Continuous scanning measuring device for wake flow of gust wind tunnel airfoil test and use method thereof

Abstract

Tail flow continuous scanning measuring device for gust wind tunnel airfoil test and use method, belong to wind tunnel test technical field. Solve the problem that existing technology cannot meet the demand of arbitrary airfoil test. Technical points: the middle part of tail flow continuous scanning rake and up-down sliding drag plate is in the wind tunnel, the universal joint is fixedly connected at the middle of the front edge of the up-down sliding drag plate; the up-down sliding slide rail is installed on the wind tunnel shell, the up-down two ends of the up-down sliding drag plate are slidably connected with the up-down sliding slide rail through the up-down sliding slide groove; the electric cylinder is installed on the wind tunnel shell, the top of the up-down sliding drag plate is fixedly connected with the bottom of the electric cylinder, the horizontal slide groove of the horizontal slide block is installed on the wind tunnel shell, the upper end of the lever is hinged with the horizontal slide block, and the lower end of the lever is hinged with the top of the up-down sliding drag plate. The driving system of the application has the advantages of high control precision, less disturbance to flow field, accurate tail flow parameter measuring point positioning, infinitely encrypted measuring point quantity, and rich airfoil tail flow field parameters.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wind tunnel test, in particular to a wake continuous scanning measurement device for wing profile test in a temporary shock wind tunnel and a use method thereof. BACKGROUND

[0002] The wing profile test is a conventional test project of the wind tunnel test, and the wing profile resistance is one of the key measurement parameters of the wing profile test. In the 1-meter temporary shock wind tunnel, due to the small size of the wind tunnel and the short blowing time, when the flow field parameters in the wing profile wake are measured, a fixed total and static pressure rake (usually referred to as a fixed wake measurement rake) is generally used for measurement. The wake measurement rake is generally designed in the form of a "1" rake, which is composed of dozens or even hundreds of total pressure pipes, a few static pressure pipes and a rake body support. During the test, the "1" rake is vertically supported at a proper position away from the wing profile model to measure the total and static pressure distribution in the vertical plane of the wing profile model wake area, so as to calculate the resistance and resistance coefficient of the wing profile model. The accuracy of the wing profile resistance measurement mainly depends on the design of the wake measurement rake. The height of the wake measurement rake needs to be able to capture the entire wing profile wake. For the wing profile high angle of attack test, the wake area is larger, and the wake measurement rake needs to be designed larger.

[0003] However, there are many limitations in using the fixed wake measurement rake in the 1-meter temporary shock wind tunnel. First, the pressure of the wing profile wake in the vertical plane near the trailing edge of the wing profile changes sharply. If the wake measurement rake is installed close to the wing profile model, the measured wing profile wake pressure distribution will be too sharp, and the accuracy of the obtained wing profile resistance cannot be guaranteed. Therefore, the wake measurement rake needs to be installed at a proper position away from the wing profile model. The height of the wake area in the vertical plane away from the wing profile will increase sharply. In order to capture the flow field parameters of the entire vertical plane wake area, the wake measurement rake needs to have sufficient height. Increasing the height of the wake measurement rake will weaken its stiffness, causing its blockage to increase, affecting the pressure distribution of the wing profile trailing edge, and further leading to distortion of the measurement results.

[0004] Secondly, in order to obtain sufficient wing profile wake parameters, in addition to the need for a high wake measurement rake to capture the flow field parameters of the entire vertical plane wake area, the total pressure pipes of the wake measurement rake should also be arranged as densely as possible to improve the accuracy of the wing profile resistance calculation results. However, when the total pressure pipes are too dense, interference will occur between the total pressure pipes, affecting the accuracy of the pressure measurement. Therefore, the number of total pressure pipes is limited, and the accuracy of the wing profile resistance calculation results is relatively low. It is necessary to design and process a wake measurement rake that matches the chord length of the wing profile model and the test angle of attack requirement for different chord lengths of the wing profile model and the test angle of attack.

