CN215492353U

CN215492353U - Backflow acoustic wind tunnel device

Info

Publication number: CN215492353U
Application number: CN202121801917.3U
Authority: CN
Inventors: 刘凤娇; 贾向阳; 刘连杰; 沈斌; 李佳
Original assignee: Bailin Electromechanical Technology Suzhou Co ltd
Current assignee: Bailin Electromechanical Technology Suzhou Co ltd
Priority date: 2021-08-04
Filing date: 2021-08-04
Publication date: 2022-01-11
Anticipated expiration: 2031-08-04

Abstract

The utility model discloses a backflow acoustic wind tunnel device which comprises a silencing chamber, a wedge, a collector, a diffusion section, a first corner, a first silencing section, a second corner, a balance seam, a power section, a second silencing section, a third corner, a backflow section, a fourth corner, a stable section and a contraction section, wherein the stable section comprises a damping net and a honeycomb device, the power section comprises a power section front section, a fan, a power section rear section and a fairing, the first silencing section and the second silencing section are both internally provided with a silencer and sound-absorbing cotton, and a nozzle of the contraction section and the front section of the diffusion section are arranged in the silencing chamber. The utility model can reduce the influence of external noise on the test, improve the measurement precision of the system and ensure the reliability of the test result.

Description

Backflow acoustic wind tunnel device

Technical Field

The utility model relates to an acoustic wind tunnel device, in particular to a backflow acoustic wind tunnel device.

Background

Wind tunnel (wind tunnel), a pipe-like experimental device that can manually generate and control air flow to simulate the flow of air around an aircraft or object, and can measure the effect of the air flow on the object and observe physical phenomena, is the most common and effective tool for aerodynamic experiments. Wind tunnel experiments are an indispensable component in aircraft development work. The method plays an important role in the research and development of aviation and aerospace engineering, and is indispensable in the fields of navigation, transportation, building construction, wind energy utilization and the like along with the development of industrial aerodynamics.

The traditional acoustic wind tunnel is improved according to an aerodynamic wind tunnel and is used for a special wind tunnel facility of a pneumatic acoustic test, and the key technical problem is how to reduce the background noise of a wind tunnel test section. With the technical progress, the existing wind tunnel arrangement can not meet the requirement that the dynamic noise reduction of the low-frequency noise of the fan is more than 50dB, or the manufacturing cost and the operation cost are high, so that the significance of a direct-flow wind tunnel is lost, and the requirement of the existing low-noise acoustic wind tunnel can not be met.

SUMMERY OF THE UTILITY MODEL

The utility model aims to overcome the defects of the prior art and provide a backflow acoustic wind tunnel device, which reduces the influence of external noise on a test so as to improve the measurement precision of the device.

In order to achieve the purpose, the utility model provides the following technical scheme: the utility model provides a backward flow acoustics wind-tunnel device, includes anechoic chamber, wedge, collector, divergent section, first turning, first anechoic section, second turning, balanced seam, power section, second anechoic section, third turning, backward flow section, fourth turning, stable section, shrink section, stable section includes damping net and honeycomb ware, power section includes power section anterior segment, fan, power section back end, radome fairing, all set up the muffler in first anechoic section and the second anechoic section and inhale the sound cotton, and the spout of shrink section and the anterior segment of divergent section arrange in an anechoic chamber.

Preferably, the opening degree of the side wall of the inlet section of the collector and the opening degree of the pressure balance hole are both adjustable, and the fiber sound attenuation layer is attached to the inner surface of the collector.

Preferably, a first silencing section is arranged between the diffusion section and the power section, and a silencer and sound-absorbing cotton are arranged in the first silencing section.

Preferably, a second silencing section is arranged at the downstream of the power section, and a silencer and sound-absorbing cotton are arranged in the second silencing section.

Preferably, the device further comprises a collector located between the convergent section and the divergent section, the collector also being located within the anechoic chamber.

Preferably, a plurality of wedges are arranged in the anechoic chamber, and the wedges are made of sound-absorbing cellucotton.

Preferably, the ratio of the cross-sectional area at the inlet to the cross-sectional area at the outlet of the constriction is 10: 1.

