JP6044762B2 - Flow field observation method and flow field observation apparatus - Google Patents

Description

  The present invention relates to a flow field observation method and a flow field observation apparatus for observing a flow of a medium around a moving body, and in particular, a flow field observation method and a flow field for observing a flow in a gap (narrow part) between a moving body and a wall surface. It relates to field observation equipment.

  In an object that moves in the vicinity of a wall surface composed of the ground surface, water surface, etc., such as an automobile, a train, and a ground effect wing machine, the fluid motion in the gap (narrow part) between the moving body and the wall surface is propulsion of the moving body. The performance will be greatly affected. Therefore, it is meaningful to measure the fluid motion in the gap (narrow part) between the moving body and the wall surface.

  By the way, generally, the fluid motion around the automobile is often measured by a wind tunnel test (see, for example, Patent Document 1 and Patent Document 2). The test apparatus described in Patent Document 1 is configured such that an automobile suspended in a wind tunnel is placed on a moving belt, and the moving belt is driven at a predetermined speed, and a wind of the same speed is caused to flow in the wind tunnel. , I try to simulate the driving state of the car.

  Further, the test apparatus described in Patent Document 2 is a wind tunnel test apparatus using a particle image velocity measurement method (PIV: Particle Image Velocimetry), and the inside of a wind tunnel to which a uniform flow of air having a predetermined flow velocity is supplied. The model of the car is placed on and the tracer particles are supplied into the uniform flow from the upstream side. PIV is a method in which particles following a fluid are mixed in a flow field, a particle displacement vector dx at a minute time dt is obtained from a visualized image taken continuously in time, and a velocity vector dx / dt is estimated. The flow in the flow field can be measured with high accuracy and precision.

JP-A-6-341920 JP 2011-17603 A

  In the wind tunnel test apparatus described in Patent Document 1 and Patent Document 2 described above, a moving body such as an automobile or a model is arranged on the moving belt or the floor surface, and the moving body and the moving belt or the floor surface are arranged. It was difficult to measure the fluid motion in the gap (narrow part) from the lower side of the moving body. Such a problem is not limited to a wind tunnel test of an automobile, and can occur in the same way when a fluid motion in a gap between a train and the ground (track) or a ground effect wing machine and a water surface (narrow part) is measured. . That is, it is difficult to easily and accurately measure the fluid motion in the gap (narrow portion) between the moving body and the wall surface (floor surface, ground, water surface, etc.).

  The present invention has been made in view of the above-described problems, and a flow field observation method and flow field observation that can easily and accurately measure fluid motion in a gap (narrow part) between a moving body and a wall surface. An object is to provide an apparatus.

According to the present invention, the tracer particles are dispersed in a medium which is a liquid in the water tank, and the moving body submerged in the medium in the water tank is moved in the spraying area of the tracer particles, and the behavior of the tracer particles is determined. In the flow field observation method for observing the flow of the medium around the moving body by measuring, a transparent wall body is disposed in the water tank along the moving direction of the moving body, and the liquid above the moving body is arranged. A liquid level suppressor that suppresses the generation of waves on the surface is disposed, and the movable body is moved along the wall surface in a state in which the movable body is brought close to the surface of the wall surface body. There is provided a flow field observation method characterized by measuring the behavior of the tracer particles.

  The measuring means for measuring the behavior of the tracer particles may be configured to move along the wall surface at the same speed as the moving body.

Further, according to the present invention, the tracer particles are dispersed in a medium that is a liquid in the water tank, and the moving body submerged in the medium in the water tank is moved in the spraying area of the tracer particles. In the flow field observation apparatus for observing the flow of the medium around the moving body by measuring the behavior, a transparent wall surface disposed in the water tank along the moving direction of the moving body, and an upper side of the water tank And a movement carriage that is movably supported along the wall surface in a state where the moving body is brought close to the surface of the wall surface, and the behavior of the tracer particles disposed on the back surface of the wall surface. A flow field observation characterized in that the traveling carriage has a flat liquid level suppressor that is disposed on the liquid level above the moving body and suppresses the generation of waves. An apparatus is provided.

It said measuring means, the travel is connected to the carriage, but it may also be configured to be movable along the wall surface member at the same speed as the moving body.