[0005] Therefore, it is urgent to propose a wake continuous scanning measurement device for wing profile test in a temporary shock wind tunnel and a use method thereof to solve the problem that the prior art cannot meet the requirements of arbitrary wing profile test. SUMMARY

[0006] In view of the above facts, in order to solve the problem that the prior art cannot meet the needs of arbitrary airfoil test, the present application further designs a wake continuous scanning measurement device for temporary-blast wind tunnel airfoil test and a use method thereof.

[0007] To achieve the above-mentioned purpose, the present application adopts the following technical scheme:

[0008] Scheme one: a wake continuous scanning measurement device for temporary-blast wind tunnel airfoil test, comprising a wake continuous scanning rake and a driving system.

[0009] The wake continuous scanning rake comprises a total pressure pipe, a static pressure pipe, a rake body, a support rod, a universal joint, a pin hole and a fixing screw.

[0010] The driving system comprises an up-down sliding drag plate, an up-down sliding slide rail, a horizontal slide block, a lever and an electric cylinder.

[0011] The wake continuous scanning rake and the middle part of the up-down sliding drag plate are both in the wind tunnel, and the universal joint is fixedly connected to the middle part of the leading edge of the up-down sliding drag plate.

[0012] The up-down sliding slide rail is installed on the wind tunnel shell, and the up-down sliding drag plate is in sliding fit with the up-down sliding slide rail through the up-down sliding slide groove.

[0013] The electric cylinder is installed on the wind tunnel shell, the top of the up-down sliding drag plate is fixedly connected to the bottom of the electric cylinder, and the up-down sliding drag plate moves horizontally along the vertical plane.

[0014] The horizontal slide groove of the horizontal slide block is installed on the wind tunnel shell, the horizontal slide block slides horizontally in the horizontal slide groove, the upper end of the lever is hinged to the horizontal slide block, and the lower end of the lever is hinged to the top of the up-down sliding drag plate.

[0015] The up-down sliding drag plate, the up-down sliding slide rail, the horizontal slide block and the lever are all in the same plane.

[0016] Further, the total pressure pipe and the static pressure pipe are connected to the rake body respectively, the rake body is connected to the support rod through the fixing screw, and the support rod is positioned and connected to the universal joint through the pin hole.

[0017] Further, the length of the pipe tip of the total pressure pipe is 35mm.

[0018] The length of the pipe tip of the static pressure pipe is 60mm.

[0019] Further, the universal joint is fixedly connected to the up-down sliding drag plate in the form of conical surface fit.

[0020] Further, the up-down sliding drag plate is of a front edge wedge structure, the wedge angle is 30°, and the thickness is 140mm.

[0021] Further, the stroke of the electric cylinder is 1200mm, the accuracy is ±0.01mm, and the speed range is 0-400mm / s.

[0022] Scheme two: a use method of the wake continuous scanning measuring device of the temporary impact type wind tunnel airfoil test of scheme one, in particular:

[0023] Step one: preset the attack angle at the first attack angle position required by the test, and the wake continuous scanning rake is opposite to the airfoil.

[0024] Step two: the electric cylinder is elongated, the up-down sliding drag plate is lowered, the up-down sliding drag plate moves horizontally along the up-down sliding slide rail, the rear end of the lever is lowered with the up-down sliding drag plate, the horizontal sliding block is slid horizontally backward, and the wake continuous scanning rake is lowered to be close to the lower wall plate of the test section of the wind tunnel.

[0025] Step three: the wind tunnel is started, data acquisition is started after the flow field is established, the electric cylinder is retracted after the data of the current position is collected, the up-down sliding drag plate is raised, the up-down sliding drag plate moves horizontally along the up-down sliding slide rail, the rear end of the lever is raised with the up-down sliding drag plate, the horizontal sliding block is slid horizontally forward, and the wake continuous scanning rake is raised.

[0026] Step four: the wake continuous scanning rake is raised to the next position for data acquisition until the wake continuous scanning rake is raised to be close to the upper wall plate of the test section of the wind tunnel.

