CN112146842A - Experimental testing device for flow field effect of flow control technology under limited passage condition - Google Patents
Experimental testing device for flow field effect of flow control technology under limited passage condition Download PDFInfo
- Publication number
- CN112146842A CN112146842A CN202010924216.2A CN202010924216A CN112146842A CN 112146842 A CN112146842 A CN 112146842A CN 202010924216 A CN202010924216 A CN 202010924216A CN 112146842 A CN112146842 A CN 112146842A
- Authority
- CN
- China
- Prior art keywords
- section
- replaceable
- flow
- wall surface
- testing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M10/00—Hydrodynamic testing; Arrangements in or on ship-testing tanks or water tunnels
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Indicating Or Recording The Presence, Absence, Or Direction Of Movement (AREA)
Abstract
An experimental test device for flow control technology acting on a flow field under the condition of a limited channel comprises a contraction section, a rectification section, a replaceable test section and a tail section which are sequentially connected and form a fluid flow area; the contraction section adopts an expansion and diameter-changing structure, and the inner diameter is increased along with the flow direction; a rectifying device is arranged in the rectifying section; two ends of the replaceable test section are respectively connected with the rectifying section and the tail section through quick-release flanges; the upper part of the replaceable test section is provided with a CCD camera for visually shooting an experiment; the replaceable testing section comprises adjustable wall surfaces, a bluff body, a partition plate and a quick-release plate, the adjustable wall surfaces are arranged on two sides of the bottom in the replaceable testing section, and the width parameter of the replaceable testing section can be changed by adjusting the placement position of the adjustable wall surfaces; the blunt body and the separation plate are arranged on the quick-release plate, and the blunt body and the separation plate are placed in the flow channel through the detachable connection of the quick-release plate and the replaceable test section. The invention has the advantages of simple disassembly and maintenance, easy adjustment of structural parameters, high experimental efficiency, accurate experimental result and the like.
Description
Technical Field
The invention belongs to a fluid flow testing device, and particularly relates to an experimental testing device for the flow field effect of a flow control technology under a limited channel condition.
Background
The passive body streaming is an important and classical fluid mechanics problem, the flow process of the passive body streaming involves the flow phenomena of vortex shedding, flow separation and the like, and a plurality of flow mechanisms are not fully understood. The bluff body flow-around phenomenon occurs in various industries, for example, the bluff body flow-around phenomenon is utilized to strengthen heat exchange or increase mass transfer rate in the chemical energy field, the bluff body flow-around phenomenon is utilized to measure fluid flow velocity in the measuring instrument industry, and the bridge vibration problem caused by bluff body flow-around must be considered in bridge engineering, so that the research on the flow mechanism in the bluff body flow-around has obvious social and economic values. In the current research of the flowing around of the bluff body, many researchers propose to apply a flow control technology to control the flow field distribution of the bluff body wake region or change the resistance coefficient of the bluff body, and the common flow control technical scheme is as follows: and adding objects (such as partition plates, control rods, hollow nets and the like) or adding disturbance (such as jet flow, rotating bluff bodies and the like) in the bluff body wake region.
At present, the research on the bypass action of the blunt body by the flow control technology is mainly focused on the non-limited channel condition, i.e. the influence action of the channel wall to the tail region of the blunt body is not considered. However, according to the researches of Blackburn and Reyes et al, the channel wall has a significant influence on the tail region of the blunt body under the condition of limited channel, so that the resistance coefficient and vortex shedding frequency of the blunt body are changed, and the reflux phenomenon of the tail region is also caused. In the engineering field, the influence of the channel wall surface on the fluid flow process should be considered in many passive body flow-around phenomena, such as cantilever magnetic heads of mechanical hard disks in the storage industry, electrolysis units of filter-press type electrolysis cells in the hydrogen production industry, heat exchange tubes of tubular heat exchangers in the process industry, and the like. At present, the flow control technology under the condition of limited channels has relatively little research on the bypass effect of the blunt body. And because the bluff body circumfluence is a nonlinear turbulent flow, the flow distribution of the bluff body wake region cannot be obtained by a mathematical analysis method, and the bluff body circumfluence needs to be obtained by an experimental and numerical simulation method and is limited by test conditions and test means. Flow field visualization experiments on the bypass action of a blunt body by a flow control technology under the condition of a limited channel are more limited, and the main problems at present are as follows:
1. the channel width of the limited channel is an important parameter, and when the influence of the channel width on the flow field structure of the bluff body wake region is examined by an experimental method, a plurality of groups of fluid channels need to be processed by continuously changing the channel width, which causes great difficulty in the experimental process.
