Aerofoil model surface pressure distribution experiment teaching demonstration platform

Abstract

The utility model belongs to the technical field of pressure test, and discloses a wing surface pressure distribution experiment teaching demonstration platform, which comprises a wind tunnel, a module plug, a test model, a hose I, a multi-tube pressure gauge and a water tank, the test model comprises a test point concentration head, a mounting chuck and an airfoil model; the mounting chuck comprises a circular plate I and a circular plate II which are connected; the measuring point concentration head is of a cubic structure and is fixedly connected with the circular plate I; the test model is provided with a plurality of pressure measuring holes and a plurality of channels, and the pressure measuring holes and the channels are the same in number. The wind tunnel is used for providing airflow for the airfoil model; the module plug comprises a cubic block and a pipe I; a plurality of through holes A are formed in the cubic block, and the through holes A are arranged into an array B; the multi-tube pressure gauge is used for measuring the pressure intensity of the pressure measuring hole; the water tank is connected with the multi-tube pressure gauge and used for supplying water to the multi-tube pressure gauge and adjusting the liquid level height in the multi-tube pressure gauge. When the hose I and the channel are disassembled and assembled, the operation is simpler and more convenient.

Description

An experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model Technical Field

[0001] This utility model belongs to the field of pressure testing technology and relates to an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil. Background Technology

[0002] A core concept in fluid mechanics is the pressure distribution generated by fluids at different velocities on the surface of an object. The lift generated by an airfoil is closely related to the pressure difference of the flow on its surface. According to Bernoulli's principle, an increase in fluid velocity leads to a decrease in pressure. This principle is crucial for understanding the performance of an airfoil at different angles of attack and velocities.

[0003] For example, the literature (Analysis of the physical principle of wing lift [J]. Modern Physics Knowledge, 2010, 22(2):20-21.) provides a testing device for the pressure change on the surface of an airfoil model (i.e., an experimental teaching demonstration platform for airfoil surface pressure distribution). The existing experimental teaching demonstration platform for airfoil model surface pressure distribution provides students with the opportunity to apply theoretical knowledge to practice, helping them understand complex aerodynamic performance. Students can recognize fluid behavior and aerodynamic characteristics, and enhance their mastery of classroom knowledge.

[0004] More specifically, the existing airfoil model surface pressure distribution experimental teaching demonstration platform includes an airfoil model, a wind tunnel, a multi-tube manometer, a water tank, and a vertical plate. The airfoil model has two pressure measurement hole groups and multiple pipes. Each pressure measurement hole group includes multiple pressure measurement holes, with one group located on the upper surface of the airfoil model and the other on the lower surface. When the airfoil model is placed horizontally, the projections of the pressure measurement holes in the two groups coincide and correspond one-to-one. One end of each of the multiple pipes is connected to a separate pressure measurement hole, and the openings at the other ends of the pipes are located on one side of the airfoil model. The multi-tube manometer includes a control tube, a connecting tube, and multiple branch tubes. The connecting tube is a closed tube at one end and is placed horizontally. A water tank connection port and multiple branch tube connection ports are located on the circumference of the connecting tube. The control tube and the multiple branch tubes are both unsealed tubes and are placed vertically. The control tube is connected to the opening at the other end of the connecting tube via a flexible hose. The lower ends of each of the multiple branch tubes are connected to a branch tube. Connection port; There are two multi-tube pressure gauges. The upper ends of the branch pipes of the multi-tube pressure gauges are connected to the openings on the side of the airfoil model through a hose and a pipe respectively; The water tank connection port of the multi-tube pressure gauge is connected to the water tank through a hose; There are multiple through holes from top to bottom on the vertical plate. The water tank is detachably fixed to the vertical plate by passing a screw through one of the through holes. The height of the water tank can be adjusted by selecting the height of the through hole, thereby adjusting the height of the liquid level in the multi-tube pressure gauge to achieve the purpose of zeroing the liquid level scale.

[0005] When the wind tunnel is started, the surface pressure of the airfoil model can be determined by the height of the liquid level in the branch pipe of the multi-tube manometer, which indicates the pressure distribution. However, this existing technology has the following problems:

[0006] (1) In this device, when the hose is connected to the channel on the airfoil model, the hose needs to be inserted into the channel one by one, and when disassembling, it also needs to be removed from the channel one by one, which makes the installation and disassembly process cumbersome.

[0007] (2) Water is injected into the multi-tube pressure gauge. Since water is transparent, it is not very convenient to read the reading and the pressure reading cannot be clearly and intuitively read.

[0008] (3) Since the through holes on the vertical plate are distributed at intervals from top to bottom, although the height of the water tank can be adjusted, the adjustment range of the height is limited and it is impossible to accurately bring the liquid level scale to zero.

[0009] Therefore, it is of great significance to study an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model in order to solve the above problems. Summary of the Invention

[0010] The purpose of this invention is to solve the problems existing in the prior art and provide an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil.

