Water tunnel test device and test method

Abstract

The invention belongs to the technical field of fluid tests, and relates to a water tunnel test device and a test method. The device comprises two water cabins and a water tunnel test section, air bags are arranged in inner cavities of the two water bins, the two air bags are communicated with an external compressed air source through breather pipes respectively, water cavities are formed between the air bags and the inner walls of the water bins where the air bags are located, and the water cavities are filled with water. A water inlet of the water tunnel test section is respectively communicated with the water cavities of the two water cabins through a water inlet three-way valve, and a water outlet of the water tunnel test section is respectively communicated with the water cavities of the two water cabins through a water outlet three-way valve. According to the invention, through inflation and deflation operation of the two air bags and regulation and control of working states of the water inlet three-way valve and the water outlet three-way valve, water circularly flows between the two water cabins and continuously flows through a water tunnel test section, so that closed cycle operation of a water tunnel test is realized through an air pressure loading mode; the problems that due to the fact that an existing closed circulating water tunnel system is directly pressurized through a pump, water flow direction conversion is complex, test stability is poor, and pressure change is difficult to accurately control are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of fluid testing, and in particular relates to a water tunnel testing device and a testing method. Background Art

[0002] In water tunnel tests, closed-loop water tunnel systems are widely used because they can reuse the test medium (water), reducing water resource consumption and test costs.

[0003] However, most of the existing closed-loop water tunnel systems use a direct pump pressurization method, which often requires a complex mechanical structure when changing the direction of water flow, which not only increases the complexity of the design and manufacturing cost, but also may affect the stability and continuity of the test due to frequent pump starts and stops. In addition, the direct use of pump pressurization also has certain limitations in pressure control, and it is difficult to achieve smooth and accurate pressure changes, which is particularly disadvantageous in water tunnel tests that require high precision in simulating water flow conditions. Summary of the invention

[0004] In view of the shortcomings existing in the related technologies, the present invention provides a water tunnel test device and a test method, aiming to solve the problems of the existing closed-loop water tunnel system, such as complex water flow direction conversion, poor test stability, and difficulty in precise control of pressure changes due to direct pressurization by a pump.

[0005] The present invention provides a water tunnel test device, comprising: The first water tank and the second water tank have air bags in their inner cavities; the two air bags are respectively connected to an external compressed air source through a vent pipe, and a water cavity is formed between each air bag and the inner wall of the water tank where it is located, and each water cavity is filled with water; The water tunnel test section has a water inlet connected to the water chambers of the first water tank and the second water tank through a water inlet three-way valve, and a water outlet connected to the water chambers of the first water tank and the second water tank through a water outlet three-way valve; The water tunnel test device is configured to inflate the airbag of the first water tank and deflate the airbag of the second water tank, adjust the working states of the water inlet three-way valve and the water outlet three-way valve, so that the water in the first water tank flows through the water tunnel test section under the inflation pressure and then enters the second water tank until the water volume in the second water tank reaches a preset value; then switch the working states of the water inlet three-way valve and the water outlet three-way valve, inflate the airbag of the second water tank and deflate the airbag of the first water tank, so that the water in the second water tank flows through the water tunnel test section under the inflation pressure and then enters the first water tank, until the water volume in the first water tank reaches a preset value; switch the working states of the water inlet three-way valve and the water outlet three-way valve again and repeat the above process to allow water to continue to flow through the water tunnel test section.

[0006] In some of the embodiments, the water tunnel test device also includes a water tank and a water supply pump; the water tank is connected to the water cavities of the first water tank and the second water tank respectively through a water injection pipe; the water supply pump is installed on the water injection pipe to pump the water in the water tank into the water cavities of the first water tank and the second water tank.

[0007] In some of the embodiments, the upper parts of the water chambers of the first water tank and the second water tank are respectively connected to the water storage tank via an overflow pipe; each overflow pipe is provided with a switchable valve.

[0008] In some of the embodiments, the airbag is a telescopic airbag, the upper end of the airbag is connected to the top of the water tank where it is located, the ventilation tube passes through the top wall of the water tank where the airbag is located and is connected to the airbag, and the lower end of the airbag can move back and forth up and down under the action of internal air pressure and external water pressure.

