A double-adjustable Renault test device and test method

Abstract

The invention discloses a dual-regulation Renault experimental device and an experimental method. The device comprises a cold water tank, a hot water tank, a water supply tank, a constant pressure water tank, a colored water storage tank and an experimental pipeline. The cold water tank is connected to a refrigeration system through a water pipe, the hot water tank is connected to a heating system through a water pipe, the cold water tank and the hot water tank are connected to one end of a mixing tube through a cold water pipe and a hot water pipe respectively, the other end of the mixing tube is connected to the water supply tank, the water supply tank is connected to a constant pressure water tank through a water inlet pipe, a thyristor stepless speed regulator is arranged on the water inlet pipe, a water outlet pipe of the constant pressure water tank is connected to the experimental pipeline through a flow control component, the tail end of a colored water pipe connected below the colored water storage tank extends into the interior of the experimental pipeline, and a control valve is arranged on the colored water pipe.

Description

Technical Field

[0001] The invention belongs to the technical field of Reynolds test, and in particular relates to a double-adjustable Reynolds test device and an test method. Background Art

[0002] In 1883, Osborne Reynolds used the Reynolds experimental device to observe that there are two flow states in liquid flow: laminar flow and turbulent flow. When the flow rate is low, the water flow moves in an orderly layered linear motion, and there is no mixing of particles between the flow layers. This flow state is called laminar flow. When the flow rate increases, the fluid particles move in a disordered linear motion, and the particles mix between the flow layers. This flow state is called turbulent flow. The Reynolds experiment also found that there is a critical flow velocity v for turbulence to transform into laminar flow. c , v c It is related to the viscosity v of the fluid and the diameter d of the tube. To determine the flow state, it is necessary to determine v in various situations. c The contribution of the Reynolds experiment is not only the discovery of two flow states, but also the use of the principle of dimensional analysis to obtain a criterion with one dimension - the Reynolds number Re, which simplifies the problem.

[0003] At present, the change of Reynolds number in the Reynolds tester is mainly achieved by changing the flow velocity in the experimental pipeline. The change of flow velocity is often achieved by adjusting the flow rate, but currently basically an electric flow control valve is used. Students only need to press a button to complete the flow adjustment operation, which leads to a poor sense of participation and causes students to observe the experiment. Secondly, the critical Reynolds number measured only by adjusting the flow rate is unstable, and this is even more so for operators who need to deploy the two flow states of water flow and their transformation relationship, which affects the teaching effect of the experiment and students have a vague understanding of the Reynolds experiment. Summary of the invention

[0004] In response to the above problems, this application proposes a dual-adjustment Reynolds experimental device and experimental method, which combines flow regulation with temperature regulation, thereby reducing the impact of water flow disturbance caused by adjusting the flow rate on the experimental structure, and at the same time changing the flow rate regulation mechanism, stimulating students' enthusiasm and improving the teaching effect of the experiment.

[0005] The technical solution adopted by the present invention is:

[0006] A dual-adjustment Renault experiment device comprises a cold water tank, a hot water tank, a water supply tank, a constant pressure water tank, a colored water storage tank and an experimental pipeline, wherein the cold water tank is connected to a refrigeration system through a water pipe, the hot water tank is connected to a heating system through a water pipe, the cold water tank and the hot water tank are connected to one end of a mixing tube through a cold water pipe and a hot water pipe respectively, the other end of the mixing tube is connected to the water supply tank, the water supply tank is connected to the constant pressure water tank through a water inlet pipe, a thyristor stepless speed regulator is arranged on the water inlet pipe, the water outlet pipe of the constant pressure water tank is connected to the experimental pipeline through a flow control component, the tail end of the colored water pipe connected below the colored water storage tank extends into the interior of the experimental pipeline, and a control valve is arranged on the colored water pipe.

[0007] Preferably, a first ball valve is provided on the cold water pipe, and a second ball valve is provided on the hot water pipe. Both the first ball valve and the second ball valve are provided with drive motors. Both drive motors are connected to a control unit, and the drive motors can be started or shut down by the control unit.

[0008] Preferably, a temperature sensor is provided in the water supply tank, a flow sensor is provided on the experimental pipeline, and both the temperature sensor and the flow sensor are connected to the control unit.

[0009] Preferably, a first partition and a second partition are provided inside the constant pressure water tank, the height of the first partition is smaller than that of the second partition, the tail end of the water inlet pipe extends into the constant pressure water tank from the top thereof, and is located between the first partition and the second partition, a plurality of water stabilizing holes are provided on the second partition, an overflow area is formed between the first partition and the inner wall of the constant pressure water tank, an overflow return pipe is provided below the constant pressure water tank, one end of the overflow return pipe is connected to the overflow area, and the other end thereof is connected to the overflow return tank.

