CN216050596U - Wind tunnel capable of generating stable arc-shaped airflow - Google Patents
Wind tunnel capable of generating stable arc-shaped airflow Download PDFInfo
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- CN216050596U CN216050596U CN202122162770.4U CN202122162770U CN216050596U CN 216050596 U CN216050596 U CN 216050596U CN 202122162770 U CN202122162770 U CN 202122162770U CN 216050596 U CN216050596 U CN 216050596U
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Abstract
The wind tunnel capable of generating stable arc-shaped airflow is characterized in that an arc-shaped guide plate (4) for guiding airflow to flow is arranged on the lower wall surface of a wind tunnel test section, and a part between an air inlet section (1) and an air outlet section (2) extends upwards to form a protruding stagnation cavity (3). The key point of the invention is that after stable linear airflow is obtained from the power section, the airflow is guided to circulate along the surface of the guide plate (4) to form an arc-shaped flow track, and the stagnation cavity (3) ensures that the airflow is not separated and diffused above the guide plate (4) and ensures the stability of the arc-shaped airflow. The air inlet section (1) is connected with the stagnation cavity (3) by a right angle to ensure that the initial airflow is not dispersed in a layered manner; the air outlet section (2) is connected with the stagnation cavity (3) by a fillet to reduce the scattering of tail airflow against the wall; the guide plate (4) is embedded and bonded with the lower wall surface to ensure that the wall surface is smooth and improve the stability of arc airflow. The air flow with different radians can be obtained by replacing the guide plates (4) with different sizes. The invention can provide a basis for the aerodynamics of the rotating device and related research thereof.
Description
Technical Field
The invention relates to a wind tunnel test device, in particular to a wind tunnel capable of generating stable arc-shaped airflow.
Background
The wind tunnel is a test platform which generates stable airflow in a manual mode and carries out controllable operation on the stable airflow, and is generally used for simulating the state of air flow and motion around a target object when an aircraft flies at high speed in the air or a static object is in strong wind. From the viewpoint of the structure of the wind tunnel, the wind tunnel platform generally comprises a power section, a diffusion section, a stabilization section, a contraction section, a test section and an exhaust section. The power section generally forms airflow by rotationally sucking or sucking air by a large-scale ventilator; the diffusion section, the stabilizing section and the contraction section are used for stabilizing the airflow generated by the power section and reducing the turbulence of the airflow to enable the airflow to be close to laminar flow; the test section is positioned at the rear, and the experimenter arranges a required test object and an observation device at the rear; and finally, the air flow is discharged from the exhaust section, and if the air flow is a backflow type wind tunnel, the exhaust section is directly connected with the power section.
For wind tunnel testing, the test section is the most important part, where the high-speed airflow and the test object generate relative motion to generate different motion states. Different test section structures can form different air flow states, including the speed, the section and the change condition of the air flow.
In order to achieve the goals of carbon peaking and carbon neutralization, wind power generation is rapidly developing all over the world. In order to improve the utilization efficiency of wind energy, the single-machine capacity of the fan is increased, the height of the fan is continuously increased, the maximum height of the blade tip of the megawatt fan is over 200m, and the length of the blade is over 50 m. When the blade rotates at rated speed to generate electricity, the maximum linear speed of the blade tip can reach 100 m/s. Under the condition of blade rotation, the blade tip and the surrounding air move relatively in a circumferential track, and if the blade is taken as a reference object, the airflow near the blade tip is arc-shaped.
Similarly, almost all devices comprising rotating elements relate to the circular track motion between a target object and air, for the current airflow in the wind tunnel, the speed of the current airflow is generally only controlled to change, the direction of the speed is always kept unchanged, namely, the generated airflow is linear, the test section of the wind tunnel is generally a regular cuboid or cylinder, and under the condition, the state of the aircraft flying at high speed in the air or the static target object in strong wind can be well simulated, so that the requirements of most of current researches are met.