  According to the flow field observation method and flow field observation apparatus of the present invention described above, a transparent wall surface body that simulates the ground surface and the water surface is disposed in the water tank, a moving body is disposed on the surface side of the wall surface body, The measuring means is arranged on the back side, and the flow of the medium in the gap (narrow part) between the moving body and the wall surface body can be measured with the wall body interposed therebetween, so that the gap between the moving body and the wall body (narrow part) ) Can be measured easily and accurately.

1 is an overall configuration diagram of a flow field observation apparatus according to a first embodiment of the present invention. It is AA arrow sectional drawing in FIG. It is BB arrow sectional drawing in FIG. It is a figure which shows the flow field observation apparatus which concerns on other embodiment of this invention, (a) has shown 2nd embodiment, (b) has shown 3rd embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. Here, FIG. 1 is an overall configuration diagram of the flow field observation apparatus according to the first embodiment of the present invention. 2 is a cross-sectional view taken along line AA in FIG. FIG. 3 is a cross-sectional view taken along the line BB in FIG.

  As shown in FIGS. 1 to 3, the flow field observation apparatus 1 according to the first embodiment of the present invention is a moving body in which tracer particles T are dispersed in the water in the water tank 11 and submerged in the water in the water tank 11. 12 is a flow field observation device that observes the water flow around the moving body 12 by moving the movement of the tracer particles T in the spraying region of the tracer particles T and measuring the behavior of the tracer particles T, along the moving direction of the moving body 12. The transparent wall surface body 2 disposed in the water tank 11 and the travel disposed above the water tank 11 and movably supported along the wall surface body 2 with the moving body 12 approaching the surface of the wall surface body 2 A carriage 3 and a measuring means 4 for measuring the behavior of the tracer particles T arranged on the back surface of the wall surface body 2 are provided.

  The water tank 11 is long in the moving direction of the moving body 12 and has a box shape with an open top, and has a pair of walls 11a in the width direction. On the upper surface of the wall 11a, for example, a rail 11b that supports the traveling carriage 3 is formed.

  The moving body 12 is a model that simulates a moving object (hereinafter referred to as an actual machine) such as an automobile, a train, and a ground effect wing aircraft. The moving body 12 is scaled down or scaled up to a size that can be tested in the water tank 11. In the present embodiment, since it is desired to visualize the flow in the gap (narrow part) between the moving body 12 and the wall surface body 2, the moving body 12 may have a shape that simulates an actual machine only on the surface facing the wall surface body 12. In addition, a shape simulating an actual machine may be used only for the facing surface and the side peripheral surface thereof, or a shape simulating the entire actual machine may be used. 1 to 3, the movable body 12 is illustrated in a rectangular parallelepiped shape for convenience of explanation.

  Further, for example, water is injected into the water tank 11 as a medium that forms a flow around the moving body 12. When water is used as the medium, the fluid motion in water can be easily converted into fluid motion in air from the Reynolds number and the kinematic viscosity coefficient. Further, if the test is to be performed in the air when the mobile body 12 is scaled down, the speed of the mobile body 12 needs to be increased by that amount. It is possible to create an environment that is easy to test.

  Moreover, since water has a higher density than air, measurement accuracy can be improved when a flow field is observed. However, the medium is not limited to water and may be other liquids such as oil. Further, air may be used as a medium in a state where the water tank 11 is emptied without injecting a liquid such as water. In the following description, it is assumed that water is used as a medium unless otherwise specified.

  The wall surface body 2 is a transparent plate comprised by an acrylic board, a glass plate, etc., for example. The wall surface body 2 is a plate member that simulates the ground surface and water surface that are close to an actual machine such as an automobile, a train, and a ground effect wing machine. As shown in FIG. 1, the wall surface body 2 is disposed on the bottom surface of the water tank 11, and is held by the support member 21 in a state perpendicular to the bottom surface. Further, as shown in FIGS. 2 and 3, the wall surface body 2 is arranged long along the moving direction of the moving body 12. 1 to 3, for convenience of explanation, the wall surface body 2 is illustrated in gray.

  Moreover, since the movement of water between the front surface and the back surface of the wall surface body 2 may affect the water flow at a location to be measured, the wall surface body 2 is preferably arranged higher than the water surface. Although not shown, the wall surface body 2 may be reinforced by a frame member or a beam member, may be formed by combining a plurality of panels, or may be fixed to the floor surface or the wall 11a. Good.

