A teaching device for fluid mechanics

Abstract

This invention provides a teaching device for fluid mechanics, comprising: a support frame, multiple sets of first demonstration components, and a water pump; the support frame is provided with a demonstration tank, and an inlet and an outlet are respectively provided on opposite sides of the demonstration tank; the first demonstration component includes a force measuring device, an elastic connector, and a demonstration piece, the force measuring device is disposed on the support frame, the demonstration piece is disposed in the demonstration tank, and the side of the demonstration piece facing the inlet has a flow-facing surface, the area of ​​the flow-facing surface of different first demonstration components being different; the water pump is connected to the inlet. Compared with the prior art, after water is filled into the demonstration tank, the fluid mechanics teaching device of this invention causes different resistances to different demonstration pieces due to the different areas of their flow-facing surfaces, resulting in different distances between the demonstration pieces and the inlet. This allows students to more intuitively observe the relationship between fluid resistance and the cross-sectional area of ​​an object, improving the teaching quality.

Description

Technical Field

[0001] This invention relates to the field of teaching equipment technology, specifically to a teaching device for fluid mechanics. Background Technology

[0002] Fluid mechanics is a branch of mechanics that mainly studies the static and dynamic states of fluids under the action of various forces, as well as the interaction and flow laws when there is relative motion between the fluid and the solid boundary.

[0003] In middle school physics teaching, it is mentioned that fluid resistance is related to both fluid velocity and the cross-sectional area of ​​an object; the larger the cross-sectional area of ​​the object, the greater the fluid resistance. However, teaching usually only uses illustrations in textbooks for demonstration, making it difficult for students to have a direct experience. Currently, there is no equipment specifically designed to demonstrate this principle, making it difficult to demonstrate through concrete experiments, which affects the quality of teaching. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings and deficiencies of the prior art and provide a teaching device for fluid mechanics.

[0005] One embodiment of the present invention provides a teaching device for fluid mechanics, comprising: a support frame, multiple sets of first demonstration components, and a water pump;

[0006] The support is provided with a demonstration tank, and the demonstration tank is provided with an inlet and an outlet on opposite sides respectively.

[0007] The first demonstration component includes a force measuring device, an elastic connector, and a demonstration component. The force measuring device is mounted on the bracket, and the demonstration component is mounted in the demonstration slot and connected to the force measuring device through the elastic connector. The side of the demonstration component facing the water inlet has a flow-facing surface, and the area of ​​the flow-facing surface varies among different first demonstration components.

[0008] The water pump is connected to the water inlet.

[0009] Compared to existing technologies, the fluid mechanics teaching equipment of this invention, after filling the demonstration tank with water, causes different demonstration pieces to experience different fluid resistances due to the different sizes of their frontal surfaces. Consequently, the distances of different demonstration pieces from the water inlet vary, allowing students to more intuitively observe the relationship between fluid resistance and the cross-sectional area of ​​the object, thus improving the quality of teaching.

[0010] In some optional embodiments, a flow equalization plate is provided inside the water inlet, and a plurality of flow equalization holes are evenly arranged on the flow equalization plate.

[0011] In some alternative implementations, a flow rate measuring instrument is provided inside the demonstration tank.

[0012] In some alternative implementations, the teaching equipment for fluid mechanics further includes: an inlet valve, a drain valve, and a check valve, wherein the inlet valve is connected to the water pump, the drain valve is connected to the outlet of the demonstration tank, and the check valve is connected to both the inlet valve and the outlet.

[0013] In some alternative implementations, a level gauge is provided in the demonstration tank, and the level gauge is signal-connected to the water inlet valve and the check valve, respectively.

[0014] In some alternative implementations, the resilient connector is detachably connected to the demonstrator.

[0015] In some alternative embodiments, the elastic connector includes a plurality of connecting ropes connected to the force gauge, the connecting ropes being connected to a buckle, and the demonstration piece being provided with a buckle that engages with the buckle.

[0016] In some alternative embodiments, the support is rotatably provided with a flip cover that can open and close the demonstration slot;

[0017] The side of the demonstration tank is provided with a transparent section;

[0018] The fluid mechanics teaching equipment also includes a switching valve, an air pump, a smoke generator, and a second demonstration component; the air pump and the water pump are both connected to the water inlet through the switching valve, the smoke generator is connected to the air pump, and the second demonstration component includes a counterweight base and an wing-shaped component set on the counterweight base, the counterweight base being set inside the demonstration slot.