[0010] Preferably, the flow control assembly comprises a regulating body, a water inlet is arranged on the left side wall of the regulating body, the water inlet is connected to the regulating chamber, an isolation plug is arranged in the regulating chamber, a plurality of connecting blocks are arranged on the left end outer wall of the isolation plug, a horizontal movable groove is arranged on the right inner wall of the regulating chamber, the isolation plug can move horizontally in the movable groove, a guide rod is arranged on the inner cavity wall of the isolation plug, a traction cylinder is arranged on the inner side wall of the movable groove, the tail end of the guide rod passes through the interior of the traction cylinder and is connected with a guide block, a first compression spring is arranged in the traction cylinder, and the first compression spring is located between the guide block and the inner side wall of the movable groove;

[0011] A limiting cylinder is arranged in the water inlet, and the limiting cylinder is fixedly connected to the end face of the adjusting body through a connecting flange and is limited in the water inlet. A semicircular movable plate which can slide horizontally along its outer wall is sleeved on the outer wall of the limiting cylinder, and a tooth groove is arranged on the outer top wall of the semicircular movable plate. An installation cavity is arranged in the top wall of the adjusting body, and an opening communicating with the water inlet is arranged on the bottom wall of the installation cavity. A gear is arranged in the installation cavity, and some teeth on the gear pass through the opening and mesh with the tooth groove. The gear is installed on a rotating shaft, and one end of the rotating shaft is movably connected to an inner side wall of the installation cavity, and the other end thereof passes through the other symmetrical side wall of the installation cavity to the outside of the adjusting body and is connected to the turntable.

[0012] Preferably, an extended ring distributed toward the outside of the limiting cylinder is provided on the left side ring wall of the limiting cylinder, and an outer clamping ring and an inner clamping ring extending toward both ends are provided on both sides of the outer wall of the extended ring, and an inner clamping groove and an outer clamping groove are respectively provided on the symmetrical end faces of the adjusting body and the connecting flange, and the outer clamping ring and the inner clamping ring are respectively confined in the outer clamping groove and the inner clamping groove, and sealing gaskets are also provided in the inner clamping groove and the outer clamping groove.

[0013] Preferably, two groups of mutually symmetrical horizontal plates are arranged on the outer side wall of the limit cylinder along its length direction, a limiting groove is arranged on the horizontal plate, and the end of the limiting groove close to the extension ring is set to an open state, and the lower end surface of the semicircular movable plate is provided with two mutually symmetrical limiting columns, the limiting columns are located in the limiting groove and can move horizontally along the limiting groove; an arc-shaped retaining ring is arranged at the connection between the water inlet and the regulating chamber, and the arc-shaped retaining ring is located below the horizontal plate and close to the lower end surface of the horizontal plate.

[0014] Preferably, a water outlet is provided on the lower end surface of the regulating body, the water outlet is communicated with the regulating chamber, and the water outlet pipe and the experimental pipeline are respectively connected to the connecting flange and the outer wall of the water outlet through a connecting assembly;

[0015] The connecting assembly includes a fixed ring, which is threadedly connected to the outer wall of the water outlet pipe or the outer wall of the experimental pipe. A movable ring is arranged on the outer wall of the fixed ring along its circumferential direction. A plurality of support rods are hinged on the movable ring along its circumferential direction. The tail ends of the support rods are hinged with fixed blocks. The lower end face of the fixed block is provided with an L-shaped block along its edge. The outer wall of the connecting flange and the outer wall of the water outlet are provided with a slot that matches the L-shaped block.

[0016] Preferably, an installation groove is provided on the inner wall of the slot, a moving rod and a second compression spring are provided in the installation groove, the second compression spring is located between one end of the moving rod and the inner end surface of the installation groove and is connected to the moving rod, the other end of the moving rod is connected to a card plate, the card plate is tightly attached to the outer wall of the L-shaped card block, and a third compression spring is also sleeved on the moving rod.

[0017] An experimental method of a double-adjustable Reynolds experimental device comprises the following steps:

[0018] Step 1: The external cold water is cooled by the refrigeration system and heated by the heating system, and then enters the cold water tank and the hot water tank for heat preservation and storage;

[0019] Step 2: Start the drive motor to adjust the first ball valve on the cold water pipe and the second ball valve on the hot water pipe, so that the cold water and hot water are mixed in the mixing pipe and flow into the water supply tank. The current temperature in the water supply tank is uploaded to the control unit through the temperature sensor. When the mixed water temperature reaches the set temperature, the first ball valve and the second ball valve are closed, and the constant temperature water in the water supply tank is sent to the constant pressure water tank through the thyristor stepless speed regulator.

[0020] Step 3: After the water in the constant pressure water tank overflows and stabilizes, the first stage of the experiment is carried out, and the Reynolds number is demonstrated from low to high;

[0021] Rotate the turntable to slightly push the isolation plug, and open the control valve on the colored water pipe to inject colored water into the experimental pipe. You can see that the colored water in the experimental pipe forms a straight line with the flow of water. The flow state at this time is laminar flow. Slowly open the adjustment chamber gradually. The flow sensor records the current flow in the experimental pipe in time. When the flow rate increases from small to large and corresponds to the experimental pipe flow rate determined by the Reynolds number of 1800±200, stop adjusting and keep the current flow adjustment setting; start to gradually adjust the first ball valve and the second ball valve to change the temperature of the mixed water in the water supply tank. You can observe the experimental pipe flow rate. The colored straight lines in the channel begin to mix, indicating that the laminar flow has just turned into turbulent flow. This is the upper critical state where the fluid flow state begins to change. Note the experimental temperature at this moment, and the actual Reynolds number of the water flow from laminar flow to turbulent flow can be solved; continue to slowly adjust the first ball valve and the second ball valve to change the temperature of the mixed water in the water supply tank. It can be observed that the colored straight lines are completely disordered, and the water flow state enters the turbulent stage. Continue to adjust the first ball valve and the second ball valve to the water temperature corresponding to Reynolds number 3000±200 and stop adjusting; readjust the thyristor stepless speed regulator to increase the flow rate;