[0011] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0012] An experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model includes a wind tunnel, a modular plug, a test model, a hose I, a multi-tube pressure gauge, and a water tank;

[0013] The test model includes a measurement point concentration head, a mounting chuck, and an airfoil model;

[0014] The mounting chuck includes two connected circular plates, I and II; the central axes of circular plates I and II coincide, and the diameter of circular plate I is larger than the diameter of circular plate II.

[0015] The measuring point concentration head is a cubic structure, and is fixedly connected to circular plate I. The airfoil model includes an upper surface (i.e., the upper arc surface), a lower surface (i.e., the lower arc surface), and two side surfaces. One side surface of the airfoil model is fixedly connected to circular plate II. The test model has multiple pressure measuring holes and multiple channels, and the number of both is the same. The pressure measuring holes are located on the upper or lower surface of the airfoil model. The opening at one end of the channel is connected to the pressure measuring hole, and the opening at the other end is located on surface A of the measuring point concentration head, which is the surface of the measuring point concentration head away from circular plate I. The openings of the multiple channels on surface A are arranged in array A.

[0016] The wind tunnel is used to provide airflow for the test model of the airfoil model, with the chord of the airfoil model parallel to the wind tunnel axis;

[0017] The module plug includes a cube and tubes I; the cube has multiple through holes A, and the multiple through holes A are arranged in an array B; the arrays A and B have the same arrangement; the number of tubes I is the same as the number of channels; one end of tube I passes through the through hole A, and both ends of tube I are located outside the cube; the number of flexible tubes I is the same as the number of channels; one end of tube I is used to insert into the opening on the surface A of the measuring point concentrator, thereby connecting with the opening on the surface A of the measuring point concentrator, and the other end of tube I is connected to one end of flexible tube I, and the other end of flexible tube I is connected to a multi-tube manometer; the multi-tube manometer is used to measure the pressure of the measuring orifice; a water tank is connected to the multi-tube manometer, and the water tank is used to supply water to the multi-tube manometer and adjust the liquid level in the multi-tube manometer.

[0018] When connecting hose I and the channel, simply insert the module plug into the measuring point concentrator, so that one end of all hoses I is inserted into the opening on surface A of the measuring point concentrator and connected to the opening on surface A of the measuring point concentrator. When disconnecting hose I and the channel, simply remove the module plug from the measuring point concentrator. This solves the problem in the prior art where, when hose I is connected to the channel on the airfoil model, it is necessary to insert hose I one by one into the channel, and when disassembling, it is also necessary to remove them one by one from the channel, which makes the installation and disassembly process cumbersome.

[0019] As a preferred technical solution:

[0020] The wind tunnel, as described above, is an experimental teaching demonstration platform for surface pressure distribution of an airfoil model. It includes a fan, a fairing, and a test chamber.

[0021] The test chamber is a transparent test chamber, which is a hollow tubular structure open at both ends;

[0022] The air outlet of the fan is connected to the fairing, and the fairing is connected to one end of the transparent test chamber;

[0023] The transparent test chamber has mounting holes on its side; the mounting holes are used to insert the airfoil model of the test model into the interior of the transparent test chamber, and the mounting holes are clearance-fitted with the circular plate II of the mounting chuck.

[0024] The above-described airfoil model surface pressure distribution experimental teaching demonstration platform has a rectangular cross-section for the transparent test chamber.

[0025] As described above, an experimental teaching demonstration platform for surface pressure distribution of an airfoil model includes a test model that also contains bumps, gaskets, and bolts.

[0026] One side of the airfoil model is fixedly connected to circular plate II, and the other side is connected to a protrusion; the surface of the protrusion away from the airfoil model has a threaded hole;

[0027] Let the side where the mounting hole is located be labeled as side A, and the side opposite to side A be labeled as side B; side B is provided with a fixing hole; when the airfoil model of the test model is inserted into the interior of the transparent test chamber, the protrusion passes through the fixing hole and the gasket in sequence, and is fixedly connected to the bolt through the threaded hole. This design makes the test model more stable when installed in the transparent test chamber; the protrusion is respectively fitted with the fixing hole and the gasket with clearance.

[0028] As described above, in an experimental teaching demonstration platform for surface pressure distribution of an airfoil model, the protrusion is formed by connecting a cylinder and a hexagonal prism; the central axis of the cylinder coincides with the central axis of the hexagonal prism; the inner diameter of the fixing hole is 0.4 mm larger than the diameter of the cylinder; when the protrusion passes through the fixing hole and the gasket in sequence, the cylinder is exposed outside the transparent test chamber.

[0029] The through holes on the gasket are stepped holes, which consist of a cylindrical hole I, a hexagonal prism hole I, and a cylindrical hole II connected in sequence. The central axes of the cylindrical hole I, the hexagonal prism hole I, and the cylindrical hole II coincide. The depth of the cylindrical hole I is equal to the length of the cylinder protruding from the outside of the transparent test chamber, and the inner diameter of the cylindrical hole I is 0.4 mm larger than the diameter of the cylinder. The depth of the hexagonal prism hole I is equal to the length of the hexagonal prism, and the side length of the hexagonal prism hole I is 1 mm larger than the side length of the hexagonal prism. The depth of the cylindrical hole II is less than the length of the threaded section of the bolt, and the inner diameter of the cylindrical hole II is 0.5 mm larger than the diameter of the threaded section.

