valve unit is adaptively adjusted according to the pressure difference between the internal air pressure and the external water pressure, and the airflow adapted to the water pressure environment is discharged from the air outlet.

2. The adaptive pressure regulation system according to claim 1, characterized in that: The pressure reducing valve core is normally open, and its opening degree h satisfies Where P1 and P2 are the pressure inside the air outlet and the external pressure, respectively; T1 and T2 are the temperature inside the air outlet and the external temperature, respectively; V2 is the volume of gas discharged from the air outlet outside the vehicle; v is the gas velocity flowing through the pressure reducing valve port; S is the effective circumference of the pressure reducing valve port; and t1 is the characteristic time.

3. The adaptive pressure regulation system according to claim 1, characterized in that: The check valve core is normally closed, and its opening range h satisfies the following conditions: Where Q is the flow rate required under actual working conditions, s is the effective perimeter of the valve opening of the check valve, t is the characteristic time, and v is the airflow velocity at the valve core of the check valve.

4. The adaptive pressure regulation system according to claim 1, characterized in that: The pressure reducing valve drive end includes a pressure reducing valve spring and a pressure reducing valve diaphragm. One end of the pressure reducing valve spring is fixed to the inner wall of the pressure reducing valve control chamber, and the other end is connected to the pressure reducing valve diaphragm. The pressure reducing valve diaphragm and the inner circumferential surface of the pressure reducing valve control chamber are in sliding sealing contact, and the pressure reducing valve spring and the pressure reducing valve core are coaxially arranged. The check valve drive end and the pressure reducing valve drive end have the same structural principle.

5. A film-type drag-reducing ventilation device, characterized in that: The adaptive air pressure regulation system according to any one of claims 1-4 has an air inlet connected to an air source via a pipeline, an air outlet leading to the surface to be drag-reduced, and a rectifier core is provided at both the air inlet and the air outlet channels, and they are connected via an airflow connection channel. The pressure reducing valve unit and check valve unit of the adaptive air pressure regulation system are arranged in parallel within the housing. Connection channels are respectively provided between the pressure reducing valve control chamber of the pressure reducing valve unit and the airflow connection channel, and between the check valve control chamber of the check valve unit and the airflow connection channel, so that the airflow entering from the airflow inlet acts on the pressure reducing valve unit and the check valve unit in real time. Based on the relationship between the water-air pressure difference at the airflow outlet and the output airflow, the internal air pressure and the pressure reducing valve unit and the check valve unit are adaptively adjusted according to the water-air pressure difference at the outlet to complete the control of the valve opening and output the required drag-reducing air film.

6. The air film drag-reducing ventilation device according to claim 5, characterized in that: The pressure reducing valve unit has two plugs at the end of the pressure reducing valve core along the moving direction. The two plugs are located on both sides of the pressure reducing valve port. When the pressure inside the housing is too low or too high, the two plugs will seal the pressure reducing valve port to block the water flow into the gas source.

7. An underwater vehicle, characterized in that: It includes an air source and multiple air film drag reduction ventilation devices as described in claim 6. The output end of the air source is connected to the input end of the main pipeline. The output end of the main pipeline is connected to multiple air film drag reduction ventilation devices through multiple branch pipelines. A main shut-off valve is installed on the main pipeline to control the air flow. The air outlets of the air film drag reduction ventilation devices are all located on the outer circumferential surface of the underwater vehicle.

8. A ship, characterized in that: It includes an air source and multiple air film drag reduction ventilation devices as described in claim 7. The output end of the air source is connected to the input end of the main pipeline. The output end of the main pipeline is connected to multiple air film drag reduction ventilation devices through multiple branch pipelines. A main shut-off valve is installed on the main pipeline to control the air flow. The air outlets of the air film drag reduction ventilation devices are all located on the bottom surface or the side of the bottom of the ship.

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