JP2018003988A - Fluid equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrict peeling of flow at fluid equipment more.SOLUTION: A fluid equipment has several structures 4 showing a shape protruded from a surface 3 of a flow path. Then, a first section 7 in parallel with a flow 1 at the structures 4 and crossing in perpendicular to the surface 3 has an oblique side 9 at a downstream side from a point 8 on the surface 3 and extending to top parts 51, 61 spaced apart from the surface 3. In addition, an inter-structure flow passage 14 is formed between the two adjoining structures 5, 6 of several structures 4. Then, an area S1 of a surface 53 at one structure 5 of the two structures 5, 6 to which fluid flowing the inter-structure flow passage 14 is different from an area S2 of the surface 63 at the other structure 6.SELECTED DRAWING: Figure 3

Description

  The present invention relates to fluid equipment such as a centrifugal compressor, a vacuum cleaner, and an air conditioner.

  In a fluid device that handles fluid such as a centrifugal compressor, a vacuum cleaner, and an air conditioner, there is a region where the cross-sectional area changes in the flow path. By changing the cross-sectional area of the flow path, the flow velocity changes. According to Bernoulli's theorem, the flow rate decreases as the pressure increases. Further, since the flow in the boundary layer of the fluid is decelerated due to the viscosity, the kinetic energy is small. For this reason, in the fluid equipment, in the vicinity of the wall surface (surface) of the member through which the fluid flows, the fluid may not flow along the surface of the member and the flow may be separated.

  The separation of the flow in such a fluid device has a problem in that the working efficiency of the fluid device is reduced and noise is caused.

As technologies related to this technical field, for example, technologies described in Patent Documents 1 to 4 exist.
Patent Document 1 discloses an impeller that prevents the expansion of the boundary layer or the separation of the flow by forming a plurality of grooves on the surface of the hub, thereby improving the efficiency of the compressor (see summary, etc.). .

  Patent Document 2 discloses a technique in which fins are provided on the inner surfaces of heat transfer tubes used for heat exchangers and other components, thereby improving the heat transfer performance (see paragraph 0001 and the like).

  Patent Document 3 discloses a technique in which a spiral rib is provided on the inner surface of a heat exchanger, thereby improving the heat transfer performance (see abstract, etc.).

  In Patent Document 4, an intake surface of an internal combustion engine in which an irregular surface having an uneven structure is provided on a wall surface of a suction pipe or a surface of a flap disposed in the suction pipe, thereby avoiding flow separation and vortex flow formation. A suction pipe for the system is disclosed (see summary etc.).

JP 2005-163640 A JP-T-2004-524502 JP-A-8-145583 JP 2005-525497 A

  In order to prevent the flow separation in the fluid equipment, the momentum exchange is generated between the boundary layer and the main flow, and the strong flow of the main flow is given to the weak flow in the boundary layer, so that the kinetic energy in the boundary layer is reduced. Increasing this is considered effective. In order to increase the kinetic energy in the boundary layer and prevent flow separation, a small vortex is generated in the boundary layer, and the vortex is further transported in the main flow direction, so that the boundary layer and the main flow are separated. It is considered to be effective to generate momentum exchange.

  In the technique described in Patent Document 1, by forming a groove along the flow direction on the surface of the hub, a small vortex may be generated in the groove. However, there is no mechanism for transporting the small vortex formed in the groove in the main flow direction, and the vortex remains in the groove, and momentum exchange is unlikely to occur between the boundary layer and the main flow.

  In the technique described in Patent Document 2, fins in two directions intersecting each other are provided on the inner surface of a heat transfer pipe used for a heat exchanger and other components. Therefore, a small vortex may be generated in the groove formed by the fin. However, there is no mechanism for carrying the small vortex formed in the groove in the main flow direction, and the vortex remains in the groove.

  In the technique described in Patent Document 3, a spiral rib is provided on the inner surface of the heat exchanger. Therefore, a small vortex may be generated in the groove formed by the spiral rib. However, there is no mechanism for carrying the small vortex formed in the groove in the main flow direction, and the vortex remains in the groove.

  In the technique described in Patent Document 4, irregularities are formed on the surface of the flap. And the unevenness | corrugation (scale) described in FIG. 5 of patent document 4 has an inclination with respect to the flow direction, and when a small vortex is generated, it is thought that it can be carried to the mainstream. It is done. However, the inclination angle of the unevenness is not described, and the effect is unknown. In addition, the shape of the cross section perpendicular to the uneven flow is not described. Therefore, it is also unclear whether small vortices are generated in the boundary layer.

