JP6590877B2 - Boundary layer control device and wind tunnel device - Google Patents

Description

  The present invention relates to a boundary layer control device and a wind tunnel device.

  A wind tunnel device is used to measure an air resistance value of a moving body or the like. For example, in an automobile wind tunnel, each main pipeline is configured so that a rectified uniform jet can be blown out in order to simulate the actual running state of the vehicle. In particular, when a test is performed near the floor surface of a wind tunnel device, the air resistance value may be underestimated due to the influence of a boundary layer that develops near the floor surface.

  Patent Document 1 discloses a wind tunnel device including a boundary layer control device for suppressing this influence. This wind tunnel device includes a suction duct that sucks air in the vicinity of the wind tunnel floor surface upstream of the measurement object.

JP 2009-156695 A

However, the boundary layer control device described in Patent Document 1 has the following problems. That is, the boundary layer develops again when the airflow passes over the stationary floor surface downstream of the suction duct. For this reason, the air flow velocity near the floor surface is lowered, and the resistance value of the measurement object may be underestimated.
In order to suppress the influence of this re-developed boundary layer, it is necessary to shorten the distance in the airflow direction of the stationary floor surface from the downstream end of the suction duct to the rear end of the measurement object. there were.

  Here, in order to shorten the above-mentioned distance, it was necessary to make the boundary layer control device smaller than the conventional one due to the structural dimension limitation of the wind tunnel device. On the other hand, if the size is inadvertently reduced, the capability of the apparatus is reduced as compared with the conventional case, and a high-precision wind tunnel experiment may not be performed.

  The present invention has been made in view of such problems, and provides a boundary layer control device capable of performing a highly accurate wind tunnel test and a wind tunnel device including the boundary layer control device.

The present invention employs the following means in order to solve the above problems.
That is, the boundary layer control device according to one aspect of the present invention has a box shape that is recessed from the inner wall surface that constitutes the airflow passage through which the airflow generated by the blower flows, and toward the downstream side of the airflow as it approaches the inner wall surface. A front plate formed in a shape toward the front is provided in the downstream of the air flow, and is provided in the chamber, and the space in the chamber is divided into an upstream duct space and a downstream ejection header. And a nozzle portion that ejects air in the ejection header to the airflow passage through an opening to the inner wall surface of the chamber, and the duct space is the main duct on the upstream side and parts, are connected to the downstream side of the main duct portion have a, and a small sub-duct depths than the main duct, viewed in the depth direction of the chamber, and the duct space occupied region The area occupied by the jet header Having become part.

According to this configuration, by integrating the suction duct and the ejection header by the chamber, the entire boundary layer control device including the suction duct and the ejection header can be made compact. In addition to partitioning the suction duct and the ejection header not only on the upstream side and the downstream side of the chamber, but also on the bottom side and the opening side of the chamber, the entire boundary layer control device can be further downsized.

  In the boundary layer control device, the size in the blowing direction in the sub duct portion may be larger than the depth of the sub duct portion in the connection portion between the sub duct portion and the main duct portion.

  According to this configuration, the stagnation pressure generated at the opening and downstream end of the suction duct can be reduced, and the pressure distribution of the air around the measurement object can be made uniform.

  In the boundary layer control device, the nozzle portion may be defined by an opening-side end portion of the partition plate and an opening-side end portion of the front plate in the chamber.

  According to this configuration, a dead space around the nozzle portion can be eliminated.

