CN116242577B

CN116242577B - Wind tunnel cluster special balance and wind tunnel system for cluster measurement

Info

Publication number: CN116242577B
Application number: CN202310501706.5A
Authority: CN
Inventors: 梁磊; 徐开明; 李付华; 张�林; 姜裕标; 高大鹏
Original assignee: Low Speed Aerodynamics Institute of China Aerodynamics Research and Development Center
Current assignee: Low Speed Aerodynamics Institute of China Aerodynamics Research and Development Center
Priority date: 2023-05-06
Filing date: 2023-05-06
Publication date: 2023-07-07
Anticipated expiration: 2043-05-06
Also published as: CN116242577A

Abstract

The invention relates to the field of wind tunnel measurement, in particular to a wind tunnel cluster special balance and a wind tunnel system for cluster measurement, which comprise a fixed frame, a floating frame, a rigid beam and a disturbance eliminating beam; the fixed frame comprises a prefabricated groove, and the floating frame is strung in the prefabricated groove by the rigid beam and the disturbance beam; the rigid beam and the disturbance eliminating beam are axially arranged along the balance, and the disturbance eliminating Liang Fenbu is arranged on two sides of the rigid beam; the rigidity of the disturbance beam in the axial direction of the balance is smaller than the rigidity of the balance in the normal direction and smaller than the rigidity of the rigid beam. The force and the moment which are axially related to the balance are intensively applied to the rigid beam, but the rigidity of the disturbance beam in the normal direction of the balance is not reduced, so that the wind tunnel cluster special balance can obtain very high measurement accuracy in all directions, and the model test task of the first 16 balance cluster measurement in the wind tunnel test field is completed.

Description

Wind tunnel cluster special balance and wind tunnel system for cluster measurement

Technical Field

The invention relates to the field of wind tunnel measurement, in particular to a wind tunnel cluster special balance and a wind tunnel system for cluster measurement.

Background

In order to obtain the aerodynamic characteristic data of the hinge moment of the aileron, the elevator and the rudder of the aircraft, a low-speed wind tunnel full-engine model test is generally adopted, and a sheet type hinge moment balance is adopted to measure the hinge moment of the control surface of the aircraft model, so that the balance is thinner along the thickness direction and is convenient to be arranged in the wing section of the control surface.

The sheet-type hinge moment balance is divided into a two-component balance and a three-component balance according to different types and numbers of simultaneously measured force and moment, of course, the more the types and the more detailed and better the data of the wing surface of the aircraft are, the more the components are, the more the structure of the balance is complicated, the higher the volume requirement of the balance is due to the fact that the application scene is the wing, the smaller volume is added to the complicated structure, the mutual interference among the measurement of each component is caused, and the measurement accuracy is further reduced, but if the two-component balance or the three-component balance with fewer components is adopted, the part of force or moment is ignored, so that the stress condition of the wing surface calculated finally is far away from the actual condition, and the measurement accuracy of the wind tunnel measurement is difficult to be improved for a long time.

Therefore, how to improve the accuracy of measuring the stress and moment of the airfoil in wind tunnel measurement is a problem to be solved by those skilled in the art.

Disclosure of Invention

The invention aims to provide a wind tunnel cluster special balance and a wind tunnel system for cluster measurement, which are used for solving the problem of poor accuracy of wind tunnel measurement in the prior art.

In order to solve the technical problems, the invention provides a wind tunnel cluster special balance, which comprises a fixed frame, a floating frame, a rigid beam and a disturbance eliminating beam;

the fixed frame comprises a prefabricated groove, and the floating frame is strung in the prefabricated groove by the rigid beam and the disturbance beam; the rigid beam and the disturbance eliminating beam are axially arranged along the balance, and the disturbance eliminating Liang Fenbu is arranged on two sides of the rigid beam;

the rigidity of the disturbance beam in the axial direction of the balance is smaller than the rigidity of the balance in the normal direction and smaller than the rigidity of the rigid beam.

Optionally, in the wind tunnel cluster special balance, the interference elimination beam is an interference elimination hinge.

Optionally, in the wind tunnel cluster special balance, the disturbance eliminating hinge is a double-arc hinge.

Optionally, in the wind tunnel cluster special balance, the fixed frame is a wing frame;

the airfoil frame and the airfoil base form an airfoil to be measured.