  As described above, none of the techniques described in Patent Documents 1 to 4 includes a mechanism for generating a vortex in the boundary layer and carrying it in the mainstream direction. Therefore, since momentum exchange is unlikely to occur between the boundary layer and the main flow, the kinetic energy in the boundary layer cannot be increased, and the flow separation cannot be sufficiently suppressed.

  This invention is made | formed in view of an above described situation, and makes it a subject to suppress the peeling of the flow in a fluid apparatus more.

  In order to achieve the above object, a fluid device according to the present invention includes a member having a surface through which a fluid flows, and a plurality of structures provided on the surface and projecting from the surface, and the fluid flow A first cross-section when the structure is cut through the top of the structure in a plane that is parallel to and perpendicular to the surface is downstream of the fluid flow from a point on the surface; A side extending to a point away from the surface, an inclination angle of the side with respect to the surface is not less than 10 degrees and not more than 45 degrees, and a structure between two adjacent structures among the plurality of structures An inter-body flow path is formed, and an area of a portion of one of the two structures that the fluid flowing through the inter-structure flow path contacts, and the fluid that flows through the inter-structure flow path contacts Surface of the part of the other of the two structures DOO are different from each other.

  According to the present invention, flow separation in a fluid device can be further suppressed.

It is a figure which shows typically the cross section of the flow path in the fluid apparatus which concerns on 1st Embodiment of this invention. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 1st Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is the vertex of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. (A) is a figure for demonstrating generation | occurrence | production of an upward flow. (B) is a figure for demonstrating generation | occurrence | production of a vortex. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 2nd Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is the vertex of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 3rd Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is an upper side bottom face of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. . (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 4th Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is an upper side bottom face of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. . (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 5th Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is the vertex of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. It is a perspective view which shows the structure provided in the surface of the flow path in the fluid apparatus which concerns on 6th Embodiment. (A) is a figure which shows the 1st cross section when the said structure is cut | disconnected through the top part which is an upper side bottom face of a structure in the plane which is parallel to the flow of a fluid, and intersects perpendicularly | vertically with the surface of a flow path. . (B) is a figure which shows the 2nd cross section when the said structure is cut | disconnected through the top part of a structure in the plane perpendicular | vertical to the flow of a fluid. It is a perspective view which shows the whole structure of the analysis model used by the numerical fluid analysis. It is an expansion perspective view which shows the structure model used for the analysis about the generation | occurrence | production effect of an upward flow. It is a graph which plots and represents the relationship between an inclination angle and the average value of z component of the flow velocity in an analysis area. (A) is an expansion perspective view which shows the 1st structure model for analyzing about the generation | occurrence | production effect of a vortex. (B) is a figure which shows a cross section when the said structure model is cut | disconnected through the top part of a structure model in the plane perpendicular | vertical to a flow. It is a graph which plots and represents the relationship between the ratio of the height of a triangle, and the average value of yz component of the vorticity in an analysis area | region, (a) shows the analysis result in case the flow velocity is 50 m / s, FIG. ) Shows the analysis result when the flow velocity is 100 m / s. (A) is an expansion perspective view which shows the 2nd structure model for analyzing about the generation | occurrence | production effect of a vortex. (B) is a figure which shows a cross section when the said structure model is cut | disconnected through the top part of a structure model in the plane perpendicular | vertical to a flow. It is a graph which plots and represents the relationship between the ratio of the length of the base of a triangle, and the average value of yz component of the vorticity in an analysis area, (a) shows the analysis result in case the flow velocity is 50 m / s, The analysis result when b) is a flow velocity of 100 m / s is shown.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
In addition, in each figure, about the same component or the same component, the same code | symbol is attached | subjected and those overlapping description is abbreviate | omitted suitably.

(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a diagram schematically showing a cross section of a flow path 2 in a fluid device 100 according to the first embodiment of the present invention. Here, a centrifugal compressor will be described as an example of the fluid device 100.

  As shown in FIG. 1, the fluid device 100 includes a flow path 2 as a member having a surface 3 through which a fluid flows, and a plurality of structures 4 provided on the surface 3 that is an inner surface of the flow path 2. Yes. The structure 4 has a shape protruding from the surface 3 of the flow path 2.

  In the present embodiment, the structure 4 is formed on the surface 3 of the flow path 2 where the flow path cross-sectional area changes in the flow 1 of the liquid or gas and there is a risk that flow separation occurs. The flow path 2 has a shape in which the cross-sectional area of the flow path increases from the upstream side to the downstream side of the flow 1, and here, it is configured as a diffuser of the fluid device 100 that is a centrifugal compressor. The diffuser is disposed on the downstream side of the impeller (not shown), and converts the dynamic pressure of the fluid flowing from the outlet of the impeller into a static pressure. However, the flow path 2 is not limited to the diffuser, and may be another flow path whose flow path cross-sectional area changes.