[0030] Along the direction perpendicular to the side of the airfoil model, the projection of the shim onto the plane containing the side of the airfoil model coincides with the side of the airfoil model. This design makes it easier for students to observe the airfoil model.

[0031] As described above, an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model has a scale ring on side A. When the angle of attack of the airfoil model needs to be adjusted, it can be achieved by rotating the mounting chuck. The scale ring is used to read the rotation angle of the circular plate I, thereby determining the angle of attack of the airfoil model.

[0032] As described above, an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model includes pressure measuring holes I and II; channels include channel I and channel II; the number of pressure measuring holes I, channel I, pressure measuring holes II, and channels is the same.

[0033] Pressure measuring hole I is located on the upper surface of the airfoil model, and channel I is located inside the test model; one end of channel I is connected to pressure measuring hole I, and the other end is located on surface A of the measuring point concentration head;

[0034] Pressure measuring hole II is located on the lower surface of the airfoil model, and channel II is located inside the test model; one end of channel II is connected to pressure measuring hole II, and the other end is located on surface A of the measuring point concentration head;

[0035] Let the opening of a channel I on surface A be called opening A, and the opening of a channel II on surface A be called opening B. All the openings A of channel I are arranged in a row on surface A to form group A of openings, and all the openings B of channel II are arranged in a row on surface A to form group B of openings. Group A of openings and group B of openings form array A.

[0036] As described above, an experimental teaching demonstration platform for surface pressure distribution of an airfoil model includes a multi-tube manometer comprising a control tube, a flexible tube II, a connecting tube, and multiple branch tubes; the number of branch tubes is the same as the number of channels I.

[0037] The connecting pipe is a pipe closed at one end and is placed horizontally. There is a water tank connection port and multiple branch pipe connection ports on the circumference of the connecting pipe. The control pipe and multiple branch pipes are all pipes with open ends and are placed vertically. The control pipe is connected to the opening of the connecting pipe through flexible hose II. The lower ends of the multiple branch pipes are each connected to a branch pipe connection port.

[0038] There are two multi-tube pressure gauges, designated as multi-tube pressure gauge I and multi-tube pressure gauge II; hose I includes hose Ia and hose Ib.

[0039] The upper ends of the branch pipes of multi-tube manometer I are each connected to an opening A in the opening A group via a hose Ia; the upper ends of the branch pipes of multi-tube manometer II are each connected to an opening B in the opening B group via a hose Ib.

[0040] The airfoil model surface pressure distribution experimental teaching demonstration platform described above further includes hoses III, IV, and V, and a tee pipe. One end of hose III is connected to the water tank connection port of multi-tube manometer I, and the other end is connected to one port of the tee pipe. One end of hose IV is connected to the water tank connection port of multi-tube manometer II, and the other end is connected to one port of the tee pipe. A water inlet is provided at the bottom of the water tank, and one end of hose V is connected to the water inlet, while the other end is connected to one port of the tee pipe. Water in the water tank is injected into multi-tube manometer I and multi-tube manometer II through the tee pipe.

[0041] The water tank is used to supply water to the multi-tube manometer I and multi-tube manometer II, and to adjust the liquid level in the branch pipes of multi-tube manometer I and multi-tube manometer II. A tracer ball is placed on the liquid surface in the branch pipes of multi-tube manometer I and multi-tube manometer II, respectively. The density of the tracer ball is lower than that of water. The tracer ball is used to assist in reading the liquid level, thereby solving the problem that reading is not very convenient in the prior art because water is transparent.

[0042] The airfoil model surface pressure distribution experimental teaching demonstration platform described above also includes a vertical plate, a horizontal fixed plate, a vertical fixed plate, and a lead screw assembly.

[0043] Let the two opposite faces of the vertical plate be face C and face D;

[0044] The vertical fixing plate has through holes B and C; the central axes of through holes B and C are on the same plane; there are two vertical fixing plates, which are respectively denoted as vertical fixing plate I and vertical fixing plate II; both vertical fixing plate I and vertical fixing plate II are fixed on surface C of the vertical plate, and the central axis of through hole C of vertical fixing plate I coincides with the central axis of through hole C of vertical fixing plate II;

[0045] The connecting tube of multi-tube pressure gauge I passes through the through hole B of vertical fixing plate I and the through hole B of vertical fixing plate II, and the two ends of the connecting tube of multi-tube pressure gauge I are located on opposite sides of the two vertical fixing plates. The connecting tube of multi-tube pressure gauge II passes through the through hole C of vertical fixing plate I and the through hole C of vertical fixing plate II, and the two ends of the connecting tube of multi-tube pressure gauge II are located on opposite sides of the two vertical fixing plates.

