A simulation teaching device for wing stall phenomenon

Abstract

The application provides a simulation teaching device for wing stall phenomenon applied to the field of fluid mechanics teaching, which can assist students to more intuitively understand the air flow state of the wing surface by simulating the air flow phenomenon with or without a real object under normal flight state and the air flow phenomenon with or without a real object under stall state, and can intuitively observe the colored smoke flow state under the normal flight and stall state in the simulation without a real object, and can make the students further understand the difference between the air flow speed and direction under the two conditions by the different real object reflections made by the wind measuring piece under the normal air flow and the separated air flow in the simulation with a real object, so that the students can effectively understand the principle of the aircraft lift and the stall state through the simulation comparison of multiple groups of different conditions, and the teaching effect is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of fluid mechanics teaching, in particular to a simulation teaching device for wing stall phenomenon. BACKGROUND

[0002] Simulation demonstration is to make some real objects lifelike. Due to objective reasons, some parts of the aircraft cannot be brought into the classroom for classroom teaching, but simulation demonstration can teach some important devices, concepts and definitions in combination with classroom teaching.

[0003] The lift of an aircraft is mainly generated by the wings. The principle of lift generation can be explained by Bernoulli's principle. However, pure theoretical explanation is too abstract and not easy to understand. Under normal circumstances, when the wind flows through the upper surface of the wing, the airflow will speed up, and the faster the speed, the smaller the pressure, thereby forming a pressure difference between the upper and lower surfaces of the wing, generating lift. Aircraft stall is caused by too large an angle of attack, causing airflow separation. The airflow flowing through the surface of the wing separates due to the adverse pressure gradient and viscous action, causing the pressure at the separation point on the upper surface to rise, thus causing the lift to drop suddenly, and the aircraft enters a stall state.

[0004] Patent No. CN202010719866.3 discloses an experimental and simulation demonstration device for wing lift and surface flow. The device can directly display the pressure difference between the upper and lower surfaces of the measured wing model and the atmospheric pressure through a multi-tube pressure gauge, thereby performing wing lift principle experiments and classroom simulation demonstrations. The device can also perform aircraft stall experiments and classroom simulation demonstrations by continuously increasing the angle of attack of the wing model through a support mechanism and combining with colored smoke flow display technology. The device combines theory with practice and greatly improves the experimental and teaching effect.

[0005] However, the above-mentioned demonstration device only directly tests the gas pressure. Since the gas pressure is related to the state of the airflow on the surface, it is difficult for students to clearly and obviously observe the flow rate and direction change of the airflow through colored smoke, and it is not easy for students to intuitively understand the wing stall principle. SUMMARY

[0006] The application aims to solve the problem that the existing simulation teaching device is difficult for students to clearly understand the airflow change on the wing surface when the aircraft stalls, and provides a simulation teaching device for wing stall phenomenon compared with the prior art, which comprises a transparent box, a smoke guide box, a flow guide grid and a fan are sequentially and fixedly connected inside the transparent box from left to right, a wing model is arranged between the smoke guide box and the flow guide grid, the wing model is rotationally connected to the inside of the transparent box through a rotating shaft, one end of the rotating shaft is movably penetrated through the transparent box and extends to the outside, a smoke storage box for storing colored smoke is fixedly connected to the left end of the transparent box, vertical cylinders are fixedly connected to the upper and lower inner walls of the transparent box, one pair of vertical cylinders are respectively located on the upper and lower sides of the wing model, a flexible pad is fixedly connected to the end of the vertical cylinder close to the wing model, a fixed plate is fixedly connected to the inside of the vertical cylinder, an elastic rope is fixedly connected to the end of the fixed plate close to the wing model, and a wind measuring element is fixedly connected to the end of the elastic rope movably penetrated through the flexible pad;

[0007] The smoke guide box comprises a box plate, a gas collection cavity is formed in the inside of the box plate, two groups of vertically distributed smoke holes are formed in the inner wall of the gas collection cavity close to the wing model, the vertical cylinder is located at the right side of one group of smoke holes, a main smoke blocking plate is slidably connected to the inside of the gas collection cavity, the upper end of the main smoke blocking plate penetrates through the inner wall of the gas collection cavity and the transparent box and extends to the outside, the upper inner wall of the gas collection cavity and the upper end of the transparent box are both provided with a main sliding hole for the main smoke blocking plate to move, a secondary smoke blocking plate is arranged on the side of the flow guide grid close to the wing model, the upper end of the secondary smoke blocking plate is movably penetrated through the transparent box from inside to outside, and a connecting rod is fixedly connected between the secondary smoke blocking plate and the main smoke blocking plate, and the upper end of the transparent box is provided with a secondary sliding hole for the secondary smoke blocking plate to move.