  The fluid flowing through the flow path 2 is, for example, air, and the flow rate is, for example, 100 m / s, but is not limited thereto. Moreover, although the material of the flow path 2 and the structure 4 is an aluminum material, for example, it is not limited to this, A metal material other than an aluminum material, an organic material, and an inorganic material may be sufficient.

  FIG. 2 is a perspective view showing the structure 4 provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the first embodiment. As shown in FIG. 2, the plurality of structures 4 include structures 5 and 6 that exhibit at least two types of different cone shapes.

FIG. 3 (a) shows the structure passing through the tops 51, 61 which are the vertices of the structure 4 in a plane parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1). It is a figure which shows the 1st cross section 7 when 4 is cut | disconnected.
In FIG. 3A, cross-sectional hatching is omitted (the same applies to other cross-sectional views).

  As shown in FIG. 3 (a), the first cross section 7 has a side 9 extending from a point 8 on the surface 3 to the tops 51, 61 that are downstream of the fluid flow 1 and away from the surface 3. , Including a triangle having a base 10 located on the surface 3. Side 9 and base 10 share a point 8 upstream of flow 1. An angle α formed by the base 10 and the side 9 constitutes an inclination angle of the side 9 with respect to the surface 3.

  FIG. 3B is a diagram showing the second cross section 11 when the structure 4 is cut through the top portions 51 and 61 of the structure 4 in a plane perpendicular to the fluid flow 1. As shown in FIG. 3B, the second cross section 11 includes triangles 12 and 13 as at least two different polygons.

  An inter-structure flow path 14 is formed between two adjacent structures 5 and 6 of the plurality of structures 4. And the area S1 of the surface 53 which is the part in one structure 5 of the two structures 5 and 6 which the fluid which flows through the flow path 14 between structures contacts, and the fluid which flows through the flow path 14 between structures The area S2 of the surface 63 which is a part of the other structure 6 out of the two structures 5 and 6 in contact with each other is different.

  The second cross-section 11 shown in FIG. 3B has different triangles 12 and 13 having a height ratio (H2 / H1) of 0.1 to 0.6, preferably 0.1 to 0.3. Contains. By setting it as more than a lower limit in this range, the state where the smaller structure 6 does not exist substantially can be avoided. Moreover, by making it into below an upper limit in this range, the difference of the area S1 of the part in one structure 5 which the fluid which flows through the flow path 14 between structures contacts, and the area S2 of the part in the other structure 6 is made into the difference. Can be noticeable. Thereby, as will be described later, vortices are more likely to occur in the boundary layer near the surface 3.

  Further, in the first cross section 7 shown in FIG. 3A, the inclination angle α of the side 9 with respect to the surface 3 is 10 degrees or more and 45 degrees or less, preferably 20 degrees or more and 30 degrees or less. By setting the lower limit value or more in such a range, the upward flow 15 (see FIG. 4) along the inclined surfaces 52 and 62 (see FIG. 2) corresponding to the side 9 can be effectively generated. Moreover, by making it into below an upper limit in this range, it can suppress that the inclined surfaces 52 and 62 act like a weir and obstruct the fluid flow 1 itself. Thereby, as will be described later, the generated vortex is more effectively carried in the mainstream direction.

Hereinafter, a method for forming the structure 4 on the surface 3 of the flow path 2 will be described.
The structure 4 of this embodiment can be formed by cutting. For the cutting process, for example, an ultra-precision vertical processing machine can be used. For example, a flat end mill made of cBN (cubic boron nitride) can be used as the tool. The rotational speed of the tool is 60000 rpm, for example. By performing such a cutting process in a direction parallel to the flow and in a direction perpendicular to the flow, the structure 4 shown in FIGS. 2 to 3 can be obtained. However, the formation method of the structure 4 is not limited to the said method.

Next, a mechanism capable of suppressing flow separation will be described with reference to FIG.
FIG. 4A is a diagram for explaining the generation of the upward flow. FIG. 4B is a diagram for explaining the generation of vortices.

  As shown in the first cross section 7 parallel to the flow 1 and perpendicular to the surface 3 in FIG. 4A, there are inclined surfaces 52 and 62 with respect to the direction parallel to the flow 1, so Ascending flow 15 is generated.

  Further, as shown in the second cross section 11 perpendicular to the flow 1 in FIG. 4B, if there is a difference in the heights H1 and H2 of the triangles 12 and 13 included in the second cross section 11, the inter-structure flow path. 14, there is a difference in the areas S1 and S2 of the surfaces 53 and 63 in contact with the fluid on the left and right as viewed from the upstream side of the flow 1. As a result, since the inter-structure flow path 14 is asymmetrical on the left and right when viewed from the upstream side of the flow 1, the flow velocity is different between a point near the surface 53 and a point near the surface 63.