Further, the boundary layer control device has a box shape that is recessed from the inner wall surface that constitutes the airflow passage through which the airflow generated by the blower flows, and is formed in a shape that goes toward the downstream side of the airflow as it approaches the inner wall surface. A chamber in which a front plate is provided on the downstream side of the air flow, a partition plate provided in the chamber, and dividing the space in the chamber into an upstream duct space and a downstream jetting header; and the jetting A nozzle portion for ejecting air in the header for air to the air flow passage through an opening to the inner wall surface of the chamber, and the duct space includes the main duct portion on the upstream side and the main duct portion. A sub-duct portion connected to the downstream side of the main duct portion and having a smaller depth than the main duct portion, and the partition plate extends from the bottom surface of the chamber toward the opening direction of the chamber, and In the bottom partition plate An intermediate partition plate connected to the opening side end of the chamber and extending from the opening side end toward the downstream side, and a downstream side of the air flow in the intermediate partition plate An opening partition plate connected to intersect the end portion and extending from the downstream end portion toward the opening side .

  According to this configuration, it is possible to make the pressure distribution around the measurement object uniform while effectively using the dead space as a flow path. Moreover, since the space which can be used for the header for ejection can be taken wider, the header for ejection can make the pressure loss at the time of operation small and can eject a more uniform jet flow.

  The boundary layer control device may further include a moving ground plate having a roller rotatable about an axis extending in a width direction of the airflow passage, and an endless belt wound around the roller and extending in the airflow distribution direction. And the front plate may be formed along the endless belt that is curved by being wound around the roller.

  According to this configuration, the entire boundary layer control device including the suction duct, the ejection header, and the moving ground plate can be made compact.

  Moreover, the wind tunnel apparatus which concerns on 1 aspect of this invention has the said air blower and the said airflow path, and further has any one boundary layer control apparatus among said boundary layer control apparatuses, It is characterized by the above-mentioned.

  According to this configuration, since the boundary layer control device is compact as a whole, it is possible to perform a wind tunnel experiment in which the influence of the development of the boundary layer is suppressed even if the dimensional constraints in the wind tunnel device are severe.

  Further, a chamber having a box shape recessed from an inner wall surface constituting an air flow passage through which an air flow generated by the blower flows, a main duct portion on the upstream side, and a downstream side of the main duct portion in the chamber. A boundary layer control device having a sub duct portion connected and having a smaller depth than the main duct portion.

  According to this configuration, it is possible to more effectively suppress the boundary layer developed on the upstream side of the object to be measured without providing the ejection header, and stagnation pressure generated at the opening and downstream end of the suction duct. By reducing the pressure, the pressure distribution of the air around the measurement object can be made uniform.

  According to the boundary layer control device and the wind tunnel device including the boundary layer control device of the present invention, a more accurate wind tunnel test can be performed.

It is a mimetic diagram showing a schematic structure of a wind tunnel device provided with a boundary layer control device concerning a first embodiment of the present invention. It is a schematic diagram of the principal part of the boundary layer control apparatus which concerns on 1st embodiment of this invention. FIG. 3 is a boundary layer control device according to the first embodiment of the present invention, and is a cross-sectional view of a plane AA shown in FIG. 2. It is explanatory drawing which shows an example of an effect | action of the boundary layer control apparatus which concerns on 1st embodiment of this invention. It is a boundary layer control apparatus (duct for wind tunnel apparatus) concerning 2nd embodiment of this invention, Comprising: It is sectional drawing equivalent to sectional drawing shown in FIG.

[First embodiment]
Hereinafter, a boundary layer control device and a wind tunnel device according to a first embodiment of the present invention will be described in detail based on the drawings.
A wind tunnel device 100 shown in FIG. 1 is used, for example, for performing a test for measuring an air resistance value of an automobile.

The wind tunnel device 100 in the present embodiment includes an airflow passage 1, a blower 2, and a boundary layer control device 5.
The airflow passage 1 is a continuous passage so as to form an annular shape. The blower 2 is provided in the airflow passage 1 and generates an airflow W by rotation of a fan or the like. The airflow W flows through the airflow passage so as to circulate through the airflow passage 1.
The airflow passage 1 is provided with a measurement chamber 3 that allows a wind tunnel test to be performed by expanding the space of a part of the airflow passage 1. The airflow passage 1 is composed of a straight section 1A and a corner section 1B. A plurality of corner vanes 4 are provided in each corner section 1B.