Optionally, in the wind tunnel cluster special balance, the floating frame comprises a fixed clamping groove;

the floating frame is connected with the structure to be tested through the fixing clamping groove.

Optionally, in the wind tunnel cluster special balance, the pre-groove comprises a proximal side and a distal side; an adjusting slit is arranged between the distal end side and the root of the fixed frame;

the adjusting slit is opened along the axial direction of the balance, so that the coupling interference of other components to the main component in the measuring process is smaller than a first threshold value.

Optionally, in the wind tunnel cluster special balance, the first threshold value ranges from 5% to 15%, including an endpoint value.

Optionally, in the wind tunnel cluster special balance, the ratio of the width of the adjustment area to the width of the proximal end side ranges from 0.4 to 0.8, including an endpoint value; the adjustment zone is the area between the adjustment slit and the distal side of the pregroove.

A wind tunnel system for cluster measurement comprises any one of the wind tunnel cluster special balances.

Optionally, in the wind tunnel system for cluster measurement, the wind tunnel system for cluster measurement includes a plurality of wind tunnel cluster special balances, and the wind tunnel cluster special balances are classified into a parent balance and a child balance;

the fixed frame of the female balance is fixedly connected with the airfoil base; the fixed frame of the secondary balance is fixedly connected with the floating frame of the corresponding primary balance.

The wind tunnel cluster special balance provided by the invention comprises a fixed frame, a floating frame, a rigid beam and a disturbance eliminating beam; the fixed frame comprises a prefabricated groove, and the floating frame is strung in the prefabricated groove by the rigid beam and the disturbance beam; the rigid beam and the disturbance eliminating beam are axially arranged along the balance, and the disturbance eliminating Liang Fenbu is arranged on two sides of the rigid beam; the rigidity of the disturbance beam in the axial direction of the balance is smaller than the rigidity of the balance in the normal direction and smaller than the rigidity of the rigid beam.

Through a large number of theoretical calculations and practical tests, it is found that when a multi-component balance with a multi-beam structure is used for measurement, adjacent beams bear forces which are not measured by the beams themselves due to the influence of the rigidity of the beams, so that the measurement accuracy is reduced. The invention also provides a wind tunnel system for cluster measurement with the beneficial effects.

Drawings

For a clearer description of embodiments of the invention or of the prior art, the drawings that are used in the description of the embodiments or of the prior art will be briefly described, it being apparent that the drawings in the description below are only some embodiments of the invention, and that other drawings can be obtained from them without inventive effort for a person skilled in the art.

FIGS. 1-1 and 1-2 are schematic structural views of an embodiment of a wind tunnel cluster special balance provided by the invention;

FIG. 2 is a schematic structural diagram of an embodiment of a wind tunnel system for cluster measurement according to the present invention;

fig. 3-1, fig. 3-2 and fig. 3-3 are schematic circuit structures of a specific embodiment of a wind tunnel cluster special balance provided by the invention;

fig. 4-1 and fig. 4-2 are schematic wind tunnel diagrams of a wind tunnel cluster special balance according to an embodiment of the present invention after being applied to a wind tunnel.

The drawings include a plurality of reference numerals, specifically a 100-fixed frame, a 200-floating frame, a 300-rigid beam, a 400-interference cancellation beam, a 101-proximal side, a 102-distal side, a 210-fixed clamping groove, a 130-pre-groove, a 110-root connecting end, a 120-adjusting slit, a 140-adjusting area, an A-mother balance, a B-child balance and 1-24-strain gauges.

Detailed Description

In order to better understand the aspects of the present invention, the present invention will be described in further detail with reference to the accompanying drawings and detailed description. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

The invention provides a wind tunnel cluster special balance, wherein the structural schematic diagram of one specific embodiment is shown in fig. 1-1 and fig. 1-2, and the wind tunnel cluster special balance is called as a specific embodiment I and comprises a fixed frame 100, a floating frame 200, a rigid beam 300 and a disturbance eliminating beam 400;

the fixed frame 100 includes a pre-groove 130, and the rigid beam 300 and the disturbance beam 400 string the floating frame 200 in the pre-groove 130; the rigid beam 300 and the interference cancellation beam 400 are axially arranged along the balance, and the interference cancellation beams 400 are distributed on two sides of the rigid beam 300;

the stiffness anisotropy of the tamper beam 400, the stiffness of the tamper beam 400 in the balance axial direction being less than the stiffness in the balance normal direction and less than the stiffness of the stiff beam 300.

