Flow path mechanism

Abstract

To reduce pressure loss when fluid flows into a flow passage.SOLUTION: A flow passage mechanism includes: a flow passage through which fluid passes; a louver which is disposed on an upstream side of the flow passage and in which a plurality of vanes tilted to the same direction with respect to an extending direction of the flow passage are arranged in a row state in a direction orthogonal to the extending direction of the flow passage; and a contraction flow passage which connects an end on the flow passage side of the louver and an end on the louver side of the flow passage and whose opening area becomes smaller toward the flow passage from the louver.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a flow path mechanism. [Background technology]

[0002] A flow path mechanism that takes in atmospheric air or the like as cooling air is equipped with a louver with multiple vanes arranged in parallel at the intake port, which serves as the entrance to the flow path. The louver can prevent foreign matter from entering and also serves as a screen for the intake port. Patent Document 1 describes a structure equipped with a louver (register for adjusting air blowout) at the outlet whose vane angle can be changed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-255255 Summary of the Invention [Problem to be solved by the invention]

[0004] Here, the louvers have a structure in which the blades are inclined relative to the direction in which the flow path extends. This causes the flow direction of the fluid passing through the louvers to change from the fluid passing through the flow path, which can lead to fluid separation at the inlet side of the flow path. The greater the separation of the fluid flow, the greater the pressure loss. Furthermore, pressure loss also occurs due to changes in the area of ​​the region through which the fluid passes, which is influenced by the change in the fluid flow and the thickness of the louver blades.

[0005] The present disclosure has been made in view of the above-mentioned problems, and has an object to provide a flow path mechanism that can reduce pressure loss when a fluid flows into a flow path. [Means for solving the problem]

[0006] To achieve the above object, the flow path mechanism of the present disclosure includes a flow path through which a fluid passes, a louver arranged upstream of the flow path and having a plurality of blades inclined in the same direction relative to the extension direction of the flow path and arranged in a row in a direction perpendicular to the extension direction of the flow path, and a contraction flow path connecting the end of the louver on the flow path side to the end of the flow path on the louver side, and having an opening area that decreases from the louver toward the flow path. [Effects of the Invention]

[0007] According to the present disclosure, pressure loss when a fluid flows into a flow path can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a flow path mechanism of the first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view showing a modified example of the first embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a flow path mechanism of the second embodiment. [Figure 4] FIG. 4 is a schematic diagram showing the installation position of the flow guide. [Figure 5] FIG. 5 is a schematic diagram showing the installation position of the flow guide. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, flow path mechanism embodiments according to the present invention will be described in detail with reference to the drawings. However, the present disclosure is not limited to these embodiments. Furthermore, the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical. Furthermore, the components in the embodiments described below can be variously omitted, replaced, or modified without departing from the spirit of the present invention. Furthermore, when there are multiple embodiments, the present invention also includes those configured by combining the respective embodiments.

[0010] [First embodiment] FIG. 1 is a schematic cross-sectional view showing a flow path mechanism of the first embodiment. FIG. 1 is a cross-sectional view taken along a plane parallel to the extension direction (extension direction) of the flow path mechanism 10. In the flow path mechanism 10 shown in FIG. 1, a fluid, which is air in this embodiment, flows in the directions indicated by arrows 50, 52, and 54. The flow path mechanism 10 has an inlet 11 that opens to the air. A mechanism that generates a force to suck air through the inlet 11, such as a blower, is connected to a path connected to the flow path mechanism 10. The flow path mechanism 10 is connected, for example, to a cooling device on the downstream side, and supplies the air that flows in through the inlet 11 to the cooling device as cooling air (a medium that recovers heat from an object of the cooling device (such as a heat dissipation fin or a heat medium)). Note that the flow path mechanism 10 of this embodiment uses the flown-in fluid as cooling air, but the object to which the flown-in fluid is supplied is not limited to the cooling device. The flow path mechanism 10 can be connected to various objects, and can supply fluid to, for example, a combustion device that combusts supplied air and fuel, a device that cools the supplied fluid, or a device that uses the supplied fluid as a carrier fluid. The flow path mechanism 10 may also have a structure in which the suction port 11 is connected to another pipe. The flow path mechanism 10 is not limited to gases as long as it can circulate a fluid, and can also circulate liquids or two-phase fluids that are mixtures of liquid and gas.