[0008] The use method of the simulation teaching device for wing stall phenomenon is as follows:

[0009] S1, normal flight, no physical airflow phenomenon simulation:

[0010] Adjust the wing model to a normal flight attitude, move the connecting rod, block the main smoke blocking plate at the group of smoke hole orifices opposite to the vertical cylinder, and then inject a sufficient amount of colored smoke into the smoke storage box;

[0011] Start the fan, the colored smoke overflows through the smoke guide box opposite to the wing model, and the colored smoke flow phenomenon is observed visually to demonstrate the wing surface airflow state when the wing is in normal flight;

[0012] S2, normal flight, physical reflection of airflow phenomenon simulation:

[0013] Keep the wing model in normal flight attitude, move the main smoke blocking plate to block the other group of smoke hole orifices;

[0014] Start the fan, the colored smoke overflows opposite to the wing model and flows through the wind measuring element, and the position change of the wind measuring element is observed visually to demonstrate the wing surface airflow speed when the wing is in normal flight;

[0015] S3, in the stall state, no physical airflow phenomenon simulation:

[0016] The wing model is adjusted to a large angle of attack stall attitude, and the main smoke baffle position in S1 is kept unchanged;

[0017] Start the fan, and the colored smoke is overflowing directly opposite the wing model, and the colored smoke flow phenomenon is observed visually to demonstrate the wing surface airflow state when the wing stalls;

[0018] S4, in the stall state, the phenomenon of reflecting the airflow with the physical object:

[0019] The wing model is adjusted to a large angle of attack stall attitude, and the main smoke baffle position in S2 is kept unchanged;

[0020] Start the fan, and the colored smoke is overflowing directly opposite the wing model and flows through the wind measuring piece, and the visual observation of the wind measuring piece position change is used to demonstrate the change of the wing surface airflow speed and direction when the wing stalls.

[0021] Optionally, the wind measuring piece includes an inner measuring piece, and a plurality of arc skeletons and a plurality of flexible cloths are arranged on the outer side of the inner measuring piece in a spaced manner, and the arc skeletons and the flexible cloths are fixedly connected with each other, the arc skeletons close to the flexible pad are fixedly connected with the elastic rope, and the outer surfaces of a pair of arc skeletons away from the flexible pad are coated with a magnetic coating.

[0022] Optionally, the wind measuring piece further includes a pull rope located on the inner side of the vertical cylinder, the pull rope is an integrated structure formed by a main rope and a pair of branch ropes, the end portions of the pair of branch ropes are movably penetrated through the flexible pad and are fixedly connected with the pair of arc skeletons with the magnetic coating respectively, and the pair of branch ropes are movably penetrated through the remaining arc skeletons on the two sides of the inner measuring piece respectively.

[0023] Optionally, the end portion of the main rope is movably penetrated through the inner wall of the transparent box and extends to the outside, and an end head is fixedly connected with the end portion.

[0024] Optionally, the wind measuring piece further includes a pair of I-shaped plates located on the outer side of the inner measuring piece, an inner shaft is fixedly connected between the pair of I-shaped plates, and the inner measuring piece is rotatably connected to the outer end of the inner shaft.

[0025] Optionally, the two end portions of the arc skeleton extend to the inner sides of the pair of I-shaped plates respectively, and the two end portions are fixedly connected with limiting rods, a pair of annular grooves are formed in the inner surfaces of the I-shaped plates, and the two end portions of the limiting rods are slidably connected to the interiors of the pair of annular grooves respectively.

[0026] Optionally, the inner measuring piece is a sphere with a concave-convex outer surface, and a colored convex block is fixedly connected to the outer end of the sphere.

[0027] Optionally, a pair of metal sensors are fixedly connected to the wing model, and the pair of metal sensors are respectively located near the pair of wind measuring members.

[0028] Optionally, the method for using the wing stall phenomenon simulation teaching device further comprises the following steps:

[0029] S5, in normal flight, the phenomenon of air flow is simulated by a physical object:

[0030] The position of the wing model and the position of the main smoke blocking plate in S2 are kept unchanged, the pull rope is manually pulled outward until it cannot be moved, the arc-shaped framework and the flexible cloth are contracted, the inner measuring member is exposed to the outside world, and the state is kept;

[0031] The fan is started, the colored smoke is overflowed and flows through the wind measuring member opposite to the wing model, the rotation phenomenon of the inner measuring member is visually observed, and the detection data result of the metal sensor is referred to, so that the wing surface air flow speed and direction change in normal flight are further deduced;

[0032] S6, in stall state, the phenomenon of air flow is simulated by a physical object:

[0033] The position of the wing model and the position of the main smoke blocking plate in S4 are kept unchanged, and the pull rope is manually pulled outward until it cannot be moved, and the state is kept;

[0034] The fan is started, the rotation phenomenon of the inner measuring member is visually observed, and the detection data result of the metal sensor is referred to, so that the wing surface air flow speed and direction change in stall state are further deduced.

