JPH02243935A - Intermittent blowout type wind tunnel testing device - Google Patents

Abstract

PURPOSE:To prevent a model to be tested from breaking by deciding that a flutter occurs during a test automatically and storing the model to be tested outside a measurement channel. CONSTITUTION:The model 1 to be tested is fixed on a metallic support 3, which is fitted with a guide mechanism 4 and can slide in a storage box 2; and the support is coupled with an actuator 5 through a push rod 6. Then when the wind channel is actuated, the model 1 is put in the storage box 2. When a start actuation decision means 8 judges that the wind channel actuation is completed, the actuator 5 presses the metallic support 3 through the push rod 6 to slide the metallic support 3 until the model 1 reaches a specific position, and rod 6 and the mechanism 4 fixes the metallic support 3 at a specific position. Then when a flutter decision means 11 decides the occurrence of the flutter, the actuator 5 draws the metallic support 3 through the rod 6 to slide the metallic support 3 until the model 1 reaches a specific position, so that the model 1 is stored in the storage box 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a technique for preventing damage to a test model when an intermittent blow-out type wind tunnel test apparatus is started up and when flutter occurs.

[Conventional technology]

Figure 6 shows an example of an intermittent blow-out type wind tunnel test device.

In the figure, 09 is the air storage tank, a19 is the main valve, αη is the pressure control valve, asFi collecting shell, (19 is the measurement barrel, and an is the diffusion barrel. The state of the measurement shell is shown, where (1) is the test model and +213 is the support. During the supersonic test, the measurement shell has a nozzle shape as shown in Figure 1 due to aerodynamic requirements. .

Its shape is adapted to predetermined wind speed parameters. FIG. 8 shows an example of a conventional model support device. The test model fl+ is fixed to the support Qυ by bolts,
Second, this support is fixed to the measurement cylinder α3 with a bolt (c).

[Problem to be solved by the invention]

When conducting a supersonic wind tunnel test using an intermittent blow-out wind tunnel test device, when the tunnel is started, the pressure control valve o71 that sets the internal pressure of the collecting shell αe opens, and the pressure of the collecting shell αg increases, resulting in a total of 4111 shells. A shock wave is generated at the nozzle section of 09. This @shock wave becomes an unsteady flow and moves downstream within the measurement shell. By the way, the test model 11 fixed in the measurement cylinder
1 is subjected to a sudden pressure f movement when this shock wave passes through, and is subjected to a very large vibration load.

On the other hand, when performing a flutter test using a zero-intermittent blow-out type wind tunnel test device, it is necessary to reduce the rigidity of the test model due to the laws of similarity in terms of aerodynamics and elastic dynamics.

For this reason, with the conventional method of fixing the test model in the measurement barrel before starting the cavity, there was a problem that the model was damaged by the above-mentioned vibration load.

Furthermore, if some flutter occurred during the test, the model would cause divergent vibrations, causing instantaneous damage.

This invention was developed to solve these problems, and it protects the test convertible mold from the vibration load when the shock wave passes through when starting the wind tunnel and the divergent vibration when flutter occurs, and prevents damage. The purpose is to

[Means to solve the problem]

The IUJ partial blowout wind tunnel test device according to the present invention is as follows.

A means for storing the model outside the shell, a means for putting the model into the measurement shell, a pressure detector for detecting the pressure inside the shell for a total of 1111H, and a means for determining the completion of startup of the wind tunnel.

This system includes a strain gauge attached to the model, means for determining the occurrence of flutter, and means for controlling the insertion of the model.

[Effect]

In this invention, when the wind tunnel is started, the test model is stored outside the measurement shell, and the signal from the pressure detector determines that the wind tunnel startup has been completed, and the model is automatically thrown into the measurement shell, and during the test. - The occurrence of flutter can be determined based on the signal from the strain gauge, and the model can be automatically stored outside the measurement barrel.

〔Example〕

FIG. 1 is an overall configuration diagram of an embodiment of the present invention. In the figure, (2) is a storage box that stores the test model.

(5) is a hydraulic actuator for loading the model.

Reference numeral 77+ is a pressure detector, and the activation determination means (8) inputting the signal from this pressure detector determines that the wind tunnel has completed activation, and based on the output, the control means (91)
The valve a3 is opened and closed to control the oil pressure from the oil pressure source α, thereby operating the actuator (5).

Further, during the test, the flutter determining means αB inputting the signal from the strain gauge 01 determines that a black phenomenon has occurred, and operates the actuator (5).