In one embodiment, the tamper beam 400 is a tamper hinge. 1-1 and 1-2, the hinge has enough flexibility in the rotation/bending direction, and has enough rigidity in the direction perpendicular to the rotation/bending direction (the extending direction of the non-hinge itself), so as to avoid bending, ensure the rigidity anisotropy of the disturbance beam 400, and realize longer service life and better working stability of the low rigidity and high bending property through the movable piece.

Further, the interference elimination hinge is a double-arc hinge. The arc side gap is very small, and when the deformation is great, the smaller side gap can play a role in protecting the structure of the hinge, so that the hinge is not damaged, and the service life and the working stability of the hinge are further improved.

In addition, as a preferred embodiment, the fixing frame 100 is a wing frame;

the airfoil frame and the airfoil base form an airfoil to be measured.

In the preferred embodiment, the wind tunnel cluster special balance is not refilled into the built airfoil to be tested, but the shape of the fixed frame 100 of the balance is changed to form a part of the airfoil to be tested, because the structure for actually measuring the mechanical parameters is the floating frame 200 and the beam connected with the floating frame 200, the fixed frame 100 only plays a role of providing a fixed platform, so that the fixed frame 100 is changed to form a part of the airfoil to be tested, the space requirement of the wind tunnel cluster special balance is greatly reduced, the universality of the wind tunnel cluster special balance is improved, and meanwhile, the integration requirement is reduced due to the increase of the available space, and the working stability is improved. More specifically, the airfoil frame is coupled to the airfoil base by a root connection 110, as shown in FIGS. 1-1.

Also, the floating frame 200 includes a fixing clip groove 210;

the floating frame 200 is connected to the structure to be tested through the fixing slot 210.

The fixing slot 210 is provided on the floating frame 200, so as to increase the connection stability between the fixing slot 210 and the structure to be tested, avoid the decrease in accuracy of the measurement structure caused by the relative displacement between the floating frame 200 and the structure to be tested in the test process, and improve the measurement accuracy and the working stability of the balance.

As another preferred embodiment, the pregroove 130 comprises a proximal side 101 and a distal side 102; an adjustment slit 120 is included between the distal side 102 and the root of the fixation frame 100;

the adjustment slit 120 is opened along the axial direction of the balance, so that the coupling interference of other components to the main component in the measurement process is smaller than a first threshold.

The distal end side 102 and the proximal end side 101 refer to a side far from the tip of the airfoil to be measured and a side near to the tip of the airfoil to be measured respectively, and it should be noted that, because the nature of the mechanical data measured by the wind tunnel cluster special balance is measured by the deformation of the beam, the deformation of the beam after being stressed is not only required to see the property of the beam itself, but also the physical characteristics of the connection parts of two ends of the beam of the balance can affect the beam, the shape of the wing is generally thicker at the root and thinner at the tip, so that the thickness of the fixed frame 100 near the distal end side 102 of the pre-groove 130 is thicker, the rigidity is stronger, and the thickness of the fixed frame 100 near the proximal end side 101 of the pre-groove 130 is thicker, the rigidity is weaker, which can make the rigid beam 300 with two ends respectively connected with the proximal end side 101 and the distal end side 102 inconsistent with the deformation of the two sides of the interference elimination beam 400, reflecting the mechanical data measured, namely the coupling interference of two main components of other teams, thereby affecting the accuracy of the measured mechanical data.

In this application, the adjustment slits 120 are disposed on the fixing frame 100 near the distal end 102, which breaks the continuity and integrity of the nearby fixing frame 100, weakens the support of the rigid beam 300 and the interference cancellation beam 400 by the root of the thicker fixing frame 100, and makes the rigidity provided by the rigid beam 300 and the fixing frames 100 on two sides of the interference cancellation beam 400 similar, so as to balance the sensitivity of each component in measurement, reduce the coupling interference of other components to the main component, and improve the measurement accuracy.