As shown in FIGS. 2 and 3, the boundary layer control device 5 is provided on the floor surface 3 </ b> A and under the floor 3 </ b> B of the measurement chamber 3. The boundary layer control device 5 has a total of three types of devices: a suction duct 10, an ejection header 12, and a moving ground plate 13 arranged adjacent to each other. Each device is arranged on the upstream side of the measurement object O in the order of the suction duct 10, the ejection header 12, and the moving ground plate 13 from the upstream side of the air flow W. The developed boundary layer that should take into account the influence on the measurement is controlled in this order by each device installed on the upstream side of the measurement object O. It should be noted that each device can operate independently.
Only the suction duct 10 is provided around the side of the measurement object O in the upstream region on both sides in the width direction (both left and right sides) of the measurement object O.

  More specifically, as shown in FIGS. 2 and 3, the suction duct 10 and the ejection header 12 in the boundary layer control device 5 are partitioned and formed in a box-like chamber 14 that is recessed from the floor surface 3 </ b> A of the measurement chamber 3. ing. The chamber 14 is provided with a front plate 16 that is inclined toward the downstream side of the airflow W toward the floor 3 </ b> A of the wind tunnel device 100, that is, toward the opening direction, on the downstream side of the chamber 14.

  A partition plate 18 is provided in the chamber 14. The partition plate 18 divides and forms the suction duct 10 and the ejection header 12 together with the chamber 14 whose interior is partitioned into two spaces by the partition plate 18. That is, among the members that partition the suction duct 10, the downstream member (partition plate 18) also serves as the upstream member that partitions the ejection header 12.

  In this embodiment, a part of the partition plate 18 divides the suction duct 10 and a part of the ejection header 12 into an upstream side and a downstream side of the chamber as well as a bottom side and an opening of the chamber. It is also divided on the side (up and down when the opening direction is up). In the present embodiment, the partition plate 18 is formed by connecting the bottom partition plate 18A, the intermediate partition plate 18B, and the opening partition plate 18C in this order.

The bottom partition plate 18 </ b> A extends from the bottom surface of the chamber 14 toward the opening direction of the chamber 14.
The intermediate partition plate 18B is connected so as to intersect the end portion on the opening side of the chamber 14 in the bottom partition plate 18A, and extends from the end portion on the opening side toward the downstream side. In the present embodiment, an intermediate partition plate bending portion 18b is provided on the upstream side of the intermediate partition plate 18B.
The opening partition plate 18C is connected so as to intersect the downstream end portion of the air flow W in the intermediate partition plate 18B, and extends from the downstream end portion toward the opening side.

  At this time, due to the shape of the partition plate 18, the space in the suction duct 10 is a main duct portion 10 </ b> A that is an upstream space, a sub-duct portion 10 </ b> B that is a space downstream and shallower than the main duct portion 10 </ b> A. The two are defined. In the present embodiment, the size of the airflow in the sub duct portion 10B is determined to be larger than the depth of the sub duct portion 10B at the connection portion between the sub duct portion 10B and the main duct portion 10A.

  In the present embodiment, the nozzle portion 21 is provided at the downstream end of the chamber 14. The nozzle portion 21 is defined by the opening side end portion of the partition plate 18 and the opening side end portion of the front plate 16 of the chamber 14. The nozzle portion 21 is formed such that the air ejection direction has the same vector component as the direction of the air flow W.

The moving ground plate 13 in the present embodiment is provided on the downstream side adjacent to the chamber 14 and has a roller 19 and an endless belt 20. The roller 19 is rotatable around an axis extending in the width direction of the airflow passage 1, and the endless belt 20 is wound around the roller 19 and extends in the flow direction of the airflow W. At the time of measurement, the endless belt 20 is controlled to rotate at the same speed as the direction of the airflow W.
In the present embodiment, the front plate 16 of the chamber 14 is formed in such a shape as the endless belt 20 that is curved by being wound around the roller 19.