If the aerodynamics of devices such as a rotating fan blade and the like and the related change conditions of electricity, thermodynamics and the like are required to be simulated, it is very important to design a wind tunnel test platform capable of generating stable arc-shaped airflow. Generally speaking, the effect of the results of the power section, the diffusion section, the stabilization section, the contraction section and the like of the wind tunnel test platform is to ensure that the airflow at the inlet of the test section is stable laminar flow, so the key point for generating the arc-shaped airflow lies in the design of the test section.
If the test section is simply designed into the circular arc tubular structure, even if the air flow at the inlet of the test section is very stable, after the test section enters the circular arc type test section, the air flow speeds at different positions are different inevitably because the arc lengths of the upper part and the lower part of the circular arc are different, so that large turbulent vortex is easily generated, and the stability requirement cannot be met. In addition, the material and process requirements for the test section to be processed into the circular arc structure are also high. Therefore, the test section structure which is easy to manufacture and can stably generate the arc-shaped airflow is designed, and the research on the airflow state of the blade tip and the influence of the airflow state on lightning strike lightning, heating, stress and the like of the blade tip on the rotation of rotating structures such as simulated rotating fan blades is very important.
SUMMERY OF THE UTILITY MODEL
Aiming at the discharge process of a high-speed rotating target object, the invention provides a multi-parameter synchronous observation platform and a test method for the discharge process of the high-speed rotating object, so that the static observation of the discharge of the high-speed rotating target object is realized, and the physical process of the lightning stroke discharge of the blades of a high-speed rotating fan can be restored.
According to an aspect of the embodiments of the present invention, an arc-shaped air deflector is disposed on a lower wall surface of a test section of the wind tunnel, and a portion between an air inlet section and an air outlet section of the test section extends upward to form a protruding stagnation cavity so as to guide an air flow separated on a surface of the air deflector to form a circular flow.
In some examples, the air inlet section, the air outlet section and the stagnation cavity are respectively processed by right angles and round angles.
In some examples, the baffle is as wide as the inlet section, the outlet section, and the stagnation chamber to occupy all airflow passage positions.
In some examples, the connection between the arc-shaped surface of the guide plate and the horizontal plane adopts a round-corner design.
In some examples, the lower wall surface of the test section is provided with a groove for placing the guide plate, and the horizontal plane of the guide plate is flush with the lower wall surface of the test section after the guide plate is placed in the groove.
In some examples, the baffle is bonded within the groove.
In some examples, the baffle fillet radius R2The fillet radius R at the joint of the stagnation cavity and the air outlet section1The ratio of (A) to (B) is between 1.8 and 2.2.
In some examples, the baffle height H and the air intake section height H1The ratio of (A) to (B) is between 1 and 2.
In some examples, the stagnation chamber height H2With the height H of the air intake section1Should be greater than 5.
In some examples, the baffle is made of an epoxy material.
Most wind tunnels can only generate linear airflow at present, and the wind tunnel test section structure with the guide plate and the stagnation cavity can generate stable arc-shaped airflow, can be used for simulating the aerodynamics of devices with rotating elements such as rotating fan blades and the like and the research of the subjects derived from the aerodynamics, and provides a test basis for researching the aerodynamics with constantly changing airflow speed.
Through reasonable setting of structural parameters of all parts, the wind tunnel test section provided by the invention can form stable arc-shaped airflow in the thickness of 5-8cm on the surface of the guide plate, and the arc angle of the airflow is the same as the curvature of the surface of the guide plate; meanwhile, due to the existence of the stagnation cavity, low-speed circulation exists in the upper area of the stable airflow of the guide plate, the circulation speed is far lower than the arc-shaped airflow speed, and the influence on the test result is extremely small.
The test object is arranged in the cavity in the guide plate, and meanwhile, the guide plate can be provided with the hole, so that the test object extends out of the surface of the guide plate from the cavity, and the convenience of test arrangement is improved.
