JPH109997A - Balance for wind tunnel test - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balance by which six component forces can be measured with good accuracy even at a small model such as an externally mounted object which is mounted on, and attached to, an airplane model by a method in which the cross-sectional shape of a drag measuring element part which is installed between coupling parts formed respectively at the front end part and the rear end part of the balance and which measures a drag load out of an air-force load is formed to be a noncircular shape. SOLUTION: The cross-sectional shape of a measuring element part which is formed between a sting coupling part and a model coupling part at a balance 1 is formed to be a noncircular shape. That is to say, the noncircular shape is formed as a longitudinal oval 2a in which a long diameter is formed from the upper part to the lower part, a transverse oval 2b in which a long diameter is formed to the right and the left, a longitudinal rectangle 2c in which long sides are formed at the upper part and the lower part, a transverse rectangle 2d in which long sides are formed at the right and the left or a lozenge 2e in which a diagonal line is arranged from the upper part to the lower part or from the right to the left. In the case of the longitudinal rectangle 2c, the transverse rectangle 2d and the lozenge 2e which comprises edges, the edges are removed, and arcs are formed in their removed parts. A cross-sectional area may be made larger or smaller than a balance 04 in conventional cases. The cross-sectional shape which is right-angled in the length direction is formed to be a noncircular cross-sectional shape so as to be an identical shape in the front and rear direction. Thereby, a bend due to an air-force load is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wind tunnel test balance used for measuring aerodynamic force (aerodynamic load) acting on a model installed in a wind tunnel in a wind tunnel test.

[0002]

2. Description of the Related Art When measuring the aerodynamic force acting on a model using a wind tunnel and a model simulating an aircraft or the like, generally a balance for a wind tunnel test (hereinafter simply referred to as a balance) is used. Measurement). FIG.
As shown in FIG. 7, in the wind tunnel 01, a rear end portion is connected to a strut 02 attached in a vertical direction of the wind tunnel 01, and the vertical movement of the strut 02 causes the wind tunnel 01 to move in the front-rear direction as shown in FIG. A sting 03 that allows the angle of attack α to be set with respect to the airflow F flowing through the sting 03 is attached.

[0003] Also, at the tip of this sting 03,
A balance 04 fitted with a sting joint 05 provided at the rear end is mounted. The model coupling portion 06 provided at the tip of the balance 04 is fitted with the model coupling portion 06 in an opening formed in the shaft center portion, and the model 07 fixed to the coupling portion 06 is mounted. , The aerodynamic force acting on the model 07 is measured. Further, the aerodynamic force, which will be described later, acting on the model 07 and measured by the balance 04 is converted into an electric quantity, and the lead wire 08 is inserted through a hole formed in the shaft portion of the balance 04 and the sting 03. Via a strut 02, the data is input to a data processing device 09 installed outside the wind tunnel 01.

As shown in FIG. 8, the balance 04 has a circular cross-sectional shape between the Sting joint portion 05 and the model joint portion 06, more precisely, a circular cross-sectional outline, and a front-rear direction (longitudinal direction).
It has a constant cross-sectional shape. Then, in a normal wind tunnel test, the three forces acting on the model 07 attached to the model coupling portion 06 at the tip end shown in FIG.
7, the three moments around the reference point 010, that is, of the pneumatic force acting on the model 07, the lift force Z acting upward, the drag force X acting backward in the axial direction, and the lateral force Y acting rightward. Among the three forces and the moment acting around the reference point 010 due to the aerodynamic force acting on the model 07, a rolling moment L acting on lowering the right, a pitching moment M acting on raising the head, and a bias acting on retreating to the right Measurement of three moments including the swing moment N is required.