[0011] The flow path mechanism 10 includes a flow path 12, a louver 14, and a contracted flow path 16. The flow path mechanism 10 is arranged in the following order from the suction port 11, that is, from upstream in the direction of fluid flow: the louver 14, the contracted flow path 16, and the flow path 12.

[0012] The flow path 12 is a pipe having a rectangular cross section and straight wall surfaces in the extension direction. Note that the flow path 12 preferably has a structure in which the wall surfaces in the extension direction are straight, but a curved structure is also acceptable. The cross section is not limited to a rectangle, and may be circular or polygonal.

[0013] The louver 14 is disposed upstream of the flow path 12 and serves as the suction port 11 of the flow path structure 10. The louver 14 has a plurality of blades 20. The blades 20 are arranged in a row at predetermined intervals in a direction perpendicular to the extension direction of the flow path 12. The fluid flowing into the flow path structure 10 passes between the blades 20 and enters the flow path 12. The blades 20 are plate materials with a constant thickness and a rectangular cross section, and the longitudinal direction is a direction intersecting the arrangement direction. Note that, although the blades 20 in this embodiment have a constant thickness, this is not limiting. The blades 20 are not limited to a rectangular cross section as in this embodiment, and may have a curved shape, an elliptical shape, a wing shape, or the like. In the cross section of FIG. 1, the extension direction of the blades 20 is inclined with respect to the extension direction of the flow path 12.

[0014] The contraction flow channel 16 is a pipe connecting the louver 14 and the flow channel 12. The upstream end of the contraction flow channel 16 is connected to the downstream end of the louver 14. The downstream end of the contraction flow channel 16 is connected to the upstream end of the flow channel 12. In the direction in which the blades 20 are arranged, both ends of the upstream end of the contraction flow channel 16 are in contact with the downstream ends of the blades 20 of the louver 14. The contraction flow channel 16 has a width in a direction perpendicular to the direction in which the blades 20 are arranged that is the same as or slightly smaller than that of the blades 20. As a result, the fluid flowing into the contraction flow channel 16 becomes a fluid that has passed between the blades 20. The opening area of ​​the upstream end of the contraction flow channel 16 is smaller than the opening area of ​​the downstream end.

[0015] In the cross section of the flow path mechanism 10 shown in FIG. 1 , that is, in a plane parallel to the arrangement direction of the vanes 20, perpendicular to the axis inclined relative to the extension direction of the flow path 12, and parallel to the extension direction of the flow path 12, the upstream end face of the flow path 12, that is, the wall surface on the side where the angle between the plane perpendicular to the extension direction of the flow path 12 and the vane 20 is an acute angle, is defined as an inner wall surface 30, and the wall surface on the side where the angle between the upstream end face of the flow path 12 and the vane 20 is an obtuse angle is defined as an outer wall surface 32.

[0016] In the contracted flow channel 16, the distance between the inner wall surface 30 and the outer wall surface 32 gradually decreases from the upstream side to the downstream side in the fluid flow direction. Furthermore, in the contracted flow channel 16, the positions of the inner wall surface 30 and the outer wall surface 32 change from the upstream side to the downstream side in the fluid flow direction in the direction from the inner wall surface 30 to the outer wall surface 32. The inner wall surface 30 has a straight portion 34 parallel to the extension direction of the blades 20 and a curved portion 36 curved from the extension direction of the blades 20 toward the extension direction of the flow channel 12. The inner wall surface 30 is connected to the louvers 14, the straight portion 34, the curved portion 36, and the flow channel 16 in this order. The outer wall surface 32 has a curved portion 38 curved from the extension direction of the blades 20 toward the extension direction of the flow channel 12, and a straight portion 39 parallel to the extension direction of the flow channel 12. The outer wall surface 32 is connected in this order with the louvers 14, the curved portion 38, the straight portion 40, and the flow path 16. In this embodiment, the curved portion 36 and the curved portion 38 are curved surfaces of the same shape.