[0019] In some alternative implementations, the resilient connector is detachably connected to the force gauge.

[0020] In some optional embodiments, the bottom of the demonstration slot is provided with a positioning slot, and the bottom of the counterweight base is provided with a positioning protrusion, which extends into the positioning slot.

[0021] To provide a clearer understanding of the present invention, the specific embodiments of the present invention will be described below in conjunction with the accompanying drawings. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a fluid mechanics teaching device according to an embodiment of the present invention;

[0023] Figure 2 This is a cross-sectional view of one side of a fluid mechanics teaching device according to an embodiment of the present invention;

[0024] Figure 3This is a top sectional view of a fluid mechanics teaching device according to an embodiment of the present invention;

[0025] Figure 4 This is a cross-sectional view of one side of a fluid mechanics teaching device according to another embodiment of the present invention;

[0026] Figure 5 This is a schematic diagram of the flow equalization plate according to an embodiment of the present invention;

[0027] Figure 6 This is an exploded view of a partial structure of an elastic connector and a demonstrator according to an embodiment of the present invention;

[0028] Figure 7 This is a cross-sectional view of a fluid mechanics teaching device according to an embodiment of the present invention, when demonstrating the fluid mechanics principle of an aircraft wing.

[0029] Figure 8 This is a cross-sectional view of a second demonstrator component according to an embodiment of the present invention;

[0030] Figure 9 This is a cross-sectional view of a second demonstrator component and smoke belt according to an embodiment of the present invention;

[0031] Figure 10 This is a schematic diagram of the counterweight and demonstration airbag according to an embodiment of the present invention.

[0032] Explanation of reference numerals in the attached figures:

[0033] 10. Support; 11. Demonstration tank; 12. Inlet; 13. Outlet; 14. Control panel; 15. Flow equalization plate; 151. Flow equalization hole; 16. Flow velocity meter; 17. Level gauge; 18. Flip cover; 19. Transparent part; 20. First demonstration component; 21. Force gauge; 22. Elastic connector; 221. Connecting rope; 222. Buckle; 23. Demonstration piece; 231. Buckle; 30. Water pump; 41. Inlet valve; 42. Drain valve; 43. Check valve; 44. Diverter valve; 50. Air pump; 60. Smoke generator; 70. Second demonstration component; 71. Counterweight base; 72. Wing profile; 73. Positioning protrusion; 80. Smoke belt; 91. Counterweight; 92. Demonstration airbag. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified, and "several" means one or more.

[0035] Please see Figures 1 to 3 , Figure 1 This is a schematic diagram of the structure of a fluid mechanics teaching device according to an embodiment of the present invention. Figure 2 This is a cross-sectional view of one side of a fluid mechanics teaching device according to an embodiment of the present invention. Figure 3 This is a top cross-sectional view of a fluid mechanics teaching device according to an embodiment of the present invention. The fluid mechanics teaching device includes: a support 10, multiple sets of first demonstration components 20, and a water pump 30.

[0036] A demonstration slot 11 is provided on the support 10, and an inlet 12 and an outlet 13 are respectively provided on opposite sides of the demonstration slot 11; the first demonstration component 20 includes a force measuring device 21, an elastic connector 22 and a demonstration component 23. The force measuring device 21 is provided on the support 10, and the demonstration component 23 is provided in the demonstration slot 11 and is connected to the force measuring device 21 through the elastic connector 22. The side of the demonstration component 23 facing the inlet 12 forms a flow-facing surface. The area of ​​the flow-facing surface of different first demonstration components 20 is different; the water pump 30 is connected to the inlet 12. During the demonstration, water is pumped into the demonstration tank 11 via pump 30. The water enters the tank 11 through inlet 12 and impacts the frontal surface of the demonstration component 23. Because different demonstration components 23 have different frontal surface areas, they experience varying fluid resistance. This causes the elastic connector 22 to be stretched to different lengths, resulting in different distances from the demonstration component 23 to the inlet 12. For example, demonstration components 23 with smaller frontal surface areas experience less fluid resistance, leading to a shorter stretch of the elastic connector 22 and placing the component closer to the inlet 12. This allows students to visually observe the relationship between fluid resistance and the cross-sectional area of ​​the object. It should be noted that the cross-section of the demonstration component 23 perpendicular to the direction from the inlet 12 to the outlet 13 should not exceed the area of ​​its frontal surface.