  The traveling carriage 3 is a drive unit that moves the moving body 12 in water. The traveling carriage 3 has wheels 3 a placed on the rails 11 b and is configured to be movable along the edge of the water tank 11. In addition, the traveling carriage 3 has, for example, a wire 3b (see FIG. 2) connected to a drum (not shown) disposed at an end of the water tank 11 so as to be able to be wound, and the wire 3b is used as a drum. Towed by winding. The traveling cart 3 may be self-propelled.

  The traveling carriage 3 includes a flat plate-like main body 31 having wheels 3a on the lower surface, a support member 32 that supports the moving body 12, and an elevating means 33 that is disposed on the main body 31 and moves the support member 32 up and down. A flat liquid level suppressor 34 disposed on the water surface above the moving body 12, a column 35 connecting the liquid level suppressor 34 and the main body 31, and an elevating means 33 disposed on the main body 31. And a casing 36 for covering.

  As shown in FIGS. 1 and 2, the traveling carriage 3 has four wheels 3a, and the main body 31 has a size capable of supporting these wheels 3a. The support member 32 is connected to the moving body 12 and penetrates the main body 31 and is connected to the lifting means 33. Since the support member 32 crosses the water surface when moving the moving body 12 in water, the cross section may have a wing shape in order to reduce the resistance. When the moving body 12 is long in the front-rear direction, the moving body 12 may be supported by a plurality of support members 32 that are branched in the front-rear direction, as shown in FIG.

  The elevating means 33 can adjust the height position (water depth) of the moving body 12 in water by moving the support member 32 up and down. The gap g between the moving body 12 and the wall surface body 2 is appropriately changed depending on conditions such as the type of actual machine to be simulated. Therefore, the movable body 12, the support member 32, and the lifting / lowering means 33 may be configured to be movable in the lateral width direction of the water tank 11 according to the size of the gap g. When adjusting the gap g, the wall surface body 2 may be moved instead of the moving body 12.

  As shown in FIG. 3, the liquid level suppression plate 34 is a plate member that covers the water surface above the moving body 12. By disposing the liquid level suppression plate 34, it is possible to suppress waves generated when the moving body 12 is moved in water, and to suppress disturbance of the water flow. In order to reduce resistance during movement, the liquid level suppressor 34 may be formed so that the width is gradually narrowed at the front, a draining portion may be formed at the tip, or a water entry angle. A tapered surface may be formed in the height direction so as to decrease. In addition, an opening 34 a through which the support member 32 of the moving body 12 is inserted is formed in the liquid level suppression plate 34.

  The number and arrangement of the support columns 35 can be arbitrarily set as long as they can stably support the liquid level suppressor 34, and are not limited to the illustrated number and arrangement. When the movable body 12, the support member 32, and the lifting / lowering means 33 are configured to be movable in the lateral width direction, the support column 35 and the liquid level suppressing plate 34 may also be configured to be movable in the lateral width direction. Further, the opening 34a is formed long in the width direction so that the movable body 12, the support member 32, and the lifting means 33 can be moved in the width direction while the support column 35 and the liquid level suppression plate 34 are fixed. Also good.

  In this way, by connecting the liquid level suppressor 34 to the traveling carriage 3 via the support column 35, the liquid level suppressor 34 can be moved at the same speed as the moving body 12, and the liquid level suppression plate that does not exist in the actual machine can be obtained. Even when the plate 34 is provided, it is possible to simulate substantially the same state as the state without the liquid level suppressor 34.

  As shown in FIG. 1, the measuring means 4 is arranged on the opposite side of the moving body 12 with the wall surface body 2 interposed therebetween, that is, on the back surface side of the wall surface body 2. The measuring means 4 supports, for example, a laser light irradiation device 41 that irradiates a laser light sheet in water in a pulsed manner, an imaging device 42 that images reflected light from the tracer particles T, and the laser light irradiation device 41 and the imaging device 42. And a support member 43 to be used. The measuring means 4 is a measuring instrument generally used in so-called particle image velocimetry (PIV). The measuring means 4 is not limited to such a measuring instrument, and may be one using a laser Doppler velocimeter (LDV) or a particle tracking measurement method (PTV). ) May be used as a measuring instrument.