  Here, when the density is ρ, Bernoulli's theorem is expressed by the following equation (1).

  When the fluid velocity U decreases from the equation (1), the pressure P increases. Therefore, the presence of asymmetry in the inter-structure flow path 14 causes a pressure difference on the left and right when viewed from the upstream side of the flow 1, and a rotating flow field 16 is generated by this pressure difference, and a vortex is easily generated. .

  As described above, the fluid device 100 according to the present embodiment includes the plurality of structures 4 that have a shape protruding from the surface 3 of the flow path 2. The first cross section 7 parallel to the flow 1 of the structure 4 and perpendicular to the surface 3 is to the tops 51 and 61 which are downstream from the point 8 on the surface 3 and away from the surface 3. It has an inclined side 9 that extends. An inter-structure flow path 14 is formed between two adjacent structures 5 and 6 among the plurality of structures 4. Then, the area S1 of the surface 53 in one structure 5 of the two structures 5 and 6 in contact with the fluid flowing through the inter-structure flow path 14 and the area S2 of the surface 63 in the other structure 6 are as follows. Is different.

Thus, the structure 4 according to the present embodiment includes a mechanism for generating a vortex and a mechanism for conveying the vortex to the mainstream. Therefore, the vortex plays a role in generating momentum exchange between the boundary layer formed near the surface 3 and the main flow. For this reason, a strong mainstream flow can be given to the weak flow in the boundary layer, and the kinetic energy of the boundary layer increases. Thereby, flow separation in the fluid device 100 can be further suppressed.
Moreover, the fall of the working efficiency of the fluid apparatus 100 and noise can be suppressed by suppressing flow separation.

  That is, in the structure 4 according to the present embodiment, the inclined surfaces 52 and 62 exist in the direction parallel to the flow 1 and the surfaces 53 and 63 with which the fluid flowing through the inter-structure flow path 14 comes into contact. It is essential that there is a difference between the areas S1 and S2.

  In the present embodiment, the first cross section 7 that is parallel to the flow 1 of the structure 4 and perpendicular to the surface 3 has an inclination angle α with respect to the surface 3 of 10 degrees or more and 45 degrees or less, preferably 20 degrees or more and 30. It has sides 9 that are less than or equal to degrees. According to this configuration, the generated vortex can be more effectively carried by the upward flow 15 in the main flow direction.

  In the present embodiment, the second cross section 11 when the structure 4 is cut through the top portions 51 and 61 of the structure 4 in a plane perpendicular to the fluid flow 1 has at least two different polygons. Contains. Thereby, the shape in which the area S1 of the surface 53 on the one structure 5 side that the fluid flowing through the inter-structure flow path 14 comes into contact with the area S2 of the surface 63 on the other structure 6 side is specifically configured. can do.

  In the present embodiment, the structure 4 has a cone shape. The first cross section 7 includes a triangle having a base 10, and the second cross section 11 includes triangles 12 and 13 having different heights as at least two different triangles. According to this structure, the structure 4 can be made into a simpler shape.

  In the present embodiment, the second cross section 11 includes different triangles having a height ratio of 0.1 to 0.6, preferably 0.1 to 0.3. According to this configuration, vortices can be generated more effectively in the boundary layer near the surface 3.

  The structure 4 shown in FIG. 2 has a quadrangular pyramid having a rectangular bottom surface, but the shape of the bottom surface is not limited to a rectangular shape, and may be another shape such as a circle or a polygon. .

(Second Embodiment)
Next, with reference to FIGS. 5 to 6, the second embodiment of the present invention will be described with a focus on differences from the first embodiment described above, and description of common points will be omitted.

  FIG. 5 is a perspective view showing the structure 4a provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the second embodiment. As shown in FIG. 5, the plurality of structures 4 a include structures 5 a and 6 a that exhibit at least two types of different cone shapes.

  FIG. 6A shows the structure passing through the tops 51 and 61 that are the vertices of the structure 4a in a plane parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1). It is a figure which shows the 1st cross section 7 when 4a is cut | disconnected. FIG. 6B is a diagram showing the second cross section 11a when the structure 4a is cut through the top portions 51 and 61 of the structure 4a in a plane perpendicular to the fluid flow 1. FIG. As shown in FIG. 6B, the second cross section 11a includes triangles 12a and 13a having different lengths W1 and W2 of the bases 21 and 22 as at least two different polygons.

  Also in the structure 4a according to the second embodiment, there are inclined surfaces 52 and 62 with respect to the direction parallel to the flow 1, and the area S1 of the surfaces 53 and 63 with which the fluid flowing in the inter-structure flow path 14 comes into contact. , S2 has a difference. Therefore, flow separation in the fluid device 100 can be further suppressed by the second embodiment.