2. The flow control technology has various modes, and the two factors are superposed together to form various combinations by combining different channel width parameters, so that the common test device cannot meet the requirements.
3. When visual shooting is carried out in the experimental process, the imaging effect of the CCD camera can be seriously influenced by the light reflection problem of a non-shooting area, and the accuracy of the measured flow field result is finally influenced.
Therefore, in order to study the mechanism problem of the bluff body bypass flow under the condition of the limited channel and increase the knowledge of the influence of the flow control technology on the bluff body wake region under the condition of the limited channel, a fluid flow experimental test device capable of obtaining the flow field structure distribution of various flow control technologies under the condition of the limited channel needs to be designed, which has significant significance for studying corresponding experimental study and providing comparative data for numerical simulation.
Disclosure of Invention
In order to overcome the defects in the prior art, the invention aims to provide an experimental testing device for the flow field effect of a flow control technology under the condition of a limited channel, wherein the fluid channel comprises a contraction section, a rectification section, a replaceable testing section and a tail section, an adjustable wall surface is arranged in the replaceable testing section to realize different channel width parameters, the investigation of flow fields of bluff trail areas by different flow control technical schemes is realized through a quick-release plate, and a PIV (particle Image velocimetry) method is adopted in a visualization experiment to realize the shooting process of fluid flow.
The invention is realized by the following technical scheme:
an experimental test device for flow control technology acting on a flow field under the condition of a limited channel comprises a contraction section, a rectification section, a replaceable test section and a tail section which are sequentially connected and form a fluid flow area; the contraction section adopts an expansion and diameter-changing structure, and the inner diameter of the contraction section is increased along with the flow direction; a rectifying device is arranged in the rectifying section; two ends of the replaceable test section are respectively connected with the rectifying section and the tail section through quick-release flanges; the upper part of the replaceable test section is provided with a CCD camera for visually shooting an experiment; the replaceable testing section comprises adjustable wall surfaces, a blunt body, a partition plate and a quick-release plate, wherein the adjustable wall surfaces are arranged on two sides of the bottom in the replaceable testing section, and the width parameter of the replaceable testing section can be changed by adjusting the placement position of the adjustable wall surfaces; the blunt body and the separation plate are arranged on the quick-release plate, and the blunt body and the separation plate are placed in the flow channel through the detachable connection of the quick-release plate and the replaceable test section.
Further, the rectifying device adopts a honeycomb structure.
Furthermore, the wall surface of the replaceable testing section and the wall surface of the adjustable wall surface are made of transparent organic glass, and black matte paint is uniformly coated on the wall surface of the non-shooting area of the replaceable testing section and the wall surface of the adjustable wall surface.
Further, the sectional shape of the blunt body is a circle, a square or a diamond.
Further, the partition plate can be replaced by a hollow net or a control rod.
Furthermore, the CCD camera is connected with the Nd, the YAG laser, the time sequence controller and the workstation.
Compared with the prior art, the invention has the following beneficial technical effects:
the invention discloses an experimental test device for flow field effect of flow control technology under limited channel condition, which comprises a contraction section, a rectification section, a replaceable test section and a tail section; the contraction section adopts an expansion diameter-changing structure, and a rectifying device with a honeycomb structure is arranged in the rectifying section, so that the fluid at the upstream of the bluff body is rectified; a blunt body is arranged in the replaceable testing section to generate vortex; the influence of different channel wall parameters on a bluff body wake region is inspected by adjusting the mounting position of an adjustable wall surface in the replaceable test section; by the aid of the quick-release plate structure, experiments on influences of different blunt bodies and flow control technologies on a flow field structure can be quickly realized; and a visual shooting process of the flow field is realized by adopting a PIV method.
Drawings
Fig. 1 is a schematic structural diagram of the device provided by the invention, and the direction of arrows indicates the direction of fluid.
Fig. 2 is a schematic diagram of the structure of the alternative test section of fig. 1.
Fig. 3 is a schematic diagram of a quick release plate structure according to various flow control solutions provided in the embodiments.
FIG. 4 is a schematic cross-sectional view of an alternative test section with the adjustable wall in different positions.
FIG. 5 is a schematic diagram of the flow field distribution of the area shot by the PIV in the embodiment.
Fig. 6 is a graph showing the effect of different partition plate lengths on the strouhal number in the example.