[0022] Step 4: Conduct the first phase of the experiment, and perform the Reynolds number demonstration experiment from low to high

[0023] Open the regulating chamber gradually and slowly. The flow sensor records the current flow in the experimental pipeline in time. Stop adjusting when the flow rate decreases from large to small, corresponding to the experimental pipeline flow velocity determined by the Reynolds number of 3000±200, and keep the current flow regulation setting; start to adjust the first ball valve and the second ball valve to change the mixed water temperature in the water supply tank, observe the experimental phenomenon of the transformation of water flow from turbulent flow to laminar flow, write down the experimental temperature at this moment, and solve the actual Reynolds number for the transformation of water flow from turbulent flow to laminar flow; continue to adjust the first ball valve and the second ball valve to change the mixed water temperature in the water supply tank, and thin straight color lines will appear in the experimental pipeline again, and the fluid flow state will change to laminar flow; stop adjusting when it corresponds to the water temperature calculated by the Reynolds number of 1800±200, readjust the flow control components, reduce the flow, and prepare for the next experiment.

[0024] Beneficial effects of the present invention:

[0025] When determining the upper critical Reynolds number, the present invention first manually adjusts the flow regulating component so that the flow velocity in the experimental pipeline increases from small to large and corresponds to the experimental pipeline flow velocity determined by the Reynolds number of 1800±200, stops adjusting, maintains the current flow regulating setting, and then adjusts the water temperature. The change in water temperature is used to adjust the kinematic viscosity coefficient of the water body instead of adjusting the experimental pipeline flow velocity by changing the flow rate and then changing the Reynolds number between laminar flow and turbulent flow, which effectively reduces the influence of water flow disturbance and improves the experimental accuracy. Similarly, when determining the lower critical Reynolds number, the flow regulating component is manually adjusted so that the flow velocity in the experimental pipeline increases from small to large and corresponds to the experimental pipeline flow velocity determined by the Reynolds number of 3000±200, stops adjusting, maintains the current flow regulating setting, and then adjusts the water temperature; and measures the lower critical Reynolds number when the experimental pipeline flow velocity changes from turbulent flow to laminar flow. The experimental results are more real and effective.

[0026] The newly designed flow regulating component of the present invention comprises a regulating body, a water inlet is arranged on the left side wall of the regulating body, the water inlet is connected to the regulating chamber, an isolation plug is arranged in the regulating chamber, a plurality of connecting blocks are arranged on the outer wall of the left end of the isolation plug, a horizontal movable groove is arranged on the right inner wall of the regulating chamber, the isolation plug can move horizontally in the movable groove, a guide rod is arranged on the inner cavity wall of the isolation plug, a traction cylinder is arranged on the inner side wall of the movable groove, the tail end of the guide rod passes through the inside of the traction cylinder and is connected with a guide block, a first compression spring is arranged in the traction cylinder, and the first compression spring is located between the guide block and the inner side wall of the movable groove; a limiting cylinder is arranged in the water inlet, and the limiting cylinder is fixedly connected to the end face of the regulating body by a connecting flange and is limited in the water inlet, a semicircular movable plate which can slide horizontally along its outer wall is sleeved on the outer wall of the limiting cylinder, and a tooth groove is arranged on the outer top wall of the semicircular movable plate, The top wall of the regulating body is provided with an installation cavity, the bottom wall of the installation cavity is provided with an opening connected with the water inlet, the installation cavity is provided with a gear, some teeth on the gear pass through the opening and mesh with the tooth groove, the gear is installed on the rotating shaft, one end of the rotating shaft is movably connected with an inner side wall of the installation cavity, and the other end thereof passes through the other symmetrical side wall of the installation cavity to the outside of the regulating body and is connected with the turntable; by rotating the turntable, the semicircular movable plate is driven by the meshing tooth groove of the gear to move toward the isolation plug, thereby squeezing the connecting block and pulling the isolation plug to move into the movable groove, thereby opening the regulating chamber, the regulating chamber is connected with the water inlet and the water outlet, and the flow rate is changed by adjusting the size of the regulating chamber. The operation is simple, and the adjustment process completely relies on rotating the turntable, which improves the students' sense of participation and allows them to better feel the change from laminar flow to turbulent flow or from turbulent flow to laminar flow, thereby increasing students' understanding of the Reynolds experiment and improving students' enthusiasm for hands-on practice.

