JP2019032219A - Attach angle setting method of aircraft model in wind tunnel model supporting device and its setting apparatus - Google Patents

Abstract

To provide an attack angle setting method that can reduce a flow resistance in a wind tunnel model supporting device installing a six-force component measuring instrument in the sting, and facilitates automatic change of an attack angle of an aircraft model, and provide its setting apparatus.SOLUTION: An attack angle setting method of an aircraft model in a wind tunnel model supporting device is provided in which a sting (1) is connected to an axial central part a longer pipe-shaped strut (2) having a central axis in the width direction of the air flow in the air flow rear edge, and the strut includes a flow-straightening cover (3) having a streamlined outer shape to the air current direction. The flow-straightening cover is loosely fitted to the strut, and the flow-straightening cover is connected to an attack angle fixing arm (4) of the flow-straightening cover with a parallel linkage mechanism through pin connections (7, 8), and then the strut (2) is rotated by an attack angle setting-arm (13).SELECTED DRAWING: Figure 2

Description

  In the wind tunnel test of the aircraft model, the present invention provides an angle setting of the aircraft model in a wind tunnel model support device in which a supporting sting is arranged in parallel to the air flow behind the model and a six component force measuring device is mounted in the sting. The present invention relates to a method and a setting device thereof.

  Wind tunnel tests play an important role in knowing the aerodynamic performance and characteristics of aircraft in research and development of aircraft. In the wind tunnel test, six component forces acting on the aircraft model are measured, and the test is performed by changing the angle of attack (pitch angle), yaw angle, and roll angle of the aircraft model.

Generally, the wind tunnel test includes a strut support type wind tunnel test in which a model is attached to the upper part of the strut and a sting support type wind tunnel test in which a model is attached to the leading end of the sting. In the case of the wind tunnel test of the strut support system, the effect of the wind hitting the strut cover is a model and the measurement accuracy becomes a problem. From this viewpoint, the sting support system wind tunnel test is preferable (Patent Documents 1 and 2, Non-Patent Documents). Reference 1 and 2 etc.).

  FIG. 6 is a diagram showing a schematic configuration of an example of a wind tunnel model support device using a sting support in the prior art, which corresponds to FIG. 9 of Patent Document 1, and details thereof are described in Patent Document 2. .

The wind tunnel model support device shown in FIG. 6 is a front sting 18 to which a model 16 is attached and a central sting 20 in which one ear is inserted into the other two forks and pivotally attached by a horizontal pin bolt. A rear joint 26 formed by inserting one ear portion into the other two forks and pivoting with a heel pin bolt, a front joint 22, and a rear joint 26. Angle adjusting and locking means for adjusting and fixing each angle to a desired angle. The rear sting 24 is supported by a strut 27 standing upright with respect to the air flow direction F, and the cross section of the strut 27 is streamlined with respect to the air flow direction in order to reduce flow resistance (see Patent Document 2). By the way, in the case of the apparatus shown in FIG. 6, all changes in the angle of attack (pitch angle), yaw angle, and roll angle of the aircraft model are performed by human work before the ventilation test.

FIG. 5 is a diagram illustrating a schematic configuration of an example of an improved wind tunnel model support device according to the related art, and corresponds to FIG. In the case of the apparatus shown in FIG. 5, the angle of attack (pitch angle) of the aircraft model is automatically changed using an actuator during ventilation.

In the wind tunnel model support device shown in FIG. 5, a wind tunnel test model 28 is arranged in a measurement section in a wind tunnel through which an air current flows, and this model 28 has one end fixed to a fixed portion (not shown) and the other end after the model. It is supported by a supporting sting 30 pivoted at the end. The support sting 30 is installed in parallel with the airflow. A translation drive actuator 32 is arranged at a position slightly above the longitudinal axis of the support sting 30, and a movable sting 36 (member on which the actuator acts) is pivotally attached to the output shaft 34 of the actuator 32, so that the model has a parallel link configuration. The angle of attack of 28 can be changed. In this case, although not shown, a position sensor for measuring the position of the output shaft 34 is attached to the actuator 32 (see Patent Document 1).