  In the second embodiment, the second cross section 11a shown in FIG. 6B has a length ratio (W2 / W1) of the bases 21 and 22 of 0.1 to 0.6, preferably 0.1. Different triangles 12a and 13a which are 0.3 or less are included. Thereby, a vortex can be more effectively generated in the boundary layer near the surface 3, and as a result, separation of the flow from the surface 3 can be prevented.

(Third embodiment)
Next, with reference to FIGS. 7 to 8, the third embodiment of the present invention will be described with a focus on differences from the first embodiment described above, and description of common points will be omitted.

  FIG. 7 is a perspective view showing the structure 4b provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the third embodiment. As shown in FIG. 7, the plurality of structures 4b include structures 5b and 6b having at least two types of different frustum shapes.

  FIG. 8A shows the structure passing through the tops 51a and 61a which are parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1), which is the upper bottom surface of the structure 4b. It is a figure which shows the 1st cross section 7a when cut | disconnecting the body 4b. As shown in FIG. 8 (a), the first cross section 7 a includes a side 9 a extending from a point 8 a on the surface 3 to the tops 51 a and 61 a downstream of the fluid flow 1 and away from the surface 3. It includes a quadrilateral having a base 10a located on the top. Side 9a and base 10a share a point 8a upstream of flow 1. An angle α formed between the base 10a and the side 9a constitutes an inclination angle of the side 9a with respect to the surface 3. In the first cross section 7a, the inclination angle α of the side 9a with respect to the surface 3 is not less than 10 degrees and not more than 45 degrees, preferably not less than 20 degrees and not more than 30 degrees. Thereby, the generated vortex can be conveyed more effectively in the mainstream direction.

  FIG. 8B is a diagram showing the second cross section 11b when the structure 4b is cut through the top portions 51a and 61a of the structure 4b in a plane perpendicular to the fluid flow 1. FIG. As shown in FIG. 8B, the second cross section 11b includes quadrilaterals 12b and 13b having different heights H1 and H2 as at least two different polygons.

  Also in the structure 4b according to the third embodiment, the inclined surfaces 52 and 62 with respect to the direction parallel to the flow 1 exist, and the area S1 of the surfaces 53 and 63 with which the fluid flowing through the inter-structure flow path 14 comes into contact. , S2 has a difference. Therefore, according to the third embodiment, flow separation in the fluid device 100 can be further suppressed.

  In the third embodiment, the second cross section 11b shown in FIG. 8B has a height ratio (H2 / H1) of 0.1 to 0.6, preferably 0.1 to 0.3. Are different squares 12b and 13b. Thereby, vortices can be generated more effectively in the boundary layer near the surface 3.

  The structure 4b shown in FIG. 7 has a quadrangular truncated pyramid having a rectangular upper bottom surface and a lower bottom surface, but the shapes of the upper bottom surface and the lower bottom surface are not limited to a quadrangle, and are circular or polygonal. Other shapes may be used.

(Fourth embodiment)
Next, with reference to FIGS. 9 to 10, the fourth embodiment of the present invention will be described with a focus on differences from the third embodiment described above, and description of common points will be omitted.

  FIG. 9 is a perspective view showing a structure 4c provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the fourth embodiment. As shown in FIG. 9, the plurality of structures 4c include structures 5c and 6c exhibiting at least two types of different frustum shapes.

  FIG. 10A shows the structure passing through the tops 51a and 61a which are parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1), which is the upper bottom surface of the structure 4c. It is a figure which shows the 1st cross section 7a when cut | disconnecting the body 4c. FIG. 10B is a diagram showing the second cross section 11c when the structure 4c is cut through the top portions 51a and 61a of the structure 4c on a plane perpendicular to the fluid flow 1. FIG. As shown in FIG. 10B, the second cross section 11c includes quadrilaterals 12c and 13c having different lengths W1 and W2 of the bases 21a and 22a as at least two different polygons.

  Also in the structure 4c according to the fourth embodiment, there are inclined surfaces 52 and 62 with respect to the direction parallel to the flow 1, and the area S1 of the surfaces 53 and 63 with which the fluid flowing through the inter-structure flow path 14 comes into contact. , S2 has a difference. Therefore, according to the fourth embodiment, the separation of the flow in the fluid device 100 can be further suppressed.

  Further, in the fourth embodiment, the second cross section 11c shown in FIG. 10B has a length ratio (W2 / W1) of the bases 21a and 22a of 0.1 or more and 0.6 or less, preferably 0.1. Different squares 12c and 13c that are 0.3 or less are included. Thereby, vortices can be generated more effectively in the boundary layer near the surface 3.