Preferably, a different number of guide vanes are respectively arranged in the first corner, the second corner, the third corner and the fourth corner.

The utility model has the beneficial effects that:

1. the device is strong in functionality, the function of the acoustic wind tunnel is expanded, and the device can be used as an independent anechoic chamber to reduce the influence of external noise on a test, improve the measurement precision of a system and ensure the reliability of a test result.

2. The device is simple and convenient to operate and good in economy, the function of the independent anechoic chamber can be realized only by simple improvement on the basis of the acoustic wind tunnel, and the benefit of the acoustic wind tunnel is improved.

4. The improvement is convenient, and current acoustics wind-tunnel only need reform transform the spout and the collection mouth in its anechoic chamber, increases to fill and just can accomplish the extension of independent anechoic chamber function with portable sound insulation and sound absorbing structure, reforms transform with low costsly.

Drawings

Fig. 1 is a schematic structural view of the present invention.

Reference numerals:

1. anechoic chamber, 2, wedge, 3, collector, 4, divergent section, 5, first corner, 6, first noise reduction section, 61, muffler, 62, inhale the sound cotton, 7, second corner, 8, balance seam, 9, power section, 91, power section anterior segment, 92, fan, 93, power section back end, 94, radome fairing, 10, second noise reduction section, 101, muffler, 102, inhale the sound cotton, 11, third corner, 12, backward flow section, 13, fourth corner, 14, stable section, 141, damping net, 142 honeycomb ware, 15, shrink section.

Detailed Description

The technical solution of the embodiment of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention.

According to the backflow acoustic wind tunnel device disclosed by the utility model, the noise reduction facilities are additionally arranged at the corresponding positions of the wind tunnel, so that the influence of external noise on a test is reduced, the measurement precision of a system is improved, and the reliability of a test result is ensured.

As shown in fig. 1, a backflow acoustic wind tunnel device disclosed in the embodiment of the present invention adopts a backflow air suction type structural layout, and includes an intake silencing chamber 1, a wedge 2, a collector 3, a diffuser section 4, a first corner 5, a first silencing section 6, a second corner 7, a balance slit 8, a power section 9, a second silencing chamber 10, a third corner 11, a backflow section 12, a fourth corner 13, and a stabilizing section 14, where the silencing chamber 1 is disposed upstream of the stabilizing section 14 for reducing noise at an entrance of the wind tunnel. Be provided with wedge 2 in the anechoic chamber 1, in order to further strengthen the noise cancelling effect, the anterior segment of the export of contraction section 15, collector 3 and diffuser section 4 is arranged in the anechoic chamber to this application embodiment, mainly is in order to reduce the influence of external noise to the test, improves the measurement accuracy of system, guarantees the reliability of test result, and balanced seam 8 is located between second turning 7 and power section 9.

In this embodiment, the collector 3 is a rectangular parallelepiped structure, and the cross-sectional area of the inlet and outlet is about 0.88m, 0.66m, and the length is about 1.08 m. The inner surface of the collector 3 is pasted with a fiber noise elimination layer, and the material is selected from a sound insulation felt to play a role in noise elimination.

The diffuser section 4 is a place for converting kinetic energy and pressure energy, and is used for reducing the guarantee of the loss of the airflow flowing down the diffuser section 4.

The first corner 5 is located between the diffuser section 4 and the first sound-attenuating section 6, which is required on the one hand for forming a closed circuit and on the other hand is primarily intended to prevent flow separation, improve the flow of the air flow and reduce losses.

The first noise elimination section 6 is arranged between the diffusion section 4 and the power section 9, mainly in order to reduce the influence of the noise of the power section 9 on the test, a silencer 61 and sound absorption cotton 62 are also arranged in the first noise elimination section 6, the sound absorption cotton 62 is made of sound absorption fiber cotton, and in the embodiment, the noise elimination amount of the first noise elimination section 6 is also determined according to the fan noise and the environmental noise of the power section 9.

The second corner 7 is located between the first muffling segment 6 and the power segment 9, on the one hand necessary for forming a closed circuit and on the other hand mainly to prevent flow separation, improve the flow of the air flow and reduce losses.