[0035] Compared with the prior art, the advantages of the present application are:

[0036] (1) The present application can simulate the presence and absence of physical air flow phenomenon in normal flight state and the presence and absence of physical air flow phenomenon in stall state, which can help students to more intuitively understand the wing surface air flow state. In the simulation without physical object, the colored smoke flow state in normal flight and stall state can be observed intuitively. In the simulation with physical object, the difference between the physical reflection of the wind measuring member under normal air flow and under separated air flow can make students further understand the difference between the air flow speed and direction in the two cases. Through the simulation and comparison of multiple different conditions, the students can effectively understand the principle of aircraft lift and stall state, and the teaching effect is greatly improved.

[0037] (2) The colored smoke flows through the wind measuring piece, and the smoke airflow drives the wind measuring piece to move. According to Bernoulli's theorem, the flow speed above the wing surface is greater than the flow speed below the wing surface. Therefore, the inclination moving range of the wind measuring piece on the upper side of the wing model is greater than the inclination moving range of the wind measuring piece on the lower side of the wing model. Through the physical reflection of the wind measuring piece under the airflow, the student can clearly understand the wing surface airflow speed in the normal flight state, and effectively assist in understanding the airplane lift principle in combination with the observation of the airflow direction without the physical airflow.

[0038] (3) When the wing is in the stall state, the airflow above the wing surface is in the separation and disorder state, the speed is reduced, and the trajectory is chaotic. At this time, the moving range of the wind measuring piece on the upper side of the wing surface will be greatly reduced compared to the normal airflow state, and fluctuations are easy to occur. Through the physical reflection of the wind measuring piece under the airflow separation state, the student can further understand the wing surface airflow speed and state in the stall state, and effectively assist in understanding the airplane stall state in combination with the airflow state without the physical airflow.

[0039] (4) Through the impact of the smoke airflow, the inner measuring piece can be driven to rotate. The colored convex block can be used as the eye focusing point in visual observation, and the rotation of the inner measuring piece can be observed from the outside. Under the normal airflow, the rotation of the inner measuring piece tends to be uniform and fast due to the stable and rapid airflow. Under the stall state, the rotation speed of the inner measuring piece is reduced due to the separation and disorder of the airflow, and the rotation may stop or even reverse at a low probability. Therefore, through the physical reflection of the inner measuring piece under the two airflow states, the effect of further assisting the student to understand the airflow state is achieved.

[0040] (5) During the rotation of the inner measuring piece, the distance between the colored convex block on the surface of the inner measuring piece and the metal sensor also changes constantly, so that the signal data detected by the metal sensor changes. On the basis of visual observation of the rotation state of the inner measuring piece, the rotation state of the inner measuring piece under the normal airflow and the stall airflow can be more accurately obtained by combining the data detection results of the metal sensor. BRIEF DESCRIPTION OF DRAWINGS

[0041] Figure 1 is a teaching simulation diagram of the present application;

[0042] Figure 2 is a perspective view of the present application;

[0043] Figure 3 is a front structure schematic diagram of example 1 of the present application;

[0044] Figure 4 is a top structure schematic diagram of example 1 of the present application;

[0045] Figure 5 is a teaching simulation schematic diagram of example 1 of the present application Figure 1 ;

[0046] Figure 6 is a schematic diagram of a teaching simulation of embodiment 1 of the present application Figure 2 ;

[0047] Figure 7 is a schematic diagram of a front structure of embodiment 2 of the present application

[0048] Figure 8 is a schematic diagram of a side structure of embodiment 2 of the present application

[0049] Figure 9 is a perspective view of a wind measuring part in embodiment 2 of the present application Figure 1 ;

[0050] Figure 10 is a perspective view of a wind measuring part in embodiment 2 of the present application Figure 2 ;

[0051] Figure 11 is a schematic diagram of a front structure of a wind measuring part in embodiment 2 of the present application

[0052] Figure 12 is a schematic diagram of a teaching simulation of embodiment 2 of the present application Figure 1 ;

[0053] Figure 13 is a schematic diagram of a teaching simulation of embodiment 2 of the present application Figure 2 ;

[0054] Figure 14 is a schematic diagram of a teaching simulation of embodiment 2 of the present application Figure 3 ;

[0055] Figure 15 is a schematic diagram of a wing model of embodiment 2 of the present application.