[0027] The present invention designs a new connecting component for connecting the flow regulating component with the pipes at both ends. The connecting component includes a fixed ring, the fixed ring is threadedly connected to the outer wall of the water outlet pipe or the outer wall of the experimental pipe, a movable ring is arranged on the outer wall of the fixed ring along its circumferential direction, a plurality of support rods are hinged on the movable ring along its circumferential direction, and the tail end of the support rod is hinged with a fixed block, the lower end face of the fixed block is provided with an L-shaped block along its edge, the outer wall of the connecting flange and the outer wall of the water outlet are both provided with a card groove matching the L-shaped block, an installation groove is provided on the inner wall of the card groove, a moving rod and a second compression spring are provided in the installing groove, the second compression spring is located between one end of the moving rod and the inner end face of the installing groove and is connected to the moving rod, the other end of the moving rod is connected with a card plate, the card plate is tightly attached to the outer wall of the L-shaped card block, and a third compression spring is also sleeved on the moving rod. When it is necessary to connect the pipeline, rotate the fixing ring and move it closer to the flow regulating component to facilitate the L-shaped block to be inserted into the slot. At this time, the card plate presses against the outer wall of the L-shaped block to limit the position of the L-shaped block. Then rotate the fixing ring back and the support rod is straightened, so that the L-shaped block is fixed in the slot, thereby realizing a fixed connection between the pipeline and the flow regulating component. The operation is simple and convenient, and the connection between the pipeline and the flow regulating component can be achieved without the aid of auxiliary tools, so the flow regulating component can be disassembled for maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 The figure shows a schematic diagram of the structure of a dual-adjustable Reynolds experimental device provided in this embodiment;

[0030] Figure 2 Shown is a connection diagram for the water supply system;

[0031] Figure 3 Shown is a cross-sectional view of a flow regulating assembly;

[0032] Figure 4 Shown Figure 3 Schematic diagram of the semicircular moving plate;

[0033] Figure 5 Shown Figure 3 A top view of the middle semicircular moving plate;

[0034] Figure 6 Shown Figure 3 Schematic diagram of the middle limit cylinder;

[0035] Figure 7 Shown Figure 3 The enlarged view of point A in the middle;

[0036] Figure 8 Shown Figure 3 Schematic diagram of the fixing ring;

[0037] Fig. 9 Shown is the flow regulation component regulation state diagram.

[0038] Among them, 1. Experimental bench;

[0039] 2. Constant pressure water tank; 201. First baffle; 202. Second baffle; 2021. Water stabilizing hole; 203. Water outlet pipe;

[0040] 3. Connecting assembly; 301. Fixed ring; 302. Movable ring; 303. Support rod; 304. Fixed block; 3041. L-shaped block; 305. Card; 306. Moving rod; 307. Second compression spring; 308. Third compression spring;

[0041] 4. Flow control assembly; 401. Adjustment body; 402. Water inlet; 4021. Arc retaining ring; 403. Adjustment chamber; 404. Moving groove; 405. Limiting cylinder; 4051. Extension ring; 4052. Outer retaining ring; 4053. Inner retaining ring; 4054. Horizontal plate; 4055. Limiting groove; 406. Connecting flange; 4061. Retaining groove; 4062. Mounting groove; 407. Semicircular moving plate; 4071. Tooth groove; 4072. First magnetic block; 4073. Limiting column; 408. Gear; 409. Rotating shaft; 410. Rotating disk; 411. Isolation plug; 4111. Connecting block; 4112. Guide rod; 4113. Second magnetic block; 412. Guide block; 413. Traction cylinder; 414. First compression spring; 415. Water outlet;

[0042] 5. Experimental pipeline; 6. Colored water storage tank; 7. Control valve; 8. Colored water pipe; 9. SCR stepless speed regulator; 10. Water inlet pipe; 11. Overflow return water tank; 12. Tail water tank; 13. Cold water tank; 14. Hot water tank; 15. Cold water pipe; 16. Hot water pipe; 17. First ball valve; 18. Second ball valve; 19. Drive motor; 20. Control unit; 21. Mixing tube; 22. Water supply tank; 23. Overflow return pipe; DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] This embodiment provides a dual-adjustable Reynolds test device, such as Figure 1 As shown, the device includes a cold water tank 13, a hot water tank 14, a water supply tank 22, a constant pressure water tank 2, a colored water storage tank 6 and an experimental pipeline 5 (a transparent pipeline is used).

[0046] Specifically, Figure 1 and 2 As shown, the cold water tank 13 is connected to the refrigeration system through a water pipe, and the hot water tank 14 is connected to the heating system through a water pipe. The cold water tank 13 and the hot water tank 14 are respectively connected to one end of the mixing tube 21 through a cold water pipe 15 and a hot water pipe 16. A first ball valve 17 is provided on the cold water pipe 15, and a second ball valve 18 is provided on the hot water pipe 16. A driving motor 19 is provided on both the first ball valve 17 and the second ball valve 18. Both the driving motors 19 are connected to a control unit 20, and the driving motor 19 can be started or shut down by the control unit 20. The other end of the mixing tube 21 is connected to the water supply tank 22, and the water supply tank 22 is connected to the constant pressure water tank 2 through the water inlet pipe 10. The water inlet pipe 10 is provided with a thyristor stepless speed regulator 9, and the outer layer of the water inlet pipe 10 can be designed with an insulation layer to ensure that the water temperature entering the constant pressure water tank 2 is stable. In order to avoid the water temperature entering the experimental pipeline 5 and the temperature measured in the water supply tank 22, an insulation layer is provided on the inner wall of the constant pressure water tank 2 to insulate the water entering the constant pressure water tank 2, so as to ensure that the water temperature entering the experimental pipeline 5 changes very little or does not change. The outlet pipe 203 of the constant pressure water tank 2 is connected to the experimental pipeline 5 through the flow control component 4, and the tail end of the colored water pipe 8 connected below the colored water storage tank 6 extends into the interior of the experimental pipeline 5, and the colored water pipe 8 is provided with a control valve 7. Among them, the tail of the experimental pipeline 5 is connected to the tail water tank 12. The experimental pipeline 5 is erected on a support, and the support is fixed on the experimental table 1 . The constant pressure water tank 2 is also arranged on the experimental table 1 .