[0009] In some of the embodiments, the first water tank and the second water tank are both cylindrical silos, the airbag is cylindrical in shape and can be axially retracted, and the airbag is coaxially arranged with the water tank in which it is located.

[0010] In some of the embodiments, the lower part of the water chamber of the first water tank is connected to the water inlet three-way valve via the first drain pipe, and is connected to the water outlet three-way valve via the first return pipe; the lower part of the water chamber of the second water tank is connected to the water inlet three-way valve via the second drain pipe, and is connected to the water outlet three-way valve via the second return pipe.

[0011] In some of the embodiments, the compressed air source is a gas tank containing compressed air.

[0012] The present invention also provides a water tunnel test method, which is carried out using the above-mentioned water tunnel test device and comprises the following steps: S1, pre-inflate the two airbags respectively, and make the initial air pressure in the first water tank airbag smaller than the initial air pressure in the second water tank airbag; S2, start the water supply pump, pump the water in the water tank into the first water tank and the second water tank, and fill the water cavity of the first water tank, the water cavity of the second water tank, the connecting pipe between the first water tank and the water tunnel test section, the connecting pipe between the second water tank and the water tunnel test section, and the water tunnel test section; turn off the water supply pump; S3, inflate the airbag of the first water tank, and deflate the airbag of the second water tank, adjust the working state of the water inlet three-way valve and the water outlet three-way valve, so that the water in the first water tank flows through the water tunnel test section under the inflation pressure and then enters the second water tank, until the water volume in the second water tank reaches a preset value; stop inflating the airbag of the first water tank; S4, switch the working states of the water inlet three-way valve and the water outlet three-way valve, inflate the airbag of the second water tank, and deflate the airbag of the first water tank, so that the water in the second water tank flows through the water tunnel test section under the inflation pressure and then enters the first water tank, until the water volume in the first water tank reaches a preset value; stop inflating the airbag of the second water tank; S5. Repeat steps S3 and S4 to allow water to continue to flow through the water tunnel test section.

[0013] In some of the embodiments, in steps S3 and S4, the air pressure in the airbag of the first water tank or the second water tank is always greater than zero during the deflation process and at the end of the deflation.

[0014] Based on the above technical scheme, the water tunnel test device and test method in the embodiment of the present invention can solve the shortcomings of the existing closed-loop water tunnel system that uses pump pressurization. By inflating and deflating the air bag and switching the two three-way valves before and after the water tunnel test section, the closed-loop operation of the air pressure-loaded water tunnel test can be realized, thereby improving the stability, continuity and reliability of the water tunnel test. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic structural diagram of the water tunnel test device of the present invention; Figure 2 It is a schematic diagram of the water flow direction when the water tunnel test device of the present invention is used to conduct a water tunnel test.

[0016] In the figure: 10, first water tank; 11, first drainage pipe; 12, first return pipe; 20, second water tank; 21, second drainage pipe; 22, second return pipe; 30, air bag; 31, ventilation pipe; 40, water tunnel test section; 41, water inlet three-way valve; 42, water outlet three-way valve; 51, water storage tank; 52, water supply pump; 53, water injection pipe; 531, water injection main pipe; 532, water injection branch pipe; 54, overflow pipe. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0018] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "top", "bottom", "inside", "outside", "left", "right", "front", "back", "vertical", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0019] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0021] refer to Figure 1 , Figure 2 As shown, the present invention provides a water tunnel test device, including a first water tank 10, a second water tank 20 and a water tunnel test section 40.

[0022] An air bag 30 is provided in the inner cavity of the first water tank 10 and the inner cavity of the second water tank 20. A water cavity is formed between each air bag 30 and the inner wall of the water tank where it is located, and each water cavity is filled with water. The two air bags 30 are respectively connected to an external compressed air source through a ventilation pipe 31. Furthermore, each air bag 30 can be inflated or deflated by the compressed air source to change the inner cavity volume of the air bag 30, thereby regulating the water pressure in each water tank.