(Fifth embodiment)
Next, with reference to FIGS. 11 to 12, the fifth embodiment of the present invention will be described with a focus on differences from the first embodiment described above, and description of common points will be omitted.

  FIG. 11 is a perspective view showing a structure 4d provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the fifth embodiment. As shown in FIG. 11, the structure 4d has a cone shape.

  FIG. 12A shows the structure 4d passing through the top 51 which is the apex of the structure 4d in a plane parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1). It is a figure which shows the 1st cross section 7 when cut | disconnecting. FIG. 12B is a diagram showing the second cross section 11d when the structure 4d is cut through the top 51 of the structure 4d in a plane perpendicular to the fluid flow 1. FIG. As illustrated in FIG. 12B, the second cross section 11 d includes a polygon that is asymmetrical when viewed from the upstream side of the flow 1. Specifically, the second cross section 11d includes triangles in which the lengths L1 and L2 of the two oblique sides 23 and 24 extending from both end points of the base 21b are different from each other.

  Also in the structure 4d according to the fifth embodiment, the inclined surface 52 with respect to the direction parallel to the flow 1 exists, and the areas S1 and S2 of the surfaces 53 and 63 with which the fluid flowing through the inter-structure flow path 14 contacts. There are differences. Therefore, according to the fifth embodiment, flow separation in the fluid device 100 can be further suppressed.

  In the fifth embodiment, the second cross section 11d shown in FIG. 12B has a ratio (L2 / L1) of the lengths L1 and L2 of the two oblique sides 23 and 24 to 0.1 or more and 0.6 or less, It includes different triangles that are preferably between 0.1 and 0.3. Thereby, vortices can be generated more effectively in the boundary layer near the surface 3.

(Sixth embodiment)
Next, with reference to FIGS. 13 to 14, the sixth embodiment of the present invention will be described with a focus on differences from the third embodiment described above, and description of common points will be omitted.

  FIG. 13 is a perspective view showing the structure 4e provided on the surface 3 of the flow path 2 (see FIG. 1) in the fluidic device 100 according to the sixth embodiment. As shown in FIG. 13, the structure 4e has a frustum shape.

  FIG. 14A shows a structure 4e passing through a top 51a, which is the upper bottom surface of the structure 4e, in a plane parallel to the fluid flow 1 and perpendicular to the surface 3 of the flow path 2 (see FIG. 1). It is a figure which shows the 1st cross section 7a when cutting | disconnecting. FIG. 14B is a diagram showing the second cross section 11e when the structure 4e is cut through the top 51a of the structure 4e in a plane perpendicular to the fluid flow 1. FIG. As shown in FIG. 14B, the second cross section 11 e includes a polygon that is asymmetrical when viewed from the upstream side of the flow 1. Specifically, the second cross section 11e includes quadrilaterals in which the lengths L1 and L2 of the two opposite sides 23a and 24a extending from both end points of the base 21c are different from each other.

  Also in the structure 4e according to the sixth embodiment, there is an inclined surface 52 with respect to the direction parallel to the flow 1, and the areas S1 and S2 of the surfaces 53 and 63 with which the fluid flowing through the inter-structure flow path 14 contacts. There are differences. Therefore, according to the sixth embodiment, flow separation in the fluid device 100 can be further suppressed.

  Further, in the sixth embodiment, the second cross section 11e shown in FIG. 14B has a ratio (L2 / L1) of the lengths L1 and L2 of the two opposite sides 23a and 24a of 0.1 to 0.6, It preferably includes different squares that are 0.1 or more and 0.3 or less. Thereby, vortices can be generated more effectively in the boundary layer near the surface 3.

(Flow analysis)
Hereinafter, the effect of suppressing flow separation in the fluid device 100 will be described based on the fluid analysis result. However, the following analysis results are used to explain the effects of the present invention, and the technical scope of the present invention is not limited by the following analysis results.

FIG. 15 is a perspective view showing the overall configuration of the analysis model used in the numerical fluid analysis.
As shown in FIG. 15, the analysis region is a rectangular parallelepiped of 9 mm in the x direction, 3 mm in the y direction, and 5 mm in the z direction. A structure model was arranged on the bottom of the rectangular parallelepiped. Then, by analyzing the state of the flow 1 when the air flows in the x direction through the flow path indicated by the rectangular parallelepiped by the numerical fluid analysis, the generation mechanism of the upward flow necessary for suppressing the separation of the flow The generation mechanism of vortex was studied.