FIGS. 2(a) and 2(b) are block diagrams of the model supporting device α core used in the embodiment of FIG. 1. In the figure, the test model (
1) is fixed with a support metal fitting (3)K. This support metal fitting (3
) is equipped with a guide mechanism (4), and the storage box (2
), and is connected to the actuator (5) via a push rod (6). FIGS. 3(a) and 3(b) are diagrams explaining the invention in detail. In the intermittent blowing wind tunnel test device configured as described above, the test model 111 is stored in the storage box (2) as shown in FIG. 2(a) (110) when the wind tunnel is started. When the determination means determines that the wind tunnel startup has been completed, the actuator (5) pushes the support fitting (3) via the push rod (6), as shown in FIGS. Slide the mounting bracket (3) in the direction of arrow (A) until the model (11) is in the designated position,
The support fitting (3) is fixed in place by the push rod (6) and the guide @tl (41). Also, during the test, the test model (ll
It is fixed at a position within the Fi measurement body measurement station. Then, it can be determined by the flutter 41 means that black has occurred.

The actuator (5) pulls the support bracket (3) through the push rod (6), and slide the mounting bracket (31) in the direction of arrow (A) until the test model (1) is in the specified position. Store the model (11) in the storage box (2).

Figure 4 is a diagram of the determination operation for determining that the wind tunnel has been started. In the figure, 10 is the time when the wind tunnel started, tl is the time when the wind tunnel has been started, and t2 is the time when a prescribed time Δt2, for example, 1 second, has elapsed from the time t1. When the wind tunnel is started at time to, the pressure inside the measurement cylinder rapidly rises from atmospheric pressure pO to a predetermined pressure p1 according to the Matsuha signal, and stabilizes at the predetermined pressure p1 at two time t1. The activation determination means (8) detects when the pressure inside the 3111 cylinders reaches a predetermined pressure based on the signal from the pressure detector 71 and this pressure is maintained for a specified time Δt, indicating that the wind tunnel activation has been completed. Make a judgment and output a signal.

FIG. 5 is a detailed diagram of the determination operation for determining whether flutter has occurred. In the figure, t3 is the time when black occurs, and t4 is the time when the signal from the strain gauge exceeds the specified voltage v1 for the first time. The signal voltage from the strain gauge corresponds to the deformation of the model, and if this voltage increases beyond a certain value, the model will be damaged.

The flutter determining means a9 determines that flutter has occurred when the signal voltage from the strain gauge exceeds a specified voltage v1, and outputs a signal.

〔Effect of the invention〕

As described above, according to the present invention, when the wind tunnel is started, the test model is stored outside the measurement shell, and it is automatically determined that the first wind tunnel has been started, and the test model is thrown into the measurement shell. , ζ etc. If flutter occurs during the test, it is automatically determined and the test model is stored outside the measurement barrel. This has the effect of preventing damage to the test model during loading and unloading.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the present invention. Figure 2 (a) is a top view of the model support device with some parts missing;
Figure ('b) is a side view of the part shown in Figure 2 (a) with some parts missing, and Figure 3 (a) is a top view of the part shown in Figure 2 (a) with some parts left out to explain the operation of the model support device. (b) is a side view of the part shown in FIG. 3(a), with some parts missing; FIG. 4 is a Akigetsu diagram of the operation of the activation determining means; FIG. 5 is a diagram for explaining the operation of the flutter determining means; Fig. 6 is a diagram showing an example of the construction of an intermittent blow-out wind tunnel test device, Fig. 1 is a diagram showing the state of the measurement cylinder when conducting a supersonic test, and Fig. 8 is a diagram of a conventional model support device. It is a figure showing an example. In the figure, fit is a test model, (2) is a storage box, (3)
is the support fitting, (4) is the guide machine 'tQ'j, f51 is the hydraulic actuator, (6) is the push rod, (7)
is a pressure detector, (8) is a start judgment means, (9) is a control means, Ql is a strain gauge, and αυ is a flutter judgment means. O3 is the hydraulic power source, (!3 is the pulp, O41 is the model support device, αri is the air storage tank, aFi is the main valve, Q7+ is the pressure control valve, Nishiki is the collecting cylinder, α3 is the 6111 cylinders in total, ■ diffusion cylinder ,
The nari is the support, and the no is the bolt. Note that the same reference numerals in Figure 9 indicate the same or corresponding parts. Figure 1

Claims (1)

[Claims] An intermittent blowing wind tunnel test device for conducting tests in the supersonic speed range, comprising: a test model; a storage box for storing the test model; a support fitting that supports the test model and is slidable inside the storage box; a guide mechanism that guides the movement of the support fitting and supports the support fitting; a hydraulic actuator that drives the support fitting; and a push rod that is attached between the support fitting and the actuator and transmits the power of the actuator to the support fitting. a pressure detector attached to the wind tunnel wall; a startup determination device for determining whether startup of the wind tunnel is complete based on a signal from the pressure detector; a strain gauge attached to the test model; An intermittent blowing wind tunnel test device comprising: a flutter determining device that determines the occurrence of flutter based on a signal; and a control device that operates the actuator based on signals from the activation determining device and the flutter determining device.