Preferably, the extending direction of the adjustment slit 120 is the axial direction of the balance, so that the rigidity of the area corresponding to each beam is consistent, and the testing accuracy is further improved.

Further, the range of the first threshold is 5% to 15%, including any one of the end values, such as 5.0%, 10.2% or 15.0%, where the range is obtained by a large number of theoretical calculations and actual tests, and the range can be obtained after correction by using parameters with fewer times, which is convenient and fast, and the coupling interference caused at the same time is also in an acceptable range, and of course, can be adjusted accordingly according to the actual situation.

Still further, the ratio of the width of the adjustment zone 140 to the width of the proximal side 101 ranges from 0.4 to 0.8, including any of the endpoints, such as 0.40, 0.59, or 0.80; the adjustment zone 140 is the area between the adjustment slit 120 and the distal side 102 of the pregroove 130. The width refers to the distance in the direction from the root to the tip of the airfoil to be measured, and after a number of theoretical calculations and practical tests, it is found that, since the tip is generally thinner and the root is thicker, the nature of the adjustment slit 120 is such that the adjustment region 140 is marked out, so that the stiffness provided by the adjustment region 140 to the stiff beam 300 and the tamper beam 400 is similar to the stiffness provided by the fixation frame 100 between the tip and the proximal side 101, and since the adjustment region 140 is thicker, the width of the adjustment region 140 should be shorter than the width between the tip and the proximal side 101.

Preferably, the interference cancellation beam 400 is respectively arranged at two sides of the rigid beam 300, that is, the wind tunnel cluster special balance provided by the invention is a three-beam balance, which can measure five components, is a balance with more general purpose and more comprehensive measurement data, and obtains better balance among complex structure, reliability and accuracy.

The wind tunnel cluster special balance provided by the invention comprises a fixed frame 100, a floating frame 200, a rigid beam 300 and a disturbance beam 400; the fixed frame 100 includes a pre-groove 130, and the rigid beam 300 and the disturbance beam 400 string the floating frame 200 in the pre-groove 130; the rigid beam 300 and the interference cancellation beam 400 are axially arranged along the balance, and the interference cancellation beams 400 are distributed on two sides of the rigid beam 300; the stiffness anisotropy of the tamper beam 400, the stiffness of the tamper beam 400 in the balance axial direction being less than the stiffness in the balance normal direction and less than the stiffness of the stiff beam 300. Through a large number of theoretical calculations and practical tests, it is found that when a multi-component balance with a multi-beam structure is measured, adjacent beams bear forces which are not measured by the beams themselves due to the influence of the rigidity of the beams, so that the measurement accuracy is reduced.

The invention also provides a wind tunnel system for cluster measurement, which is called a second specific embodiment and comprises any one of the wind tunnel cluster special balances.

As a preferred embodiment, the wind tunnel system for cluster measurement comprises a plurality of wind tunnel cluster special balances, wherein the wind tunnel cluster special balances are classified into a mother balance and a child balance;

the fixed frame 100 of the mother balance is fixedly connected with the airfoil base; the fixed frame 100 of the sub-balance is fixedly connected with the floating frame 200 of the corresponding parent balance.

Please refer to fig. 2, fig. 2 is a schematic structural diagram of the preferred embodiment, the fixed frame 100 of the sub-balance is connected to the floating frame 200 of the corresponding parent balance, and the floating frame 200 of the sub-balance may further be provided with another structure to be measured (not shown in fig. 2), so that the data measured by the parent balance is the sum of the mechanical data of the face of the sub-balance and the mechanical data of the other structure to be measured, and the data measured by the sub-balance is the mechanical data of the other structure to be measured, and the two are subtracted to obtain the mechanical data of the face of the sub-balance.

The wind tunnel system for cluster measurement provided by the invention comprises any one of the wind tunnel cluster special balances. The wind tunnel cluster special balance comprises a fixed frame 100, a floating frame 200, a rigid beam 300 and a disturbance eliminating beam 400; the fixed frame 100 includes a pre-groove 130, and the rigid beam 300 and the disturbance beam 400 string the floating frame 200 in the pre-groove 130; the rigid beam 300 and the interference cancellation beam 400 are axially arranged along the balance, and the interference cancellation beams 400 are distributed on two sides of the rigid beam 300; the stiffness anisotropy of the tamper beam 400, the stiffness of the tamper beam 400 in the balance axial direction being less than the stiffness in the balance normal direction and less than the stiffness of the stiff beam 300. Through a large number of theoretical calculations and practical tests, it is found that when a multi-component balance with a multi-beam structure is measured, adjacent beams bear forces which are not measured by the beams themselves due to the influence of the rigidity of the beams, so that the measurement accuracy is reduced.