First, the generation effect of upward flow was analyzed.
FIG. 16 is an enlarged perspective view showing the structure model used for the analysis of the upward flow generation effect. The structure model is a wedge-shaped structure having a height H = 0.1 mm, a width W = 0.05 mm, and an inclination angle α. The arrangement interval D in the y direction of the structure model was set to D = 0.05 mm. The analysis was performed by changing the inclination angle α. The analysis was performed at flow rates of 50 m / s and 100 m / s.

  FIG. 17 is a graph plotting the relationship between the inclination angle α and the average value of the z component of the flow velocity in the analysis region. In FIG. 17, the upper graph shows the analysis result when the flow velocity is 100 m / s, and the lower graph shows the analysis result when the flow velocity is 50 m / s.

  As shown in FIG. 17, it was found that the z component of the flow velocity becomes the maximum when the inclination angle α is about 25 degrees, and the effect of generating the upward flow is the highest for both the flow velocity 50 m / s and the flow velocity 100 m / s. In order to enhance the effect of suppressing the separation of the flow, it was found that the inclination angle α is preferably 10 degrees or more and 45 degrees or less, and more preferably 20 degrees or more and 30 degrees or less.

Next, the effect of vortex generation was analyzed using two structure models.
FIG. 18A is an enlarged perspective view showing a first structural body model for analyzing the effect of generating vortices. FIG. 18B is a diagram illustrating a cross section when the structure model is cut through the top of the structure model in a plane perpendicular to the flow. The structure model shown in FIG. 18 corresponds to the first embodiment shown in FIGS.

  As shown in FIG. 18 (a), the structure model was provided with an inclination angle α of 27 degrees, which revealed the effect of generating the upward flow in the analysis. In the cross section shown in FIG. 18B, triangles having height H1 and base length W1 and triangles having height H2 and base length W2 were alternately arranged. In the analysis, H1 = 0.1 mm, W1 = 0.2 mm, and W2 = 0.2 mm, and the analysis was performed by changing the value of H2. The analysis was performed at flow rates of 50 m / s and 100 m / s.

FIG. 19 is a graph plotting the relationship between the ratio of the height of the triangle (H2 / H1) and the average value of the yz component ω _yz of the vorticity ω (vector quantity) in the analysis region. a) shows an analysis result when the flow velocity is 50 m / s, and FIG. 19B shows an analysis result when the flow velocity is 100 m / s.
Here, ω _yz is an index representing the strength of a vortex having an axis in a direction parallel to the flow, and is represented by the following equations (2) and (3). U in the equation (2) is the fluid velocity (vector quantity).

As shown in FIG. 19, ω _yz is minimum when the height of the triangle is equal to H2 / H1 = 1.0 at both the flow velocity of 50 m / s and the flow velocity of 100 m / s, and the vortex of the triangle is different when the height of the triangle is different. It was found that the generation effect is high. In order to increase the effect of preventing flow separation, the ratio of the heights of the triangles (H2 / H1) is preferably 0.1 or more and 0.6 or less, and further 0.1 or more and 0.3 or less. It turns out to be desirable.

  FIG. 20A is an enlarged perspective view showing a second structural body model for analyzing the vortex generation effect. FIG. 20B is a diagram showing a cross section when the structure model is cut through the top of the structure model in a plane perpendicular to the flow. The structure model shown in FIG. 20 corresponds to the second embodiment shown in FIGS.

  As shown in FIG. 20 (a), the structure model was provided with an inclination angle α of 27 degrees, which revealed the effect of generating the upward flow in the analysis. In the cross section shown in FIG. 20B, triangles having a height H1 and a base length W1 and triangles having a height H2 and a base length W2 were alternately arranged. In the analysis, H1 = 0.1 mm, W1 = 0.2 mm, and H2 = 0.1 mm, and the analysis was performed by changing the value of W2. The analysis was performed at flow rates of 50 m / s and 100 m / s.

FIG. 21 is a graph plotting the relationship between the ratio of the base lengths of the triangles (W2 / W1) and the average value of the yz component ω _yz of the vorticity ω in the analysis region. Shows the analysis result when the flow velocity is 50 m / s, and FIG. 21B shows the analysis result when the flow velocity is 100 m / s.

As shown in FIG. 21, in both the flow velocity 50 m / s and the flow velocity 100 m / s, ω _yz is minimized and the triangle base length is different when the triangle base length is equal to W2 / W1 = 1.0. It has been found that the effect of generating vortices sometimes increases. In order to enhance the effect of preventing flow separation, the ratio of the lengths of the bases of the triangles (W2 / W1) is preferably 0.1 or more and 0.6 or less, and more preferably 0.1 or more and 0.3 or less. We found it desirable to:

  In the analysis, analysis was performed with specific dimensions, shapes, and conditions. However, in the present invention, as described above, there is an inclined surface with respect to a direction parallel to the flow, and there is a difference in the area of the portion (surface) where the fluid flowing through the inter-structure flow path contacts. Is the essence. Therefore, it is possible to obtain the effect of suppressing the separation of the flow even when the dimensions and the number of the structures, the installation interval, and the flow rate of the liquid or gas are changed.