In the wind tunnel device 100 including the boundary layer control device 5 having the above-described configuration, the suction duct 10 and the ejection header 12 are integrated by the chamber 14, and the members that partition each of them can be made common. For this reason, the dead space which arises when each of the suction duct 10 and the ejection header 12 is installed separately can be eliminated and effectively used as a flow path of the boundary layer control device 5. In addition, since the front plate 16 of the chamber 14 is inclined, even when the movable ground plate 13 is further provided, if the front plate 16 is formed along the adjacent endless belt 20, the dead space is eliminated. The dimensions necessary for exhibiting the respective functions can be ensured.
Therefore, the distance in the air flow W direction of the stationary floor surface 3A from the downstream end of the duct to the rear end of the measurement object O can be significantly shortened without sacrificing the capability of each device. .

In addition, the flow resistance in the suction of air via the sub-duct portion 10B having a relatively shallow depth is larger than the flow resistance in the main duct portion 10A. The velocity vector of the airflow W sucked in the vicinity of the opening of the suction duct 10 in the wind tunnel at this time will be described. As shown in FIG. 4, the chamber depth direction component V of the airflow velocity vector gradually decreases from V ₀ to V ₁ toward the downstream end of the suction duct 10. As a result, the velocity vector change of the airflow W near the opening of the duct 10 for suction in the wind tunnel and at the downstream end becomes slow, and the stagnation pressure of the airflow W generated in the region is reduced. Accordingly, the distribution of atmospheric pressure around the measurement object O is uniform.

Further, the effect of deceleration of the depth direction component of the airflow W is also affected by the size of the sub duct portion 10B in the blowing direction. In the present embodiment, the size in the blowing direction in the sub duct portion 10B is determined to be larger than the depth of the sub duct portion 10B in the connection portion between the sub duct portion 10B and the main duct portion 10A. Thereby, since the above-mentioned flow path resistance is sufficiently ensured, the stagnation pressure of the airflow W generated in the region is effectively reduced, and the atmospheric pressure distribution of the object to be measured O becomes uniform.
Furthermore, according to the structure of this embodiment, the space which can be used for the header 12 for ejection can be taken more widely. Therefore, during operation, the pressure loss can be reduced, so that the operation efficiency is good, and more uniform jet can be ejected.

  Therefore, according to the measurement boundary layer control device 5 and the wind tunnel device 100 according to the present embodiment, the influence on the measurement accompanying the generation of the boundary layer can be suppressed, and the resistance value of the measurement object O can be measured with higher accuracy. be able to.

[Second Embodiment]
Next, a second embodiment will be described with reference to FIG. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The second embodiment differs from the first embodiment in the configuration of the chamber 15 and its interior.
In the present embodiment, there is only a wall surface corresponding to the wall surface that partitions the suction duct 11 in the first embodiment, and this wall surface is constituted by one chamber 15. Therefore, there is no configuration for partitioning the ejection header 12.

In the boundary layer control device 6 and the wind tunnel device 101 configured as described above, the airflow on the stationary floor surface 3A from the downstream side end portion of the suction duct 11 to the rear end portion of the measurement object O is the same as in the first embodiment. The distance in the W direction can be greatly shortened. Therefore, since the boundary layer that develops again on the downstream side of the suction duct 11 is minimized, a wind tunnel test with high measurement accuracy can be performed without providing the ejection header 12.
In addition, in this embodiment, the space occupied by the downstream side of the chamber 15 is small, so that the chamber 15 can be arranged even when the size constraint is severe, such as when the chamber 15 is as close as possible to the moving ground plate 13. it can.