The power section 9 is used for providing a wind speed condition required by the test, and in this embodiment, the power section 9 includes a power section front section 91, a fan 92, a power section rear section 93 and a fairing 94 which are sequentially distributed along the airflow direction. In this embodiment, the fan 92 is an axial flow variable frequency fan, and the power is about 7.5 kw.

The third corner 11 is located between the second sound attenuating section 10 and the return section 12, which is needed on the one hand to form a closed circuit and on the other hand mainly to prevent the flow of the gas flow from separating, to improve the flow of the gas flow and to reduce losses.

The second muffling segment 10 is installed downstream of the power segment 9, and is mainly used for reducing exhaust noise, and is used for reducing exhaust loss, and the speed of the air flow is minimized, and the kinetic energy is converted into pressure energy close to the external atmospheric pressure as much as possible, so that the minimum exhaust pressure loss is ensured. The first sound absorbing section 10 is also provided with a silencer 101 and sound absorbing cotton 102, the material of the sound absorbing cotton 102 is sound absorbing fiber cotton, in the embodiment, the sound absorbing amount of the second sound absorbing section 10 is determined according to the fan noise and the environmental noise of the power section 9.

The fourth corner 13 is located between the return section 12 and the stabilizing section 14, which is required on the one hand for forming a closed circuit and on the other hand mainly for preventing flow separation, improving flow of the gas flow and reducing losses.

The stabilizing section 14 is provided with a honeycomb device 141 close to the wind tunnel air inlet (i.e. the outlet of the air inlet silencer) and at least one layer of rectifying devices such as a damping net 142, so that the air is more uniform, and the air flow quality is improved.

The constriction 15 comprises a curve distributed in the direction of the air flow for boundary layer correction and is optimized using a special aerodynamic optimization tool, wherein the curve section tapers in cross section in the direction of the air flow. In this embodiment, the ratio of the cross-sectional areas of the inlet of the curved portion and the outlet of the straight portion (i.e., the contraction ratio) is 10:1, which can ensure excellent flow field quality and uniform and stable gas flow.

Therefore, the scope of the present invention should not be limited to the disclosure of the embodiments, but includes various alternatives and modifications without departing from the scope of the present invention, which is defined by the claims of the present patent application.

Claims

1. The utility model provides a backward flow acoustics wind-tunnel device, includes anechoic chamber, wedge, collector, divergent section, first turning, first noise damping section, second turning, balanced seam, power section, second noise damping section, third turning, backward flow section, fourth turning, stable section, shrink section, stable section includes damping net and honeycomb ware, power section includes power section anterior segment, fan, power section back end, radome fairing, all set up the muffler in first noise damping section and the second noise damping section and inhale the sound cotton, and the spout of shrink section and the anterior segment of divergent section arrange a noise damping indoor in.

2. The device according to claim 1, wherein the opening of the side wall of the inlet section of the collector and the opening of the pressure balance hole are adjustable, and the inner surface of the collector is attached with a fiber noise elimination layer.

3. A returned acoustic wind tunnel device according to claim 1, wherein a first noise damping section is provided between said diffuser section and said power section, and wherein a noise damper and a noise damping cotton are provided in said first noise damping section.

4. A returned acoustic wind tunnel device according to claim 3, wherein a second muffling section is provided downstream of said power section, and wherein a muffler and sound-absorbing cotton are provided in said second muffling section.

5. A backdraft acoustic wind tunnel device according to claim 1, further comprising a collector located between the convergent section and the divergent section, said collector also being located within said anechoic chamber.

6. The device according to claim 1, wherein a plurality of wedges are arranged in the anechoic chamber, and the wedges are made of sound-absorbing cellucotton.

7. A returned acoustic wind tunnel device according to claim 1, wherein the ratio of the cross-sectional area at the entrance to the cross-sectional area at the exit of said convergent section is 10: 1.

8. The returned acoustic wind tunnel device according to claim 1, wherein a different number of deflectors are arranged in each of the first corner, the second corner, the third corner and the fourth corner.