The principle of force measurement by the balance 04 is based on Hooke's law that "force and strain are proportional" with an elastic material. That is, an elastic strain generated by the pneumatic force acting on the model 07 is generated in the measuring section of the balance 04, the amount of this strain is detected by a strain gauge attached to the measuring section, and converted into an electric quantity, as described above. The data is transmitted to the outside of the wind tunnel 01 by the lead wire 08, and converted into physical quantities by a data processing device 09 installed outside the wind tunnel 01 to obtain the physical quantity.

Therefore, as shown in a perspective view of FIG. 10, the balance 04 is provided with a large amount of strain in a direction perpendicular to the axis of the balance 04 to increase the lift Z, the lateral force Y, and the rolling moment. L, a pitching moment M, and a yawing moment N, a five-component force measuring element unit 011 configured to measure two forces and three moments, and a large amount of strain in the axial direction to increase a drag X Is formed between the Sting coupling part 05 and the model coupling part 06.

[0007] Further, a measuring unit 013 formed so that the strain amount of the 5-component force measuring element unit 011 and the drag measuring element unit 012 becomes large, for example, provided in a drag measuring element unit 012 shown in FIG. In the measuring unit 013, the thickness in the axial direction is reduced, and the arrow E-E in FIG.
As shown in FIG. 8B, which is an arrow FF diagram of FIG. 8, the measuring unit 013 is formed so that the width is small and the strain amount is increased with respect to the load in the axial direction. As shown in 11,
The strain gauge 014 is attached, and a large amount of strain generated in the measuring unit 013 by the aerodynamic force acting on the model 07 is detected by the strain gauge 014.

The strain amount detected by the strain gauge 014 is converted into an electric quantity as described above, and transmitted to the lead 08 via the gauge lead 015. Before performing the wind tunnel test, the above-mentioned three Z, X, Y and three moments L, M, N are loaded on the model 07 set in the wind tunnel 01, and the strain and the amount of strain are determined. Calibration (calibration) is performed in advance, and based on this calibration, the amount of strain that generates a wind tunnel test is calculated using the calibration value.
One force Z, X, Y and three moments L, M, N are determined.

As described above, the balance 04 used in the conventional wind tunnel test is located at the main part of the balance, that is, between the sting coupling part 05 and the model coupling part 06, as described above, and has the measuring element part 011. , 012 are provided, the outer cross-sectional shape of the central portion of the balance 04 is usually circular and has a constant cross-sectional shape in the front-rear direction. For this purpose, the aerodynamic force acting on a small model, such as an external load mounted on a model simulating an aircraft manufactured on a reduced scale that can be installed in the wind tunnel 01, as in an external load test of an aircraft, is measured. In such a case, in such a balance 04 having a constant circular cross section, the diameter of the balance 04 becomes very small, and in particular, it may not be possible to secure a space for the drag measurement element unit 012.

That is, in order to measure the drag X, as described above, the amount of strain generated by the load in the axial direction is generated in the measuring unit 013 arranged in the direction orthogonal to the axial direction of the balance 04. Therefore, it is necessary to increase the diameter of the balance 04 and increase the amount of strain by increasing the longitudinal movement of the upper and lower ends of the measuring unit 013 due to the aerodynamic force acting on the model 07, for example. If the diameter of the balance 04 is small, the magnitude of the amount of distortion becomes equal to the magnitude of noise generated due to various factors, and measurement becomes impossible.

For this reason, although data acquired by a 6-component force balance is necessary for design and other reasons,
When the component force data cannot be obtained, a model that acquires the five-component force measurement data excluding the drag and measures only the remaining drag X using a five-component force balance that measures the other five component forces excluding the drag X 07 and the balance 04 are newly manufactured, a wind tunnel test is separately performed, and measurement data is supplemented. However, in the wind tunnel test for acquiring the 6-component force measurement data in this way, the production cost of the model 07 and the balance 04 is increased, and the use time of the wind tunnel 01 is increased, and the cost is increased, and the 5-component force measurement is performed. And drag measurement test conditions,
There is a problem that the accuracy of the measurement data is deteriorated due to, for example, inability to completely match.