Wherein: 1-a contraction section; 2-a rectifying section; 2.1-a rectifying device; 3-quick-release flange; 4-replaceable test section; 5-tail section; 6-CCD camera; 7-Nd is YAG laser; 8-a time schedule controller; 9-a workstation; 10-adjustable wall surface; 11-a bluff body; 12-a partition plate; 13-quick release plate; 14-a hollow mesh; 15-control rod.
Detailed Description
The present invention will now be described in further detail with reference to specific examples, which are intended to be illustrative, but not limiting, of the invention.
Referring to the attached figures 1-4, an experimental testing device for flow control technology acting on a flow field under a limited channel condition comprises a contraction section 1, a rectification section 2, a replaceable testing section 4 and a tail section 5 which are sequentially connected and form a fluid flow area; the contraction section 1 adopts an expansion and diameter-changing structure, and the inner diameter is increased along with the flow direction; a rectifying device 2.1 with a honeycomb structure is arranged in the rectifying section 2; two ends of the replaceable test section 4 are respectively connected with the rectifying section 2 and the tail section 5 through quick-release flanges 3; the upper part of the replaceable testing section 4 is provided with a CCD camera 6 for visually shooting the experiment; the replaceable testing section 4 comprises an adjustable wall surface 10, a bluff body 11, a partition plate 12 and a quick-release plate 13, the adjustable wall surface 10 is arranged on two sides of the bottom in the replaceable testing section 4, and the width parameter of the replaceable testing section 4 can be changed by adjusting the placement position of the adjustable wall surface 10; the blunt body 11 and the separation plate 12 are arranged on a quick-release plate 13, and the blunt body 11 and the separation plate 12 are placed in the flow channel through the detachable connection of the quick-release plate 13 and the replaceable testing section 4.
The wall surface of the replaceable testing section 4 and the adjustable wall surface 10 are made of transparent organic glass. The sectional shape of the blunt body 11 may be in the form of a circle, a square, or a diamond.
The CCD camera 6 is connected with the Nd-YAG laser 7, the time schedule controller 8 and the workstation 9.
When the fluid passes through the contraction section 1 and the rectification section 2, the fluid is rectified and forms a flow velocity distribution which fully develops flow upstream of the blunt body 11. When the fluid flows through the blunt body 11, due to the viscous force of the fluid and the action of the wall surface, a flow separation phenomenon is formed on the surface of the blunt body 11 to cause vortex shedding, thereby causing an unstable flow phenomenon in the wake region of the blunt body. When visual experiment shooting is carried out, the time schedule controller 8 provides a trigger signal to the Nd-YAG laser 7, laser is emitted to illuminate a flow field plane to be shot in the replaceable testing section 4, the CCD camera 6 captures position information of tracer particles in the flow field under the shooting signal provided by the time schedule controller 8, and the workstation 9 carries out corresponding processing on the obtained position information of the tracer particles to obtain the motion tracks of the tracer particles and finally obtain the velocity vector distribution of the flow field.
As shown in fig. 2, 3 and 4, by detaching the quick-release plate 13, the partition plate 12 can be replaced by a flow control solution such as a hollow net 14 or a control rod 15; through dismantling quick detach flange 3, can separate replaceable test section 4 and experimental apparatus, adjust the required passageway width parameter in order to satisfy different experiment operating modes to the mounted position of adjustable wall 10, can also maintain replaceable test section in addition. As the flow process of the fluid is captured by the PIV (particle Image velocimetry) method, black matte paint needs to be uniformly coated on the wall surfaces of the non-shooting areas of the replaceable testing section 4 and the adjustable wall surface 10, so that the laser emitted by the Nd: YAG laser 7 in the experiment is prevented from being reflected on the wall surfaces of the non-shooting areas, the shooting quality of the CCD camera 6 on the measured flow field area is improved, and the system error of the PIV visualization experiment is reduced.
Examples of the invention are as follows:
the length of the replaceable test segment 4 is 1000mm, the cross section dimension is 100mm multiplied by 50mm, the flow velocity of the fluid is 0.08 m/s-0.10 m/s, and the corresponding Reynolds number Re is 2400-3000. The bluff body 11 is a cylinder with the diameter of 30mm, the partition plates 12 are tightly attached to the tail of the cylinder, and five groups of partition plate lengths (15mm, 22.5mm, 30mm, 37.5mm and 45mm) are considered. The flow field of the cylindrical wake region is shot by a PIV method.
