JPH07167737A - Twist angle measuring instrument of wind tunnel testing model - Google Patents

Abstract

PURPOSE:To provide a twist angle measuring instrument of a wind tunnel testing model which can measure air force load applied to a model and at the same time the twist of the model. CONSTITUTION:The instrument consists of a fairing body 3 which is installed in a wind tunnel, where the state of air flow operated on an elastic model for performing wind tunnel test is shaped so that it is less affected at a speed region for performing test, and which is provided at a specific position of wind tunnel which is less affected and laser displacement measuring instruments 1 and 2 with laser light transmitter/receiver opposing the twist measuring part of the elastic model while being installed where they are surrounded by the fairing body 3 while being separated in the direction of the air flow of the wind tunnel.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a wind tunnel test or the like for measuring static aeroelastic characteristics of an aircraft, which is performed by using a model formed of an elastic body (hereinafter referred to as an elastic model). The present invention relates to a device for measuring a twist angle of a wind tunnel test model for measuring a generated twist angle.

[0002]

2. Description of the Related Art Conventionally, in a wind tunnel test for performing aeroelasticity tests such as flutter characteristics of an aircraft wing using an elastic model, data on the torsion angle of the elastic model are important in designing an aircraft as well as loads applied to the elastic model. Despite this, the measurement has not been performed. This is because when measuring the twist angle of a model, the twist angle measuring device must be installed in the wind tunnel, and the installation changes the state of the air flow acting on the model installed in the wind tunnel and affects the measurement data. This is because In order to measure the twist angle of an elastic model without changing the air flow state that acts on this model, either install the twist angle measuring device in the wind tunnel floor or install it inside the wind tunnel, or make the floor of the wind tunnel transparent. There is no better way to measure it from outside the wind tunnel than to make it from a different material. However, no matter which method is adopted, there is a problem that the wind tunnel itself needs a large-scale repair. In order to accurately estimate the static aeroelastic characteristics of an aircraft and reflect them in the design of the aircraft, load measurement alone is not enough, and as described above, data on the twist angle of the model in the wind tunnel test is necessary.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an elastic model in a wind tunnel test using an elastic model in each velocity range such as subsonic velocity and supersonic ventilation velocity range without requiring a large-scale modification of the wind tunnel. An object of the present invention is to provide a twist angle measuring device for a wind tunnel test model that can measure the twist angle of an elastic model by eliminating or reducing the disturbance of the airflow state that acts.

[0004]

For this reason, the wind tunnel test model torsion angle measuring apparatus of the present invention uses the following means.

(1) A plurality of laser displacement measuring devices capable of transmitting a laser beam to a measuring section of an elastic model which requires measurement of the twist angle of the elastic model and receiving reflected light from the measuring section. They were placed apart in the flow direction.

(2) The state of air flow acting on the elastic model is such that the fairing body faired in a shape that is not disturbed or less disturbed in the velocity range in which the wind tunnel test is performed A laser displacement measuring instrument was installed surrounding the location in the wind tunnel where the velocity was not disturbed in the velocity range or was less disturbed in the velocity range.

[0007]

According to the above-mentioned means, in the torsion angle measuring device for the wind tunnel test model of the present invention, the laser light transmitted from the light emitting portions of the plurality of laser displacement measuring devices arranged in the fairing body is
It is reflected at the torsion angle measurement target point on the elastic model and received by the light receiving portion of the laser displacement measuring device, and the torsion angle can be measured from the displacement amount of the two points at the transmitting and receiving positions.

Further, the laser displacement measuring device is formed into a shape that does not disturb or hardly disturbs the air flow state acting on the elastic model to be subjected to the wind tunnel test in the velocity range to be tested. Since it is attached by covering the fairing body installed at a specific place of the model, it is possible to measure the displacement and the displacement of the elastic model at the same time without major renovation of the wind tunnel. It is possible to contribute to improving the accuracy of aircraft design.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the twist angle measuring device for a wind tunnel test model of the present invention will be described below with reference to the drawings. 1 and 2
[FIG. 3] is a diagram showing a first embodiment of the present device and is used for a supersonic wind tunnel test. As shown in FIG. 1, this embodiment comprises laser displacement measuring instruments 1 and 2 and a fairing body 3 covering and supporting the laser displacement measuring instruments 1 and 2. The height h and the width w of the fairing body 3 depend on the sizes of the laser displacement measuring devices 1 and 2, and the length 1 indicates the size of the laser displacement measuring devices 1 and 2 and the elasticity model 4 for measuring the twist angle. Airflow direction 1 of laser displacement measuring instruments 1 and 2 determined by the length of the measuring part
It depends on the distance to zero. Further, the tip 7 of the fairing body 3 is formed into a quadrangular pyramid, and the zenith angle θ determines the angle of the shock wave 9 generated from the fairing tip 8 depending on its value and the Mach number of the air flow. Considering the Mach number and the distance between the elastic model 4 and the torsion angle measuring device, the shock wave 9 is determined so as not to hit the elastic model 4. The laser displacement measuring instruments 1 and 2 are rotatable about hinges 5 and 6 provided on both sides thereof,
The fairing is installed so that the laser transmitter / receiver is tilted toward the upstream side of the airflow 10 so that the laser can be emitted toward the measurement part of the elastic model 4 for measurement and the laser reflected from the measurement part can be received. It is fixed to the body 3. Further, the laser displacement measuring instruments 1 and 2 are fixed to the fairing body while most of the volume is surrounded by the fairing body 3, and a shock wave 9 (Mach cone) generated from the fairing tip 8 is provided.
It is designed to fit inside. However, when the torsional displacement of the elastic model 4 becomes large, in the laser displacement measuring instruments 1 and 2 in which the wave receiving section that receives the laser reflected from the measuring section is paired with the laser transmitting section, In such a case, it is possible that the wave cannot be received. In such a case, the laser displacement measurement with the wave transmitter and the wave receiver as separate bodies should be taken into consideration in consideration of the size of the wind tunnel and the amount of torsional displacement of the measurement unit. It is necessary to use an appropriate laser displacement measuring instrument such as using a measuring instrument.