The following is a corresponding supplement to the background and specific structure of the present invention, and the data processing process includes:

in order to obtain the aerodynamic characteristic data of the hinge moment of the aileron, the elevator and the rudder of the airplane, a low-speed wind tunnel full-engine model test is generally adopted, and the model ratio is 1:6. The model consists of four parts including a fuselage, wings, a tail wing and a radome. Wherein the wind tunnel adopts an 8m x 6m open type large low-speed wind tunnel. The length of the second test section is 15m, the width is 8m, the height is 6m, and the cross section is a corner cut rectangle; the effective area of the center section of the test section is 47.4m2; the wind speed is usually 20-80 m/s. The supporting system of the wind tunnel test is an extra-large attack angle test device, the extra-large attack angle test device mainly comprises an angle-changing mechanism, a Y-direction mechanism, a base, an auxiliary device, a hydraulic pressure and control measuring system, test equipment is positioned at the rear part of a second test section of the wind tunnel, and the mounting base (center line of a double vertical plate) of the test equipment is 6800mm away from the center of a turntable of the test section, and 1700mm away from the center of a first ring beam of a diffusion section.

Wherein, the aileron includes: (1) left aileron; (2) Right aileron.

The elevator includes: (1) left elevator; (2) right elevator.

The rudder comprises: (1) a right inner rear rudder; (2) a left inner rear rudder; (3) right outer upper rear rudder; (4) left outer upper rear rudder; (5) a right outer lower front rudder; (6) left outer lower front rudder; (7) left outer upper front rudder; (8) right outer upper front rudder; (9) left outer upper rear rudder; (10) right outer upper rear rudder; (11) a left inner front rudder; (12) right inner front rudder.

The main interference source of the test is a propeller and a control system thereof, and a propeller driving system mainly comprises a 120kW permanent magnet brushless direct current motor, a speed regulating device, an operation console, cooling water and other systems. The main parameters of the 120kW motor and the control system are as follows:

rated power … … … … kW;

rated speed … … … … 6700RPM;

rated torque … … … … N.m;

the outer diameter of the motor … … … … phi 180mm.

The beneficial effects of the invention will be demonstrated by experimental data, noting that Fy represents normal force, fx represents axial force, mz represents hinge moment, my represents yaw moment, mx represents roll moment

And (3) carrying out additional rigidity analysis on the special balance in the wind tunnel cluster according to the data of actual inspection, outputting the sensitivity of the balance as a reference value, changing the rigidity of a calibration connecting plate, changing the additional rigidity of the balance along with the change of the additional rigidity of the balance, wherein the sensitivity change of Fy, fx and Mx is less than 0.5%, and the sensitivity change of Mz and My is less than 3%.

And then carrying out calibration with a loading head and control surface loading, specifically measuring Fy, mz, fx, my, mx five components, carrying out test loading with the control surface after static calibration of the balance, wherein the sensitivity change of Fy, mz, fx, mx is less than 0.5%, the main term coefficient change of My components is less than 2% in two states, and the balance formula is not corrected.

Five-component special test balances based on the wind tunnel cluster special balance are provided below, wherein the installation positions and the directions (deflection directions) of the balances are different, and the five-component special test balances are respectively NQ (inner front) balance, WSQL (outer upper front left) balance, WXQL (outer lower front left) balance, WSQR (outer upper front right) balance and WXQR (outer lower front right) balance, wherein a Y axis is a hinge axis, and an X axis is a resistance direction. The design load of each balance is shown in Table 1, where the model dead weight effect has been considered.