Through the inside cavity structure of design guide plate, greatly increased the space scope that the test object arranged, can trompil on the guide plate simultaneously, stretch out the guide plate surface with the test object from the cavity for study sample aerodynamics under the arc air current.
The lower wall surface of the guide plate and the test section is adhered by polyurethane glue, and the guide plate with different bending degrees can be replaced according to different requirements in the later stage to obtain arc-shaped air flows with different radians.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings of the embodiments will be briefly described below.
FIG. 1 is an overall structural view of a wind tunnel test section according to the present invention.
FIG. 2 is a schematic diagram showing the arrangement of each key part of the test section.
Fig. 3 is a schematic diagram of the internal structure and fixed position of the baffle in the cross-sectional view of the experimental section.
FIG. 4 is a drawing of the test segment structure dimension.
Detailed Description
The invention provides a wind tunnel test section capable of generating stable arc-shaped airflow, which can generate stable and speed-controllable arc-shaped airflow. The conventional wind tunnel platform generally comprises a power section, a diffusion section, a stabilization section, a contraction section, a test section and an exhaust section, as shown in fig. 1, an arc-shaped guide plate 4 for guiding airflow to flow is arranged on the lower wall surface of the test section, a part between an air inlet section 1 and an air outlet section 2 of the test section extends upwards to form a protruding stagnation cavity 3, and the stagnation cavity 3 is used for guiding airflow separated from the surface of the guide plate 4 to form a circulation flow without interfering with the surface of the guide plate 4 to stabilize the arc-shaped airflow. After the test section is connected to the contraction section, the air inlet section 1 obtains stable linear airflow from the stabilized flow. This stabilize sharp air current and flow forward along air inlet section 1 is stable, when stabilizing the air current and meetting arc guide plate 4, because the blockking of guide plate 4, the air current begins the arc motion along guide plate 4 surfaces, tentatively forms the arc air current this moment. As the air flow moves further along the surface of the baffle 4 to the highest point of the baffle 4, the stabilized air flow separates here: part of the airflow is separated from the guide plate 4 along with inertia, moves upwards at a small angle, collides with the wall surface of the stagnation cavity 3 along with the upward movement of the wall surface, and returns to the guide plate again after circulating for a circle in the stagnation cavity 3 because the upper end of the stagnation cavity 3 is in a closed state; the other part of the air flow continues to move along with the surface of the guide plate 4 until leaving the air outlet section 2. As the air flow continuously flows into the air intake section 1, the circulation speed in the stagnation chamber 3 gradually becomes stable due to the closed state inside the chamber, and it can be considered that the air volume in the part is almost constant, that is, the "stagnation" state is reached. At this time, the air flow still flows into the air inlet section 1 stably, and it can be considered that most of the air flow does not enter the stagnation chamber 3 to form a circular flow at this time, but flows out of the air outlet section 2 along the surface of the guide plate 4.
As shown in fig. 2, the flow guide plate 4 is of a hollow structure, a cavity 9 is formed inside the flow guide plate, a plurality of test devices can be arranged in the cavity, and meanwhile, holes can be formed in the surface of the flow guide plate 4 to extend the test devices out of the surface of the flow guide plate 4, so that the aerodynamics of a test article under arc-shaped airflow can be researched. The fixed mode of guide plate 4 is, dig out the recess 7 that can place guide plate 4 in the wall under the wind-tunnel, adopt the adhesion of polyurethane glue, when guaranteeing fixed tight reality, lower wall is followed the smooth transition to guide plate 4 by air inlet section 1, can not cause the disturbance of air current. Fig. 3 is a part of a sectional view of the test section, from which the cavity 9 and the groove 7 can be clearly seen. The fillet 8 design is adopted at the junction of the arc-shaped surface of the guide plate 4 and the horizontal plane, so that the smooth transition of the airflow is ensured. The joints of the air inlet section 1, the air outlet section 2 and the stagnation cavity 3 are respectively processed by adopting a right angle 5 and a fillet 6, which are obtained by a great deal of calculation and simulation with creative labor, wherein the right angle 5 can ensure that most of air flow flows along the surface of the guide plate 4 after entering the stagnation cavity 3 and does not move upwards immediately; the fillet 6 ensures that the air flow can directly leave from the air outlet section 2 to form a complete arc-shaped air flow after passing through the surface of the guide plate 4 without impacting the wall surface to move upwards.