[0027] Step five: when the test is finished, preset the attack angle at the next attack angle position required by the test, repeat the steps two to four until the whole test is completed.

[0028] Further, in the step five, the rotating window on the test section is rotated to drive the airfoil installed on the rotating window to rotate, so that the change of the attack angle is realized.

[0029] The beneficial effects of the present application are:

[0030] 1. The driving system of the present application is arranged outside the wind tunnel except the middle part of the up-down sliding drag plate, and the up-down sliding drag plate is located downstream away from the airfoil, so that the interference of the device on the flow field is avoided.

[0031] 2. The driving system of the present application has high control accuracy, and has the advantages of accurate positioning of wake parameter measuring points, infinitely encrypted number of measuring points, and rich airfoil wake flow field parameters obtained.

[0032] 3. The application realizes the continuous scanning measurement of the tail flow of the continuous scanning rake in the vertical plane by the electric cylinder driving, and obtains sufficient wing type tail flow flow field parameters, and the use requirement of the different distance between the tail flow continuous scanning rake and the wing type can be met by adjusting the position of the group of pin holes on the rear section of the support rod, the tail flow continuous scanning rake can meet the test requirement of any wing type, and has strong applicability. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is the overall structural diagram of the application;

[0034] Figure 2 It is the position relation diagram of the tail flow continuous scanning rake and the driving system in the application;

[0035] Figure 3 It is the size schematic diagram of the total pressure pipe in the application;

[0036] Figure 4 It is the size schematic diagram of the static pressure pipe in the application;

[0037] Figure 5 It is the comparison diagram of the pressure coefficient of two points on the rear edge of the upper surface of the wing type;

[0038] Figure 6 It is the comparison diagram of the pressure coefficient of two points on the rear edge of the lower surface of the wing type;

[0039] Figure 7 It is the comparison diagram of the wing type wake curve.

[0040] In the figure, 1 is a total pressure pipe, 2 is a static pressure pipe, 3 is a rake body, 4 is a support rod, 5 is a universal joint, 6 is a pin hole, 7 is a fixing screw, 8 is an up-down sliding drag plate, 9 is an up-down sliding slide rail, 10 is a horizontal sliding block, 11 is a lever, 12 is an electric cylinder, 13 is a wind tunnel shell, 14 is a test section, 15 is a test section upper wall plate, 16 is a test section lower wall plate, 17 is a wing type, and 18 is a rotating window. DETAILED DESCRIPTION

[0041] In order to make the people in the technical field better understand the scheme of the application, the technical scheme in the embodiments of the application will be clearly and completely described in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only a part of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all the other embodiments obtained by the people in the field without creative labor should belong to the protection scope of the application.

[0042] The terms "set", "connected", "fixed" should be understood broadly. For example, "connected" can be fixed connection, detachable connection, or integral structure; can be mechanical connection, can be directly connected, or indirectly connected through intermediate medium, or internal communication between two devices, elements or components. The specific meaning of the above terms in the present application can be understood according to the specific circumstances by those skilled in the art.

[0043] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0044] The preferred embodiments of the present application will be described in detail below with reference to the drawings.

[0045] Embodiment 1: Reference Figures 1 to 4 To explain this embodiment in detail, the wake continuous scanning measuring device for the wing profile test of the transient wind tunnel in this embodiment comprises a wake continuous scanning rake, a driving system, etc.

[0046] The wake continuous scanning rake comprises a total pressure pipe 1, a static pressure pipe 2, a rake body 3, a supporting rod 4, a universal joint 5, a pin hole 6, and a fixing screw 7.

[0047] The driving system comprises an up-down sliding drag plate 8, an up-down sliding slide rail 9, a horizontal slide block 10, a lever 11, and an electric cylinder 12.

[0048] The wake continuous scanning rake and the middle part of the up-down sliding drag plate 8 are both in the wind tunnel, and the universal joint 5 is fixedly connected to the middle part of the leading edge of the up-down sliding drag plate 8.