[0017] In the flow path mechanism 10, louvers 14 are disposed upstream of the flow paths 12, and the flow paths 12 and the louvers 14 are connected by contracted flow paths 16. In the flow path mechanism 10, a fluid located upstream of the louvers 14 flows into the louvers 14 in a flow direction 50, flows between the blades 20 of the louvers 14 along the blades 20 in a flow direction 52, passes through the contracted flow paths 16, and then flows in the flow paths 12 in a flow direction 54. In the flow path mechanism 10, the fluid that has passed through the louvers 14 in the flow direction 52 changes its flow direction in the contracted flow paths 16, and becomes a flow in the flow direction 54.

[0018] In the contracted flow channel 16 of this embodiment, the straight portion 34 of the inner wall surface 30 is oriented along the blades 20, and the straight portion 40 of the outer wall surface 32 is oriented in the same direction as the flow channel 12, so that the inner wall surface 30 side is narrowed relative to the flow channel 12, and the opening area on the downstream side is smaller than that on the upstream side (a one-sided contracted shape). out The width of the upstream end of the contracted flow path 16 (the width of the downstream end of the louver 14) is W in In this case, W in >W out This becomes:

[0019] By providing the flow path mechanism 10 with the contracted flow path 16, it is possible to reduce the difference between the flow path area of ​​the region where the louvers 14 are arranged and the flow path area of ​​the flow paths 12. Furthermore, by providing the contracted flow path 16, the flow path mechanism 10 can reduce the flow turbulence that occurs when the flow direction changes at the upstream end of the contracted flow path 16, i.e., the downstream end of the louvers 14, and the louvers 14 are eliminated, thereby increasing the flow path area, thereby reducing pressure loss. Reducing the pressure loss of the flow path mechanism 10 allows more fluid to pass through efficiently (with less energy).

[0020] Furthermore, as in this embodiment, by narrowing the inner wall surface 30 side, which is the wall surface in the direction in which the fluid that has passed through the louvers 14 departs, that is, by making the shape such that the change in angle with the louvers 14 is small, separation of the flow from the inner wall surface 30, as in flow direction 56, can be suppressed, thereby reducing pressure loss. Furthermore, by making at least a portion of the contracted flow channel 16 curved in cross section, as in this embodiment, it is possible to change the flow direction while forming a flow that follows the wall surface, thereby suppressing the occurrence of separation.

[0021] Here, if the inclination angle θ1 is the angle between the direction in which the end of the contracting flow channel 16 on the louver 14 side extends and the direction in which the flow channel 12 extends (the direction parallel to the wall surface of the flow channel 12), and the inclination angle θ2 is the angle between the direction in which the end of the blade 20 on the contracting flow channel 16 side extends and the direction in which the flow channel 12 extends, then it is preferable that the inclination angle satisfy the relationship -30°≦θ1-θ2≦30°. By keeping the difference in angle at the connection point between the louver 14 and the contracting flow channel 16 within the above range, it is possible to reduce pressure loss of the fluid. It is preferable that the difference between the inclination angle θ1 and the inclination angle θ2 is small.

[0022] The flow path mechanism 10 has a width W of the flow path 12. out , the width of the upstream end of the contracted flow channel 16 is W in , the thickness of the louver 14 is t, and the number of blades 20 of the louver 14 is N, W out ≦W in It is preferable to set the value to -t×0.8×N. This allows the flow path area to be appropriately reduced in the contracted flow path 16, and the occurrence of separation can be suppressed.

[0023] Fig. 2 is a diagram showing a modified example of the first embodiment. The flow path mechanism 10a shown in Fig. 2 includes a louver 14, a contracted flow path 16a, and a flow path 12. Here, the louver 14 and the flow path 12 are similar to the respective parts of the flow path mechanism 10 shown in Fig. 1, and therefore a description thereof will be omitted.