  As a further improvement of the wind tunnel model support device shown in FIG. 6 and FIG. There has been considered a system in which a sting is connected to a long tubular strut and the angle of attack is automatically changed by rotating the long tubular strut (details will be described later). This system has an advantage that the configuration relating to the automatic change of the angle of attack is easy and the flow resistance can be reduced, and is the basic configuration adopted in the present invention. In this case, it is desirable that the long tubular struts are covered with a streamlined rectifying cover to further reduce the flow resistance. The reason is as follows.

  When a cylindrical object is placed in a uniform flow of fluid, flow separation occurs at a certain point on the surface of the cylindrical object, a vortex region is formed behind it, and the flow becomes untargeted before and after the cylindrical object. When a vortex is formed, the pressure in that portion decreases and the cylindrical body receives a force (pressure drag) from the fluid in the direction of flow. In addition, vibration is generated in the cylindrical object due to the generation of the vortex.

On the other hand, if the shape of the object becomes streamlined, the separation point moves to the rear of the object, the generation of vortices is suppressed, the pressure drag is reduced, and the generation of vibrations is also suppressed. By the way, even the wind tunnel model support device configured to cover the long tubular struts as described above with the streamline type rectifying cover has the following problems.

  Even if the flow direction of the air flow coincides with the central axis direction of the rectifying cover when the angle of attack is zero, when the change of the angle of attack is automatically changed by rotating the long tubular strut in the wind tunnel test, When the streamlined rectifying cover that covers the long tubular strut rotates together with the long tubular strut, there is a problem that the central axis direction of the rectifying cover is shifted from the flow direction of the air flow and the rectifying cover itself becomes a flow resistance. It was.

JP 2004-101456 A Japanese Patent Laid-Open No. 5-187961

Hidehiko Nishiwaki and two others, “About a large angle-of-attack wind tunnel test for small high-performance aircraft”, May 1982, Journal of the Japan Aerospace Society, Vol. 30, No. 340, pp. 60-66 Atsushi Hashimoto and three others, “Analysis of the whole transonic wind tunnel”, Japan Aerospace Exploration Agency (JAXA), ahashi@chofu.jaxa.jp

  The present invention has been made in view of the above-described problems, and an object of the present invention is to reduce flow resistance in a wind tunnel model support device in which a six component force measuring device is mounted in a sting, and to meet the problem. Automatic angle change is easy, and even when the angle of attack of the model is changed automatically, the problem that the flow straightening cover itself becomes a flow resistance is solved, and the angle of attack setting method of the model that can maintain the reduction of the flow resistance and It is to provide the setting device.

  In order to solve the above-described problem, the angle-of-attack setting method of the present invention is as follows. That is, in a wind tunnel test of an aircraft model, a wind tunnel model support apparatus that supports an aircraft model installed in a wind tunnel and that can change the angle of attack of the model, and is provided at the rear end of the model for 6 minutes. A sting that is equipped with a force detector is pivotally connected, and the sting is connected to the axially central portion of a long tubular strut having a central axis in the width direction of the airflow at the rear end of the airflow. Is a method of setting the angle of attack of the model in a wind tunnel model support device comprising a rectifying cover having a streamlined outer shape with respect to the air flow direction, wherein the rectifying cover is loosely fitted to the strut, In addition, the straightening cover is connected to the angle-of-attack fixing arm of the straightening cover having a parallel link mechanism through a pin connection, and then the strut is By rolling, and sets the angle of attack of the model that are connected to the stinger.

  Furthermore, the following configuration is preferable as an apparatus for carrying out the invention. That is, the stings, the struts to which the stings can be connected, the straightening covers divided on both sides of the sting in the axial direction of the struts, and the reception of each straightening cover provided with the parallel link mechanism. An angle fixing arm, and the angle-of-attack setting arms provided at both ends of the strut in the axial direction, respectively, and the parallel link mechanism is configured such that the angle of attack of the two rectifying covers arranged in parallel and spaced apart from each other Each one end of the fixing arm is connected to the first connecting plate via a first pin connection, and each other end is connected to the second connecting plate via a second pin connection, and the struts An angle-of-attack adjusting mechanism having a rotation drive device for rotation by each arm for setting an angle of attack is provided, and each arm for setting an angle of attack is connected to a strut at an axial end portion of the strut. Further, each rectifier cover is characterized by being connected to the second connecting plate at its axial ends.