[0047] In this embodiment, a temperature sensor (not shown) is provided in the water supply tank 22, a flow sensor (not shown) is provided on the experimental pipe 5, and both the temperature sensor and the flow sensor are connected to the control unit 20. The control unit 20 here can be a control panel structure.

[0048] Again Figure 1 As shown, in this embodiment, the constant pressure water tank 2 is provided with a first partition 201 and a second partition 202, the height of the first partition 201 is less than the height of the second partition 202, the tail end of the water inlet pipe 10 extends from the top of the constant pressure water tank 2 into the interior thereof, and is located between the first partition 201 and the second partition 202, a plurality of water stabilizing holes 2021 are provided on the second partition 202, an overflow area is formed between the first partition 201 and the inner wall of the constant pressure water tank 2, an overflow return pipe 23 is provided below the constant pressure water tank 2, one end of the overflow return pipe 23 is connected to the overflow area, and the other end thereof is connected to the overflow return water tank 11. When the water in the overflow return water tank 11 is full, it is connected to the refrigeration system or the heating system through a pipeline for repeated use.

[0049] like Figure 3-9As shown, the flow control component 4 includes a regulating body 401, a water inlet 402 is arranged on the left side wall of the regulating body 401, and the water inlet 402 is connected to the regulating chamber 403, an isolation plug 411 is arranged in the regulating chamber 403, a plurality of connecting blocks 4111 are arranged on the left end outer wall of the isolation plug 411, a horizontal movable groove 404 is arranged on the right inner wall of the regulating chamber 403, and the isolation plug 411 can move horizontally in the movable groove 404, a guide rod 4112 is arranged on the inner cavity wall of the isolation plug 411, a traction cylinder 413 is arranged on the inner side wall of the movable groove 404, the tail end of the guide rod 4112 passes through the interior of the traction cylinder 413 and is connected with the guide block 412, a first compression spring 414 is arranged in the traction cylinder 413, and the first compression spring 414 is located between the guide block 412 and the inner side of the movable groove 404 Walls; a limiting cylinder 405 is arranged in the water inlet 402, and the limiting cylinder 405 is fixedly connected to the end face of the adjusting body 401 through a connecting flange 406 and is limited in the water inlet 402, a semicircular movable plate 407 which can slide horizontally along its outer wall is sleeved on the outer wall of the limiting cylinder 405, a tooth groove 4071 is arranged on the outer top wall of the semicircular movable plate 407, an installation cavity is arranged in the top wall of the adjusting body 401, an opening communicating with the water inlet 402 is arranged on the bottom wall of the installation cavity, a gear 408 is arranged in the installation cavity, some teeth on the gear 408 pass through the opening and mesh with the tooth groove 4071, the gear 408 is installed on a rotating shaft 409, one end of the rotating shaft 409 is movably connected to an inner side wall of the installation cavity, and the other end thereof passes through the other symmetrical side wall of the installation cavity to the outside of the adjusting body 401 and is connected to a turntable 410.

[0050] Specifically, a second magnetic block 4113 is disposed on the side wall of the connecting block 4111, and a first magnetic block 4072 is disposed on the inner end surface of the semicircular movable plate 407 to cooperate with the second magnetic block 4113. When the turntable 410 is rotated and the gear 408 engages with the tooth groove 4071 to drive the semicircular movable plate 407 to move toward the isolation plug 411, the first magnetic block 4072 and the second magnetic block 4113 are attracted to each other, thereby stably pushing the isolation plug 411 to move into the movable groove.

[0051] In order to firmly limit the limiting cylinder 405 between the connecting flange 406 and the adjusting body 401, an extended ring 4051 distributed toward the outside of the limiting cylinder is provided on the left side ring wall of the limiting cylinder 405, and the outer wall of the extended ring 4051 is provided with an outer clamping ring 4052 and an inner clamping ring 4053 extending toward both ends respectively on both sides thereof, and the adjusting body 401 and the connecting flange 406 are provided with an inner clamping groove and an outer clamping groove on the symmetrical end faces respectively, and the outer clamping ring 4052 and the inner clamping ring 4053 are respectively limited in the outer clamping groove and the inner clamping groove, and sealing gaskets are also provided in the inner clamping groove and the outer clamping groove.

[0052] In order to improve the smooth movement of the semicircular movable plate 407 along the outer wall of the limiting cylinder 405, two groups of horizontal plates 4055 are arranged symmetrically along the length direction of the limiting cylinder 405 on the outer wall of the limiting cylinder 405, and a limiting groove 4054 is arranged on the horizontal plate 4055. The limiting groove 4054 is arranged in an open state at one end close to the extension ring 4051, and two symmetrical limiting columns 4073 are arranged on the lower end face of the semicircular movable plate 407. The limiting columns 4073 are located in the limiting groove 4055 and can move horizontally along the limiting groove 4055. At the same time, in order to prevent the water in the regulating chamber 403 from flowing back into the water inlet 402, an arc-shaped retaining ring 4021 is provided at the connection between the water inlet 402 and the regulating chamber. The arc-shaped retaining ring 4021 is located below the horizontal plate 4054 and is close to the lower end surface of the horizontal plate 4054, so that the horizontal plate 4054 and the arc-shaped retaining ring 4021 are used to seal the gap between the water inlet 402 and the limiting cylinder 405.