Further, the degree of freedom for selecting the balance 04 from the space inside the model 07 on which the balance 04 is mounted is limited,
Since a balance with a constant circular cross section is mounted in a narrow space, it is necessary to use a balance 04 that is smaller than necessary, and thus the balance capacity is reduced, and the conditions of the wind tunnel test such as wind speed and angle of attack in the wind tunnel test are limited. Sometimes.

That is, despite the necessity of performing a wind tunnel test at a larger wind speed or a larger angle of attack and acquiring measurement data, the balance 04 having a small balance capacity and a small rigidity must be used. Because it cannot be obtained, when a wind tunnel test is performed at a large wind speed or a large angle of attack range, for example, the combined body of the model 01 and the balance 04 shown in FIG. Model 01
Since the inner peripheral surface of the rear end portion comes into contact with the outer peripheral surface of the sting 03, data cannot be obtained, and the test range is limited.

[0014]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned disadvantages of the conventional balance for wind tunnel testing by measuring an aerodynamic force by an externally mounted test, such as an externally mounted object mounted on an aircraft model. It is necessary to conduct a wind tunnel test with a balance that can secure a measuring element that can accurately measure 6-minute force even with a small model, and that can withstand a large wind speed or a large angle of attack. An object of the present invention is to provide a balance for a wind tunnel test from which measurement data at a model posture or wind speed can be obtained.

[0015]

Therefore, a first wind tunnel test balance of the present invention has the following means. (1) Drag measurement that measures the drag load among the aerodynamic loads acting on the model to which the balance is attached, which is disposed at the main part of the balance, that is, at the center between the Sting joint and the model joint. The cross-sectional shape of the element part, however, the drag measurement element part is provided with a part connected to the model side and a part connected to the sting side, and a slit is provided between them to prevent contact However, the cross-sectional shape assuming that these slits were filled was made a non-circular shape.

The term "non-circular" refers to an oval, elliptical or rectangular shape, or a shape obtained by cutting off a diamond-shaped ridge to provide a rounded shape.
The non-circular portion may be a portion other than the drag measuring element.

The balance for the wind tunnel test of the present invention has the following advantages. (1) The length of the measuring part of the drag measuring element is larger than that of a conventional circular balance having the same sectional area by the means (1). Can be increased. As a result, even if the diameter of the model on which the balance is mounted is reduced, the reduction in the diameter of the model is not significantly affected by the installation, and the lifting force Z, the lateral force Y, the rolling moment L, the pitching moment M, and the yawing moment N are five. At the same time as the component force measurement, a certain length is required in the direction orthogonal to the balance axis direction,
The measurement of the drag X, which is greatly affected by the reduction in the diameter of the model, can be easily and accurately performed. Therefore,
It is not necessary to separately perform the wind tunnel test for the five-component force measurement and the drag X measurement, so that it is possible to reduce the production cost of the model and the balance, the operation cost of the wind tunnel, and the like, and to improve the accuracy of the measurement data.

(B) A conventional circular shape having the same cross-sectional area by forming a non-circular cross-sectional shape by increasing the length of the combined body of the model and the balance in the direction in which the amount of deflection increases. Compared to a balance for a wind tunnel test, the amount of deflection that becomes larger than necessary due to a large aerodynamic load acting on a model due to wind speed and angle of attack can be reduced. In other words, even with a balance having the same cross-sectional area as a conventional balance, a wind tunnel test with a larger wind speed and angle of attack than before can be performed.
This can be performed without causing any trouble such as contact between the model and the sting. As a result, data at a large wind speed and a large angle of attack, which have been supplemented by estimation and the like, can be acquired, and the design accuracy and the like can be improved.