[0024] In the cross section shown in FIG. 2 , the contracting flow channel 16a has an inner wall surface 30a and an outer wall surface 32a. The outer wall surface 32a has a curved portion 38 and a straight portion 40, similar to the contracting flow channel 16. The inner wall surface 30a has a straight portion 34a and a curved portion 36a. The straight portion 34a is located upstream of the contracting flow channel 16a and connects to the louver 14. The straight portion 34a is inclined in the same direction as the blades 20 of the louver 14. The curved portion 36a connects the straight portion 34a to the flow channel 12. The curved portion 36a has a first curved portion 42 and a second curved portion 44. The first curved portion 42 connects to the straight portion 34a and the second curved portion 44. The second curved portion 44 connects to the first curved portion 42 and the flow channel 12. The first curved portion 42 and the second curved portion 44 are connected at an inflection point 46. That is, the curved portion 36a changes its concave / convex shape relative to the space through which the fluid flows at the inflection point 46. The first curved portion 42 is concave relative to the space through which the fluid flows. The second curved portion 44 is convex relative to the space through which the fluid flows.

[0025] In this way, the flow path mechanism 10a may have a structure in which the curved portion 36a of the inner wall surface 30a is a combination of a plurality of curved lines.

[0026] [Second embodiment] FIG. 3 is a schematic diagram showing a flow path mechanism of the second embodiment. In the flow path mechanism 10b shown in FIG. 3, a flow guide 60 is arranged in the flow path mechanism 10a. In the flow path mechanism 10b, the same structures as those in the flow path mechanism 10a are assigned the same reference numerals, and detailed description thereof will be omitted. The flow path mechanism 10b shown in FIG. 3 includes a flow path 12, a louver 14, a contracted flow path 16a, and a flow guide 60.

[0027] The flow guide 60 is disposed inside the contraction flow channel 16a in the fluid flow direction. The flow guide 60 is a plate-shaped member whose longitudinal direction is the fluid flow direction. Similar to the blades 20 of the louver 14, a plurality of flow guides 60 of this embodiment are disposed in a direction perpendicular to the fluid flow direction. The plurality of flow guides 60 of this embodiment are disposed at equal intervals in the direction perpendicular to the fluid flow direction. The flow guide 60 has a curved shape along the fluid flow direction of the contraction flow channel 16a, that is, a shape that is bent from a direction parallel to the longitudinal direction of the blades 20 to a direction parallel to the extension direction of the flow channel 12.

[0028] By disposing the flow guide 60 in the flow path mechanism 10b, the flow direction of the fluid can be changed by the flow guide 60, and the change in the flow direction of the fluid occurring in the contracted flow path 16 can be performed with less pressure loss. In addition, the occurrence of separation of the fluid in the contracted flow path 16 can be further reduced.

[0029] In the flow path mechanism 10b, where dL is the distance between the downstream end of the louver 14 and the upstream end of the flow guide 60 in the extension direction of the blades 20 and p is the distance between adjacent blades 20, it is preferable that dL≧0.5×p. By arranging the flow guide 60 at a position that satisfies the above range, it is possible to prevent the fluid that has passed through the louver 14 from reaching the flow guide 60 immediately after reaching the contraction flow path 16 and significantly changing the flow path area, thereby preventing large pressure fluctuations in the contraction flow path 16a. In addition, the pressure loss that occurs in the flow guide 60 can be reduced.

[0030] It is preferable that the downstream end of the flow guide 60 in the fluid flow direction is the downstream end of the contracted flow channel 16a. This allows the flow guide 60 to guide the flow in the direction along the flow channel 12. Furthermore, it is possible to reduce the variation in the opening area within the contracted flow channel 16a, thereby reducing pressure loss.

[0031] It is preferable that the inclination angle of the downstream end of the flow guide 60 with respect to the direction in which the flow passage 12 extends is parallel to the direction in which the flow passage 12 extends, thereby making it possible to further reduce pressure loss.

[0032] When the inclination angle of the flow guide 60, which is the angle of the extension direction of the upstream end relative to the extension direction of the flow channel 12, is θ3 and the inclination angle of the extension direction of the end of the blade 20 on the contraction flow channel 16a side relative to the extension direction of the flow channel 12 is θ2, it is preferable that the inclination angle of the flow guide 60 satisfies -10°≦θ3−θ2≦10°. By forming the flow guide 60 within the above range, separation of the fluid at the wall surface of the flow guide 60 can be suppressed.