FIG. 2 is a diagram showing a supersonic wind tunnel test, showing how to install the apparatus of the above-described embodiment in the wind tunnel. As shown in the figure, when installing this device in a wind tunnel, the installation location must be such that the shock wave 9 generated from the tip of the fairing 3 does not interfere with the elastic model 4. Must be installed downstream of, and is determined by the speed (Mach number) at which the wind tunnel test is performed. Therefore, as described with reference to FIG. 1, the laser displacement measuring instruments 1 and 2 are tilted to emit the laser light toward the upstream. According to this embodiment, the twist angle of the model at supersonic speed can be measured.

Next, FIG. 3 is a perspective view showing a second embodiment of this apparatus, which is used for a subsonic and transonic wind tunnel test. It is composed of laser displacement measuring instruments 11 and 12 and a fairing body 13 covering the laser displacement measuring instruments 11 and 12. At subsonic speed, the disturbance generated in the downstream propagates in the upstream, so even if the laser displacement measuring instruments 11 and 12 are tilted to irradiate the laser beam from the downstream side of the elastic model as in the supersonic wind tunnel test, the effect is not affected. Influences the air flow acting on the elastic model 4. Therefore, in order to minimize the influence of the installation of the twist angle measuring device in the wind tunnel, it is necessary to make it a streamline shape having a small cross-sectional area in the air flow direction. Therefore, the laser displacement measuring instruments 11, 12
The wave transmission / reception part of will be installed parallel to the wind tunnel floor.
For the same reason, the upper surface of the fairing body 13 is parallel to the floor surface of the wind tunnel, and the laser displacement measuring instruments 11 and 12 are provided inside thereof.
Enclose the whole and cover this. Furthermore, the tip end side surface of the fairing body 13 is designed so that the flow smoothly divides into the right and left, and the tip side is designed to flow in the wind tunnel so that the laser displacement measurement 11 and 12 are arranged directly below the measuring portion of the elastic model 4. Install.

[0012]

According to the torsion angle measuring device for a wind tunnel test model of the present invention, bolt holes for fixing a fairing are formed on the upper / lower wall or the side wall of the wind tunnel which is the wind tunnel testing device, by the structure shown in the claims. The twist angle of the model, which could not be conventionally measured in wind tunnel tests in the subsonic, transonic, and supersonic speed ranges, can be measured only by making repairs. Further, the effect of static aerodynamics can be confirmed not only from the load but also from the aspect of displacement, which contributes to improvement in accuracy in aircraft design.

[Brief description of drawings]

FIG. 1 is a first twist angle measuring device for a wind tunnel test model according to the present invention.
A perspective view showing an embodiment,

FIG. 2 is a side view for explaining the installation position of the device in the wind tunnel,

FIG. 3 is a perspective view showing a second embodiment of the device of the present invention.

[Explanation of symbols]

 1, 11 (front) laser displacement measuring instrument 2, 12 (rear) laser displacement measuring instrument 3, 13 fairing body 4 elastic model 5 (front) hinge 6 (rear) hinge 7 fairing body tip molded body 8 Tip of fairing 9 Shock wave (Fairing tip) 10 Airflow

Claims (1)

[Claims] 1. An apparatus for measuring a twist angle of an elastic model to be subjected to a wind tunnel test during a wind tunnel test, wherein an air flow acting on the elastic model to be subjected to the wind tunnel test is close to a uniform flow in each velocity range. The fairing body arranged in the wind tunnel and the transmitter / receiver arranged on the upper surface and separated from each other in the direction of the air flow are respectively opposed to the measuring units for measuring the torsion angle of the elastic model. A twist angle measuring device for a wind tunnel test model, comprising: a plurality of laser displacement measuring instruments held by a fairing body.