The second balance for wind tunnel test of the present invention employs the following means. (2) A cross-section of a measuring element portion arranged at a main portion of the balance, that is, a central portion between the Sting connection portion and the model connection portion, for measuring an aerodynamic load acting on the model on which the balance is mounted. The shape was non-uniform along the length of the balance. Note that non-uniform means that a bulging portion is provided in a part of the balance in the length direction such that the cross-sectional areas of the five-component force measuring element portion and the drag measuring element portion of the measuring element portion are different from each other. In the lengthwise direction of the measuring element portion, a taper may be provided so as to gradually change the cross-sectional area.Moreover, the shape of the cross section is circular in the lengthwise direction of the measuring element portion, Alternatively, a non-circular shape may be used.

In the wind tunnel test balance according to the present invention, the measuring element for which the length in the direction perpendicular to the axial direction of the balance needs to be increased in the aerodynamic load measurement by means of the above (2), for example, a drag force Only the measurement element section can increase the thickness of the measurement section, and can provide a balance having the same operation as (a) and the same effect as (a). Also, by increasing the cross-sectional area of the position where the measuring element unit for measuring the force or moment in which the amount of bending of the combined body of the model and the balance becomes large, the capacity of the balance can be increased,
A balance having the same effect as the above (b) and the same effect as the above (b) can be obtained.

The third means for wind tunnel test according to the present invention employs the following means. (3) A wind tunnel test balance provided with the above-mentioned means (2) is the same as the above-mentioned means (1).

The balance for a wind tunnel test of the present invention is a balance which has the same effect as the above (a) and (b) and the same effect as the above (a) and (b) by means of the above (3). can do. In particular, with the conventional small-diameter model, the measurement of the drag X, which has been difficult to measure, is facilitated, and the accuracy of the measurement data can be further improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the balance for wind tunnel test according to the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a measuring element unit showing a first embodiment of a wind tunnel test balance of the present invention.

As shown in the figure, a balance 1 of the present embodiment is shown.
Are the Sting connection part 05 and the model connection part 0 shown in FIG.
The cross-sectional shape of the measuring element section 2 formed between the measuring element section 6 and the measuring element section 6 is made non-circular with respect to the perfectly round measuring element section of the conventional balance 01 shown by a dotted line in the figure.

That is, as shown in FIG.
FIG. 1 (b) shows a vertically long oval 2a having a long diameter, and a horizontally long oval 2b having a left and right long diameter as shown in FIG. 1 (b).
As shown in FIG. 1 (c), a vertical rectangle 2c with long sides provided vertically, as shown in FIG. 1 (d), a horizontal rectangle 2d with long sides provided on left and right sides, as shown in FIG. 1 (e). In addition, a diagonal line is arranged on the upper, lower, or left and right sides to form a diamond 2e, which is non-circular. In addition, the vertical rectangle 2c with a ridge, the horizontal rectangle 2d,
The rhombus 2e has an edge removed to form an arc at this portion.

Also, as shown by the vertical oblong circle 2a and the horizontal oblong circle 2b, the vertical rectangular shape 2c, the horizontal rectangular shape 2d, and the rhombus 2
As shown by e, the cross-sectional area of the conventional balance 01 can be made larger or smaller. Furthermore, in the balance 1 of the present embodiment, the cross-sectional shape is made as described above, and is formed so as to have the same cross-sectional shape over the entire length of the measuring element unit in the front-rear direction.

As described above, in the balance 1 of the present embodiment,
By making the cross-sectional shape perpendicular to the longitudinal direction a non-circular cross-sectional shape and making it the same shape in the front-rear direction, the model 07,
The balance due to the aerodynamic load of the balance 1 is reduced and the model 0
7 makes it difficult for the rear end to come into contact with the sting 03, and enables a wind tunnel test in a wider range of attack angle and a larger speed range.