[0037] Please see Figure 4This is a cross-sectional view of one side of a fluid mechanics teaching device according to another embodiment of the present invention. In this embodiment, the force gauge 21 is a spring force gauge. Of course, the structure of the spring force gauge is not limited to this, and those skilled in the art can choose other suitable structures according to the teachings of the present invention. In addition, in this embodiment, a control panel 14 is provided on the bracket 10, and a display screen is provided on the panel. The force gauge 21 is electrically connected to the display screen of the control panel 14, and the display screen shows the magnitude of the pulling force measured by the force gauge 21. Of course, some force gauges 21 also have their own measuring degree, so that the force can be directly observed and read. In this case, the force gauge 21 can be placed in a position on the bracket 10 that is convenient for students to observe, so that students can easily determine the resistance of the fluid received by the corresponding demonstration piece 23 based on the magnitude of the pulling force displayed by the corresponding force gauge 21.

[0038] Please see Figure 5 This is a schematic diagram of the flow equalization plate in one embodiment of the present invention. In order to make the water flow velocity more uniform at various positions in the demonstration tank 11, in some optional embodiments, a flow equalization plate 15 is provided in the water inlet 12, and a plurality of flow equalization holes 151 are evenly arranged on the flow equalization plate 15.

[0039] In some alternative implementations, a flow velocity meter 16 is provided in the demonstration tank 11. The flow velocity meter 16 can measure the fluid flow velocity in the demonstration tank 11, which is convenient for numerical calculations in the teaching process.

[0040] In some alternative embodiments, the teaching equipment for fluid mechanics also includes: an inlet valve 41, a drain valve 42, and a check valve 43, wherein the inlet valve 41 is connected to the water pump 30, the drain valve 42 is connected to the outlet 13 of the demonstration tank 11, and the check valve 43 is connected to both the inlet valve 41 and the outlet 13. The water source is connected to the inlet valve 41. Before the demonstration, the outlet valve and check valve 43 are closed, and the inlet valve 41 is controlled to connect to the water source and disconnect from the check valve 43, thus connecting the water source and the water pump 30. The water pump 30 pumps water from the inlet 12 into the demonstration tank 11. When the water level in the demonstration tank 11 reaches a sufficiently high level, the check valve 43 is opened, and the inlet valve 41 is switched to connect to the check valve 43 and disconnect from the water source. At this time, the water in the demonstration tank 11 returns to the inlet valve 41 through the check valve 43, and is then pumped back to the demonstration tank 11 by the water pump 30, allowing the water flow to circulate and avoiding water waste. At the end of the demonstration, the check valve 43 is closed and the drain valve 42 is opened, allowing the water to drain out from the drain valve 42.

[0041] In some optional embodiments, a level gauge 17 is installed in the demonstration tank 11, and the level gauge 17 is connected to the inlet valve 41 and the check valve 43 respectively. During the water filling stage of the demonstration tank 11 before the demonstration, when the water level in the demonstration tank 11 reaches a sufficiently high level, the level gauge 17 sends a detection signal to the inlet valve 41 and the check valve 43, causing the check valve 43 to open and the inlet valve 41 to switch to a state of being connected to the check valve 43 and disconnected from the water source, thereby automatically entering the water circulation state, which facilitates the operation of the user.

[0042] In this embodiment, the control panel 14 is connected to the water pump 30, the drain valve 42, the inlet valve 41 and the check valve 43 respectively. The detection signal sent by the level gauge 17 is transmitted to the control panel 14, and then the control panel 14 sends control signals to the inlet valve 41 and the check valve 43 to control the operation of the check valve 43 and the inlet valve 41.

[0043] Please see Figure 6 This is an exploded view of a partial structure of the elastic connector and the demonstration piece according to an embodiment of the present invention. To facilitate the disassembly and replacement of the demonstration piece 23, in some optional embodiments, the elastic connector 22 and the demonstration piece 23 are detachably connected. The detachable connection method of the elastic connector 22 and the demonstration piece 23 can be selected according to actual needs. For example, in some optional embodiments, the elastic connector 22 includes several connecting ropes 221, which are elastic and connected to a force gauge. A buckle 222 is connected to the end of each connecting rope 221. A buckle 231 is provided on the demonstration piece 23, and the buckle 231 and the buckle 222 engage to achieve the detachability of the connecting rope 221 and the demonstration piece 23. Alternatively, hooks can be provided on both sides of the demonstration piece 23, and the connecting rope 221 can be tied to the hooks.