[0053] In this embodiment, a water outlet 415 is provided on the lower end surface of the regulating body 401, and the water outlet 415 is connected to the regulating chamber 403. The water outlet pipe 203 and the experimental pipeline 5 are respectively connected to the connecting flange 406 and the outer wall of the water outlet 415 through the connecting component 3.

[0054] The connecting assembly 3 includes a fixed ring 301, which is threadedly connected to the outer wall of the water outlet pipe 203 or the outer wall of the experimental pipe 4, and a movable ring 302 is arranged on the outer wall of the fixed ring 301 along its circumferential direction, and a plurality of support rods 303 are hinged on the movable ring 302 along its circumferential direction, and a fixed block 304 is hinged at the tail end of the support rod 303, and an L-shaped block 3041 is arranged on the lower end face of the fixed block 304 along its edge, and the outer wall of the connecting flange 406 and the outer wall of the water outlet 415 are both provided. There is a card slot 4061 that cooperates with the L-shaped card block 3041, and an installation groove 4062 is arranged on the inner wall of the card slot 4061. A moving rod 306 and a second compression spring 307 are arranged in the installation groove 4062. The second compression spring 307 is located between one end of the moving rod 306 and the inner end surface of the installation groove 4062 and is connected to the moving rod 306. The other end of the moving rod 306 is connected to a card plate 305, and the card plate 305 is tightly attached to the outer wall of the L-shaped card block 3041. The moving rod 306 is also sleeved with a third compression spring 308.

[0055] When it is necessary to connect the pipeline and the flow regulating body, first insert the interface end of the pipeline into the inner end surface of the connecting flange 306 or the inner end surface of the water outlet 415 to ensure the flatness of the connection. Then rotate the fixing ring 301 to approach the regulating body 401, and the L-shaped clamping block 3041 is clamped into the clamping groove 4061. The clamping plate 305 squeezes the L-shaped clamping block 3041 under the action of the second spring 307 and the third spring 308, thereby achieving the vertical stability of the L-shaped clamping block 3041. Finally, rotate the fixing ring 301 back to straighten the support rod 303 to achieve the horizontal fixation of the L-shaped clamping block 3041, that is, to achieve the fixed connection between the pipeline and the regulating body, which is simple to operate and convenient to install and disassemble.

[0056] This embodiment also provides an experimental method of a dual-adjustable Reynolds experimental device, comprising the following steps:

[0057] Step 1: External cold water is cooled by the refrigeration system and heated by the heating system, and then enters the cold water tank 13 and the hot water tank 14 for heat preservation and storage;

[0058] Step 2: Start the drive motor 19 to adjust the first ball valve 17 on the cold water pipe 13 and the second ball valve 18 on the hot water pipe 14, so that the cold water and the hot water are mixed in the mixing pipe 21 and flow into the water supply tank 22. The current temperature in the water supply tank 22 is uploaded to the control unit 20 through the temperature sensor. When the mixed water temperature reaches the set temperature, the first ball valve 17 and the second ball valve 18 are closed, and the constant temperature water in the water supply tank 21 is sent to the constant pressure water tank 2 through the thyristor stepless speed regulator 9;

[0059] Step 3: After the water in the constant pressure water tank 2 overflows and becomes stable, the first stage experiment is carried out, and the Reynolds number is demonstrated from low to high;

[0060] Rotate the turntable 410 to slightly push the isolation plug 411, and open the control valve 7 on the colored water pipe 8 to inject colored water into the experimental pipe 5. It can be seen that the colored water in the experimental pipe 5 forms a straight line with the flow of water. The flow state at this time is laminar flow. Gradually and slowly open the adjustment chamber. The flow sensor records the current flow in the experimental pipe 5 in time. When the flow rate increases from small to large and corresponds to the experimental pipe flow rate determined by the Reynolds number 1800±200, stop adjusting and keep the current flow adjustment setting; start to gradually adjust the first ball valve 17 and the second ball valve 18 to change the temperature of the mixed water in the water supply tank 21. It can be observed that the actual The colored straight lines in the test pipe 5 begin to mix, indicating that the laminar flow has just turned into turbulent flow. This is the upper critical state where the fluid flow state begins to change. The experimental temperature at this moment can be recorded to solve the actual Reynolds number of the water flow from laminar flow to turbulent flow. Continue to slowly adjust the first ball valve 17 and the second ball valve 18 to change the temperature of the mixed water in the water supply tank 21. It can be observed that the colored straight lines are completely disordered and the water flow state enters the turbulent stage. Continue to adjust the first ball valve 17 and the second ball valve 18 to stop adjusting when the water temperature corresponding to the Reynolds number 3000±200 is determined; readjust the thyristor stepless speed regulator 9 to increase the flow rate;

[0061] Step 4: Conduct the first phase of the experiment, and perform the Reynolds number demonstration experiment from low to high