Table 1 balance design load

The measuring element is a three-column beam combined element, and the central beam measures Fx and My components; the perimeter beams measure Fy, mz, mx components. The decomposition of Fx/My component and Fy/Mz/Mx component adopts electric decoupling. Meanwhile, in order to improve the sensitivity of the lateral force, double-arc hinges are symmetrically arranged on the peripheral beam. The WSQR balance has the same load as the WSQL balance, the model space is consistent, and the two are symmetrical about the center of the aircraft model; the WXQR balance has the same load as the WXQL balance, the model space is consistent, and the WXQR balance and the WXQL balance are symmetrical about the center of the aircraft model. The filling performance parameters of each control surface obtained after the experiment are shown in table 2.

Table 2 balance performance parameters for each control surface

The following expands on the description of one embodiment from a full flow of mounting to measurement, including:

firstly, performing balance installation:

the two special aileron test balances are symmetrically arranged on the wing in a left-right mode, the fixed ends of the balances are connected with the wing, and the other ends of the balances are connected with the ailerons through angle blocks. The trailing edge of the aileron control surface is deflected downwards to be deflected forwards, and the deflection of the left and right aileron control surfaces is the same during test.

The two elevator special test balances are respectively arranged on the left and right horizontal tails, the fixed end of the strain balance is connected with the horizontal tail stabilizer, and the other end of the strain balance is connected with the elevators through angle blocks. The trailing edge of the elevator control surface deflects downwards to forward deflection.

The 12 rudder special test balances are symmetrically arranged on the tail wing from left to right, wherein the front 6 rudder balances are designed into a vertical fin stabilizer shape, and are used as measuring elements and are connected with the horizontal fin through model connecting pieces; the 6 rudder balances on the rear side are connected with the rear rudder through angle blocks and are mounted on the front rudder balance through angle blocks as shown in fig. 2.

The left deflection of the rear edge of the rudder surface is forward deflection. All rudder deflection angles are consistent in the test, and the rear side rudder deflects the same angle on the basis of the front rudder deflection.

Setting external conditions:

model

The plane where the horizontal construction line of the machine body is positioned is taken as a reference measurement, and the range is-8 degrees to 23 degrees;

model

The longitudinal symmetry plane of the model is taken as a reference measurement, and the range is-20 degrees to 20 degrees.

Measuring the torque of an unpowered control surface hinge: the actual running speed is 2750Pa, the nominal wind speed is 70m/s, and the test Reynolds number based on the average aerodynamic chord length of the full-machine model is 2.37×106.

Measuring the moment of a hinge with a power control surface: the components were measured as shown in table 3 below:

table 3 data of the moment measurement of the powered control surface hinge

The specific measurement comprises:

A. moment measurement of the hinges of the ailerons with or without power (the left aileron and the right aileron are biased together);

B. measuring the moment of a hinge of the elevator with or without power;

C. and the moment measurement of the hinge of the unpowered rudder (the front rudder and the rear rudder deflect simultaneously and the angles are the same).

Furthermore, the force and moment borne by the aileron, the elevator and the rudder are respectively measured by 16 special test balances arranged on the whole machine model, and the measured results enter a computer for processing and outputting through a data acquisition system. The attack angle and the sideslip angle of the model are realized by a cantilever system of the extra-large attack angle test device, and the attack angle measurement is realized by an attack angle sensor in the model. And processing, displaying and storing test results in real time.

Test data were collected by the PXI system. The data acquisition is carried out in a conventional mode, and the sampling mode is as follows: the pre-sampling delay is 5s, the sampling time is 6s, and the sampling frequency is 500Hz per channel.

Wherein, data acquisition includes:

establishing a finite element analysis model: and establishing a three-dimensional solid model of a balance in SolidWorks software and dividing grids, wherein the balance elements refine the grids by adopting a grid control technology, and the unit size is 1mm and the ratio is 1.5.

Adding boundary conditions: the finite element analysis is carried out under five working conditions, fx, fy, mx, my, mz is loaded on the balance moment reference center, and a strain cloud image of the balance measuring element is obtained.

Performing finite element simulation calculation: the strain balance measuring circuit adopts a Wheatstone full-bridge circuit and is excited by a direct current constant voltage source.