[0044] Please see Figures 7 to 9 , Figure 7 This is a cross-sectional view of a fluid mechanics teaching device according to an embodiment of the present invention, used to demonstrate the fluid mechanics principles of an aircraft wing. Figure 8 This is a cross-sectional view of the second demonstration component according to an embodiment of the present invention. Figure 9This is a cross-sectional view of the second demonstration component and smoke belt according to one embodiment of the present invention. To increase the functionality of the teaching equipment, in some optional embodiments, a flip cover 18 is rotatably provided on the support 10, which can open and close the demonstration slot 11; a transparent part 19 is provided on the side of the demonstration slot 11, so that students can easily observe the fluid movement changes in the demonstration slot 11 from one side. In this embodiment, the transparent part 19 is transparent glass or acrylic plate. The fluid mechanics teaching equipment also includes a switching valve 44, an air pump 50, a smoke generator 60, and a second demonstration component 70; the air pump 50 and the water pump 30 are both connected to the water inlet 12 through the switching valve 44, the smoke generator 60 is connected to the air pump 50, and the second demonstration component 70 includes a counterweight base 71 and an wing-shaped component 72 disposed on the counterweight base 71, the counterweight base 71 being disposed inside the demonstration slot 11. The basic principle of fluid mechanics is that slower-moving air has higher pressure, while faster-moving air has lower pressure. Therefore, the pressure on the lower surface of an aircraft wing is higher than the pressure on the upper surface. This invention uses smoke to demonstrate the fluid mechanics principle of an aircraft wing. During the demonstration, the switching valve 44 is connected to the air pump 50 and disconnected from the water pump 30. The smoke generator 60 and the air pump 50 are activated, allowing the smoke to flow to the flow equalization plate 15. After the smoke passes through the flow equalization orifice 151, it can be observed that the smoke is divided into smoke bands 80 by the flow equalization plate 15, achieving a rectification effect. This allows students to observe the individual smoke bands 80. Some of the smoke bands 80 pass through the wing contour piece in the demonstration slot 11. 72 is curved, while the smoke trail 80 that does not pass through the wing profile 72 is straight. Since the top of the wing is curved, let's take two smoke trails 80 as examples. These two smoke trails 80 are divided into an upper smoke trail and a lower smoke trail. The upper smoke trail passes through the wing profile 72 and wraps around to the top of the wing profile 72, appearing curved. The lower smoke trail passes directly through the bottom of the wing profile 72, appearing straight. By observing the smoke trails 80, we can see that the upper smoke trail, which wraps around the top of the wing, has a longer path than the lower smoke trail. This indicates that the fluid velocity is higher and the pressure is lower at the upper smoke trail, while the pressure is relatively higher at the lower smoke trail, thus providing lift to the wing. Of course, this also involves theoretical knowledge such as the Coanda effect and Stokes' law, but in secondary school teaching, only the relevant principles of fluid mechanics need to be mentioned. Furthermore, when demonstrating the relationship between fluid resistance and the cross-sectional area of ​​an object using flowing water, the switching valve 44 is connected to the water pump 30 and disconnected from the air pump 50.

[0045] Both the inlet valve 41 and the switching valve 44 can be three-way valves.

[0046] The counterweight base 71 helps to prevent the wing profile 72 from shifting.

[0047] In some alternative embodiments, the elastic connector 22 is detachably connected to the force gauge 21, so that when demonstrating the hydrodynamic principles of the aircraft wing, the elastic connector 22 can be removed, thereby removing the elastic connector 22 and the demonstration piece 23 from the demonstration slot 11 to avoid the elastic connector 22 and the demonstration piece 23 obstructing the observation of the smoke strip 80.

[0048] In some alternative embodiments, the bottom of the demonstration slot 11 is provided with a positioning slot, and the bottom of the counterweight base 71 is provided with a positioning protrusion 73, which extends into the positioning slot to prevent the counterweight base 71 from being blown away and shifting its position.