[0033] In the flow path mechanism 10b, the flow guide 60 has an arc shape and a rectangular cross section, but is not particularly limited to this configuration. The flow guide 60 may have an arc-straight shape, a wing shape, or another curved shape. It is also preferable that the downstream end of the flow guide 60 has an angular shape. The shape of the upstream end of the flow guide 60 is not particularly limited, and may be cylindrical or acute-angled.

[0034] The flow guides 60 may be arranged at different pitches within the contracted flow channel 16a. In this case, it is preferable that the pitch of the inner wall surface 30a of the contracted flow channel 16a is narrower than the pitch of the outer wall surface 32. This makes it possible to appropriately control the flow of fluid on the inner wall surface 30a side, where separation is likely to occur, and reduce pressure loss. The number of flow guides 60 is not particularly limited, and the effect can be obtained by arranging at least one.

[0035] 4, the flow guide 60 of this embodiment is disposed at a position that does not overlap with an extension line of the extending direction of the blades 20, that is, at a position that does not overlap with the blades 20 in the arrangement direction of the blades 20. This makes it possible to more suitably obtain the effect of guiding the fluid by the flow guide 60. Since the flow guide 60 can obtain the above-mentioned effect, it is preferable to position it as shown in FIG. 4, but the flow guide 60a may also be disposed on an extension line of the louver 14 as shown in FIG.

[0036] As described above, the flow path mechanism 10 comprises a flow path 12 through which a fluid passes, a louver 14 arranged upstream of the flow path 12 and having a plurality of blades 20 inclined in the same direction relative to the extension direction of the flow path 12 and arranged in a row in a direction perpendicular to the extension direction of the flow path, and a contraction flow path 16 connecting the end of the louver 14 on the flow path 12 side to the end of the flow path 12 on the louver 14 side, and the opening area of ​​which decreases from the louver 14 toward the flow path 12.

[0037] This configuration can suppress variations in the flow path area and separation of the flow when the flow passes through the flow path mechanism 10. This can reduce pressure loss and drift of the flow.

[0038] At least a part of the wall surface of the contracted flow channel 16 is curved from the direction in which the blades extend to the direction in which the flow channel extends, thereby further suppressing flow separation.

[0039] The contracted flow channel 16 is made up of smoothly connected curved and straight lines on the wall surface in a cross section in the direction in which the blades 20 are inclined relative to the extension direction of the flow channel 12. This makes it possible to further suppress flow separation.

[0040] In the contracted flow channel 20, the wall surface (inner wall surface) where the angle between the blade and the channel is 180 degrees or more when viewed from inside the channel is curved toward the channel side, and the wall surface (outer wall) where the angle between the blade and the channel is less than 180 degrees when viewed from inside the channel is curved toward the louver side, thereby further suppressing flow separation.

[0041] The width of the flow path is W out , the width of the upstream end of the contracted flow channel is W in , where t is the thickness of the blade and N is the number of blades of the louver, W out ≦W in -t×0.8×N is satisfied. This reduces the fluctuation in the opening area.

[0042] If the inclination angle θ1 is the angle between the direction in which the louver-side end of the contracting flow channel extends and the direction in which the flow channel extends, and the inclination angle θ2 is the angle between the direction in which the flow channel extends and the direction in which the contracting flow channel-side end of the blade extends, then the relationship -30°≦θ1-θ2≦30° is satisfied. The opening angle between the wall surface and the flow can be reduced. As a result, the Coanda effect makes it difficult for the flow to separate, reducing pressure loss and flow drift.

[0043] A flow guide 60 is provided, which is disposed inside the contracted flow channel and extends from the louver toward the channel. This allows the flow guide 60 to reduce the local flow deflection angle. This makes it possible to suppress local flow separation, reducing pressure loss and flow drift. Furthermore, by installing the flow guide 60, the dimensions (representative dimensions) that affect the flow downstream of the channel are reduced, allowing the length of the channel to be reduced relatively. This results in a more compact channel.