[0056] Explanation of reference numerals in the drawings:

[0057] 1 transparent box, 2 smoke storage box, 3 smoke guide box, 31 box plate, 3101 smoke hole, 32 main smoke resistance plate, 4 flow guide grid, 401 auxiliary smoke resistance plate, 5 fan, 6 vertical cylinder, 7 wind measuring part, 71 arc-shaped framework, 72 flexible cloth, 73 inner measuring part, 74 I-shaped plate, 75 pull rope, 76 end, 77 inner shaft, 78 limiting rod, 8 elastic rope, 9 fixed plate, 10 flexible pad, 11 rotating shaft, 12 metal sensor. DETAILED DESCRIPTION

[0058] The embodiments will be described in detail in conjunction with the drawings of the present application, and all other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor shall fall within the scope of protection of the present application. EMBODIMENT

[0059] The application provides a simulation teaching device for wing stall phenomenon, please refer to Figure 1 and Figure 2 , including a transparent box 1, combined Figure 3 , the inside of the transparent box 1 is sequentially and fixedly connected with a smoke guide box 3, a flow guide grid 4 and a fan 5 from left to right, a wing model (indicated by N in the drawing) is arranged between the smoke guide box 3 and the flow guide grid 4, as shown in Figure 4 , the wing model is rotationally connected to the inside of the transparent box 1 through a rotating shaft 11, one end of the rotating shaft 11 is movably penetrated through the transparent box 1 and extends to the outside, a nut is threadedly connected to the outer end of the rotating shaft 11, so that the rotating shaft 11 can be fixed on the transparent box 1, thereby manually controlling the rotation of the wing model and positioning the wing model, so that the wing model presents a normal flight state or a stall state, the left end of the transparent box 1 is fixedly connected with a smoke storage box 2 for storing colored smoke, when the fan 5 is started, the fan 5 performs air extraction on the inside of the transparent box 1, so that the colored smoke flows out from the smoke guide box 3 towards the wing model, simulating the airflow flowing through the airfoil surface, and students can intuitively understand the airflow state by visually observing the flow of the colored smoke.

[0060] Please refer to Figure 2 , the upper and lower inner walls of the transparent box 1 are fixedly connected with vertical tubes 6, one pair of vertical tubes 6 are respectively located on the upper and lower sides of the wing model, one end of each vertical tube 6 close to the wing model is fixedly connected with a flexible pad 10, the inside of each vertical tube 6 is fixedly connected with a fixed plate 9, one end of each fixed plate 9 close to the wing model is fixedly connected with an elastic rope 8, the end of each elastic rope 8 is movably penetrated through the flexible pad 10 and fixedly connected with a wind measuring piece 7, the wind measuring piece 7 is made of light and hard material, in the initial state, the wind measuring piece 7 and the flexible pad 10 are in contact with each other, and the elastic rope 8 is in a slightly stretched state.

[0061] Please refer to Figure 3 and Figure 4 , the smoke guide box 3 comprises a box plate 31, a gas collection cavity is formed in the inside of the box plate 31, two groups of vertically distributed smoke holes 3101 are formed in the inner wall of the gas collection cavity close to the wing model, one vertical tube 6 is located at the right side of one group of smoke holes 3101, a main smoke blocking plate 32 is slidably connected in the inside of the gas collection cavity, the upper end of the main smoke blocking plate 32 sequentially penetrates through the inner wall of the gas collection cavity and the transparent box 1 and extends to the outside, the upper inner wall of the gas collection cavity and the upper end of the transparent box 1 are both provided with main sliding holes for the main smoke blocking plate 32 to move, a secondary smoke blocking plate 401 is arranged on the side of the flow guide grid 4 close to the wing model, the upper end of the secondary smoke blocking plate 401 is movably penetrated through the transparent box 1 from inside to outside and is fixedly connected with a connecting rod between the main smoke blocking plate 32, and the upper end of the transparent box 1 is provided with a secondary sliding hole for the secondary smoke blocking plate 401 to move.