[0046] The horizontal fixing plate has two rows of through holes D; the number of through holes D in each row is the same as the number of channels I; the horizontal fixing plate is fixed to the vertical plate and is located above the vertical fixing plate; the lower ends of the branch pipes of multi-tube pressure gauge I pass through one of the through holes D in the same row and connect to one of the branch pipe connection ports of multi-tube pressure gauge I; the lower ends of the branch pipes of multi-tube pressure gauge II pass through one of the through holes D in the same row and connect to one of the branch pipe connection ports of multi-tube pressure gauge II; through the design of the horizontal fixing plate and the vertical fixing plate, multi-tube pressure gauge I and multi-tube pressure gauge II can be fixed on the vertical plate;

[0047] The lead screw assembly is fixed on surface D of the vertical plate; the water tank and the lead screw assembly are fixedly connected by the lead screw nut, and the lead screw assembly controls the height of the water tank through the lead screw nut. This design can overcome the problem of limited water tank height adjustment range in the existing technology.

[0048] The vertical plate has two through holes E; one end of the hose III passes through one through hole E and connects to the water tank connection port of the multi-tube pressure gauge I, and the other end connects to one port of the tee pipe; one end of the hose IV passes through one through hole E and connects to the water tank connection port of the multi-tube pressure gauge II, and the other end connects to one port of the tee pipe.

[0049] As described above, the airfoil model surface pressure distribution experimental teaching demonstration platform also has multiple elongated through holes on the vertical plate, with the length direction of the elongated through holes being vertical; the number of elongated through holes is the same as the number of branch pipes of the multi-tube pressure gauge I; the elongated through holes are used to adjust the height of the water tank, making it convenient to read the liquid level height from the side where surface D of the vertical plate is located.

[0050] Beneficial effects:

[0051] (1) When disassembling the connecting hose I and the channel, the module plug can be directly removed from the measuring point concentrator. This solves the problem in the prior art that when the hose I is connected to the channel on the airfoil model, the hose I needs to be inserted into the channel one by one, and the hose I also needs to be removed from the channel one by one, which makes the installation and disassembly process cumbersome.

[0052] (2) This utility model places a tracer ball on the liquid surface in the branch tube of multi-tube manometer I and the branch tube of multi-tube manometer II respectively. The density of the tracer ball is lower than that of water. The tracer ball is used to assist in reading the height of the liquid level, thereby solving the problem that the reading is not very convenient in the prior art because water is transparent.

[0053] (3) The screw assembly of this utility model can control the height of the water tank through the screw nut. This design can overcome the problem of limited water tank height adjustment range in the prior art. Attached Figure Description

[0054] Figure 1 is a schematic diagram of an experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to this utility model;

[0055] Figure 2 is a schematic diagram of the airfoil model of this utility model fixed in a wind tunnel;

[0056] Figure 3 is a partial enlarged view of the airfoil model of this utility model fixed in a wind tunnel;

[0057] Figure 4 is a side view of the test model of this utility model without the gasket and bolt installed;

[0058] Figure 5 is a schematic diagram of the measuring point concentrator and mounting chuck of this utility model;

[0059] Figure 6 is a top view of the test model of this utility model without the gaskets and bolts installed;

[0060] Figure 7 is a schematic diagram of the internal structure of the test model of this utility model;

[0061] Figure 8 shows the three views of the gasket of this utility model;

[0062] Figures 9 to 11 are three views of the module plug of this utility model;

[0063] Figure 12 is a schematic diagram showing the connection relationship between the module plug, the measuring point concentration head, and the hose I of this utility model.

[0064] Figure 13 is a schematic diagram of the fairing of this utility model;

[0065] Figure 14 is a schematic diagram of the multi-tube pressure gauge I and multi-tube pressure gauge II of this utility model on the vertical plate;

[0066] Figure 15 is a schematic diagram showing the connection relationship between the vertical plate, the horizontal fixing plate and the vertical fixing plate of this utility model.

[0067] Figure 16 is a schematic diagram of the multi-tube pressure gauge of this utility model;

[0068] Among them, 1-wind tunnel, 2-test model, 3-measuring point concentration head, 4-installation chuck, 5-airfoil model, 7-multi-tube pressure gauge, 8-water tank, 9-fan, 10-fairing, 11-test chamber, 12-protrusion, 13-gasket, 14-bolt, 15-cylinder, 16-hexagonal prism, 17-cylindrical hole I, 18-hexagonal prism hole I, 19-cylindrical hole II, 20-reference tube, 21-hose II, 22-connecting pipe, 23-branch pipe, 24-teet pipe, 25-horizontal fixing plate, 26-vertical fixing plate, 28-screw assembly, 29-module plug. Detailed Implementation

[0069] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0070] An experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model, as shown in Figures 1 to 16, includes a wind tunnel 1, a module plug 29, a test model 2, a hose I, a multi-tube pressure gauge 7, a water tank 8, a hose III, a hose IV, a hose V, a tee pipe 24, a vertical plate, a horizontal fixing plate 25, a vertical fixing plate 26, and a lead screw assembly 28.