[0049] The up-down sliding slide rail 9 is installed on the wind tunnel shell 13, and the up-down sliding drag plate 8 is in sliding fit with the up-down sliding slide rail 9 through the up-down sliding slide groove.

[0050] The electric cylinder 12 is installed on the wind tunnel shell 13, the top of the up-down sliding drag plate 8 is fixedly connected to the bottom of the electric cylinder 12, and the up-down sliding drag plate 8 moves horizontally along the vertical plane.

[0051] The horizontal slide groove of the horizontal slide block 10 is installed on the wind tunnel shell 13, the horizontal slide block 10 slides horizontally in the horizontal slide groove, the upper end of the lever 11 is hinged to the horizontal slide block 10, and the lower end of the lever 11 is hinged to the top of the up-down sliding drag plate 8.

[0052] The up-down sliding drag plate 8, the up-down sliding slide rail 9, the horizontal slide block 10, and the lever 11 are all in the same plane.

[0053] More specifically: the total pressure pipe 1 and the static pressure pipe 2 are connected with the rake body 3 respectively, the rake body 3 is connected with the support rod 4 through the fixing screw 7, and the support rod 4 is positioned and connected with the universal joint 5 through the pin hole 6.

[0054] More specifically: the length of the pipe tip of the total pressure pipe 1 is 35mm;

[0055] The length of the pipe tip of the static pressure pipe 2 is 60mm.

[0056] More specifically: the universal joint 5 is fixedly connected with the up-and-down sliding drag plate 8 in the form of taper surface cooperation.

[0057] More specifically: the up-and-down sliding drag plate 8 is of a front edge wedge structure, the wedge angle is 30°, and the thickness is 140mm.

[0058] More specifically: the stroke of the electric cylinder 12 is 1200mm, the accuracy is ±0.01mm, and the speed range is 0-400mm / s, which meets the requirement of the wing profile wake measurement range of the 1-meter order temporary impulse wind tunnel wing profile test.

[0059] More specifically: the electric cylinder 12 is the power device of the driving system.

[0060] More specifically: the up-and-down sliding slide rail 9 can guarantee the up-and-down translation of the up-and-down sliding drag plate 8 on the fixed plumb surface, so as to realize the up-and-down translation of the wake continuous scanning rake on the fixed plumb surface, and finally realize the continuous scanning measurement of the wing profile wake.

[0061] More specifically: after the installation of the wake continuous scanning rake, the total pressure pipe 1 and the static pressure pipe 2 are guaranteed to face the airflow, and the wake continuous scanning rake in the middle of the front edge of the up-and-down sliding drag plate 8 is driven by the electric cylinder 12 to continuously scan and measure the flow field parameters in the wing profile wake area in the vertical surface downstream of the wing profile model.

[0062] Embodiment 2: a use method of the wake continuous scanning measurement device of the temporary impulse wind tunnel wing profile test in embodiment 1, specifically:

[0063] Step one: preset the attack angle at the first attack angle position required by the test, and the wake continuous scanning rake faces the wing profile 17;

[0064] Step two: the electric cylinder 12 is elongated, the up-and-down sliding drag plate 8 is sunken, the up-and-down sliding drag plate 8 is translated along the up-and-down sliding slide rail 9, the rear end of the lever 11 is lowered with the up-and-down sliding drag plate 8, the horizontal sliding block 10 is slid horizontally backward, and the wake continuous scanning rake is sunken to the position close to the test section lower wall plate 16.

[0065] Step three: after the wind tunnel starts and the flow field is established, data collection begins. After collecting data at the current position, the electric cylinder 12 retracts, the up-and-down sliding carriage 8 rises, the up-and-down sliding carriage 8 moves horizontally along the up-and-down sliding rail 9, the rear end of the lever 11 rises with the up-and-down sliding carriage 8, driving the horizontal slider 10 to slide horizontally forward, and driving the continuous wake scanning rake to rise;

[0066] Step four: the continuous wake scanning rake rises to the next position for data collection until it rises to near the upper wall plate 15 of the test section.

[0067] Step five: when the test is completed, the angle of attack is preset at the next angle of attack required by the test, and the steps two to four are repeated until the entire test is completed.