The WXQL balance group bridge scheme is shown in fig. 3-1, 3-2 and 3-3, wherein the fig. 3-1 and 3-2 are structural diagrams of the wind tunnel cluster special balance at different angles, positions of different strain gauges forming the bridge are indicated, the fig. 3-3 is a circuit diagram of different bridges, 1 to 24 in the diagram represent different strain gauges (part of reference numerals are written in brackets and indicate that the strain gauges marked in the brackets are blocked at the same position), the strain gauges are ZF200-2AA normal temperature strain gauges, 6 bridges in total are adopted, and each bridge B1/B2/B3/B4 consists of 4 strain gauges and Fy/Mz/Mx components are measured; B5/B6 each bridge consisted of 4 strain gauges measuring the Fx/My components. The supply bridge voltage u=6v.

The NQ balance and the WSQL balance are the same as the WXQL balance group bridge method.

Based on the principle of virtual calibration of the strain balance, a virtual bridge is formed, and the calibration of the balance unit is simulated. The "virtual" load calibration sequence is: fx, fy, mx, my, mz, taking the average strain value of the patch position (2 mm from the element root), the principal output strain and the primary disturbance output strain of each component can be obtained (the disturbance strain is added by absolute values).

The calculation formula (1) of the output voltage signals of each component of the balance is as follows:

…………………………………………（1）

wherein:

is the output signal of the bridge, mV; k is the sensitivity coefficient of the strain gauge, k=2; u is bridge excitation voltage, mV; n is the number of bridge groups; />

The strain is output for the bridge average.

And determining the strain of the strain gauge pasting part of the balance measuring element along the wire grid direction of the strain gauge under the load action through finite element simulation calculation, so that the output signals of all components of the balance can be obtained, and further, the output results of all component signals of the balance are obtained.

The data processing method comprises the following steps:

and (3) carrying out model attack angle correction, rapid pressure correction and control surface deflection angle correction on balance data of each special test, outputting data by using a control surface body shafting, and giving a result by using a dimensionless coefficient.

Wherein the data is dimensionless obtained by the following formula (2):

…………………………………………（2）

wherein C is _N As normal force coefficient, Y _t For normal force of control surface, q is test rapid compression, S is area behind hinge line of control surface, C _A As an axial force coefficient, X _t For controlling the axial force of the surface, C _h As the moment coefficient of the hinge, C _n For yaw moment, C _l For the roll moment coefficient, M _zt For controlling the surface hinge moment, M _yt For moment around the Y-axis of the control surface body axis system, M _xt C is the moment around the X axis of the control surface body axis system _A The average aerodynamic chord length after the hinge line is the control surface.

The shafting in the experiment is briefly defined as follows:

aileron special test balance shafting: the device is fixedly connected with an aileron special test balance, an origin OT is a calibration center, a left aileron XT axis is parallel to an aileron rotating shaft (points to the left side of a model), a chord plane when a YT axis is perpendicular to the aileron by 0 DEG points downwards, a ZT axis perpendicular to the rotating shaft points backwards, and the directions accord with a right hand rule; the right aileron XT axis is parallel to the aileron rotation axis (pointing to the right of the model), the YT axis points downwards perpendicular to the chord plane when the aileron is 0 DEG, the ZT axis points forwards perpendicular to the rotation axis, and the pointing accords with the right hand rule. Referring to fig. 4-1 and fig. 4-2, both of which are schematic views of an aircraft in a wind tunnel, wherein fig. 4-1 is a cross-sectional view along the wind tunnel axis, fig. 4-2 is a cross-sectional view perpendicular to the wind tunnel axis, the aircraft head faces the outside of the paper, the aircraft model is positive y, the aircraft nose direction is positive x, and the aircraft nose direction is positive z along the wing (left wing) as shown in the figure.

Balance shafting for elevator special test: the left elevator XT axis is parallel to the elevator rotating shaft (pointing to the left of the model), the chord plane when the YT axis is vertical to the elevator by 0 DEG points upwards, the ZT axis vertical rotating shaft points forwards, and the pointing accords with the right hand rule; the right elevator XT axis is parallel to the elevator shaft (pointing to the right of the model), the YT axis points upwards perpendicular to the chord plane when the elevator is 0 DEG, the ZT axis points backwards perpendicular to the shaft, and the pointing meets the right hand rule.

