JP3229157B2 - Boundary layer turbulence generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boundary layer turbulence generator applied to a wind tunnel test apparatus for obtaining aerodynamic performance data required for evaluating wind stability of bridges, chimneys and other structures.

[0002]

2. Description of the Related Art In general, wind tunnel experiments are performed as one of means for obtaining aerodynamic performance data for examining characteristics such as wind resistance of large structures installed on the ground in a specific area such as bridges and chimneys. Have been. To conduct such a wind tunnel experiment, the airflow that forms in the wind path where the model that simulates the building is installed is reproduced in the wind path by reproducing the turbulent natural wind that occurs at the construction point where the building is installed. It is important to simulate wind resistance phenomena, etc., and conventionally, a three-dimensional block or a triangular plate spyer is installed upstream of the model of the building installed in the wind path, disturbing the main flow, turbulence close to natural wind Efforts are being made to achieve the reproduction requirements by generating an airflow that has been generated.

[0003] FIG. 11 is a diagram for realizing such a reproduction requirement.
It is a figure which shows an example of the boundary layer turbulence generator conventionally used. As shown in the figure, on the bottom surface 03 of the air passage 01 connected to the air outlet 02 of the wind tunnel, a plurality of spyers 04 composed of isosceles triangular plates are turned in the air passage width direction in a cross section perpendicular to the main flow 09 direction. It is movably arranged to generate disturbance of the main stream 09.

A rotating shaft 015 fixed to the center of the spyer 04 is erected through the floor surface 03, and the lower end thereof is connected to a link arm 014 of a drive mechanism provided under the floor. A drive rod 013 connected to the drive rod 013 is engaged with a pinion 011 attached to a rotation shaft of the pulse motor 010 by a rack 012 provided at an end of the drive rod 013.
By reciprocating in the width direction of the air passage, the link arm 01 is moved.
By rotating the rotating shaft 015 via the rotating shaft 4 and rotating the spyer 04 to open and close a part of the air passage 01, a disturbance is generated in the main flow 09.

Further, an external data storage device 50 to which data of a natural wind of a construction site of a structure simulated by the test model is inputted, a computer 60, and a sensor for detecting a state of an air flow 09 in the wind path 01 are provided. And a controller 70 for inputting, analyzing, and analyzing data from the controller and sending a signal to the pulse motor 010.
The swing angle and cycle of the wind are determined, and an airflow close to the natural wind is created.

However, the turbulence generated by the above-described conventional device that oscillates the spyer 04 made of a triangular plate to generate turbulence of the main flow 09 in the air passage 01 that simulates a turbulent natural wind is caused by wind speed in the horizontal and horizontal directions. The turbulence that fluctuates is predominant, and the frequency is higher and the scale of the fluctuation is smaller than the required value that approximates the turbulence of the natural wind.The similarity with the natural wind is not always sufficient. There was a problem that only this could occur. Further, the amount of fluctuation in the vertical direction of the airflow in the air passage 01 is extremely small, and in this respect, it cannot be said that the natural wind is approximated, and improvement is demanded in this respect as well.

[0007]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the conventional boundary layer turbulence generator and can produce a turbulent airflow which is rich in variation and approximates natural wind. , An airflow that is extremely close to the natural wind at the construction site of the structure simulated by the test model can be obtained, and data that can accurately predict the aerodynamic performance of the structure such as bridges and chimneys can be obtained. The object of the present invention is to provide a boundary layer turbulence generator capable of more reliably.

[0008]

For this reason, the boundary layer turbulence generator of the present invention has the following means. (1) Each of the triangular spears arranged in a horizontal plane of the air path orthogonal to the main flow direction, that is, arranged side by side at intervals in the air path width direction, is composed of two or three triangular plates. by a set of one side on one axis, while being erected on the bottom surface of the air passage, at a minimum, two triangular plates of Sankakuban is about an axis, swinging plate can 搖 dynamic wind path width direction And In addition, the spyer that forms the rocking plate has
Each generates a turbulent airflow that meets the requirements of natural wind reproduction
Drive each of the rocker plates independently so that
With a swinging motor that can swing in phase
And In addition, each of the triangular plates may be a right-angled triangle. When the spyer is composed of three triangular plates, the remaining one excluding the two triangular plates serving as the swinging plate may be fixed to the bottom of the air passage or may be swingable around the axis.

Further, the boundary layer turbulence generator of the present invention employs the following means in addition to the above (1). (2) The swing plate is
On, it is divided into the lower and above the upper swinging plate dividing line, is the lower swinging plate downward, mainly in axial with each each independently driven <br/> different phases, air passage width Rocking independently
It was assumed to be oscillating in phase becomes. The upper rocking plate and the lower rocking plate may be independently rockable, or may be rockable simultaneously while maintaining a certain angle difference. Further, the remaining one triangular plate excluding the triangular plate forming the rocking plate may be divided into upper and lower parts.