That is, since the conventional balance 04 has a circular cross-sectional shape, it has isotropic rigidity. For example, when the model 07 is set at a large angle of attack, a large deflection is caused in the head-raising direction of the model 07. Model 07 with a constant gap
Although the rear end may come into contact with the sting 03, reliable measurement data could not be obtained even when the wind tunnel test was performed. However, the oblong circle 2a shown in FIGS. By using the balance 1 having a rectangular cross section in the shape of a rectangle 2c, it is possible to make the balance capacity relatively rigid in the longitudinal direction, reduce the bending, and perform a wind tunnel test using the conventional balance 04. In the above, what was limited to the angle of attack, the wind speed, etc. is relaxed, and the wind tunnel test at a large angle of attack and a large wind speed can be performed.

In the case where the wind tunnel test is performed by greatly changing the side slip angle in the horizontal direction corresponding to the above-described vertical angle of attack, the results are shown in FIGS. 1 (b) and 1 (d). By forming the balance 1 having the horizontal cross section of the oblong circle 2b and the horizontal rectangle 2d as described above, it is possible to reduce the deflection caused by the side slip angle. In the conventional balance 04, the side slip angle β and the wind speed in the wind tunnel test can be reduced. What was restricted was eased,
Wind tunnel tests in a wide range of sideslip angles and wind speeds can be performed, which is convenient. As described above, if the cross-sectional shape shown in FIG. 1 is properly used according to the shape and the posture angle of the model 07, the model 07
However, wind tunnel tests can be performed at high wind speeds and a wide range of attitude angles.

Further, in the blow-out type wind tunnel, a large load, a so-called starting load, may be applied to the model 07 at the time of starting or stopping, and the capacity of the balance needs to be determined in consideration of this load. Change the load characteristics by grasping the load characteristics and changing the cross-sectional shape to change the balance capacity, clear this load problem, or prevent deterioration of measurement data due to contact between the model 07 and the sting 03. Can also.

Further, by making the non-circular cross-sectional shape other than the circular cross-sectional shape as in the conventional balance 04,
The application corresponding to various models 07 can be performed. That is, the length in the vertical direction can be lengthened by using the balance 1 having the cross section of the vertically long circle 2a and the vertically long rectangle 2c shown in FIGS. 1A and 1C. A space for increasing the length of the measuring unit 013 provided in the element unit 012 can be secured.
Although the length of 3 could not be secured and only 5 component force could be measured, a 6 component force balance that can simultaneously measure 6 component force including drag can be used.

As a result, the accuracy of measuring the six-component force, particularly the drag, can be improved, and the cost of producing a model, balance, or wind tunnel operation required for a wind tunnel test can be significantly reduced.

FIG. 2 is a view showing a second embodiment of the balance for wind tunnel test according to the present invention. FIG. 2 (a) is a longitudinal sectional view, and FIG.
FIG. 2B is a cross-sectional view taken along a line AA in FIG. When the diameter of the balance becomes very small, in order to solve the problem when the space of the drag measurement element unit 012 cannot be secured with the conventional balance 04 having a constant circular cross-sectional shape,
In the present embodiment, the balance 3 is provided with a partial bulge 5 that increases the diameter only in the vicinity of the drag measuring element unit 4 and a drag measuring unit 6 is provided in this portion.

In this way, the drag measuring unit 6 for increasing the strain amount, that is, the drag measuring unit 6 for which the length in the direction orthogonal to the axial direction of the balance 3 needs to be increased is installed. A space can be secured, and by attaching the strain gauge 7 to the drag measuring section 6, the drag can be measured with high measurement accuracy. In addition, swelling 5
May be formed linearly as shown by a solid line in the figure, or may be formed into a curved bulge 5 as shown by a broken line. The front and rear positions of the bulge 5 are shown in FIG.
It can be provided at any position, whether it is located in front of arrow 3 shown in FIG.

In the case of the balance for wind tunnel test of the present embodiment, when the model 07 is mounted on the balance 3, depending on the model 07, for example, the rear part of the model 07 may be divided into upper and lower parts. It may be necessary to mount the balance 3 between them.