[0062] Slowly and gradually open the regulating chamber 403, and the flow sensor will record the current flow in the experimental pipeline in time. When the flow rate decreases from large to small and corresponds to the experimental pipeline flow velocity determined by the Reynolds number of 3000±200, stop adjusting and keep the current flow regulation setting; start to adjust the first ball valve 17 and the second ball valve 18 to change the mixed water temperature in the water supply tank, observe the experimental phenomenon of the water flow transforming from turbulent flow to laminar flow, record the experimental temperature at this moment, and solve the actual Reynolds number for the water flow transforming from turbulent flow to laminar flow; continue to adjust the first ball valve 17 and the second ball valve 18 to change the mixed water temperature in the water supply tank, and a thin straight color line will appear in the experimental pipeline 5 again, and the fluid flow state will transform into laminar flow; stop adjusting when it corresponds to the water temperature calculated by the Reynolds number of 1800±200, readjust the flow control component, reduce the flow, and prepare for the next experiment.

[0063] The above description is only used to illustrate the technical solution of the present invention rather than to limit it. Other modifications or equivalent substitutions made to the technical solution of the present invention by ordinary technicians in this field should be included in the scope of the claims of the present invention as long as they do not depart from the spirit and scope of the technical solution of the present invention.

Claims

1. A dual-adjustable Reynolds test device, characterized in that: The device comprises a cold water tank, a hot water tank, a water supply tank, a constant pressure water tank, a colored water storage tank and an experimental pipeline. The cold water tank is connected to a refrigeration system through a water pipe, the hot water tank is connected to a heating system through a water pipe, the cold water tank and the hot water tank are connected to one end of a mixing tube through a cold water pipe and a hot water pipe respectively, the other end of the mixing tube is connected to the water supply tank, the water supply tank is connected to the constant pressure water tank through a water inlet pipe, a thyristor stepless speed regulator is arranged on the water inlet pipe, the water outlet pipe of the constant pressure water tank is connected to the experimental pipeline through a flow control component, the tail end of the colored water pipe connected below the colored water storage tank extends into the interior of the experimental pipeline, and a control valve is arranged on the colored water pipe; The flow control assembly includes a regulating body, a water inlet is arranged on the left side wall of the regulating body, the water inlet is connected to the regulating chamber, an isolation plug is arranged in the regulating chamber, a plurality of connecting blocks are arranged on the left end outer wall of the isolation plug, a horizontal movable groove is arranged on the right inner wall of the regulating chamber, the isolation plug can move horizontally in the movable groove, a guide rod is arranged on the inner cavity wall of the isolation plug, a traction cylinder is arranged on the inner side wall of the movable groove, the tail end of the guide rod passes through the interior of the traction cylinder and is connected with a guide block, a first compression spring is arranged in the traction cylinder, and the first compression spring is located between the guide block and the inner side wall of the movable groove; A limiting cylinder is arranged in the water inlet, and the limiting cylinder is fixedly connected to the end face of the adjusting body through a connecting flange and is limited in the water inlet; a semicircular movable plate which can slide horizontally along its outer wall is sleeved on the outer wall of the limiting cylinder, and a tooth groove is arranged on the outer top wall of the semicircular movable plate; a mounting cavity is arranged in the top wall of the adjusting body, and an opening communicating with the water inlet is arranged on the bottom wall of the mounting cavity; a gear is arranged in the mounting cavity, and some teeth on the gear pass through the opening and mesh with the tooth groove; the gear is mounted on a rotating shaft, and one end of the rotating shaft is movably connected to an inner side wall of the mounting cavity, and the other end thereof passes through the other symmetrical side wall of the mounting cavity to the outside of the adjusting body and is connected to the turntable; A second magnetic block is arranged on the side wall of the connecting block, and a first magnetic block is arranged on the inner end surface of the semicircular movable plate to cooperate with the second magnetic block; when the turntable is rotated, the gear meshes with the tooth groove to drive the semicircular movable plate to move toward the isolation plug, the first magnetic block and the second magnetic block attract each other, thereby stably pushing the isolation plug to move into the movable groove; An extended circular ring distributed toward the outside of the limiting cylinder is arranged on the left side ring wall of the limiting cylinder, and an outer clamping ring and an inner clamping ring extending toward both ends are arranged on both sides of the outer wall of the extending circular ring, and an inner clamping groove and an outer clamping groove are arranged on the symmetrical end faces of the adjusting body and the connecting flange, respectively, and the outer clamping ring and the inner clamping ring are respectively confined in the outer clamping groove and the inner clamping groove, and sealing gaskets are also arranged in the inner clamping groove and the outer clamping groove; Two groups of mutually symmetrical horizontal plates are arranged on the outer side wall of the limiting cylinder and along the length direction thereof, a limiting groove is arranged on the horizontal plate, and one end of the limiting groove close to the extension ring is arranged to be in an open state, and two mutually symmetrical limiting columns are arranged on the lower end surface of the semicircular movable plate, and the limiting columns are located in the limiting groove and can move horizontally along the limiting groove; an arc-shaped retaining ring is arranged at the connection between the water inlet and the regulating chamber, and the arc-shaped retaining ring is located below the horizontal plate and is close to the lower end surface of the horizontal plate; The lower end surface of the regulating body is provided with a water outlet, the water outlet is communicated with the regulating chamber, and the water outlet pipe and the experimental pipeline are respectively connected to the connecting flange and the outer wall of the water outlet through the connecting assembly; The connection assembly includes a fixed ring, which is threadedly connected to the outer wall of the water outlet pipe or the outer wall of the experimental pipe, and a movable ring is arranged on the outer wall of the fixed ring along its circumferential direction, and a plurality of support rods are hinged on the movable ring along its circumferential direction, and the tail ends of the support rods are hinged with fixed blocks, and the lower end surface of the fixed block is provided with an L-shaped block along its edge, and the outer wall of the connecting flange and the outer wall of the water outlet are both provided with a card slot that matches the L-shaped card block; An installation groove is provided on the inner wall of the card slot, and a moving rod and a second compression spring are provided in the installation groove. The second compression spring is located between one end of the moving rod and the inner end surface of the installation groove and is connected to the moving rod. The other end of the moving rod is connected to a card plate, and the card plate is tightly attached to the outer wall of the L-shaped card block. A third compression spring is also sleeved on the moving rod.