  PIV is a method in which particles following a fluid are mixed in a flow field, a particle displacement vector dx at a minute time dt is obtained from a visualized image taken continuously in time, and a velocity vector dx / dt is estimated. In order to acquire this visualized image, a laser light sheet developed in a flat film shape is projected into water at regular intervals, and the reflected light of the tracer particles T is imaged. The laser light irradiation device 41 is configured by an optical system device such as a light source or a reflection mirror. The imaging device 42 includes a camera that acquires a still image, a video camera that captures a moving image, and the like.

  In the present embodiment, since it is desired to observe the water flow in the gap (narrow part) between the moving body 12 and the wall surface body 2, the laser light irradiation device 41 passes the wall surface body 2 through the wall body 2. It is arranged at a position where the laser light sheet can be irradiated.

  Further, the imaging device 42 is also arranged at a position where the surface of the moving body 12 that is close to the wall surface body 2 can be imaged via the wall surface body 2. As illustrated in FIG. 2, the imaging device 42 includes a first imaging device 42 a that images the rear surface of the moving body 12, and a second imaging device 42 b that images the downstream water flow of the moving body 12. You may have. In this way, by observing the water flow before and after the moving body 12, the analysis accuracy of the fluid motion in the gap (narrow portion) between the moving body 12 and the wall surface body 2 can be improved.

  The support member 43 is a component that connects the laser light irradiation device 41 and the imaging device 42 to the traveling carriage 3. The support member 43 may be configured to be movable to the traveling carriage 3 so that the positions of the laser beam irradiation device 41 and the imaging device 42 with respect to the moving body 12 or the wall surface body 2 can be adjusted. Further, the laser light irradiation device 41 and the imaging device 42 may have support members that are individually supported, and may be individually connected to the traveling carriage 3. Thus, by connecting the measuring means 4 to the traveling carriage 3, it can be moved along the wall surface body 2 at the same speed as the moving body 12.

  In addition, the measuring unit 4 operates a control device (not shown) that operates the laser light irradiation device 41 and the imaging device 42, stores the measurement result by the imaging device 42, and analyzes the flow field from the measurement result. Connected by wire or wireless. Such a control device may be disposed at a location separated from the water tank 11 or may be mounted on the traveling carriage 3. The control device may have display means such as a display for displaying the analysis result.

  In order to observe the water flow around the moving body 12 by the flow field observation apparatus 1 described above, first, as shown in FIG. 3, it is necessary to uniformly spray the tracer particles T in the water of the water tank 11. The tracer particles T are composed of nylon particles having the same specific gravity as the medium (for example, water). When the medium is air, smoke may be used as the tracer particles T.

  The tracer particles T are sprayed so as to have a uniform distribution in water by a spraying device used in a general water tank test. Thereafter, the wire 3b connected to the traveling carriage 3 is wound up and the traveling carriage 3 is pulled to move on the rail 11b. The moving body 12 is disposed so as to have a predetermined gap g with respect to the wall surface body 2, and the wall surface body 2 is disposed along the moving direction of the moving body 12. Thus, the moving body 12 moves underwater while maintaining a certain gap g with the wall surface body 2. Then, when the moving body 12 is moved within the spraying region of the tracer particles T, the tracer particles T move along the water flow, and the behavior of the tracer particles T is measured by the measuring means 4.

  That is, according to the flow field observation device 1 described above, the tracer particles T are sprayed in the water in the water tank 11, and the moving body 12 submerged in the water in the water tank 11 is moved in the spraying area of the tracer particles T, thereby A flow field observation method for observing a water flow around a moving body 12 by measuring the behavior of particles T, wherein a transparent wall body 2 is arranged in a water tank 11 along the moving direction of the moving body 12, The flow field observation method is implemented in which the moving body 12 is moved along the wall surface body 2 with the moving body 12 approaching the surface of the body 2 and the behavior of the tracer particles T is measured from the back surface of the wall surface body 2. can do.

  Moreover, according to the flow field observation apparatus 1 according to the present embodiment, the transparent wall surface body 2 that simulates the ground surface and the water surface is disposed in the water tank 11, the moving body 12 is disposed on the surface side of the wall surface body 2, and the wall surface The measuring means 4 is arranged on the back side of the body 2 so that the water flow can be measured in the gap (narrow part) between the moving body 12 and the wall surface body 2 with the wall surface body 2 interposed therebetween. The fluid motion in the gap (narrow part) with 2 can be measured easily and accurately.