Although the present embodiment is applied to a conventional circular cross section having a constant shape in the front-rear direction, the third embodiment of the wind tunnel test balance of the present invention.
As shown in FIG. 3, the cross-sectional shape may be a vertically elliptical shape and the shape in the front-rear direction may be constant. That is, in the present embodiment in which the first embodiment shown in FIG. 1A and the second embodiment shown in FIG. 2 are combined, the respective effects of the first embodiment and the second embodiment are obtained. This has a greater effect than the superimposition, and can greatly contribute to the solution of the problem that has been demanded by the conventional wind tunnel test balance.

That is, in addition to the five-component force that was impossible with the conventional balance, a six-component force balance capable of measuring drag can be more easily made.
In order to reduce the deflection of the balance 8 combination more effectively and increase the accuracy of the measurement data, it is preferable to make the gap smaller. The contact between the rear end of the model 07 and the sting 03 is
It will be more difficult to perform, and it will be possible to perform wind tunnel tests in a wide angle of attack and speed range. Similarly, FIG.
It is needless to say that the present invention can be combined with the first embodiment shown in FIGS. 1 (b) to 1 (e).

FIG. 4 is a view showing a fourth embodiment of the balance for wind tunnel test according to the present invention. FIG. 4 (a) is a longitudinal sectional view, and FIG.
FIG. 4B is a cross-sectional view taken along the line CC of FIG. In the case where the diameter of the balance is extremely small, the present embodiment is to solve the problem in the case where the space of the drag measuring element unit 012 cannot be secured with the conventional balance 04 having a constant circular cross-sectional shape in the front-rear direction. Here, the balance 9 has a tapered portion 10 provided in the front-rear direction of the measuring element portion.

Thus, the outer shape of the balance 9 is formed,
By arranging the drag measuring element section 11 in a portion having a large cross-sectional area, the drag measuring section 12 in which the amount of strain is increased, that is, the drag in which the length in the direction orthogonal to the axial direction of the balance 9 is increased. By attaching the strain gauge 13 to the drag measuring unit 11 in which a space for installing the measuring unit 12 can be secured and the amount of strain due to aerodynamic load is increased, it is possible to measure the drag with high measurement accuracy.

As shown in the figure, the tapered portion 10 is tapered such that the rear portion becomes thinner. On the contrary, the taper portion 10 is tapered so that the front portion becomes thinner and the rear portion becomes thicker. May be provided. Thereby, an operation similar to that of the above-described second embodiment is performed, and a similar effect is obtained. Further, when the model 07 is mounted on the balance 9 as in the second embodiment,
According to the model 07, the rear part of the model 07 had to be divided into upper and lower parts. However, in the present embodiment, this is not necessary, and this is advantageous in terms of the production of the model 07.

The present embodiment has a circular cross section in the front-rear direction similarly to the conventional balance 04. FIG. 5 shows a fifth embodiment of the balance for wind tunnel test according to the present invention. As shown in (1), the cross-sectional shape can be a vertically long oval. That is, in the present embodiment in which the first embodiment shown in FIG. 1A and the fourth embodiment shown in FIG. 4 are combined, the respective effects of the first embodiment and the fourth embodiment are overlapped. The combined effect is greater than the combined effect, and can greatly contribute to solving the problem.

That is, 5 which was impossible with a conventional balance
In addition to the component force, it is easier to make a 6-component force balance capable of measuring the drag force, and it is also possible to more effectively reduce the deflection of the combination of the model 07 and the balance 14 so that the model 0
7 Make the contact between the rear end and the sting 03 more difficult,
This enables a wind tunnel test in a wide angle of attack and speed range. Similarly, the first embodiment shown in FIGS. 1B to 1E and the fourth embodiment shown in FIG. 4 can be combined, and a larger effect obtained by superimposing those effects can be obtained. It goes without saying that you can enjoy

[0043]

As described above, according to the balance for wind tunnel test of the present invention, the configuration shown in the claims makes it possible to: (1) reduce the deflection of the combined model and balance, and stabilize the model with the rear end. And allows wind tunnel testing over a wider angle of attack and speed range. (2) It is easy to secure a space for the drag measuring element, which requires a length in a direction perpendicular to the axial direction of the balance,
With a conventional balance having a circular cross-sectional shape, a 6-component force balance that can measure a drag can be used together with another 5-component force measurement that can be relatively easily performed, which is not possible with a small model drag measurement installation.