[0071] As shown in Figures 3 to 6 and Figure 7, the test model 2 includes a measuring point concentration head 3, a mounting chuck 4, an airfoil model 5, a protrusion 12, a gasket 13, and a bolt 14;

[0072] The mounting chuck 4 includes connected circular plates I and II; the central axes of circular plates I and II coincide, and the diameter of circular plate I is larger than the diameter of circular plate II;

[0073] The measuring point concentration head has a cubic structure and is fixedly connected to the circular plate I.

[0074] The protrusion 12 is formed by connecting a cylinder 15 and a hexagonal prism 16, with the central axis of the cylinder 15 coinciding with the central axis of the hexagonal prism 16.

[0075] Airfoil model 5 includes an upper surface (i.e., the upper arc surface), a lower surface (i.e., the lower arc surface), and two side surfaces;

[0076] One side of the airfoil model 5 is fixedly connected to the circular plate II, and the other side is connected to the protrusion 12; the surface of the protrusion 12 away from the airfoil model 5 is provided with a threaded hole;

[0077] As shown in Figure 7, the test model 2 is equipped with multiple pressure measurement holes and multiple channels;

[0078] The pressure measuring holes include pressure measuring hole I and pressure measuring hole II; the channels include channel I and channel II; the number of pressure measuring holes I, channel I, pressure measuring holes II, and channels is the same; pressure measuring hole I is located on the upper surface of airfoil model 5, and channel I is located inside test model 2; one end of channel I is connected to pressure measuring hole I, and the other end is located on surface A of the measuring point concentration head, surface A being the surface of the measuring point concentration head away from circular plate I; pressure measuring hole II is located on the lower surface of airfoil model 5, and channel II is located inside test model 2; one end of channel II is connected to pressure measuring hole II, and the other end is located on surface A of the measuring point concentration head;

[0079] Let the opening of a channel I on surface A be called opening A, and the opening of a channel II on surface A be called opening B; all the openings A of channel I are arranged in a row on surface A to form group A of openings, and all the openings B of channel II are arranged in a row on surface A to form group B of openings. Group A of openings and group B of openings form array A.

[0080] Wind tunnel 1 includes a fan 9, a fairing 10, and a test chamber 11; wind tunnel 1 is used to provide airflow for airfoil model 5, and the chord of airfoil model 5 is parallel to the axis of wind tunnel 1.

[0081] Test chamber 11 is a transparent test chamber, which is a hollow tubular structure with openings at both ends and a rectangular cross-section. As shown in Figures 2 and 13, the air outlet of the fan 9 is connected to the shroud 10, and the shroud 10 is connected to one end of the transparent test chamber.

[0082] The transparent test chamber has mounting holes on its side. The mounting holes are used to insert the airfoil model of the test model into the interior of the transparent test chamber, and the mounting holes are clearance-fitted with the circular plate II of the mounting chuck.

[0083] The side where the mounting hole is located is designated as side A, and the side opposite to side A is designated as side B. Side A is provided with a scale ring, which is used to read the rotation angle of the circular plate I. Side B is provided with a fixing hole. The inner diameter of the fixing hole is 0.4 mm larger than the diameter of the cylinder 15.

[0084] When the airfoil model 5 is inserted into the transparent test chamber, the protrusion 12 passes through the fixing hole and the gasket 13 in sequence, and is fixedly connected to the bolt 14 through the threaded hole. At this time, the cylinder 15 is exposed outside the transparent test chamber; wherein, the protrusion 12 is clearance-fitted with the fixing hole and the gasket 13 respectively.

[0085] As shown in Figures 3 and 8, the through hole on the gasket 13 is a stepped hole, which consists of a cylindrical hole I17, a hexagonal prism hole I18, and a cylindrical hole II 19 connected in sequence. The central axis of the cylindrical hole I17, the central axis of the hexagonal prism hole I18, and the central axis of the cylindrical hole II 19 coincide. The depth of the cylindrical hole I17 is equal to the length of the cylinder 15 protruding outside the transparent test chamber, and the inner diameter of the cylindrical hole I17 is 0.4 mm larger than the diameter of the cylinder 15. The depth of the hexagonal prism hole I18 is equal to the length of the hexagonal prism 16, and the side length of the hexagonal prism hole I18 is 1 mm larger than the side length of the hexagonal prism 16. The depth of the cylindrical hole II 19 is less than the length of the threaded section of the bolt 14, and the inner diameter of the cylindrical hole II 19 is 0.5 mm larger than the diameter of the threaded section.

[0086] Along the direction perpendicular to the side of the airfoil model 5, the projection of the shim 13 onto the plane containing the side of the airfoil model 5 coincides with the side of the airfoil model 5.

[0087] As shown in Figures 14 to 16, the vertical plate has two through holes E and multiple elongated through holes; the length direction of the elongated through holes is vertical.