[0062] By controlling the position of the main smoke blocking plate 32, the colored smoke can be controlled to overflow through the required smoke holes 3101, and by adjusting the position of the secondary smoke blocking plate 401, the colored smoke can be made to enter the corresponding position in the flow guide grid 4, as Figure 4The color smoke is shown to flow through the airfoil in an orderly strip, and is selectively passed through the position of the vertical cylinder 6, facilitating observation of the airflow state under different conditions. In addition, the position of the main smoke blocking plate 32 and the auxiliary smoke blocking plate 401 can be adjusted synchronously through the connecting rod, facilitating user operation.

[0063] Please refer to Figure 5 and Figure 6 The use method of the wing stall phenomenon simulation teaching device is as follows:

[0064] S1. When flying normally, no physical airflow phenomenon simulation:

[0065] Adjust the wing model to a normal flight attitude, move the connecting rod, and block the main smoke blocking plate 32 at the orifice of a group of smoke holes 3101 opposite the vertical cylinder 6 (combined with Figure 4 ), and then inject a sufficient amount of colored smoke into the smoke storage tank 2;

[0066] Start the fan 5, and the colored smoke is overflowed opposite the wing model through the smoke guide tank 3, and is not easy to pass through the position of the vertical cylinder 6 when flowing through the airfoil. The airflow phenomenon of the colored smoke flowing is observed visually, so as to demonstrate the wing surface airflow state when the wing is flying normally.

[0067] S2. When flying normally, reflect the airflow phenomenon with physical objects:

[0068] Keep the wing model in a normal flight attitude, and move the main smoke blocking plate 32 to block it at the orifice of another group of smoke holes 3101;

[0069] Start the fan 5, and the colored smoke is overflowed opposite the wing model and flows through the wind measuring piece 7. The position change of the wind measuring piece 7 is observed visually, so as to demonstrate the wing surface airflow speed when the wing is flying normally.

[0070] As Figure 5 shown, when the colored smoke flows through the vertical cylinder 6 and the wind measuring piece 7, the smoke airflow can drive the wind measuring piece 7 to move along the flow direction, and the elastic rope 8 is stretched. According to Bernoulli's theorem, the flow speed above the wing surface is greater than that below the wing surface, so the inclination movement amplitude of the upper wind measuring piece 7 of the wing model is greater than that of the lower wind measuring piece 7.

[0071] This step makes the students clearly understand the wing surface airflow speed condition when flying normally through the physical reflection of the wind measuring piece 7 under the airflow, in combination with the airflow flow direction observation in step S1, to assist in understanding the principle of airplane lift.

[0072] S3. When stalling, no physical airflow phenomenon simulation:

[0073] Adjust the wing model to a large angle of attack stall attitude, and keep the position of the main smoke blocking plate 32 unchanged in S1;

[0074] Start the fan 5, the colored smoke is overflowing opposite to the wing model, through visual observation of the colored smoke flow phenomenon, to this wing stall wing surface airflow state (such as Figure 6 Indicated) when the wing stall is performed;

[0075] S4, in the stall state, the phenomenon of reflecting the airflow by the physical simulation:

[0076] The wing model is adjusted to a large angle of attack stall attitude, the main smoke resistance plate 32 position in S2 is kept unchanged;

[0077] Start the fan 5, the colored smoke is also overflowing opposite to the wing model and flows through the wind measuring element 7, the visual observation of the wind measuring element 7 position change, to this wing stall wing surface airflow speed and direction change.

[0078] As Figure 6 Indicated, when the wing is in stall state, the airflow on the upper side of the wing is in a separated and chaotic state, through step S3, the airflow flow state under the separated state can be observed more clearly, combined with step S4, due to the airflow separation, the speed is reduced, the trajectory is chaotic, at this time, the moving range of the wind measuring element 7 on the upper side of the wing will be greatly reduced compared with S2, and fluctuations are easy to produce (such as Figure 5 Indicated), therefore, through the physical reflection made by the wind measuring element 7 under the airflow separation state, the students can further understand the wing surface airflow speed and state under the stall, combined with the no physical airflow state of S3, to assist understanding the stall state of the aircraft.