[0068] More specifically: in step five, the rotating window 18 on the rotating test section 14 is rotated, driving the airfoil 17 installed on the rotating window 18 to rotate, thereby changing the angle of attack.

[0069] More specifically: during the test, the continuous wake scanning rake can start from outside the wake region and scan from top to bottom (or from bottom to top) step by step through the wake region. The size of the scanning area can be adjusted according to the height of the local airfoil wake region, and the scanning step can be adjusted according to the measurement requirements. Finally, the total and static pressure values in the airfoil wake region are obtained, and the drag of the airfoil is calculated by the momentum method.

[0070] More specifically: for airfoil tests of different chord lengths, the rear end of the support rod 4 can be adjusted along the axial pin hole 6 to adapt to the use requirements of different distances between the continuous wake scanning rake and the airfoil 17.

[0071] More specifically: the pressure coefficient formula is:

[0072] ;

[0073] Wherein: is the corresponding pressure coefficient;

[0074] is the static pressure of the measurement point (Pa);

[0075] is the static pressure of the wind tunnel inflow (Pa);

[0076] q is the static pressure of the wind tunnel inflow (Pa);

[0077] q = 0.7 ;

[0078] Wherein: is the Mach number of the wind tunnel inflow;

[0079] The momentum method drag coefficient calculation formula is:

[0080] ;

[0081] wherein: Cf is the profile drag coefficient;

[0082] C is the profile chord length (m);

[0083] wl is the integration region, i.e. the wake region;

[0084] is the drag;

[0085] is the drag coefficient of the wake region;

[0086] ;

[0087] wherein: Ptot is the total pressure of the wake region (Pa);

[0088] Ptot is the total pressure of the wind tunnel inflow (Pa);

[0089] Pstat is the static pressure of the wind tunnel inflow (Pa);

[0090] P is the average static pressure of the wake region (Pa);

[0091] k is 1.4.

[0092] More specifically: with reference to Figures 5 to 7 , the test effect of the wake continuous scanning measurement device is compared with that of the fixed wake measurement rake:

[0093] A: the fixed wake measurement rake has a large height and a large degree of blockage, which affects the pressure distribution of the trailing edge of the airfoil, and the measured value has certain differences with that when there is no wake rake;

[0094] The structure design of the wake continuous scanning measurement device has the advantages of small influence on the flow field and high precision of wake parameter measurement, and the data obtained by the wake continuous scanning measurement device has better consistency with the data when there is no wake rake;

[0095] B: the size of the wake continuous scanning rake of the wake continuous scanning measurement device is small, and its driving system is arranged outside the wind tunnel shell, which has small disturbance to the flow field, the measurement step can be infinitely encrypted, and the distance between the wake continuous scanning measurement device and the airfoil can be adjusted according to the requirement;

[0096] C: the wake continuous scanning measurement device has high control precision, has the advantages of accurate positioning of wake parameter measurement points, infinitely encrypted number of measurement points to obtain sufficient airfoil wake flow field parameters, and the airfoil wake curve is more smooth (the curve in the figure is more smooth), and the device can meet the test requirement of any airfoil and size, and has strong applicability.

[0097] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, the technical solutions described in the foregoing examples can be modified, or some or all of the technical features thereof can be replaced by equivalents; as long as there is no structural conflict, each feature in the specific embodiments disclosed in the present application can be used in any way, and the corresponding technical solutions will not deviate from the scope of the technical solutions of the present application.