[0023] The water tunnel test section 40 is used for conducting tests such as fluid mechanics, and has a water inlet and a water outlet at the front and rear ends of the water tunnel test section 40. The water inlet of the water tunnel test section 40 is connected to the water chambers of the first water tank 10 and the second water tank 20 respectively through the water inlet three-way valve 41; specifically, the water inlet three-way valve 41 has two inlets and one outlet, the water chamber of the first water tank 10 is connected to one inlet of the water inlet three-way valve 41 through the first drainage pipe 11, the water chamber of the second water tank 20 is connected to the other inlet of the water inlet three-way valve 41 through the second drainage pipe 21, and the water inlet of the water tunnel test section 40 is connected to the outlet of the water inlet three-way valve 41. The water outlet of the water tunnel test section 40 is connected to the water chambers of the first water tank 10 and the second water tank 20 respectively through the water outlet three-way valve 42; specifically, the water outlet three-way valve 42 has an inlet and two outlets, the water outlet of the water tunnel test section 40 is connected to the inlet of the water outlet three-way valve 42, the water chamber of the first water tank 10 is connected to one outlet of the water outlet three-way valve 42 through the first water return pipe 12, and the water chamber of the second water tank 20 is connected to the other outlet of the water outlet three-way valve 42 through the second water return pipe 22. Thus, the water tunnel test section 40 is located between the first water tank 10 and the second water tank 20, and the two water tanks are connected to each other through the water tunnel test section 40. Furthermore, by adjusting the working state of the water inlet three-way valve 41, that is, switching the two inlets of the water inlet three-way valve 41, the source of water entering the water tunnel test section 40 can be regulated; by adjusting the working state of the water outlet three-way valve 42, that is, switching the two outlets of the water outlet three-way valve 42, the outlet of the water out of the water tunnel test section 40 can be regulated.

[0024] To further illustrate, the water tunnel test device is configured to inflate the air bag 30 of the first water tank 10 to increase the water pressure in the first water tank 10, and to deflate the air bag 30 of the second water tank 20, and to adjust the working states of the water inlet three-way valve 41 and the water outlet three-way valve 42 (that is, the water inlet three-way valve 41 is opened toward the inlet of the first water tank 10 and closed toward the inlet of the second water tank 20, and the water outlet three-way valve 42 is closed toward the outlet of the first water tank 10 and opened toward the outlet of the second water tank 20), so that the water in the first water tank 10 is discharged from the first water tank 10 under the inflation pressure, and the water flows through the first drain pipe 11, the water inlet three-way valve 41, the water tunnel test section 40, the water outlet three-way valve 42 and the second return pipe 22 in sequence and then enters the second water tank 20, refer to Figure 2The water in the first water tank 10 flows into the second water tank 20 in the direction indicated by the dotted arrow (i.e., the water in the first water tank 10 flows into the second water tank 20) ​​until the amount of water in the second water tank 20 reaches a preset value; then the working states of the water inlet three-way valve 41 and the water outlet three-way valve 42 are switched (i.e., the water inlet three-way valve 41 is closed toward the inlet of the first water tank 10 and opened toward the inlet of the second water tank 20, and the water outlet three-way valve 42 is opened toward the outlet of the first water tank 10 and closed toward the outlet of the second water tank 20), air is inflated into the airbag 30 of the second water tank 20 to increase the water pressure in the second water tank 20, and the airbag 30 of the first water tank 10 is deflated so that the water in the second water tank 20 is discharged from the second water tank 20 under the inflation pressure, and the water flows through the second drain pipe 21, the water inlet three-way valve 41, the water tunnel test section 40, the water outlet three-way valve 42 and the first return pipe 12 in sequence and then enters the first water tank 10, refer to Figure 2 The flow direction is shown by the midpoint arrow (i.e., the water in the second water tank 20 flows into the first water tank 10) until the water volume in the first water tank 10 reaches a preset value; the working states of the water inlet three-way valve 41 and the water outlet three-way valve 42 are switched again and the aforementioned process is repeated, thereby enabling water to continue to flow through the water tunnel test section 40, making it convenient for the water tunnel test section 40 to conduct fluid mechanics and other tests.