[0079] The present application can assist students to more intuitively understand the wing surface airflow state by simulating the physical and non-physical airflow phenomena under normal flight state and stall state, in the non-physical simulation, the colored smoke flow direction state under normal flight and stall state can be observed intuitively, in the physical simulation, through the different physical reflections made by the wind measuring element 7 under normal airflow and separated airflow, the students can further understand the difference between the airflow speed and direction under the two conditions, through the simulation and comparison of multiple different conditions, the students can effectively assist the understanding of the principle of aircraft lift and stall state, and the teaching effect is greatly improved. Embodiment

[0080] Compared with embodiment 1, the structure of the wind measuring element 7 is set as follows in this embodiment, and the remaining structure remains unchanged: combined with Figure 7 , Figure 9 And Figure 10 , the wind measuring element 7 includes an inner measuring element 73, a plurality of arc skeletons 71 and a plurality of flexible cloths 72 are arranged on the outer side of the inner measuring element 73 in a spaced manner, and the arc skeletons 71 and the flexible cloths 72 are fixedly connected with each other, the arc skeleton 71 close to the flexible pad 10 is fixedly connected with the elastic rope 8, and the outer surfaces of the pair of arc skeletons 71 away from the flexible pad 10 are coated with a magnetic coating;

[0081] like Figure 7 and Figure 9 As shown, when not affected by external forces, a pair of arc-shaped skeletons 71 farther from the flexible pad 10 are in a mutually adsorbed and fitted state, wrapping the inner measuring piece 73. The wind measuring piece 7 also includes a pull rope 75 located on the inner side of the vertical tube 6. The pull rope 75 is an integrated structure formed by a main rope and a pair of branch ropes. The ends of a pair of branch ropes movably pass through the flexible pad 10 and are respectively fixedly connected to a pair of arc-shaped skeletons 71 with magnetic coatings, and a pair of branch ropes movably pass through the remaining arc-shaped skeletons 71 on both sides of the inner measuring piece 73. The end of the main rope movably passes through the fixed plate 9 and the inner wall of the transparent box 1 and extends to the outside world, and its end is fixedly connected with an end 76. When the main rope is pulled outward, the main rope can drive a pair of branch ropes to move toward the inside of the vertical tube 6, so that the arc-shaped skeleton 71 and the flexible cloth 72 are in a state of being attracted to each other and wrapped. Figure 10 In the retracted state shown, the inner measuring member 73 is exposed. At the same time, the wind measuring member 7 of this embodiment can smoothly realize the tilting movement process in steps S2 and S4 through the relaxed state 35, that is, it does not affect the simulation teaching of embodiment 1;

[0082] Combine Figure 10 and Figure 11 The wind measuring piece 7 also includes a pair of I-shaped plates 74 located on the outside of the inner measuring piece 73. An inner shaft 77 is fixedly connected between the pair of I-shaped plates 74. The inner measuring piece 73 is rotatably connected to the outer end of the inner shaft 77. The two end portions of the arc-shaped skeleton 71 extend to the inner sides of the pair of I-shaped plates 74 respectively, and both ends are fixedly connected to the limiting rods 78. A pair of annular grooves are provided on the inner surface of the I-shaped plates 74. The two ends of the limiting rods 78 are slidably connected to the inside of the pair of annular grooves respectively. Through the above structure, the stable rotation of the arc-shaped skeleton 71 on the outside of the inner measuring piece 73 is achieved, thereby realizing its own contracted state and the wrapped state of the inner measuring piece 73.

[0083] The inner measuring part 73 is a sphere with a concave-convex outer surface. The concave-convex surface can be easily affected by airflow, and a colored protrusion is fixedly connected to the outer end of the sphere.

[0084] A wing stall simulation teaching device, the use method of which further includes the following steps:

[0085] S5. During normal flight, simulate the airflow phenomenon using real objects.

[0086] like Figure 13 As shown, the position of the wing model and the main smoke baffle 32 in S2 is kept unchanged, and the pull rope 75 is manually pulled outward until it cannot move, so that the arc-shaped skeleton 71 and the flexible cloth 72 are contracted, and the internal test piece 73 is exposed to the outside world, and this state is maintained;

[0087] Start the fan 5, non-ferrous smoke is spilled against the wing model and flows through the wind measuring piece 7, visually observe the rotation phenomenon of the inner measuring piece 73, and further deduce the change of the wing surface airflow speed and direction when the wing is in normal flight;

[0088] S6, in the stall state, the phenomenon of reflecting the airflow with the real object is simulated:

[0089] As Figure 14 shown, keep the position of the wing model and the main smoke baffle 32 in S4 unchanged, and also manually pull the pull rope 75 outward until it cannot move, keep this state;

[0090] Start the fan 5, visually observe the rotation phenomenon of the inner measuring piece 73, and further deduce the change of the wing surface airflow speed and direction when the wing is in stall.