[0098] In addition, it should be understood that, although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity, and those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

Claims

1. A device for continuous scanning measurement of wake flow in a wing profile test of a transient wind tunnel, characterized in that, The tail flow continuous scanning rake includes a total pressure pipe (1), a static pressure pipe (2), a rake body (3), a support rod (4), a universal joint (5), a pin hole (6), and a fixing screw (7). The tail flow continuous scanning rake includes a total pressure pipe (1), a static pressure pipe (2), a rake body (3), a support rod (4), a universal joint (5), a pin hole (6), and a fixing screw (7). The driving system includes an up-and-down sliding drag plate (8), an up-and-down sliding slide rail (9), a horizontal slide block (10), a lever (11), and an electric cylinder (12). The tail flow continuous scanning rake and the middle part of the up-and-down sliding drag plate (8) are in the wind tunnel, and the universal joint (5) is fixedly connected to the middle part of the front edge of the up-and-down sliding drag plate (8). The up-and-down sliding slide rail (9) is installed on the wind tunnel shell (13), and the up-and-down sliding drag plate (8) is slidably connected to the up-and-down sliding slide rail (9) through the up-and-down sliding slide groove. The electric cylinder (12) is installed on the wind tunnel shell (13), the top of the up-and-down sliding drag plate (8) is fixedly connected to the bottom of the electric cylinder (12), and the up-and-down sliding drag plate (8) moves up and down along the vertical plane. The horizontal slide groove of the horizontal slide block (10) is installed on the wind tunnel shell (13), the horizontal slide block (10) slides horizontally in the horizontal slide groove, the upper end of the lever (11) is hinged to the horizontal slide block (10), and the lower end of the lever (11) is hinged to the top of the up-and-down sliding drag plate (8). The up-and-down sliding drag plate (8), the up-and-down sliding slide rail (9), the horizontal slide block (10), and the lever (11) are in the same plane.

2. The apparatus according to claim 1, wherein The total pressure pipe (1) and the static pressure pipe (2) are connected to the rake body (3), the rake body (3) is connected to the support rod (4) through the fixing screw (7), and the support rod (4) is positioned and connected to the universal joint (5) through the pin hole (6).

3. The device according to claim 2, wherein The length of the pipe tip of the total pressure pipe (1) is 35 mm. The length of the pipe tip of the static pressure pipe (2) is 60 mm.

4. The apparatus according to claim 1, wherein The universal joint (5) is fixedly connected to the up-and-down sliding drag plate (8) in the form of conical surface cooperation.

5. The apparatus of claim 1, wherein, The up-and-down sliding drag plate (8) has a front edge wedge structure, the wedge angle is 30°, and the thickness is 140 mm.

6. The apparatus of claim 1, wherein, The stroke of the electric cylinder (12) is 1200 mm, the accuracy is ±0.01 mm, and the speed range is 0-400 mm / s.

7. A method of using the wake survey apparatus for a transient wind tunnel airfoil test of claim 1, wherein, Specifically, Step one: preset the angle of attack at the first angle of attack position required by the test, and the tail flow continuous scanning rake is opposite to the airfoil (17); Step two: the electric cylinder (12) is extended, the up-and-down sliding drag plate (8) is lowered, the up-and-down sliding drag plate (8) moves horizontally along the up-and-down sliding slide rail (9), the rear end of the lever (11) swings with the up-and-down sliding drag plate (8), the horizontal slide block (10) slides horizontally backward, and the tail flow continuous scanning rake is lowered to the position close to the lower wall plate (16) of the wind tunnel test section; Step three: the wind tunnel is started, data collection is started after the flow field is established, the electric cylinder (12) is retracted after the data of the current position are collected, the up-and-down sliding drag plate (8) is raised, the up-and-down sliding drag plate (8) moves horizontally along the up-and-down sliding slide rail (9), the rear end of the lever (11) swings with the up-and-down sliding drag plate (8), the horizontal slide block (10) slides horizontally forward, and the tail flow continuous scanning rake is raised. Step four: the wake continuous scanning rake is raised to the next position for data collection until it is close to the upper wall plate (15) of the wind tunnel test section; Step five: when the test is over, the angle of attack is preset at the next angle of attack position required by the test, and the steps two to four are repeated until all tests are completed.

8. The method of using a wake scan device for a transient wind tunnel airfoil test according to claim 7, wherein, In the step five, the rotating window (18) on the rotating test section (14) is rotated to drive the airfoil (17) installed on the rotating window (18) to rotate, so as to change the angle of attack.

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