[0088] Let the two opposite faces of the vertical plate be face C and face D;

[0089] The vertical fixing plate 26 is provided with through holes B and C; the central axes of through holes B and C are on the same plane; there are two vertical fixing plates 26, which are respectively referred to as vertical fixing plate I and vertical fixing plate II; both vertical fixing plate I and vertical fixing plate II are fixed on the C surface of the vertical plate, and the central axis of the through hole C of vertical fixing plate I coincides with the central axis of the through hole C of vertical fixing plate II;

[0090] The horizontal fixing plate 25 is provided with two rows of through holes D; the number of through holes D in each row is the same as the number of channels I; the horizontal fixing plate 25 is fixed on the vertical plate and is located above the vertical fixing plate 26.

[0091] The multi-tube pressure gauge 7 includes a reference tube 20, a flexible tube II 21, a connecting tube 22, and multiple branch tubes 23; the number of branch tubes 23 is the same as the number of channels I; the multi-tube pressure gauge 7 is used to measure the pressure of the pressure measuring hole;

[0092] The connecting pipe 22 is a pipe closed at one end; the connecting pipe 22 has a water tank connection port and multiple branch pipe 23 connection ports on its circumference;

[0093] The control tube 20 and multiple branch tubes 23 are all unsealed tubes at both ends and are placed vertically; the control tube 20 is connected through the opening of the flexible tube II 21 and the connecting tube 22.

[0094] There are two multi-tube pressure gauges 7, which are designated as multi-tube pressure gauge I and multi-tube pressure gauge II respectively; the number of branch tubes 23 of multi-tube pressure gauge I is the same as the number of elongated through holes;

[0095] The connecting pipe 22 of the multi-tube pressure gauge I passes through the through hole B of the vertical fixing plate I and the through hole B of the vertical fixing plate II, and the two ends of the connecting pipe 22 of the multi-tube pressure gauge I are located on opposite sides of the two vertical fixing plates 26.

[0096] The lower ends of the branch pipes 23 of the multi-tube pressure gauge I each pass through one of the through holes D in the same row of through holes D and are connected to one of the branch pipe connection ports of the multi-tube pressure gauge I.

[0097] The connecting pipe 22 of the multi-tube pressure gauge II passes through the through hole C of the vertical fixing plate I and the through hole C of the vertical fixing plate II, and the two ends of the connecting pipe 22 of the multi-tube pressure gauge II are located on opposite sides of the two vertical fixing plates 26.

[0098] The lower ends of the branch pipes 23 of the multi-tube pressure gauge II each pass through one of the through holes D in the same row of through holes D and are connected to one of the branch pipe connection ports of the multi-tube pressure gauge II.

[0099] The lead screw assembly 28 is fixed to surface D of the vertical plate; the water tank 8 and the lead screw assembly 28 are fixedly connected by the lead screw nut, and the lead screw assembly 28 controls the height of the water tank 8 through the lead screw nut; the bottom of the water tank 8 is provided with a water inlet; one end of the hose III passes through a through hole E and connects to the water tank connection port of the multi-tube pressure gauge I, and the other end is connected to one port of the tee pipe 24; one end of the hose IV passes through a through hole E and connects to the water tank connection port of the multi-tube pressure gauge II, and the other end is connected to one port of the tee pipe 24. One end of the hose V is connected to the water inlet, and the other end is connected to one port of the three-way pipe 24; the water tank 8 is used to supply water to the multi-tube manometer I and the multi-tube manometer II, and adjusts the liquid level in the branch pipe 23 of the multi-tube manometer I and the branch pipe 23 of the multi-tube manometer II through the screw assembly 28; a tracer ball is placed on the liquid surface in the branch pipe 23 of the multi-tube manometer I and the branch pipe 23 of the multi-tube manometer II respectively. The density of the tracer ball is lower than that of water. The tracer ball is used to assist in reading the liquid level.

[0100] As shown in Figures 9 to 12, the module plug 29 includes a cubic block and a tube I;

[0101] The cube has multiple through holes A, and the multiple through holes A are arranged in array B; array A and array B have the same arrangement; the number of tubes I is the same as the number of channels;

[0102] One end of tube I passes through through hole A, and both ends of tube I are located outside the cube;

[0103] The number of hoses I is the same as the number of channels; hoses I include hose Ia and hose Ib;

[0104] The upper ends of the branch pipes 23 of the multi-tube pressure gauge I are each connected to one end of a tube I inserted into the through hole A through a flexible tube Ia. The other end of the tube I inserted into the through hole A is used to insert into an opening A on the surface A of the measuring point concentration head, thereby connecting with the opening on the surface A of the measuring point concentration head.

[0105] The upper ends of the branch pipes 23 of the multi-tube pressure gauge II are each connected to one end of the pipe I inserted into the through hole B through a flexible tube Ib. The other end of the pipe I inserted into the through hole B is used to insert into the opening B on the surface A of the measuring point concentration head, thereby connecting with the opening on the surface A of the measuring point concentration head.