  According to the angle of attack setting method of the model and the invention of the setting device, the rectifying cover is connected to the angle-of-attack fixing arm of the rectifying cover having a parallel link mechanism through pin coupling, as will be described in detail later. Above, the angle of attack of the model connected to the sting is set by rotating the strut with the arm for setting the angle of attack, so that the angle of attack of the model connected to the sting is, for example, a horizontal state where the angle is zero When the desired angle is set by the parallel link mechanism from the position, the model connected to the sting rotates to the desired angle, but the rectifying cover rotates based on the principle of operation of the parallel link. It is maintained at a horizontal angle zero state without moving. Therefore, the problem that the rectifying cover itself becomes a flow resistance, which was a conventional problem, is solved. And according to the said invention, the automatic change of the attack angle of a model is also easy.

  Further, as the device of the invention, it is preferable that each angle-of-attack adjusting mechanism for rotationally driving the strut by each angle-of-attack setting arm includes a synchronous drive control device for rotationally driving in synchronization with each other. .

  Since the rectifying cover is divided and arranged on both sides of the sting in the axial direction of the strut, it is natural that the rectifying cover itself needs to be rotated synchronously in order to prevent the rectifying cover itself from becoming a flow resistance. .

  Further, in the device according to the invention, the rectifying cover is loosely fitted to the strut via a loose fitting ring connected to each end of the rectifying cover. It is preferable that the angle adjusting mechanism and each of the first connecting plates are disposed and supported on a support frame for supporting the device on the device mounting base.

  In addition, a yaw angle adjustment mechanism for setting a yaw angle of the model is provided between the support frame and the device mounting base, and a roll angle of the model is set between the sting and the strut. It is preferable to provide a roll angle adjusting mechanism for setting. Here, the yaw angle is the rotation angle around the vertical axis of the aircraft, and the roll angle is the rotation angle of the rotational motion component of the central axis of the aircraft. The angle of attack is also called a pitching angle and is a rotation angle around the left and right axes of the aircraft.

Furthermore, in the apparatus of the above invention, the rectifying cover that is divided and arranged on both sides of the sting in the axial direction of the strut is a gap for suppressing airflow from flowing in the gap between the divided rectifying covers. A flow prevention device is preferably provided.
In addition, the angle-of-attack adjusting mechanism may include a balance weight arm on an arm axis line of the angle-of-attack setting arm connected to the angle-of-attack adjusting mechanism and on the side opposite to the angle-of-attack setting arm. preferable.

  According to the present invention, in a wind tunnel model support device in which a six component force measuring device is mounted in a sting connected to a strut, the rectifying cover connected to the strut is connected to the rectifying cover provided with the parallel link mechanism via the pin coupling. Rotating the strut with the angle-of-attack setting arm after connecting to the angle-of-attack-fixing arm, the flow resistance can be reduced and the angle of attack can be changed automatically. Even when the change is made, it is possible to provide a model angle-of-attack setting method and apparatus capable of solving the problem that the rectifying cover itself becomes a flow resistance.

It is an Example of the wind tunnel model support apparatus which concerns on this invention, Comprising: (a) is the top view which looked at the apparatus from upper direction, (b) is the side view which looked at the apparatus from the inflow direction of air. The figure which shows the structure of the parallel link which concerns on the angle-of-attack setting method of this invention. The figure which shows the fluctuation | variation of the angle of attack which concerns on this invention. The typical block diagram explaining the angle-of-attack variation mechanism which concerns on this invention. The figure which shows an example of the conventional wind tunnel model support apparatus. The figure which shows an example of the conventional wind tunnel model support apparatus different from FIG.

  Based on FIGS. 1-4, embodiment of the model angle-of-attack setting method and its setting apparatus of this invention is described below. 1 to 4, members having the same function are denoted by the same reference numerals, and redundant description is omitted.

FIG. 1 is an embodiment of a wind tunnel model support device according to the present invention, FIG. 1 (a) is a plan view of the device viewed from above, and FIG. 1 (b) is a side view of the device viewed from the air inflow direction. FIGS. 4A and 4B show both cases where the left side of the support frame center axis 17 of the support frame 10 has an angle of attack of 0 degrees and the right side has an angle of attack of 60 degrees (see FIG. 3). Note that an air outlet 19 is shown in the upper part of the support frame center axis 17 in FIG.