In the boundary layer control device 6 having the above-described configuration and the wind tunnel device 101 including the boundary layer control device 6 as well, the velocity vector change of the air flow W near the opening portion of the wind tunnel suction duct 11 and at the downstream end is slow as in the first embodiment. The stagnation pressure of the airflow W generated in the region is reduced, and the atmospheric pressure distribution in the object to be measured O is uniform.
Therefore, according to the above configuration, the measurement object O can be accurately measured even when the ejection header 12 cannot be provided because the dimensional constraint or the cost constraint is more severe than the first embodiment. The air resistance value can be measured.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes design changes and the like within a scope not departing from the gist of the present invention. .
In the above embodiment, the partition plate 18 is formed by connecting three flat plates of the bottom partition plate 18A, the intermediate partition plate 18B, and the opening partition plate 18C. However, the present invention is not limited to this. For example, the partition plate 18 may be formed by bending a single plate, and a region corresponding to the intermediate partition plate 18B in the above embodiment may be a flat surface.

100, 101 Wind tunnel device 1 Airflow passage 1A Straight section 1B Corner section 2 Blower 3 Measurement room 3A Floor 3B Under floor 4 Corner vanes 5, 6 Boundary layer control devices 10, 11 Suction ducts 10A, 11A Main duct sections 10B, 11B Sub Duct portion 12 Jet header 13 Moving ground plates 14, 15 Chamber 16, 17 Front plate 18 Partition plate 18A Bottom partition plate 18B Intermediate partition plate 18b Intermediate partition plate bending portion 18C Opening partition plate 19 Roller 20 Endless belt 21 Nozzle Part O Object to be measured W Airflow V Chamber depth direction component of airflow velocity vector

Claims (6)

A front plate formed into a box shape that is recessed from the inner wall surface constituting the air flow path through which the air flow generated by the blower circulates, and toward the downstream side of the air flow as it approaches the inner wall surface, is downstream of the air flow A chamber provided in
A partition plate provided in the chamber and partitioning the space in the chamber into an upstream duct space and a downstream jetting header;
A nozzle portion for ejecting air in the ejection header to the air flow passage through an opening to the inner wall surface of the chamber;
The duct space, possess a main duct portion of the upstream side, and a small sub-duct depths than is connected to the downstream side of the main duct portion main duct portion,
A boundary layer control device having a portion where an area occupied by the duct space and an area occupied by the ejection header overlap when viewed in the depth direction of the chamber . A front plate formed into a box shape that is recessed from the inner wall surface constituting the air flow path through which the air flow generated by the blower circulates, and toward the downstream side of the air flow as it approaches the inner wall surface, is downstream of the air flow A chamber provided in
A partition plate provided in the chamber and partitioning the space in the chamber into an upstream duct space and a downstream jetting header;
A nozzle portion for ejecting air in the ejection header to the air flow passage through an opening to the inner wall surface of the chamber;
The duct space, possess a main duct portion of the upstream side, and a small sub-duct depths than is connected to the downstream side of the main duct portion main duct portion,
The partition plate extends from the bottom surface of the chamber toward the opening direction of the chamber; and
An intermediate partition plate that is connected so as to intersect the end portion on the opening side of the chamber in the bottom partition plate and extends from the end portion on the opening side toward the downstream side,
A boundary layer control device , comprising: an opening partition plate connected to intersect the downstream end portion of the airflow in the intermediate partition plate and extending from the downstream end portion toward the opening side . The boundary layer control device according to claim 1 or 2 , wherein a dimension in the flow direction of the airflow in the sub duct portion is larger than a depth of the sub duct portion in a connection portion between the sub duct portion and the main duct portion. The boundary layer control device according to any one of claims 1 to 3, wherein the nozzle portion is defined by an opening-side end portion of the partition plate and an opening-side end portion of the front plate in the chamber. A moving ground plate having a roller rotatable about an axis extending in the width direction of the airflow passage, and an endless belt wound around the roller and extending in the flow direction of the airflow;
The boundary layer control device according to any one of claims 1 to 4, wherein the front plate is formed along the endless belt that is curved by being wound around the roller. The wind tunnel apparatus which has the said air blower and the said airflow path, and further has the boundary layer control apparatus as described in any one of Claim 1 to 5 .

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