2. A dual-adjustable Reynolds test device according to claim 1, characterized in that: The cold water pipe is provided with a first ball valve, the hot water pipe is provided with a second ball valve, the first ball valve and the second ball valve are both provided with drive motors, both drive motors are connected to a control unit, and the drive motors can be started or shut down by the control unit.

3. A dual-adjustable Reynolds test device according to claim 1, characterized in that: A temperature sensor is arranged in the water supply tank, a flow sensor is arranged on the experimental pipeline, and both the temperature sensor and the flow sensor are connected to the control unit.

4. A dual-adjustable Reynolds test device according to claim 1, characterized in that: A first partition and a second partition are provided inside the constant pressure water tank, wherein the height of the first partition is smaller than that of the second partition, the tail end of the water inlet pipe extends into the constant pressure water tank from the top thereof and is located between the first partition and the second partition, a plurality of water stabilizing holes are provided on the second partition, an overflow area is formed between the first partition and the inner wall of the constant pressure water tank, an overflow return water pipe is provided below the constant pressure water tank, one end of the overflow return water pipe is connected to the overflow area, and the other end thereof is connected to the overflow return water tank.

5. The experimental method of a dual-adjustable Renault test device according to any one of claims 1 to 4, characterized in that: The following steps are involved: Step 1: The external cold water is cooled by the refrigeration system and heated by the heating system, and then enters the cold water tank and the hot water tank for heat preservation and storage; Step 2: Start the drive motor to adjust the first ball valve on the cold water pipe and the second ball valve on the hot water pipe, so that the cold water and hot water are mixed in the mixing pipe and flow into the water supply tank. The current temperature in the water supply tank is uploaded to the control unit through the temperature sensor. When the mixed water temperature reaches the set temperature, the first ball valve and the second ball valve are closed, and the constant temperature water in the water supply tank is sent to the constant pressure water tank through the thyristor stepless speed regulator. Step 3: After the water in the constant pressure water tank overflows and stabilizes, the first stage of the experiment is carried out, and the Reynolds number is demonstrated from low to high; Rotate the turntable to slightly push the isolation plug, and open the control valve on the colored water pipe to inject colored water into the experimental pipe. You can see that the colored water in the experimental pipe forms a straight line with the flow of water. The flow state at this time is laminar flow. Slowly open the adjustment chamber gradually. The flow sensor records the current flow in the experimental pipe in time. When the flow rate increases from small to large and corresponds to the experimental pipe flow rate determined by the Reynolds number of 1800±200, stop adjusting and keep the current flow adjustment setting; start to gradually adjust the first ball valve and the second ball valve to change the temperature of the mixed water in the water supply tank. You can observe the experimental pipe flow rate. The colored straight lines in the channel begin to mix, indicating that the laminar flow has just turned into turbulent flow. This is the upper critical state where the fluid flow state begins to change. Note the experimental temperature at this moment, and the actual Reynolds number of the water flow from laminar flow to turbulent flow can be solved; continue to slowly adjust the first ball valve and the second ball valve to change the temperature of the mixed water in the water supply tank. It can be observed that the colored straight lines are completely disordered, and the water flow state enters the turbulent stage. Continue to adjust the first ball valve and the second ball valve to the water temperature corresponding to Reynolds number 3000±200 and stop adjusting; readjust the thyristor stepless speed regulator to increase the flow rate; Step 4: Conduct the first phase of the experiment, and perform the Reynolds number demonstration experiment from low to high Open the regulating chamber gradually and slowly. The flow sensor records the current flow in the experimental pipeline in time. Stop adjusting when the flow rate decreases from large to small, corresponding to the experimental pipeline flow velocity determined by the Reynolds number of 3000±200, and keep the current flow regulation setting; start to adjust the first ball valve and the second ball valve to change the mixed water temperature in the water supply tank, observe the experimental phenomenon of the transformation of water flow from turbulent flow to laminar flow, write down the experimental temperature at this moment, and solve the actual Reynolds number for the transformation of water flow from turbulent flow to laminar flow; continue to adjust the first ball valve and the second ball valve to change the mixed water temperature in the water supply tank, and thin straight color lines will appear in the experimental pipeline again, and the fluid flow state will change to laminar flow; stop adjusting when it corresponds to the water temperature calculated by the Reynolds number of 1800±200, readjust the flow control components, reduce the flow, and prepare for the next experiment.

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