FIG. 1 shows a sting (1), a strut (2) that can be connected to the sting, a straightening cover (3) that is divided on both sides of the sting in the axial direction of the strut, and a parallel that will be described later. An angle-of-attack fixing arm (4) of a rectifying cover provided with a link mechanism and an angle-of-attack setting arm (13) provided at both axial ends of the strut (2) are shown. The divided rectifying cover (3) includes a gap flow prevention device (not shown) for suppressing airflow from flowing in a gap between the divided rectifying covers.

Moreover, the apparatus of FIG. 1 is equipped with the angle-of-attack adjustment mechanism (14) which has the rotation drive device for rotating the said strut (2) by each arm for angle-of-attack setting (13), respectively, and said angle-of-attack adjustment The mechanism (14) has a balance weight on the arm axis line of the angle-of-attack setting arm (13) connected to the angle-of-attack adjusting mechanism (14) and opposite to the angle-of-attack setting arm (13). Arm (15). Each angle-of-attack adjusting mechanism (14) for rotationally driving the strut (2) by each angle-of-attack setting arm (13) includes a synchronous drive control device (not shown) for rotationally driving in synchronization. Prepare.

Furthermore, a yaw angle adjustment mechanism (11) for setting the yaw angle of the model is provided between the support frame (10) and the apparatus mounting base (20).

Next, FIGS. 2 to 4 will be described. 2 is a diagram showing the configuration of the parallel link according to the angle-of-attack setting method, FIG. 3 is a diagram showing the variation of the angle of attack, and FIG. 4 is a schematic configuration diagram for explaining an embodiment of the angle-of-attack variation mechanism according to the present invention. is there. In FIG. 4, the sting (1) is actually connected to the intersection with the support frame center axis (17) in the axial direction of the strut (2), but this is omitted for convenience of explanation. The figure which the rectification | straightening cover (3) is not arrange | positioned separately is shown.

  2 and 4 show the angle-of-attack fixing arm (4) of the rectifying cover provided with a parallel link mechanism, and the parallel link mechanism has an angle of attack of two rectifying covers arranged in parallel and spaced apart from each other. Each end of the fixing arm (4) is connected to the first connecting plate (5) via the first pin coupling (8), and the other end is connected to the second connecting plate via the second pin coupling (7). Connected with (6). FIG. 2 shows that the strut (2) rotates 20 degrees from the horizontal line X together with the sting (1) around the rotation center O, and the rectifying cover (3) maintains a horizontal state based on the parallel link mechanism. The situation is shown.

  Further, as is clear from FIG. 4, the rectifying cover (3) is loosely connected to the strut (2) via a loose fitting ring (9) connected to the end of the rectifying cover (3). The angle-of-attack adjusting mechanism (14) and the first connecting plate (5) are fitted and supported on a support frame (10) for supporting the device on the device mounting base (20).

  FIG. 3 shows the variation of the angle of attack, and the strut (2) rotates together with the sting (1) around the rotation center O. At this time, the rectifying cover is based on the parallel link mechanism as in FIG. (3) shows the situation where the horizontal state is maintained. As the angle of attack that fluctuates, three stages of 0 degree, -20 degrees, and +60 degrees are typically shown. 3 schematically shows that a roll angle adjusting mechanism (12) for setting the roll angle of the model is provided between the sting (1) and the strut (2). .

  By the way, the angle of attack (pitch angle) is normally adjusted in the range of -20 degrees to +60 degrees, the yaw angle is adjusted in the range of -20 degrees to +20 degrees, and the roll angle is adjusted in the range of -15 degrees to +15 degrees. The roll angle is usually adjusted manually, and the yaw angle is adjusted manually or automatically.

  According to the apparatus, the straightening cover connected to the strut is connected to the angle-of-attack fixing arm of the straightening cover having the parallel link mechanism via the pin coupling, and then the strut is rotated by the angle-of-attack setting arm. Therefore, the flow resistance can be reduced and the automatic change of the angle of attack is easy, and even when the angle of attack of the model is automatically changed, the problem that the rectifying cover itself becomes a flow resistance can be solved. .