[0091] When the inner measuring piece 73 is exposed to the outside world and the colored smoke flows through the wind measuring piece 7, the rotation of the inner measuring piece 73 around the inner shaft 77 can be driven by the impact of the smoke airflow. The colored protrusions can be used as the eye focusing point for visual observation, making it easy to observe the rotation of the inner measuring piece 73 from the outside world. Under normal airflow, the rotation of the inner measuring piece 73 tends to be uniform and fast due to stable and rapid airflow. In the stall state, the rotation speed of the inner measuring piece 73 decreases due to airflow separation and disorder, and there is a low probability of rotation stagnation or even reversal. Therefore, by observing the physical reflection of the inner measuring piece 73 under the two airflows, the embodiment 1 further assists students in understanding the airflow state. Embodiment

[0092] Based on embodiment 2, a pair of metal sensors 12 for monitoring the rotation process of the inner measuring piece 73 are added, which are specifically set as follows: a pair of metal sensors 12 are fixedly connected to the wing model, and a processor electrically connected to the metal sensors 12 is fixedly installed at the outer end of the transparent box 1. The pair of metal sensors 12 are respectively located near the pair of wind measuring pieces 7, and the colored protrusions on the inner measuring piece 73 are made of metal material.

[0093] During the rotation of the inner measuring piece 73, the colored protrusions on its surface made of metal material constantly change the distance from the metal sensor 12, so that the signal data detected by the metal sensor 12 changes; therefore, in steps S5 and S6 of embodiment 2, based on the visual observation of the rotation state of the inner measuring piece 73, the data detection results of the metal sensor 12 can be combined to more accurately obtain the rotation state of the inner measuring piece 73 under normal airflow and stall airflow.

[0094] The above is only the best implementation method adopted by the present application in combination with the current actual demand, but the protection scope of the present application is not limited thereto.

Claims

1. A wing stall simulation teaching device, comprising a transparent box (1), wherein a smoke guide box (3), a guide grille (4) and a fan (5) are fixedly connected to the interior of the transparent box (1) from left to right in sequence, a wing model is provided between the smoke guide box (3) and the guide grille (4), the wing model is rotatably connected to the interior of the transparent box (1) via a rotating shaft (11), and one end of the rotating shaft (11) movably passes through the transparent box (1) and extends to the outside, the left end of the transparent box (1) is fixedly connected to a smoke storage box (2) for storing colored smoke, and the device is characterized in that: The upper and lower inner walls of the transparent box (1) are fixedly connected to vertical cylinders (6), a pair of the vertical cylinders (6) are respectively located on the upper and lower sides of the wing model, one end of the vertical cylinder (6) close to the wing model is fixedly connected to a flexible pad (10), the interior of the vertical cylinder (6) is fixedly connected to a fixed plate (9), the end of the fixed plate (9) close to the wing model is fixedly connected to an elastic rope (8), and the end of the elastic rope (8) movably passes through the flexible pad (10) and is fixedly connected to a wind measuring piece (7); The smoke guide box (3) includes a box plate (31), an air collection cavity is provided inside the box plate (31), and two groups of vertically distributed smoke holes (3101) are provided on the inner wall of the air collection cavity close to the wing model, and the vertical cylinder (6) is located on the right side of one group of smoke holes (3101). The air collection cavity is slidably connected to a main smoke blocking plate (32), and the upper end of the main smoke blocking plate (32) passes through the inner wall of the air collection cavity and the transparent box (1) in sequence and extends to the outside. The upper inner wall of the air collection cavity and the upper end of the transparent box (1) are both provided with main sliding holes for the movement of the main smoke blocking plate (32). The guide grille (4) is provided with a secondary smoke blocking plate (401) on the side close to the wing model, and the upper end of the secondary smoke blocking plate (401) moves from the inside to the outside and passes through the transparent box (1) and is fixedly connected to the main smoke blocking plate (32) by a connecting rod. The upper end of the transparent box (1) is provided with a secondary sliding hole for the movement of the secondary smoke blocking plate (401).

2. The wing stall simulation teaching device according to claim 1, characterized in that: The usage is: S1. During normal flight, there is no physical airflow simulation: Adjust the wing model to a normal flight posture, move the connecting rod so that the main smoke blocking plate (32) is blocked at the opening of a group of smoke holes (3101) facing the vertical cylinder (6), and then inject a sufficient amount of colored smoke into the smoke storage box (2); The fan (5) is started, and colored smoke overflows toward the wing model through the smoke guide box (3). The flow of colored smoke is visually observed to deduce the airflow state of the wing surface during normal flight; S2. During normal flight, simulate the airflow phenomenon with real objects: Keeping the wing model in normal flight posture, move the main smoke blocking plate (32) so that it blocks the opening of another group of smoke holes (3101); The fan (5) is started, and colored smoke overflows toward the wing model and flows through the wind measuring piece (7). The position change of the wind measuring piece (7) is visually observed to deduce the airflow velocity on the wing surface during normal flight; S3, Stall state, no physical airflow simulation: Adjust the wing model to a high angle of attack stall attitude, and keep the position of the main smoke baffle (32) in S1 unchanged; The fan (5) is started, and colored smoke overflows toward the wing model. The flow of colored smoke is visually observed to deduce the airflow state on the wing surface when the wing stalls; S4. Simulation of airflow phenomena using physical objects in stall state: Adjust the wing model to a high angle of attack stall attitude, and keep the position of the main smoke baffle (32) in S2 unchanged; The fan (5) is started, and the colored smoke overflows towards the wing model and flows through the wind measuring piece (7). The position change of the wind measuring piece (7) is visually observed to deduce the change of the airflow speed and direction on the wing surface when the wing stalls.