The rudder special test balance shafting rudder special test balance is fixedly connected, and an origin OT is a calibration center:

the XT axis of the left outer upper rear rudder and the left outer lower rear rudder is parallel to the rudder rotating shaft (pointing to the lower part of the model), the YT axis is perpendicular to the chord plane when the rudder is 0 DEG and points to the right side of the model, and the ZT axis is perpendicular to the rotating shaft and points to the rear direction and accords with the right hand rule;

the XT axis of the right outer upper rear rudder is parallel to the rudder rotating shaft (pointing to the lower part of the model), the YT axis is perpendicular to the chord plane when the rudder is 0 DEG pointing to the left side of the model, the ZT axis is perpendicular to the rotating shaft pointing forwards, and the pointing accords with the right hand rule;

the XT axis of the right outer lower back, the left inner back and the right inner back rudder is parallel to the rudder rotating shaft (pointing to the upper part of the model), the chord plane when the YT axis is perpendicular to the rudder by 0 DEG points to the left side of the model, the ZT axis is perpendicular to the rotating shaft to point backwards, and the pointing accords with the right hand rule;

the XT axis of the left inner front, the right inner front, the left outer upper front, the right outer upper front and the right outer lower front rudders is parallel to the rudder rotation axis (pointing to the upper part of the model), the chord plane when the ZT axis is perpendicular to the rudder by 0 DEG points to the right side of the model, the YT axis is perpendicular to the rotation axis and points backwards, and the direction accords with the right hand rule;

the XT axis of the left outer lower front rudder is parallel to the rudder rear rudder rotating shaft (pointing to the lower part of the model), when the ZT axis is perpendicular to the rudder by 0 DEG, the chord plane points to the left side of the model, and when the YT axis is perpendicular to the rotating shaft, the pointing direction accords with the right hand rule.

Control surface body shafting: the control plane is fixedly connected with each control plane respectively, an origin Ot is positioned on a hinge line of the control plane and at the midpoint of the intersection point of the hinge shaft and the end face of the control plane, an Xt axis is positioned in a chord plane of the control plane and is perpendicular to the hinge line, and the direction of the Xt axis to the front of the model is positive; the Yt axis is perpendicular to the chord plane of the control surface, the pointing upper surface is positive (the rudder points to the right surface and is positive, and the rudder looks along the heading); the Zt axis coincides with the hinge line, and is determined according to the right-hand rectangular coordinate system rule, and the direction to the right is positive (the direction of the rudder is downward positive); the moment sign is determined by the right hand rule.

The method comprises the steps of obtaining a pneumatic coefficient by adopting a least square method, and obtaining the derivative of the control surface pneumatic coefficient on the control surface deflection angle according to a nominal deflection angle. Rudder and aileron efficiency deriving range-10 deg. to 10 deg., elevator efficiency deriving range-15 deg. to 15 deg..

In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, so that the same or similar parts between the embodiments are referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant points refer to the description of the method section.

It should be noted that in this specification, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.

Claims

1. The wind tunnel cluster special balance is characterized by comprising a fixed frame, a floating frame, a rigid beam and a disturbance eliminating beam;

2. The wind tunnel cluster specialty balance of claim 1, wherein said tamper beam is a tamper hinge.

3. The wind tunnel cluster specialty scale of claim 2, wherein said tamper hinge is a bi-circular hinge.

4. The wind tunnel cluster specialty balance of claim 1, wherein said fixed frame is a wing frame;

the airfoil frame and the airfoil base form an airfoil to be measured.

5. The wind tunnel cluster specialty balance of claim 1, wherein said floating frame includes a fixed slot;

6. Wind tunnel cluster specialty balance according to any of claims 1 to 5, wherein said pre-groove comprises a proximal side and a distal side; an adjusting slit is arranged between the distal end side and the root of the fixed frame;

7. The wind tunnel cluster specialty scale of claim 6, wherein said first threshold value ranges from 5% to 15%, inclusive.

8. The wind tunnel cluster specialty balance of claim 7, wherein the ratio of the width of the adjustment zone to the width of the proximal side ranges from 0.4 to 0.8, inclusive; the adjustment zone is the area between the adjustment slit and the distal side of the pregroove.

9. Wind tunnel system for cluster measurement, comprising a wind tunnel cluster specialty balance according to any of claims 1 to 8.

10. The clustered measurement wind tunnel system of claim 9 including a plurality of the wind tunnel clustered specialty balances classified as parent and child balances;