  For example, any number of the structures 4, 4 a to 4 e shown in the first to sixth embodiments may be formed on the surface 3 of the flow path 2. Moreover, the said analysis was performed in two cases, 50 m / s and 100 m / s, respectively, and the analysis result was obtained in different Reynolds numbers. As a result, any analysis result was effective in enhancing the effect of suppressing flow separation. Therefore, it is considered effective for suppressing flow separation even at other flow rates.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. It is possible to add, delete, and replace other configurations for a part of the configuration of the above-described embodiment.

  For example, in the above-described embodiment, the centrifugal compressor has been described as the fluid device, but the present invention is not limited to this. The present invention is applicable to all fluid devices that handle fluids, such as centrifugal compressors, vacuum cleaners, and air conditioners.

  In the above-described embodiment, the case where the structure is provided on the surface of the flow path configured as a diffuser has been described, but the present invention is not limited to this. The structure may be provided on a surface through which a fluid flows in other various members such as an impeller.

2 Channel (member)
3 Surface 4, 4a to 4e Structure 5, 5a to 5c Structure 6, 6a to 6c Structure 7, 7a First section 8, 8a Point 9, 9a Side 10, 10a Bottom 11, 11, 11a to 11e Second section 12 , 13, 12a, 13a Triangle 12b, 13b, 12c, 13c Square 14 Inter-structure flow path 15 Upflow 16 Rotating flow field 21, 22, 21a, 22a, 21b, 21c Bottom 23, 24 Slope 23a, 24a Opposite side 51 , 61 Apex (top)
51a, 61a Upper bottom surface (top)
52, 62 Inclined surface 53, 63 surface (part)
100 Fluid equipment S1, S2 Area α Inclination angle

Claims (13)

A member having a surface through which fluid flows;
A plurality of structures provided on the surface and projecting from the surface;
A first cross-section when the structure is cut through the top of the structure in a plane that is parallel to the fluid flow and perpendicular to the surface is downstream of the fluid flow from a point on the surface. Side and extending to a point away from the surface,
The inclination angle of the side with respect to the surface is 10 degrees or more and 45 degrees or less,
An inter-structure flow path is formed between two adjacent structures of the plurality of structures,
The area of one part of the two structures that the fluid flowing through the inter-structure flow path contacts, and the area of the other part of the two structures that the fluid flowing through the inter-structure flow path contact A fluid device characterized by being different from   The second cross-section when the structure is cut through the top of the structure in a plane perpendicular to the fluid flow includes at least two different polygons. Fluid equipment. The structure has a cone shape;
The first cross section includes a triangle having a base that shares a point upstream of the flow with the side;
The inclination angle is an angle formed by the base and the side,
The fluid device according to claim 2, wherein the second cross section includes at least two different types of triangles.   The fluid device according to claim 3, wherein the second cross section includes different triangles having a height ratio of 0.1 to 0.6.   The fluid device according to claim 3, wherein the second cross section includes different triangles having a base length ratio of 0.1 to 0.6. The structure has a frustum shape,
The first cross section includes a quadrilateral having a base that shares a point upstream of the flow with the side;
The inclination angle is an angle formed by the base and the side,
The fluid device according to claim 2, wherein the second cross section includes at least two different types of quadrangles.   The fluid device according to claim 6, wherein the second cross section includes different squares having a height ratio of 0.1 to 0.6.   The fluid device according to claim 6, wherein the second cross section includes different squares having a base length ratio of 0.1 to 0.6.   2. The fluid device according to claim 1, wherein the second cross section when the structure is cut through the top of the structure in a plane perpendicular to the fluid flow includes an asymmetric polygon. The structure has a cone shape;
The first cross section includes a triangle having a base that shares a point upstream of the flow with the side;
The inclination angle is an angle formed by the base and the side,
The fluid device according to claim 9, wherein the second cross section includes a triangle in which two oblique sides extending from both end points of the base are different in length.   The fluid device according to claim 10, wherein a ratio of the lengths of the two oblique sides is not less than 0.1 and not more than 0.6. The structure has a frustum shape,
The first cross section includes a quadrilateral having a base that shares a point upstream of the flow with the side;
The inclination angle is an angle formed by the base and the side,
The fluid device according to claim 9, wherein the second cross section includes a quadrilateral in which two opposite sides extending from both end points of the bottom are different in length.   The fluid device according to claim 12, wherein a ratio of lengths of the two opposite sides is 0.1 or more and 0.6 or less.

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