[0010]

[0011]

According to the boundary layer turbulence generator of the present invention, the above-mentioned means (1) is used to (1) swing a plate composed of two triangular plates with respect to a main flow direction centering on an edge formed by gathering them on a common axis. In the orthogonal direction, that is, by oscillating in a different phase in the wind path width direction, in the wind path width direction, the cross section of the air path closed by the spears arranged at intervals in the wind path width direction, It can vary between the center of the road and near the side walls. That is, the swing angle of the spyer installed near the center and the side wall of the wind path is
The closing effect of the cross-sectional area of the air passage can be changed in the central portion and the vicinity of the side wall by operating them differently or changing the size of the spyer. This allows
The air current meanders in the air passage, and the fluctuation of the wind speed in the air passage width direction can be a large scale at a low frequency.

In addition, the spyer forming the swinging plate swings.
A motor is provided to drive each of the rocking plates independently,
Generated at the construction site
An airflow that can reproduce the natural wind that occurs can be generated . Further, by the triangular plate in three, two swinging plate and lever to so as to swing the different triangular plate of generating a more complex turbulence of the air flow
It can be. Further, by fixing the bottom surface of the other triangular plate to the bottom of the air passage, the wind resistance of the spyer can be increased, and the axis on which the swing plate swings can be made thin.

The boundary layer turbulence generator according to the present invention further comprises (2) an upper rocking plate which is an upper portion of a rocking plate divided into upper and lower portions by means of (2) in addition to the above (1). By changing the phase of the lower rocking plate, which is the lower portion, and oscillating symmetrically, it is possible to generate turbulence in the airflow having a wind speed fluctuation larger than the vertical wind speed fluctuation by means of the above (1). it can. Also, swing plate up and down
Separate upper swing plate and lower swing plate formed separately
By swinging, in the wind path width direction and the vertical direction,
Any turbulent airflow can be formed. As a result, it is to Rukoto to flow to approximate the natural wind Ri by the airflow in the air passage. Thus, the boundary layer turbulence generator of the present invention
Creates an airflow in the wind path that is very close to the natural wind at the construction site
And set it in a wind path to make it more similar to the natural wind.
Experiment on a model that simulates a building
Get and provide the more accurate data you need
I can .

[0014]

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a boundary layer turbulence generator according to the present invention will be described below with reference to the drawings. FIG. 1 is an overall perspective view showing a first embodiment of a boundary layer turbulence generator of the present invention, and FIG.
FIG. 2 is a detailed perspective view of the spyer shown in FIG. 1.

In FIG. 1, a plurality of spiders are provided standing upright in the width direction 2 of the air duct, vertically from the floor 3 near the entrance of the wind tunnel air duct 1, and in a plane perpendicular to the direction of the main flow 10. 4
Is formed by combining the common edges 6 of the three right-angled triangular plates, and of the three right-angled triangular plates, the wake plate 5 arranged in parallel with the mainstream 10 is fixed to the floor surface 3. As shown in FIG. 2, two of the right-angled triangular plates are swinging plates 7 as left and right movable triangular plates swinging around an edge 6.
a and 7b.

FIG. 3 is an overall perspective view showing a second embodiment of the present invention, and FIG. 4 is a detailed view of the spyer shown in FIG. In the present embodiment, it is the same as in the first embodiment that a plurality of spyers 4 are erected near the entrance of the wind tunnel wind path 1, but the spyer 4 of the present embodiment is different from the first embodiment. Each of the oscillating plates 7a and 7b is divided into upper and lower parts, and is divided into upper triangular upper oscillating plates 9a and 9b above the dividing line and trapezoidal lower oscillating plates 8a and 8b below the dividing line. , 9b and the lower oscillating plates 8a, 8b swing and open and close while changing the phase, and the upper oscillating plates 9a and 9b and the lower oscillating plates 8a and 8b respectively oscillate symmetrically in the wind path width direction 2, The area for blocking the air path 1 is changed above and below a dividing line that divides the upper and lower parts into two.