As shown in fig. 5 and 6, the velocity field distribution of the wake region of the cylinder is obtained by the PIV method, and it is found that the vortex center position of the wake vortex downstream of the cylinder is changed and moved downstream as the length of the partition plate increases when the partition plate 12 is applied as the flow control technique. In addition, under the combined action of the partition plate 12 and the wall surface of the limited passage, the shear layers on the upper side and the lower side of the cylinder develop along the length direction of the partition plate, the partition plate blocks the interaction of the shear layers on the upper side and the lower side, and the vortex shedding position is delayed. The vortex suppression by the partition plate is enhanced by the wall of the restricted passage compared to the non-restricted passage.
In summary, the experimental test device for testing the flow field effect of the flow control technology under the condition of the limited channel disclosed by the invention can be used for inspecting the influence of different channel wall parameters and various flow control technologies on the flow process of the bluff body wake region through a PIV (particle image velocimetry) visualized experimental method, and has the advantages of simplicity in disassembly and maintenance, easiness in adjusting structural parameters, high experimental efficiency, accurate experimental result and the like.
The exemplary embodiments, however, can be embodied in many forms and should not be construed as limited to the embodiments set forth herein, and one of ordinary skill in the art can, in light of the present disclosure, make many changes to the embodiments without departing from the spirit of the disclosure or the scope of the appended claims.
Details not described in this specification are within the skill of the art that are well known to those skilled in the art.
Claims (6)
1. An experimental test device for flow control technology acting on a flow field under the condition of a limited channel is characterized by comprising a contraction section (1), a rectification section (2), a replaceable test section (4) and a tail section (5) which are sequentially connected and form a fluid flow area; the contraction section (1) adopts an expansion and diameter-changing structure, and the inner diameter of the contraction section increases along with the flow direction; a rectifying device (2.1) is arranged in the rectifying section (2); two ends of the replaceable testing section (4) are respectively connected with the rectifying section (2) and the tail section (5) through quick-release flanges (3); the upper part of the replaceable testing section (4) is provided with a CCD camera (6) for visually shooting an experiment; the replaceable testing section (4) comprises an adjustable wall surface (10), a blunt body (11), a partition plate (12) and a quick-release plate (13), the adjustable wall surface (10) is arranged on two sides of the bottom in the replaceable testing section (4), and the width parameter of the replaceable testing section (4) can be changed by adjusting the placement position of the adjustable wall surface (10); the blunt body (11) and the separation plate (12) are arranged on a quick-release plate (13), and the blunt body (11) and the separation plate (12) are placed in the flow channel through the detachable connection of the quick-release plate (13) and the replaceable test section (4).
2. The apparatus for flow control technology experimental testing of flow field effects under limited passage conditions of claim 1, wherein: the rectifying device (2.1) adopts a honeycomb structure.
3. The apparatus for flow control technology experimental testing of flow field effects under limited passage conditions of claim 1, wherein: the wall surface of the replaceable testing section (4) and the wall surface of the adjustable wall surface (10) are made of transparent organic glass, and black matte paint is uniformly smeared on the wall surface of the non-shooting area of the replaceable testing section (4) and the wall surface of the adjustable wall surface (10).
4. The apparatus for flow control technology experimental testing of flow field effects under limited passage conditions of claim 1, wherein: the section of the blunt body (11) is round, square or diamond.
5. The apparatus for flow control technology experimental testing of flow field effects under limited passage conditions of claim 1, wherein: the partition plate (12) can be replaced by a hollow net (14) or a control rod (15).
