JPH01134223A - Intermittent blowout type wind tunnel testing device - Google Patents

Abstract

PURPOSE:To reduce a vibration load placed on a wind channel balance when a shock wave passes by projecting a lock pin in a sting when the wind channel is actuated, and fixing a model to be tested. CONSTITUTION:The model 1 to be tested which is placed at a measurement part has aerodynamic characteristics measured under specific conditions by the wind tunnel balance 2 inserted into the model 1 to be measured. When the wind channel 1 is actuated, the lock pin 5 is protruded from the sting 3 and the model 1 to be tested is fixed. When a stationary measurement is taken after the shock wave passes, an accurate measurement can not be taken if the model 1 to be tested is fixed, so the lock pin is pulled in the sting 3. Thus, the model to be tested is fixed with the lock pin when the shock wave passes at the time of the wind channel actuation to reduce the vibration load placed on the wind channel balance inserted into the model to be tested when the shock wave passes.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a technique for reducing the load on a wind tunnel balance when starting up a wind tunnel test device and improving measurement accuracy during measurement.

[Conventional technology]

Fig. 4 is a diagram showing an example of the configuration of a 9-intermittent blow-out type wind tunnel test device, and in Fig. 4, +1 (I is a measurement cylinder).

aυ is the air storage tank, fiz is the main valve, α3 is the pressure control valve, fi
41 is a collection cylinder, aS is a model support cylinder, and ae is a diffusion cylinder. Figure 5 is a diagram showing the state of the measurement cylinder when conducting a wind tunnel test in the supersonic region. In Figure 5, (1) is the test model, (21 is the wind tunnel balance, C3) is the sting, (
8) is a bod, and (9) is a strut.

□During supersonic tests, the measuring section is
As shown in the figure, it has a nozzle shape.

Its shape is adapted to the given wind speed parameters. Further, the aerodynamic characteristics of the test model (1) placed in the measurement section are measured under predetermined conditions by a wind tunnel balance (2) inserted into the test model ill.

[Problem that the invention seeks to solve]

When starting a wind tunnel when performing a supersonic test using an intermittent blow-out type wind tunnel test device, the pressure control valve α that sets the internal pressure of the collection shell I is
3 begins to open, the pressure inside the collection cylinder increases, and a shock wave is generated in the nozzle section of the measurement cylinder +IQ. This shock wave becomes an unsteady flow and moves downstream of the measurement cylinder. By the way, the test model (11 and wind tunnel balance (2) placed in the measurement area.

When this unsteady shock wave passes through, it undergoes rapid pressure fluctuations and is subjected to a very large vibration load. This photographing load may exceed the capacity of the wind tunnel balance (2) inserted into the test model +11 at 1 o'clock, which poses a problem that the wind tunnel balance (2) may be damaged.

In order for the wind tunnel balance (21) to sufficiently withstand the vibration load, it is necessary to provide the wind tunnel balance (2) with a large capacity. Since the aerodynamic load is much larger than the acting aerodynamic load, a large-capacity wind tunnel balance must be used to measure the small aerodynamic load, which poses the problem of poor measurement accuracy.

This invention was made to solve this problem, and aims to reduce the vibration load on the wind tunnel balance when shock waves pass through when starting up the wind tunnel, and improve measurement accuracy.

[Means for solving problems]

The intermittent blowout wind tunnel test device according to the present invention has a solenoid and a lock pin operated by the solenoid built into the sting that supports the test model and the wind tunnel balance.
The solenoid can be controlled from the outside.

[Effect]

In this invention, when the wind tunnel is started, the lock pin in the sting is protruded by a solenoid to fix the test model, and the vibration load applied to the wind tunnel balance when the shock wave passes can be reduced. After the shock wave has passed, the lock pin is retracted into the sting by a solenoid and a regular measurement is performed.

〔Example〕

FIG. 1 is a diagram showing an embodiment of the present invention.

In Figure 1, (1) is the test model and (2) is the wind tunnel balance.

(3) is a sting, (4) is a solenoid, (5) is a lock pin, (6) is an electric wire, and (7) is a solenoid control device.

As shown in Figure 1, the sting (3) has a built-in solenoid (4) and lock pin (5). The solenoid (4) is connected by an electric wire (6) to a solenoid control device (7) located outside the wind tunnel. Lock pin (5)
is normally retracted into the sting (3), but by fully operating the solenoid (4), the sting +31
The test model (1) can be fixed by protruding from the side.
When the solenoid (4) is released, the locking pin (5) is retracted into the sting (3). Also, solenoid (4)
How does it work?

This is done by a solenoid control device (7).

FIGS. 2 and 3 are diagrams showing the operation of the present invention. In the intermittent blowing type wind tunnel test apparatus configured as described above, when the wind tunnel is started, the lock pin is closed as shown in FIG. (5) is made to protrude from the sting (3) and is completely fixed to the test model (1). During steady measurement after the shock wave has passed,
Accurate measurements cannot be made if the test model (1) is fixed, so fix the lock pin (3) as shown in Figure 3.
withdraw inside.

As mentioned above, when the first impact wave passes when starting the wind tunnel,
By fixing the test model with lock pins, it is possible to reduce the vibration load applied to the wind tunnel balance inserted into the test model when the shock wave passes through.

〔Effect of the invention〕

As explained above, this invention prevents the vibration load applied to the wind tunnel balance inserted into the test model by fixing the test model with a lock pin when the shock wave passes through when starting up the wind tunnel. This has the effect of preventing damage to the wind tunnel balance. Furthermore, there is no need to use a wind tunnel balance that has a large capacity that can withstand the vibration load.

Another effect is that the measurement accuracy during measurement can be improved.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIGS. 2 and 3 are diagrams showing the operation of the present invention, and FIG. 4 is a diagram showing an example of the configuration of an intermittent blow type wind tunnel test apparatus. Figure 5 is a diagram showing the state of the measurement cylinder when conducting a supersonic test. In Figure 91, (1) is the test model, (2) is the wind tunnel balance, (3) is the sting, and (4) is the solenoid. , (5) is a lock pin, (6) is an electric wire, and (7) is a solenoid control device. (8) is the bod, (9) is the strut, Ql is the measurement cylinder, (Ill is the air storage tank, (2) is the main valve, r13 is the pressure control valve, (14 is the collection cylinder. T1 is the model support cylinder, is is a diffusion cylinder. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] In an intermittent blow-out wind tunnel test device that performs tests in the supersonic speed region using a model angle device that supports a test model and a wind tunnel balance inserted in the test model from behind by a stay, By incorporating a solenoid built into the stay, a lock pin built into the stay that protrudes outside the stay when the solenoid is activated, and a solenoid control device that operates the solenoid, the lock pin protrudes when the wind tunnel is started, and the lock pin protrudes outward when the solenoid is activated. An intermittent blow-out type wind tunnel test device, characterized in that the test model is fixed, and the lock pin is retracted into the stay after a shock wave passes through during start-up.