3. The wing stall simulation teaching device according to claim 2, characterized in that: The wind measuring piece (7) includes an inner measuring piece (73), and the outer side of the inner measuring piece (73) is provided with a plurality of arc-shaped frames (71) and a plurality of flexible cloths (72) distributed at intervals, and the arc-shaped frames (71) and the flexible cloths (72) are fixedly connected to each other, the arc-shaped frames (71) close to the flexible pad (10) are fixedly connected to the elastic rope (8), and the outer surfaces of a pair of arc-shaped frames (71) away from the flexible pad (10) are both coated with a magnetic coating.

4. The wing stall simulation teaching device according to claim 3, characterized in that: The wind measuring component (7) further includes a pull rope (75) located inside the vertical cylinder (6), wherein the pull rope (75) is an integrated structure formed by a main rope and a pair of branch ropes, wherein the ends of the pair of branch ropes movably pass through the flexible pad (10) and are respectively fixedly connected to a pair of arc-shaped skeletons (71) with magnetic coatings, and the pair of branch ropes movably pass through the remaining arc-shaped skeletons (71) on both sides of the inner measuring component (73).

5. The wing stall simulation teaching device according to claim 4, characterized in that: The end of the main rope movably passes through the fixed plate (9) and the inner wall of the transparent box (1) and extends to the outside, and the end thereof is fixedly connected to a terminal (76).

6. The wing stall simulation teaching device according to claim 3, characterized in that: The wind measuring member (7) further comprises a pair of I-shaped plates (74) located outside the inner measuring member (73), an inner shaft (77) being fixedly connected between the pair of I-shaped plates (74), and the inner measuring member (73) being rotatably connected to the outer end of the inner shaft (77).

7. The wing stall simulation teaching device according to claim 6, characterized in that: The two ends of the arc-shaped skeleton (71) extend to the inner side of a pair of I-shaped plates (74), and the two ends are fixedly connected to the limiting rods (78). The inner surface of the I-shaped plates (74) is provided with a pair of annular grooves, and the two ends of the limiting rods (78) are slidably connected to the inside of the pair of annular grooves.

8. The wing stall simulation teaching device according to claim 3, characterized in that: The inner measuring piece (73) is a sphere with a concave-convex outer surface, and a colored protrusion is fixedly connected to the outer end of the sphere.

9. The wing stall simulation teaching device according to claim 8, characterized in that: A pair of metal sensors (12) are fixedly connected to the wing model, and the pair of metal sensors (12) are respectively located near a pair of wind measuring parts (7), and the colored protrusions on the inner measuring part (73) are made of metal material.

10. The wing stall simulation teaching device according to claim 9, characterized in that: The method of use also includes the following steps: S5. During normal flight, simulate the airflow phenomenon using real objects. Keeping the position of the wing model and the main smoke blocker (32) in S2 unchanged, manually pull the pull rope (75) outward until it cannot move, so that the arc-shaped skeleton (71) and the flexible cloth (72) shrink, and the inner test piece (73) is exposed to the outside world, and this state is maintained; Start the fan (5), and colored smoke overflows toward the wing model and flows through the wind measuring piece (7). Visually observe the rotation phenomenon of the internal measuring piece (73), and refer to the detection data results of the metal sensor (12) to further deduce the changes in the airflow speed and direction of the wing surface during normal flight; S6. Simulation 2 of the airflow phenomenon in the stall state using real objects: Keep the position of the wing model and the main smoke blocker (32) in S4 unchanged, and manually pull the pull rope (75) outward until it cannot move, and maintain this state; Start the fan (5), visually observe the rotation phenomenon of the internal test piece (73), and refer to the detection data results of the metal sensor (12) to further deduce the changes in the airflow speed and direction of the wing surface when the wing stalls.

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