6. The apparatus for flow control technology experimental testing of flow field effects under limited passage conditions of claim 1, wherein: the CCD camera (6) is connected with the Nd-YAG laser (7), the time sequence controller (8) and the workstation (9).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010924216.2A CN112146842A (en) | 2020-09-04 | 2020-09-04 | Experimental testing device for flow field effect of flow control technology under limited passage condition |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010924216.2A CN112146842A (en) | 2020-09-04 | 2020-09-04 | Experimental testing device for flow field effect of flow control technology under limited passage condition |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112146842A true CN112146842A (en) | 2020-12-29 |
Family
ID=73889748
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010924216.2A Pending CN112146842A (en) | 2020-09-04 | 2020-09-04 | Experimental testing device for flow field effect of flow control technology under limited passage condition |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112146842A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114593929A (en) * | 2022-03-18 | 2022-06-07 | 南京航空航天大学 | Blunt wake flow field generating device for PET (positron emission tomography) detector and using method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110061469A1 (en) * | 2009-09-17 | 2011-03-17 | Sean P. Palacios | Vortex Generator for Extended Flow Ranges and Faster Response |
| CN103808486A (en) * | 2014-02-25 | 2014-05-21 | 中国计量学院 | Variable section test segment of air cooling heat radiator test system |
| CN111537190A (en) * | 2020-05-19 | 2020-08-14 | 水利部交通运输部国家能源局南京水利科学研究院 | Test device for flow-induced vibration of passive body of pressure high chord-thickness ratio air box |
-
2020
- 2020-09-04 CN CN202010924216.2A patent/CN112146842A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110061469A1 (en) * | 2009-09-17 | 2011-03-17 | Sean P. Palacios | Vortex Generator for Extended Flow Ranges and Faster Response |
| CN103808486A (en) * | 2014-02-25 | 2014-05-21 | 中国计量学院 | Variable section test segment of air cooling heat radiator test system |
| CN111537190A (en) * | 2020-05-19 | 2020-08-14 | 水利部交通运输部国家能源局南京水利科学研究院 | Test device for flow-induced vibration of passive body of pressure high chord-thickness ratio air box |
Non-Patent Citations (2)
| Title |
|---|
| JYOTI CHAKRABORTY ET AL.: "Wall effects in flow past a circular cylinder in a plane channel:a numerical study", 《CHEMICAL ENGINEERING AND PROCESSING》 * |
| KAI LIU ET AL.: "Experimental study on the confined flow over a circular cylinder with a splitter plate", 《FLOW MEASUREMENT AND INSTRUMENTATION》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114593929A (en) * | 2022-03-18 | 2022-06-07 | 南京航空航天大学 | Blunt wake flow field generating device for PET (positron emission tomography) detector and using method |
| CN114593929B (en) * | 2022-03-18 | 2022-12-23 | 南京航空航天大学 | Blunt body wake flow field generating device for PET detector and using method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Chen et al. | Passive jet control of flow around a circular cylinder | |
| Yen et al. | Flow patterns and vortex shedding behavior behind a square cylinder | |
| Wen et al. | An experimental and numerical investigation of flow patterns in the entrance of plate-fin heat exchanger | |
| Kieft et al. | On the wake structure behind a heated horizontal cylinder in cross-flow | |
| CN112146842A (en) | Experimental testing device for flow field effect of flow control technology under limited passage condition | |
| Oruç et al. | Suppression of asymmetric flow behavior downstream of two side-by-side circular cylinders with a splitter plate in shallow water | |
| Pinarbasi et al. | Shallow water experiments of flow past two identical square cylinders in tandem | |
| Wen et al. | PIV experimental investigation of entrance configuration on flow maldistribution in plate-fin heat exchanger | |
| Liu et al. | Study on the near wake of a honeycomb disk | |
| Khan et al. | Flow past two rotationally oscillating cylinders | |
| Zhdanov et al. | Velocity field behind a plate installed in the inner region of a turbulent boundary layer | |
| Nishimura et al. | The influence of tube layout on flow and mass transfer characteristics in tube banks in the transitional flow regime | |
| Segawa et al. | Turbulent drag reduction by means of alternating suction and blowing jets | |
| Jian et al. | PIV investigations of flow patterns in the entrance configuration of plate-fin heat exchanger | |
| Dumont et al. | Computational fluid dynamic modeling of electrostatic precipitators | |
| Janetzke et al. | Time resolved investigations on flow field and quasi wall shear stress of an impingement configuration with pulsating jets by means of high speed PIV and a surface hot wire array | |
| Ozgoren et al. | Quantitative flow characteristics for side-by-side square cylinders via PIV | |
| Ladjedel et al. | Experimental study of pressure drop reduction on in-line tube bundle using passive control | |
| Tong et al. | Numerical simulation of the particle deposition on a tube with coupled lattice Boltzmann method and finite volume method | |
| Gnatowska et al. | Stability of flow around two rectangular cylinders in tandem | |
| Umeda et al. | Occurrence of flip-flop flows in diamond-shaped cylinder bundles | |
| Muniyammal et al. | On the Instability of a Flow Past a Spherical Cap Body Check for updates | |
| Vitkovic | Water distribution characteristics of spray nozzles in a cooling tower | |
| Sharma et al. | Flow Characteristics Behind Surface Mounted Rounded Slit Ribs | |
| Zając et al. | Experimental investigation of heat transfer performance coefficient in tube bundle of shell and tube heat exchanger in two-phase flow |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20201229 |