  Next, a flow field observation apparatus 1 according to another embodiment of the present invention will be described with reference to FIG. Here, FIG. 4 is a figure which shows the flow field observation apparatus which concerns on other embodiment of this invention, (a) has shown 2nd embodiment, (b) has shown 3rd embodiment. In addition, about the same component as the flow field observation apparatus 1 which concerns on 1st embodiment mentioned above, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted.

  The flow field observation device 1 according to the second embodiment shown in FIG. 4A is obtained by omitting the liquid level suppressor 34 described above. Even when the medium is a liquid such as water, when the water depth D of the moving body 12 is sufficiently deep, even if the moving body 12 is moved, the waves generated on the water surface are moved by the moving body 12. There is little influence on the fluid motion in the gap (narrow part) between the wall surface body 2 and the wall surface body 2. Therefore, in such a case, the liquid level suppressor 34 may be omitted. When the medium is air, there is no liquid level that the support member 32 crosses, and thus the liquid level suppressor 34 can be omitted.

  The flow field observation apparatus 1 according to the third embodiment shown in FIG. 4B is configured such that the surface side of the wall surface body 2 is recessed to form a curved shape, and the moving body 12 is formed into a spherical shape. Depending on the relationship between the actual machine to be simulated and the wall surface, the gap (narrow portion) between the moving body 12 and the wall surface body 2 may be configured by a curved surface. For example, the third embodiment can be applied when simulating the relationship between a pipe and an object or substance flowing in the pipe, the relationship between a barrel and a shell, the relationship between a blood vessel, a white blood cell, or a red blood cell. In addition, the moving body 12 does not need to be a spherical shape, may be a cylindrical shape having an axis in the moving direction, and may be a rectangular parallelepiped shape as in the first embodiment.

  In the first embodiment and the second embodiment described above, when simulating a real machine having a tire or a wheel that rotates in contact with a wall surface, such as an automobile or a train, the tire or wheel that can rotate on the moving body 12 May be arranged.

  In the first embodiment to the third embodiment described above, the case where the wall surface body 2 is erected in the direction perpendicular to the bottom surface of the water tank 11 has been described, but the wall surface body 2 is inclined with respect to the bottom surface of the water tank 11. Alternatively, the wall surface body 2 may be disposed in the horizontal direction near the liquid surface, and the moving body 12 may be disposed below the wall surface body 2.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Flow field observation apparatus 2 Wall body 3 Traveling trolley 4 Measuring means 11 Water tank 12 Moving body 34 Liquid level suppression board

Claims (4)

The movement is carried out by spraying tracer particles in a medium that is a liquid in the water tank, moving a moving body submerged in the medium in the water tank within the spraying area of the tracer particles, and measuring the behavior of the tracer particles. In the flow field observation method that observes the flow of the medium around the body,
A transparent wall surface body is disposed in the water tank along the moving direction of the moving body, a liquid level suppressor for suppressing the generation of waves is disposed on the liquid surface above the moving body, and the surface of the wall surface body is disposed. A flow field observation method, wherein the moving body is moved along the wall surface with the moving body approached, and the behavior of the tracer particles is measured from the back surface of the wall surface.   The flow field observation method according to claim 1, wherein the measuring unit that measures the behavior of the tracer particles is moved along the wall surface at the same speed as the moving body. The movement is carried out by spraying tracer particles in a medium that is a liquid in the water tank, moving a moving body submerged in the medium in the water tank within the spraying area of the tracer particles, and measuring the behavior of the tracer particles. In the flow field observation device that observes the flow of the medium around the body,
A transparent wall body disposed in the water tank along the moving direction of the moving body;
A traveling carriage disposed above the water tank and movably supported along the wall surface in a state where the moving body is brought close to the surface of the wall surface;
Measuring means for measuring the behavior of the tracer particles arranged on the back surface of the wall body ,
The traveling carriage has a flat liquid level suppressor that is disposed on the liquid level above the moving body and suppresses the generation of waves.
A flow field observation device characterized by that.   The flow field observation device according to claim 3, wherein the measuring unit is connected to the traveling carriage and configured to be movable along the wall surface at the same speed as the moving body. .