  1: Sting, 2: Strut, 3: Rectification cover, 4: Arm for fixing the angle of attack of the rectification cover, 5: First connecting plate, 6: Second connecting plate, 7: Second pin coupling, 8: First 9: loose fitting ring, 10: support frame, 11: yaw angle adjustment mechanism, 12: roll angle adjustment mechanism, 13: arm for angle of attack setting, 14: angle of attack adjustment mechanism, 15: for balance weight Arm: 17: Support frame center axis, 19: Air outlet, 20: Device mounting frame, F: Air flow direction, O: Rotation center, X: Horizontal line.

Claims (8)

In a wind tunnel test of an aircraft model, a wind tunnel model support device that supports an aircraft model installed in a wind tunnel and can change the angle of attack of the model, and detects a six-component force at the rear end of the model A sting (1) with a vessel is pivotally attached, and the sting (1) is attached to the axially central portion of a long tubular strut (2) having a central axis in the width direction of the airflow at the rear end of the airflow. In the method for setting the angle of attack of the model in a wind tunnel model support device comprising a rectifying cover (3) having a streamlined outer shape with respect to the air flow direction, the strut (2) being connected,
The rectifying cover (3) is loosely fitted to the strut (2), and the rectifying cover (3) is provided with a parallel link mechanism via pin couplings (7, 8). The angle of attack of the model connected to the sting (1) is set by rotating the strut (2) with the arm for angle of attack setting (13) after connecting to the arm for fixing the angle of attack (4) A method characterized by:   It is an apparatus for implementing the angle-of-attack setting method of Claim 1, Comprising: The said sting (1), the said strut (2) which enabled the connection of the said sting, and the said sting in the axial direction of the said strut The rectifying cover (3) divided and disposed on both sides with the sandwiching mechanism, the angle-of-attack fixing arm (4) of each rectifying cover provided with the parallel link mechanism, and the axial ends of the strut (2), respectively. The angle-of-attack setting arm (13), and the parallel link mechanism includes a first pin on each end of the angle-of-attack fixing arms (4) of the two rectifying covers arranged in parallel and spaced apart from each other. The first connecting plate (5) is connected via a coupling (8), and the other end is connected to the second connecting plate (6) via a second pin coupling (7). (2) by each angle-of-attack setting arm (13) An angle-of-attack adjusting mechanism (14) having a rotational drive device for rolling is provided, and each angle-of-attack setting arm (13) is connected to the strut (2) at an axial end of the strut (2). Furthermore, each said rectification | straightening cover (3) is connected to the said 2nd connection board (6) in the axial direction edge part, The apparatus characterized by the above-mentioned.   3. The apparatus according to claim 2, wherein each angle-of-attack adjusting mechanism (14) for rotationally driving the strut (2) by each angle-of-attack setting arm (13) is configured to rotate in synchronization with each other. A device comprising a synchronous drive control device.   4. The loose fitting ring (9) according to claim 2, wherein the straightening cover (3) is connected to each end of the straightening cover (3) with respect to the strut (2). The angle-of-attack adjusting mechanism (14) and the first connecting plate (5) are supported by a device mounting frame (20) to support the device. A device characterized by being disposed and supported on.   5. The apparatus according to claim 4, further comprising a yaw angle adjusting mechanism (11) for setting a yaw angle of the model between the support frame (10) and the apparatus mounting base (20). Equipment.   The apparatus according to any one of claims 2 to 5, wherein a roll angle adjusting mechanism (12) for setting a roll angle of the model is provided between the sting (1) and the strut (2). A device characterized by comprising.   The apparatus according to any one of claims 2 to 6, wherein the rectifying cover (3) divided and arranged on both sides of the sting in the axial direction of the strut has a gap between the rectifying covers arranged separately. An apparatus comprising a gap flow prevention device for suppressing airflow from flowing in the air.   The apparatus according to any one of claims 2 to 7, wherein the angle-of-attack adjusting mechanism (14) is on an arm axis of the angle-of-attack setting arm (13) connected to the angle-of-attack adjusting mechanism (14). The apparatus further comprises a balance weight arm (15) on the opposite side of the angle-of-attack setting arm (13).