[0044] The flow guide has an upstream end located between the blades in a direction perpendicular to the extending direction of the blades, thereby reducing pressure loss.

[0045] The flow guide satisfies dL≧0.5×p, where p is the distance between adjacent blades and dL is the distance between the downstream end of the blade and the upstream end of the flow guide in the direction in which the blades extend. This makes it possible to reduce the loss of the downstream bending of the louver 12.

[0046] The flow guide satisfies -10°≦θ3−θ2≦10°, where θ3 is the inclination angle of the upstream end relative to the flow path, and θ2 is the inclination angle of the contraction flow path side end of the blade relative to the flow path. This makes it possible to suppress separation. [Explanation of symbols]

[0047] 10 Flow path mechanism 11 Intake port 12 Flow path 14 Louver 16 Contraction channel 20 feather boards 30 Inner wall 32 Outside wall 34, 40 Straight section 36, 38 curved section 50, 52, 54 Flow direction 60 Flow Guide

Claims

1. a flow path through which a fluid passes; a louver disposed upstream of the flow path, the louver including a plurality of blades inclined in the same direction with respect to the direction of extension of the flow path and arranged in a row in a direction perpendicular to the direction of extension of the flow path; a contraction flow path that connects an end of the louver on the flow path side and an end of the flow path on the louver side, and whose opening area decreases from the louver toward the flow path, The blades are plate materials having a constant thickness and a rectangular cross section, The contracted flow channel is in contact with the blades at both ends in a direction perpendicular to the direction in which the flow channel extends.

2. The contracted flow channel has a wall surface at least partly formed by an extension of the blades. The flow path mechanism according to claim 1 , wherein the flow path mechanism is curved from a direction in which the flow path extends to a direction in which the flow path extends.

3. 3. The flow path mechanism according to claim 1, wherein the contracted flow path has wall surfaces formed of smoothly connected curved and straight lines in a cross section in a direction in which the blades are inclined relative to the direction in which the flow path extends.

4. the contracted flow channel has a wall surface, at which the angle between the blade and the flow channel is 180 degrees or more as viewed from inside the flow channel, that is curved on the flow channel side; The flow path mechanism according to claim 3 , wherein a wall surface where the angle formed between the blade and the flow path is less than 180 degrees when viewed from inside the flow path has a curve on the louver side.

5. The width of the flow path is W ｏｕｔ , the width of the upstream end of the contracted flow channel is W ｉｎ , where t is the thickness of the blade and N is the number of blades of the louver, W ｏｕｔ ≦W ｉｎ The flow path mechanism according to any one of claims 1 to 4, which satisfies -t x 0.8 x N.

6. 6. The flow path mechanism according to claim 1, wherein an inclination angle that is an angle between the direction in which the louver-side end of the contraction flow path extends and the direction in which the flow path extends is θ1, and an inclination angle that is an angle between the direction in which the flow path extends and the direction in which the end of the blade on the contraction flow path side extends is θ2, satisfies -30°≦θ1−θ2≦30°.

7. The flow path mechanism according to claim 1 , further comprising a flow guide disposed inside the contracted flow path and extending from the louver toward the flow path.

8. The flow path mechanism according to claim 7 , wherein an upstream end of the flow guide is disposed between the blades in a direction perpendicular to the extending direction of the blades.

9. 8. The flow path mechanism according to claim 7, wherein the flow guide satisfies dL≧0.5×p, where p is the distance between adjacent vanes and dL is the distance between the downstream end of the vane and the upstream end of the flow guide in the direction in which the vanes extend.

10. 10. The flow path mechanism according to claim 7, wherein an inclination angle of the flow guide, which is an angle formed by a direction in which the upstream end portion extends with respect to a direction in which the flow path extends, is θ3, and an inclination angle of the flow guide, which is an angle formed by a direction in which an end portion of the vane on the contraction flow path side extends with respect to the direction in which the flow path extends, is θ2, satisfies -10°≦θ3−θ2≦10°.

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