[0025] The above-mentioned schematic embodiment realizes the construction of an air pressure-driven closed-loop water tunnel system by setting two water tanks and their internal air bags 30, and setting two three-way valves before and after the water tunnel test section 40. The water pressure can be controlled by air pressure loading to achieve smooth discharge and inflow of water in the water tank, and the circulation of water between the two water tanks and the quick switching of the water flow direction can be realized, thereby realizing the closed-loop operation of the water tunnel test. Compared with the existing closed-loop water tunnel system that uses a pump for direct pressurization, the air pressure-loaded water tunnel test device of this embodiment has a simple structure, is easy to maintain, has a low cost, and is highly practical. It can control the water flow pressure more accurately and smoothly, switch the water flow direction more accurately and quickly, and improve the stability and continuity of the water tunnel test. It is particularly suitable for water tunnel tests with high precision in simulating water flow conditions.

[0026] refer to Figure 1 , Figure 2As shown, in some embodiments, the water tunnel test device further includes a water storage tank 51 and a water supply pump 52. The water storage tank 51 is connected to the water chambers of the first water tank 10 and the second water tank 20 through a water injection pipe 53; specifically, the water injection pipe 53 includes a water injection main pipe 531 and two water injection branches 532, one end of the water injection main pipe 531 is connected to the water storage tank 51, and the other end is connected to one end of the two water injection branches 532, and the other ends of the two water injection branches 532 are respectively connected to the water chambers of the two water tanks. The water supply pump 52 is installed on the water injection main pipe 531 of the water injection pipe 53, and is used to pump the water in the water storage tank 51 into the water cavities of the first water tank 10 and the second water tank 20; specifically, when the water supply pump 52 is started, the water in the water storage tank 51 is pumped into the water cavities of the first water tank 10 and the second water tank 20, and the water cavities of the two water tanks, the connecting pipes between the two water tanks and the water tunnel test section 40 (i.e., the first drainage pipe 11, the first return pipe 12, the second drainage pipe 21 and the second return pipe 22), and the water tunnel test section 40 are all filled with water; after the water supply pump 52 is turned off, the water in the two water tanks will not flow back into the water storage tank 51. Furthermore, in some embodiments, the upper parts of the water cavities of the first water tank 10 and the second water tank 20 are respectively connected to the water storage tank 51 via an overflow pipe 54, and each overflow pipe 54 is provided with a switchable valve (not shown); refer to Figure 2 The solid arrow in the middle shows the flow direction. When the water supply pump 52 is started to pump water to the two water tanks, the valve on the overflow pipe 54 is opened. When water in the overflow pipe 54 continuously flows back into the water storage tank 51, it indicates that the water injection operation of the water tunnel test device is completed. Then, the valve on the overflow pipe 54 and the water supply pump 52 are closed, thereby ensuring that the amount of water in the water tunnel test device is sufficient and constant during the test.

[0027] refer to Figure 1 As shown, in some embodiments, the airbag 30 is a foldable telescopic airbag 30, and the upper end of the airbag 30 is connected to the top of the cavity of the water tank where it is located; one end of the ventilation tube 31 passes through the top wall of the water tank where the airbag 30 is located and is connected to the airbag 30, and the other end of the ventilation tube 31 is located outside the water tank and is connected to an external compressed air source (not shown); when the airbag 30 is inflated and deflated by the compressed air source, the volume of the airbag 30 will change accordingly, and the lower end of the airbag 30 can move back and forth up and down under the combined action of the internal air pressure and the external water pressure; thus, by adjusting the inflation and deflation speed and air pressure of the airbag 30, the water flow pressure and flow rate can be accurately and smoothly controlled.

[0028] refer to Figure 1 As shown, in some embodiments, the first water tank 10 and the second water tank 20 are both cylindrical silos, the airbag 30 is cylindrical in shape and can be axially retracted, the airbag 30 and the water tank in which it is located are coaxially arranged, and the ventilation pipe 31 and the airbag 30 are also coaxially arranged; thereby, the water tunnel test device has a compact and regular structure.

[0029] refer to Figure 1 As shown, in some embodiments, the first drain pipe 11 and the first return pipe 12 are both connected to the lower part of the water cavity of the first water tank 10, and the second drain pipe 21 and the second return pipe 22 are both connected to the lower part of the water cavity of the second water tank 20, that is, the drain pipe and the return pipe are both located at the bottom end in the extension direction of the airbag 30, which is conducive to the smooth discharge and inflow of water in the water tank.