Next, FIG. 5 is a perspective view showing, for example, a driving device for driving the rocking plates 7a and 7b of the first embodiment.
Oscillating shafts 18 and 19 for fixing the rims 6 of the oscillating plates 7a and 7b, which oscillate in opposite directions to each other around the rim 6 in FIG.
Are erected along the edge 6. This swing axis 18, 1
9 The lower end portion extends through the floor surface 3 and extends below the floor,
Two gears 15a, 15b meshing with the pinion 11 attached to the shaft end of the pulse motor 12 rotate in opposite directions with the rotation of the pinion 11, rotate the drive shafts 13a, 13b, and rotate the drive shafts 13a, 13b. The wheel 17a mounted on the lower end of the oscillating shaft 18 and the wheel 17b mounted on the lower end of the oscillating shaft 19 are rotated in opposite directions by the worm gears 16a, 16b mounted on the
8 and the oscillating shaft 19 are rotated in reverse at substantially the same speed.
And 19 each having an edge 6 secured thereto.
As shown by arrows in FIG. 2, a and 7b swing symmetrically in the wind path width direction 2.

The pulse motor 12 includes an external data storage device 50 for inputting data of a natural wind in a predetermined period at a construction point of a structure simulated as a model installed in the wind path 1, and a computer 60. And a controller 70 for analyzing and analyzing data from a sensor for detecting the air flow 10 in the air passage 1 and sending a signal to the pulse motor 12, whereby the swing plate 7 a of the spyer 4 is provided. , 7b are determined, and an airflow closer to a natural wind is created. Also, the driving device of the second embodiment may use a known mechanism similar to this, or may be equipped with a pulse motor for each spyer described later so as to rotate freely.

That is, when the upper rocking plates 9a and 9b and the lower rocking plates 8a and 8b shown in FIGS. 3 and 4 are rocked by the driving device shown in FIG. 5, as shown in FIG. Each edge 6 of the upper rocking plate 9a and the lower rocking plate 8b
The boss 20 is attached so as to embrace the swing shaft 19, and in the same figure, the lower surface of the lowermost boss 20 of the lower swing plate 8b
The surface A where the upper surface of the hollow swing shaft 18 contacts is fixed by welding,
Next, if the upper surface of the uppermost boss 20 of the lower rocking plate 8b and the lower surface of the lowermost boss 20 of the upper rocking plate 9a are welded to each other, the lower rocking plate 8b and the upper rocking plate 9b are welded.
a swings by the rotation of the swing shaft 18. Further, the lower rocking plate 8a and the upper rocking plate 9b are connected to a boss 21 provided on each edge 6 and a rocking shaft 9 by a set screw (not shown).
Can be rocked by the rotation of the rocking shaft 19.

In this manner, the upper and lower rocking plates 8
When the a, 8b, 9a, 9b are set at right angles to the wind axis 10, each of the lower rocking plates 8a, 8b and the upper rocking plate 9
a and 9b are plan views as shown in FIG.
And the upper rocking plates 9a and 9b
The lower swing plates 8a and 8b can swing the target in the wind path width direction with phases different from each other.

Further, a driving device can be provided for each spyer to drive the first embodiment and the second embodiment. FIG. 7 shows such a driving device. This is an example provided in the second embodiment described above. In the figure, between the oscillating motor 12 and the spyer 4, upper oscillating plates 9a and 9b and lower oscillating plates 8a and 8b as shown in FIG.
Although a transmission device is provided, it is not shown here.

Control devices such as an external data storage device 50 for sending a signal to the pulse motor 12 in FIGS. 5 and 6 are the same as those used in the conventional example shown in FIG. ing.

Since the present embodiment is constructed as described above, for example, the two swing plates 7 of the spyer shown in FIG.
By opening and closing the a and b toward the windward side, for example, as shown in FIG. Can form a flow that flows inward from both sides as shown by arrows. As shown in FIG. 8 (b), when both sides are opened and the center is closed, the wind spreads outward from the center as indicated by the arrow. In this case, the flow of FIG. 8A and FIG.
When the spyer 4 is again brought into the same state as shown in FIG. 8 (a) as shown in FIG. 8 (c) in order to proceed toward the downstream of the wind path, the flow is again in the same state as in FIG. The flow in the wind path 1 has a certain period and the flow pattern (a)
And (b) are alternately repeated.

As described above, the two rocking plates 7a and 7b are
A plurality of spyers 4 configured to oscillate symmetrically in the wind width direction 2 facing the main flow 10 around the edges gathered on a common axis are moved in different phases, thereby moving the spyers 4. The effect of closing the cross-sectional area of the wind path can be changed between the central portion and the vicinity of the side wall. This allows the flow to meander in the air path, and the horizontal and horizontal wind speed fluctuations can be of low frequency and large scale.