[0106] The above-mentioned device is used as follows: after the test model is inserted into the transparent test chamber, the protrusion is passed through the fixing hole and the gasket in sequence, and then fixedly connected with the bolt through the threaded hole. Then, the height of the water tank is controlled by the screw assembly to make the liquid level scale return to zero.

[0107] Then, the fan is turned on to blow air onto the upper and lower surfaces of the airfoil model. The airflow acting on the upper and lower surfaces is then introduced into the multi-tube manometer I and multi-tube manometer II through multiple pressure measuring holes and channels on the test model. Subsequently, the liquid level in the branch pipe and the height of the tracer ball are automatically adjusted according to the amount of airflow. Finally, the liquid level is read with the help of the tracer ball to obtain the surface pressure distribution of the airfoil model.

Claims

1. A demonstration platform for experimental teaching of pressure distribution on the surface of an airfoil model, characterized in that, The system includes a wind tunnel, a module connector, a test model, hose I, a multi-tube pressure gauge, and a water tank. The test model includes a measurement point concentrator, a mounting chuck, and an airfoil model. The mounting chuck consists of connected circular plates I and II. The central axes of circular plates I and II coincide, and the diameter of circular plate I is larger than that of circular plate II. The measurement point concentrator has a cubic structure and is fixedly connected to circular plate I. One side of the airfoil model is fixedly connected to circular plate II. The test model has multiple pressure measurement holes and multiple channels, and the number of both is the same. The pressure measurement holes are located on the upper or lower surface of the airfoil model. One end of the channel is connected to the pressure measurement hole, and the other end is located on surface A of the measurement point concentrator, which is the surface of the measurement point concentrator away from circular plate I. The openings of the multiple channels on surface A are arranged in array A. Used to provide airflow for an airfoil model, the airfoil model's chord is parallel to the wind tunnel axis; the module plug includes a cube and tube I; the cube has multiple through holes A, and the multiple through holes A are arranged in an array B; the arrays A and B have the same arrangement; the number of tubes I is the same as the number of channels; one end of tube I passes through the through hole A, and both ends of tube I are located outside the cube; the number of hoses I is the same as the number of channels; one end of tube I is used to insert into the opening on the surface A of the measuring point concentrator, thereby connecting with the opening on the surface A of the measuring point concentrator, the other end of tube I is connected to one end of hose I, and the other end of hose I is connected to a multi-tube manometer; the multi-tube manometer is used to measure the pressure of the measuring orifice; a water tank is connected to the multi-tube manometer, the water tank is used to supply water to the multi-tube manometer and adjust the liquid level in the multi-tube manometer.

2. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 1, characterized in that, The wind tunnel includes a fan, a fairing, and a test chamber. The test chamber is a transparent test chamber, which is a hollow tubular structure open at both ends. The fan outlet is connected to the fairing, and the fairing is connected to one end of the transparent test chamber. The side of the transparent test chamber has mounting holes. The mounting holes are used to insert the airfoil model of the test model into the interior of the transparent test chamber, and the mounting holes are clearance-fitted with the circular plate II of the mounting chuck.

3. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 2, characterized in that, The transparent test chamber has a rectangular cross-section.

4. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 3, characterized in that, The test model also includes a bump, a gasket, and a bolt; one side of the airfoil model is fixedly connected to the circular plate II, and the other side is connected to the bump; the surface of the bump away from the airfoil model has a threaded hole; the side where the mounting hole is located is denoted as side A, and the side opposite to side A is denoted as side B; a fixing hole is provided on side B; when the airfoil model is inserted into the interior of the transparent test chamber, the bump passes through the fixing hole and the gasket in sequence, and is fixedly connected to the bolt through the threaded hole; wherein, the bump is clearance-fitted with the fixing hole and the gasket respectively.

5. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 4, characterized in that, The protrusion is composed of a cylinder and a hexagonal prism; the central axis of the cylinder coincides with the central axis of the hexagonal prism; the inner diameter of the fixing hole is 0.4 mm larger than the diameter of the cylinder; when the protrusion passes through the fixing hole and the gasket in sequence, the cylinder protrudes outside the transparent test chamber; the through hole on the gasket is a stepped hole, which is composed of a cylindrical hole I, a hexagonal prism hole I, and a cylindrical hole II connected in sequence, and the central axes of the cylindrical hole I, the hexagonal prism hole I, and the cylindrical hole II coincide; the depth of the cylindrical hole I is equal to the diameter of the cylinder. The length of the column protruding outside the transparent test chamber; the inner diameter of cylindrical hole I is 0.4 mm larger than the diameter of the cylinder; the depth of hexagonal prism hole I is equal to the length of the hexagonal prism, and the side length of hexagonal prism hole I is 1 mm larger than the side length of the hexagonal prism; the depth of cylindrical hole II is less than the length of the threaded section of the bolt, and the inner diameter of cylindrical hole II is 0.5 mm larger than the diameter of the threaded section; along the direction perpendicular to the side of the airfoil model, the projection of the shim onto the plane containing the side of the airfoil model coincides with the side of the airfoil model.

6. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 5, characterized in that, A scale ring is provided on side A, which is used to read the rotation angle of circular plate I.

7. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 6, characterized in that, The pressure measuring holes include pressure measuring hole I and pressure measuring hole II; the channels include channel I and channel II; the number of pressure measuring holes I, channel I, pressure measuring holes II and channels is the same; Pressure testing hole I is located on the upper surface of the airfoil model, and channel I is located inside the test model; One end of channel I is connected to pressure measuring hole I, and the other end is located on surface A of the measuring point concentration head; pressure measuring hole II is located on the lower surface of the airfoil model, and channel II is located inside the test model; one end of channel II is connected to pressure measuring hole II, and the other end is located on surface A of the measuring point concentration head; let one opening of channel I on surface A be called opening A, and one opening of channel II on surface A be called opening B; all openings A of channel I are arranged in a row on surface A to form opening group A, and all openings B of channel II are arranged in a row on surface A to form opening group B.

8. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 7, characterized in that, The multi-tube manometer includes a control tube, hose II, connecting tube, and multiple branch tubes; the number of branch tubes is the same as the number of channels I; the connecting tube is a closed tube at one end and is placed horizontally; the connecting tube has a water tank connection port and multiple branch tube connection ports on its circumference; the control tube and multiple branch tubes are both unsealed at both ends and are placed vertically; the control tube is connected to the opening of the connecting tube through hose II; the lower end of each of the multiple branch tubes is connected to a branch tube connection port; there are two multi-tube manometers, denoted as multi-tube manometer I and multi-tube manometer II; hose I includes hose Ia and hose Ib; the upper ends of the branch tubes of multi-tube manometer I are each connected to a hose Ia and an opening A; the upper ends of the branch tubes of multi-tube manometer II are each connected to a hose Ib and an opening B.

9. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 8, characterized in that, The airfoil model surface pressure distribution experimental teaching demonstration platform also includes hoses III, IV, and V, and a tee pipe. One end of hose III is connected to the water tank connection port of multi-tube manometer I, and the other end is connected to one port of the tee pipe. One end of hose IV is connected to the water tank connection port of multi-tube manometer II, and the other end is connected to one port of the tee pipe. A water inlet is provided at the bottom of the water tank, and one end of hose V is connected to the water inlet, and the other end is connected to one port of the tee pipe. The water tank is used to supply water to multi-tube manometer I and multi-tube manometer II, and to adjust the liquid level in the branch pipes of multi-tube manometer I and multi-tube manometer II. A tracer ball is placed on the liquid surface in the branch pipes of multi-tube manometer I and multi-tube manometer II, respectively. The density of the tracer ball is lower than that of water, and the tracer ball is used to assist in reading the liquid level.

10. The experimental teaching demonstration platform for pressure distribution on the surface of an airfoil model according to claim 9, characterized in that, The airfoil model surface pressure distribution experimental teaching demonstration platform also includes a vertical plate, a horizontal fixed plate, a vertical fixed plate, and a lead screw assembly. The two opposite surfaces of the vertical plate are denoted as surface C and surface D. The vertical fixed plate has through holes B and C; the central axes of through holes B and C are on the same plane. There are two vertical fixed plates, denoted as vertical fixed plate I and vertical fixed plate II. Both vertical fixed plates I and II are fixed to surface C of the vertical plate, and the central axis of through hole C in vertical fixed plate I coincides with the central axis of through hole C in vertical fixed plate II. The connecting pipe of multi-tube pressure gauge I passes through through holes B in both vertical fixed plate I and vertical fixed plate II, with both ends of the connecting pipe of multi-tube pressure gauge I located on opposite sides of the two vertical fixed plates. The connecting pipe of multi-tube pressure gauge II passes through through holes C in both vertical fixed plate I and vertical fixed plate II, and the connecting pipe of multi-tube pressure gauge II... The two ends are located on opposite sides of two vertical fixing plates; the horizontal fixing plate has two rows of through holes D; the number of through holes D in each row is the same as the number of channels I; the horizontal fixing plate is fixed on the vertical plate and is located above the vertical fixing plate; the lower ends of the branch pipes of multi-tube pressure gauge I pass through one of the through holes D in the same row and connect to one branch pipe connection port of multi-tube pressure gauge I; the lower ends of the branch pipes of multi-tube pressure gauge II pass through one of the through holes D in the same row and connect to one branch pipe connection port of multi-tube pressure gauge II; the screw assembly is fixed on the D surface of the vertical plate; the water tank and the screw nut of the screw assembly are fixedly connected, and the screw assembly controls the height of the water tank through the screw nut; the vertical plate has two through holes E; one end of hose III passes through one through hole E and connects to the water tank connection port of multi-tube pressure gauge I; one end of hose IV passes through one through hole E and connects to the water tank connection port of multi-tube pressure gauge II.

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