[0030] In some embodiments, the compressed air source is an air tank filled with compressed air, which provides a reliable air pressure driving source for the water tunnel test device.

[0031] refer to Figure 1 , Figure 2 As shown, the present invention also provides a water tunnel test method, which is carried out using the above-mentioned water tunnel test device. The water tunnel test method comprises the following steps: S1, pre-inflate the airbags 30 of the first water tank 10 and the second water tank 20 respectively through a compressed air source, and make the initial air pressure in the airbag 30 of the first water tank 10 smaller than the initial air pressure in the airbag 30 of the second water tank 20; S2. Open the valve on the overflow pipe 54, start the water supply pump 52, pump the water in the water storage tank 51 into the first water tank 10 and the second water tank 20, and fill the water cavity of the first water tank 10, the water cavity of the second water tank 20, the connecting pipeline between the first water tank 10 and the water tunnel test section 40, the connecting pipeline between the second water tank 20 and the water tunnel test section 40, and the water tunnel test section 40; close the valve on the overflow pipe 54 and the water supply pump 52; S3, inflate the airbag 30 of the first water tank 10, and deflate the airbag 30 of the second water tank 20, adjust the working states of the water inlet three-way valve 41 and the water outlet three-way valve 42, so that the water in the first water tank 10 flows through the first drain pipe 11, the water inlet three-way valve 41, the water tunnel test section 40, the water outlet three-way valve 42 and the second water return pipe 22 in sequence under the inflation pressure and then enters the second water tank 20 until the water volume in the second water tank 20 reaches a preset value; stop inflating the airbag 30 of the first water tank 10 and stop deflation of the airbag 30 of the second water tank 20; S4, switch the working states of the water inlet three-way valve 41 and the water outlet three-way valve 42, inflate the airbag 30 of the second water tank 20, and deflate the airbag 30 of the first water tank 10, so that the water in the second water tank 20 flows through the second drain pipe 21, the water inlet three-way valve 41, the water tunnel test section 40, the water outlet three-way valve 42 and the first return pipe 12 in sequence under the inflation pressure and then enters the first water tank 10 until the water volume in the first water tank 10 reaches a preset value; stop inflating the airbag 30 of the second water tank 20 and stop deflation of the airbag 30 of the first water tank 10; S5. Repeat steps S3 and S4 to allow water to continuously flow through the water tunnel test section 40, thereby achieving a closed-loop operation of the water tunnel test and ensuring the continuity of the water tunnel test.

[0032] The above-mentioned schematic embodiment enables water to circulate between the two water tanks and continuously flow through the water tunnel test section 40 by inflating and deflating the air bags 30 in the two water tanks and switching the working states of the two three-way valves before and after the water tunnel test section 40, thereby realizing the closed-loop operation of the water tunnel by means of air pressure loading, solving the problems of the existing closed-loop water tunnel system such as complex water flow direction conversion, poor test stability, and difficulty in precise control of pressure changes due to direct pressurization by a pump. The system is easy to operate, runs smoothly, can control the water flow pressure more accurately and smoothly, and can switch the water flow direction more accurately and quickly, thereby improving the stability, continuity and reliability of the water tunnel test.

[0033] In some embodiments, in steps S3 and S4, the air pressure in the airbag 30 of the first water tank 10 or the second water tank 20 is always greater than zero during and at the end of the deflation process, thereby providing back pressure for the water tunnel test to avoid adverse conditions such as cavitation.

[0034] In summary, the water tunnel test device and test method of the present invention solve the problems of the existing closed-loop water tunnel system, such as complex water flow direction conversion, poor test stability, and difficulty in precise control of pressure changes due to the use of a pump for direct pressurization. The device and test method can realize the closed-loop operation of the air pressure-loaded water tunnel test through the inflation and deflation of the airbag 30 and the switching operation of the two three-way valves before and after the water tunnel test section 40. It has a compact structure and is easy to maintain. It is suitable for various types of water tunnel tests, especially water tunnel tests with strict requirements on water flow conditions.