[0049] Please see Figure 10 This is a schematic diagram of the structure of the counterweight and demonstration airbag in one embodiment of the present invention. In addition, in order to enhance the teaching function of the fluid mechanics teaching equipment of the present invention, in some optional embodiments, the fluid mechanics teaching equipment also includes a counterweight 91 and two demonstration airbags 92. Demonstration airbags 92 are respectively provided on both sides of the counterweight 91. An air cavity is formed inside the demonstration airbag 92. The air cavity of the demonstration airbag 92 is connected to the inflation connector through an inflation tube. The inflation connector is detachably connected to the air pump 50. The principle of submarine buoyancy and descent can be demonstrated by using the demonstration airbag 92. The specific demonstration process is as follows: the demonstration tank 11 is filled with water. When the demonstration airbag 92 is placed in the demonstration tank 11, due to insufficient buoyancy, the demonstration airbag 92 will sink to the bottom of the demonstration tank 11 under the gravity of the counterweight 91. After the inflation connector is detachably connected to the air pump 50, a certain amount of gas is injected into the air chamber of the demonstration airbag 92 through the air pump 50, so that the demonstration airbag 92 gradually floats up. By controlling the amount of gas injected into the demonstration airbag 92, the demonstration airbag 92 can float above the water surface in the demonstration tank 11, or it can be kept below the water surface and not in contact with the bottom of the demonstration tank 11, thus demonstrating the principle of submarine buoyancy and descent.

[0050] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A hydromechanics teaching device, characterized by The utility model relates to a fluid mechanics teaching equipment, including: Support, first demonstration component group and water pump, demonstration groove is provided with on the support, and the opposite sides of demonstration groove are provided with water inlet and water outlet respectively, the first demonstration component includes force gage, elastic connecting piece and demonstration piece, the force gage is set up on the support, and the demonstration piece is set up in demonstration groove, and it is connected with the force gage through the elastic connecting piece, and the side of demonstration piece towards water inlet forms the flow face, and the area size of the flow face of different first demonstration component is different, the water pump communicates with water inlet.

2. A fluid mechanics teaching apparatus according to claim 1, wherein: The water inlet is provided with a flow uniforming plate, and a plurality of flow uniforming holes are uniformly arranged on the flow uniforming plate.

3. The device of claim 1, wherein: A flow velocity measuring instrument is arranged in the demonstration tank.

4. The fluid mechanics teaching apparatus according to claim 1, wherein Further comprising: A water inlet valve, a drain valve and a one-way valve, the water inlet valve communicates with the water pump, the drain valve communicates with the water outlet of the demonstration tank, and the one-way valve communicates with the water inlet valve and the water outlet respectively.

5. A fluid mechanics teaching apparatus as claimed in claim 4, wherein: A liquid level instrument is arranged in the demonstration tank, and the liquid level instrument is signal connected with the water inlet valve and the one-way valve respectively.

6. A fluid mechanics teaching apparatus according to any one of claims 1 to 5, wherein: The elastic connecting piece is detachably connected with the demonstration piece.

7. A fluid mechanics teaching apparatus as claimed in claim 6, wherein: The elastic connecting piece includes a plurality of connecting ropes, the connecting ropes are connected with the force gage, the connecting ropes are connected with buckle seats, buckles are arranged on the demonstration piece, and the buckles and the buckle seats are buckled.

8. The device of claim 2, wherein: A flip cover is rotatably arranged on the support, the flip cover can open and close the demonstration tank, a transparent part is arranged on the side of the demonstration tank, the fluid mechanics teaching equipment further comprises a conversion valve, an air pump, a smoke generator and a second demonstration component, the air pump and the water pump communicate with the water inlet through the conversion valve, the smoke generator is connected with the air pump, the second demonstration component includes a counterweight base and a wing profile arranged on the counterweight base, and the counterweight base is arranged in the demonstration tank.

9. A fluid mechanics teaching apparatus as claimed in claim 8, wherein: The elastic connecting piece is detachably connected with the force gage.

10. The fluid mechanics teaching apparatus of claim 8, wherein: A positioning groove is arranged at the bottom of the demonstration tank, a positioning protruding part is arranged at the bottom of the counterweight base, and the positioning protruding part extends into the positioning groove.

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