Further, using a similar spyer 4, each of the spyers 4 is provided with a rocking motor for rocking individually, and as shown in FIG. 9, the two rocking plates 7a and 7b are rocked by sequentially changing the phase. In the air path 1, two vortices are generated alternately, and the center of the vortex moves in the air path width direction. Therefore wind axis (mainstream)
The wind speed fluctuation in the direction perpendicular to the direction becomes uniform at each point in the wind path width direction, so that large scale turbulence can be obtained. That is, FIG. 9 illustrates the open / closed state of the spyer 4 in FIG. 2 and the obtained flow pattern in FIGS. 9A to 9F. From these, the flow velocity distribution in the air path is shown. This shows that the direction of the vortex and the vortex can be freely selected.

Further, the two oscillating plates symmetrically oscillating in the direction facing the main flow 10 are divided into upper and lower halves, and a phase difference is given to the upper and lower upper oscillating plates 9a and 9b and the lower oscillating plates 8a and 8b. When the rocking motion is performed, the projected area with respect to the main flow 10 changes, and the increase and decrease of the area are inverted up and down, so that a vertical meandering flow is generated in the wind path as shown in FIG. Can be. The flow of the vertically split spyer 4 shown in FIG. 10 is the same as in FIG.
(C) shows a continuous change in the flow, and shows that the flow in the wind path 1 can be changed into an upward flow and a downward flow in a certain cycle and generated.

[0028]

As described above, according to the boundary layer turbulence generating apparatus of the present invention, the following effects can be obtained by the structure shown in the claims.

As compared with the conventional boundary layer turbulence generator, a turbulent airflow which is much more varied can be generated, and therefore, an airflow remarkably approaching the reproduction of natural wind can be generated. This makes it possible to accurately evaluate the structure from the aerodynamic performance data obtained by the wind tunnel test, and to more reliably design the wind resistance of the structure such as a bridge or a chimney.

[Brief description of the drawings]

FIG. 1 is an overall perspective view showing a first embodiment of a boundary layer turbulence generator according to the present invention;

FIG. 2 is a detailed perspective view of the spyer shown in FIG. 1,

FIG. 3 is an overall perspective view showing a second embodiment of the present invention,

FIG. 4 is a detailed perspective view of the spyer shown in FIG. 3;

FIG. 5 is a perspective view and a measurement block diagram showing a driving device for driving the boundary layer turbulence generator of the present invention;

6 is a view showing a driving mechanism of the embodiment shown in FIG. 3, and FIG.
6A is a perspective view, FIG. 6B is a plan view,

FIG. 7 is an overall perspective view and a measurement block diagram of a third embodiment of the present invention;

FIG. 8 is a plan view showing an operation state of the embodiment shown in FIG. 2 and turbulence of an airflow caused by the operation;

FIG. 9 is a plan view showing an airflow pattern obtained by the embodiment shown in FIG. 2;

FIG. 10 is a perspective view showing a turbulence of an air flow that causes an operation state of the embodiment shown in FIG. 4;

FIG. 11 is a perspective view and a measurement block diagram showing an example of a conventional boundary layer turbulence generator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air path 2 air path width direction 3 floor surface 4 spyer 5 wake plate 6 edge 7a, 7b rocking plate 8a, 8b lower rocking plate 9a, 9b upper rocking plate 10 airflow 11 pinion 12 pulse motor 13a, 13b drive shaft 15a, 15b gear 16a, 16b worm gear 17a, 17b wheel 18 swing axis 19 swing axis 20 boss 21 boss 50 external data storage device 60 computer 70 controller

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takehiko Nagayama 5-717-1 Fukahori-cho, Nagasaki-shi Mitsubishi Heavy Industries, Ltd. Nagasaki Research Laboratory (72) Inventor Katsuhiko Sato 5-717-1 Fukahori-cho, Nagasaki-shi Mitsubishi (56) References JP-A-6-300661 (JP, A) JP-A-5-187959 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01M 9/04

Claims (2)

(57) [Claims] In order to evaluate the aerodynamic characteristics of a model simulating a structure installed in an air passage, a plurality of triangular spears are erected at intervals on a bottom surface of the air passage in an air passage width direction. A turbulent boundary layer generator for generating an airflow simulating a natural wind at a place where the building is installed, wherein each of the spyers is constituted by two or three triangular plates having a common side. , the rocking plate for 搖 moving around the axis erected along the one side two of the triangular plate, before
A rocking motor for rocking the rocking plate is provided for each of the spyers.
And the rocking plates are independently driven so as to have different phases.
A boundary layer turbulence generator characterized by being moved . 2. The rocking plate is divided into upper and lower portions, each of which is
Differently driven independently around the axis by the oscillating motor
Upper swinging plate can swing phase, and a lower swinging plate Tona
Boundary layer turbulence generator according to claim 1, characterized in that that.