[Brief description of the drawings]

FIG. 1 is a front view of a measuring element unit showing a first embodiment of a wind tunnel test balance of the present invention, in which FIG. 1 (a) is a vertically long balance, FIG. 1 (b) is a horizontally long balance, and FIG. 1 (c) is a total rectangular balance, FIG. 1 (d) is a horizontal rectangular balance, FIG. 1 (e) is a front view of a measuring element portion of a rhombic balance,

FIG. 2 is a diagram showing a second embodiment of the present invention;
(A) is a longitudinal sectional view, and FIG. 2 (b) is an arrow A- of FIG. 2 (a).
A cross-sectional view at A

FIG. 3 is a diagram showing a third embodiment of the present invention;
(A) is a longitudinal sectional view, and FIG. 3 (b) is an arrow B- of FIG. 3 (a).
B cross section,

FIG. 4 is a diagram showing a fourth embodiment of the present invention.
4 (a) is a longitudinal sectional view, and FIG. 4 (b) is an arrow C- of FIG. 4 (a).
Cross section at C,

FIG. 5 is a diagram showing a fifth embodiment of the present invention.
5A is a longitudinal sectional view, and FIG.
D cross-sectional view,

FIG. 6 is a side view showing a model installed in a wind tunnel,

FIG. 7 is a side view showing the model shown in FIG.

8A and 8B are views showing a conventional balance, FIG. 8A is a side view partially cut away, and FIG. 8B is a view taken along the line EE in FIG. 8A.
Cross section at

9 (a) is a side view, FIG. 9 (b) is a view from behind, FIG. 9 (c) is a plan view,

FIG. 10 is a perspective view showing a conventional balance,

FIG. 11 is a plan view of a strain gauge for measuring the amount of deflection and strain of the measuring unit of the balance.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Balance 2a, 2b, 2c, 2d, 2e Measuring element part 3 Balance 4 Drag measuring element part 5 Swelling 6 Drag measuring part 7 Strain gauge 8 Balance 9 Balance 10 Taper part 11 Drag measuring element part 12 Drag measuring part 13 Strain gauge 14 Balance 01 Wind tunnel 02 Strut 03 Sting 04 Balance 05 Sting connection part 06 Model connection part 07 Model 08 Lead wire 09 Data processing device 010 Reference point 011 Five-component measurement element part 012 Drag measurement element part 013 Measurement part 014 Strain gauge 015 Gauge lead line

Claims (3)

[Claims] 1. A wind tunnel test balance mounted on a model installed in a wind tunnel and measuring an aerodynamic load generated on the model, between a joint formed at a front end and a rear end of the balance. A balance for a wind tunnel test, wherein a cross-sectional shape of a drag measuring element portion installed for measuring a drag load of the aerodynamic load is non-circular. 2. A wind tunnel test balance mounted on a model installed in a wind tunnel and measuring an aerodynamic load generated on the model, wherein the balance is arranged between joints formed at a front end and a rear end, respectively. And a measuring element for measuring the aerodynamic load, wherein a longitudinal shape of the measuring element has a non-uniform cross-sectional shape. 3. A balance for a wind tunnel test provided with a measuring element portion having a non-uniform cross-sectional shape in the longitudinal direction, wherein at least one of the measuring element portions has a non-uniform cross-sectional shape. 3. The balance for wind tunnel testing according to claim 2, wherein the balance is circular.