The test segment of the present invention is shown in fig. 4 with a scale. The height H of the lower wall surface of the flow guide plate 4 extending out is 16cm, and the height H of the air inlet section 1 and the air outlet section 2110cm, height H of stagnation chamber 3275 cm; the radiuses R1 and R2 of the fillets 6 and 8 are equal and are both 8 cm; the radius R of the guide plate 4 is 20 cm; the overall wall thickness is 5mm and the depth of the grooves 7 is 3mm, and these parameters are suitable for generating 100m/s arc-shaped airflow.
According to the previous turbulence simulation calculation, H and H are calculated to ensure the stability of the arc-shaped airflow area1The ratio should be between 1 and 2, H2And H1Should be greater than 5. Under the size, a stable arc-shaped airflow section with the thickness of 5-8cm exists on the guide plate 4.
Compared with the prior wind tunnel technology, the wind tunnel platform test section which is simple in structure and convenient to manufacture and can generate stable arc-shaped airflow is provided, the pneumatic characteristics and relevant characteristics of rotating devices such as fan blades and the like are greatly researched, and an idea is provided for aerodynamic tests under the arc-shaped airflow.
Claims (10)
1. A wind tunnel capable of generating stable arc-shaped airflow is characterized in that an arc-shaped guide plate for guiding airflow to flow is arranged on the lower wall surface of a wind tunnel test section, and a part between an air inlet section and an air outlet section of the test section extends upwards to form a protruding stagnation cavity so as to guide airflow separated from the surface of the guide plate to form circulation.
2. The wind tunnel according to claim 1, wherein the connection between said air inlet section, said air outlet section and said stagnation chamber is processed by right angle and fillet.
3. A wind tunnel according to claim 1 wherein said deflector is of the same width as said inlet section, said outlet section and said stagnation chamber to occupy all of the flow path positions.
4. The wind tunnel according to claim 1, wherein the connection between the arc surface of said deflector and the horizontal plane is designed as a rounded corner.
5. The wind tunnel according to claim 4, wherein said lower wall of said test section has a recess for receiving said deflector, said deflector being disposed within said recess such that its horizontal plane is flush with said lower wall of said test section.
6. A wind tunnel according to claim 5 wherein said deflectors are bonded within said recesses.
7. A wind tunnel according to claim 4 wherein said deflector fillet radius R2The fillet radius R at the joint of the stagnation cavity and the air outlet section1The ratio of (A) to (B) is between 1.8 and 2.2.
8. A wind tunnel according to claim 1 wherein said height H of said deflector and said height H of said air inlet section are such that a steady curved flow of air is generated1The ratio of (A) to (B) is between 1 and 2.
9. A wind tunnel according to claim 1 wherein said stagnation chamber has a height H2With the height H of the air intake section1Has a large ratio ofAt 5.
10. A wind tunnel according to claim 1 wherein said deflector is made of an epoxy resin material.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122162770.4U CN216050596U (en) | 2021-09-08 | 2021-09-08 | Wind tunnel capable of generating stable arc-shaped airflow |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122162770.4U CN216050596U (en) | 2021-09-08 | 2021-09-08 | Wind tunnel capable of generating stable arc-shaped airflow |
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| Publication Number | Publication Date |
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| CN216050596U true CN216050596U (en) | 2022-03-15 |
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| CN202122162770.4U Active CN216050596U (en) | 2021-09-08 | 2021-09-08 | Wind tunnel capable of generating stable arc-shaped airflow |
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- 2021-09-08 CN CN202122162770.4U patent/CN216050596U/en active Active
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