[0035] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0036] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A water tunnel test device, characterized in that: include: The first water tank and the second water tank have air bags in their inner cavities; the two air bags are respectively connected to an external compressed air source via a vent pipe, and a water cavity is formed between each air bag and the inner wall of the water tank where it is located, and each water cavity is filled with water; A water tunnel test section, whose water inlet is connected to the water chambers of the first water tank and the second water tank respectively through a water inlet three-way valve, and whose water outlet is connected to the water chambers of the first water tank and the second water tank respectively through a water outlet three-way valve; The water tunnel test device is configured to inflate the airbag of the first water tank and deflate the airbag of the second water tank, adjust the working states of the water inlet three-way valve and the water outlet three-way valve, so that the water in the first water tank flows through the water tunnel test section under the inflation pressure and then enters the second water tank until the water volume in the second water tank reaches a preset value; then switch the working states of the water inlet three-way valve and the water outlet three-way valve, inflate the airbag of the second water tank and deflate the airbag of the first water tank, so that the water in the second water tank flows through the water tunnel test section under the inflation pressure and then enters the first water tank, until the water volume in the first water tank reaches a preset value; switch the working states of the water inlet three-way valve and the water outlet three-way valve again and repeat the above process to allow water to continue to flow through the water tunnel test section.

2. The water tunnel test device according to claim 1, characterized in that: The water tunnel test device also includes a water tank and a water supply pump; the water tank is connected to the water cavities of the first water tank and the second water tank respectively through a water injection pipe; the water supply pump is installed on the water injection pipe to pump the water in the water tank into the water cavities of the first water tank and the second water tank.

3. The water tunnel test device according to claim 2, characterized in that: The upper parts of the water chambers of the first water tank and the second water tank are respectively connected to the water storage tank via an overflow pipe; each overflow pipe is provided with a switchable valve.

4. The water tunnel test device according to claim 2, characterized in that: The airbag is a telescopic airbag, the upper end of which is connected to the top of the water tank where it is located, the ventilation tube passes through the top wall of the water tank where the airbag is located and is connected to the airbag, and the lower end of the airbag can move back and forth up and down under the action of internal air pressure and external water pressure.

5. The water tunnel test device according to claim 4, characterized in that: The first water tank and the second water tank are both cylindrical silos. The airbag is cylindrical in shape and can be extended and retracted along the axial direction. The airbag is coaxially arranged with the water tank where it is located.

6. The water tunnel test device according to claim 4, characterized in that: The lower part of the water chamber of the first water tank is connected to the water inlet three-way valve via the first drainage pipe, and is connected to the water outlet three-way valve via the first return pipe; the lower part of the water chamber of the second water tank is connected to the water inlet three-way valve via the second drainage pipe, and is connected to the water outlet three-way valve via the second return pipe.

7. The water tunnel test device according to claim 2, characterized in that: The compressed air source is an air storage tank filled with compressed air.

8. A water tunnel test method, characterized in that: The water tunnel test device according to any one of claims 2 to 7 is used, comprising the following steps: S1, pre-inflate the two airbags respectively, and make the initial air pressure in the first water tank airbag smaller than the initial air pressure in the second water tank airbag; S2, start the water supply pump to pump the water in the water storage tank into the first water tank and the second water tank, and fill the water cavity of the first water tank, the water cavity of the second water tank, the connecting pipe between the first water tank and the water tunnel test section, the connecting pipe between the second water tank and the water tunnel test section, and the water tunnel test section; turn off the water supply pump; S3, inflate the airbag of the first water tank, and deflate the airbag of the second water tank, adjust the working states of the water inlet three-way valve and the water outlet three-way valve, so that the water in the first water tank flows through the water tunnel test section under the inflation pressure and then enters the second water tank, until the water volume in the second water tank reaches a preset value; stop inflating the airbag of the first water tank; S4, switching the working states of the water inlet three-way valve and the water outlet three-way valve, inflating the airbag of the second water tank, and deflating the airbag of the first water tank, so that the water in the second water tank flows through the water tunnel test section under the inflation pressure and then enters the first water tank, until the water volume in the first water tank reaches a preset value; stop inflating the airbag of the second water tank; S5. Repeat steps S3 and S4 to allow water to continue to flow through the water tunnel test section.

9. The water tunnel test method according to claim 8, characterized in that: In steps S3 and S4, the air pressure in the airbag of the first water tank or the second water tank is always greater than zero during the deflation process and at the end of the deflation.

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