A low-flow-resistance open platform jet flow noise reduction device

Abstract

The application belongs to the technical field of engine noise reduction, and particularly relates to a low-flow-resistance open-air platform jet noise reduction device, which is fixed on a base assembly on an experimental platform; a conical cylinder assembly is installed on the base assembly through a support, a small-end of the conical cylinder assembly faces an engine nozzle, and the conical cylinder assembly is coaxially arranged with the engine nozzle; a straightening plate assembly comprises a plurality of straightening plates with different diameters which are distributed along an axial direction of the conical cylinder assembly, the straightening plates have flow channel holes in centers of the straightening plates to allow engine nozzle airflow to pass through, the straightening plates have a plurality of circumferentially distributed perforations on plate surfaces of the straightening plates, and the plurality of straightening plates are respectively sleeved in the conical cylinder assembly along an axial direction of the conical cylinder assembly, so that the noise reduction device has small flow resistance and small influence on aerodynamic performance of the nozzle.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of engine noise reduction, and particularly relates to a low-flow-resistance open-air platform jet flow noise reduction device. BACKGROUND

[0002] The noise of a nearby village is in an over-standard state in the intermediate state of engine test on an open-air platform of a certain type of aircraft, which leads to that the engine test in the intermediate state and the afterburning state cannot be carried out according to the plan due to the restriction of environmental protection regulations. Jet flow noise is the main noise source of an aircraft engine, and the jet flow noise reduction effect directly affects the far-field noise radiation level of the engine. The main methods for reducing the jet flow noise of the engine mainly include changing the shape of the tail edge of the nozzle and increasing the mixing of the nozzle outlet. The serrated nozzle is a main method for reducing the jet flow noise of the engine by changing the shape of the tail edge of the nozzle, and the characteristic of the serrated nozzle is that the edge shape of the nozzle is triangular or serrated in other shapes, which has the effect of low-frequency noise reduction. Jet flow noise reduction is a main technical method for jet flow noise mixing reduction, which reduces the far-field sound propagation of the jet flow noise by increasing the mixing of the airflow at the nozzle outlet. For a standardized nozzle, the shape of the tail edge of the nozzle cannot be changed. The jet flow noise reduction technology has a large flow loss at the nozzle outlet, and the flow and pressure control system structure of the high-pressure jet flow is relatively complex, which needs to be modified on the part or the whole machine platform, and is not easy to realize on the part or the whole machine platform. In view of the present situation, it is urgent to develop a low-flow-resistance, high-noise-reduction and simple-structure open-air jet flow noise reduction device.

[0003] The existing technical solution one: in the existing technical solution, the frequency of the jet flow noise source is shifted from low-frequency noise to high-frequency noise by changing the shape of the nozzle outlet, the dissipation of the sound source is increased, and the effect of far-field noise reduction is achieved. The existing technical solution one has the following disadvantages: for a standardized nozzle, the shape of the tail edge of the nozzle cannot be changed, and the noise reduction purpose cannot be achieved by changing the tail edge of the nozzle. The existing technical solution two: in the existing technical solution, the jet flow flow, jet flow pressure, jet flow angle and other parameter control are completed through a complex jet flow control pipeline in the nozzle, and the jet flow noise reduction control and research are achieved. The existing technical solution two has the following disadvantages: 1. the structure of the jet flow auxiliary pipeline control system is relatively complex, and the test site needs to be modified on the platform; 2. the jet flow needs to be separately provided with a high-pressure water source or a gas source, and the requirement for the platform resources is high; 3. the mixing of the high-pressure jet flow and the nozzle outlet is relatively violent, which brings a large flow loss and has a great influence on the aerodynamic performance of the nozzle. SUMMARY

[0004] In order to solve the above problems, the application provides a low-flow-resistance open-air platform jet flow noise reduction device, which comprises:

[0005] A base assembly fixed on an experimental platform;

[0006] A conical cylinder assembly installed on the base assembly through a support, the small-end of the conical cylinder assembly faces the engine nozzle, and the conical cylinder assembly is coaxially arranged with the engine nozzle.

[0007] The rectifier plate assembly comprises a plurality of rectifier plates with different diameters distributed along the axial direction of the cone assembly, the center of the rectifier plate has a flow passage hole for the engine nozzle gas flow, the distance of the flow passage hole of the rectifier plate gradually increases along the flow direction of the engine nozzle gas flow, the farther the distance from the engine nozzle, the larger the flow passage hole, the plate surface of the rectifier plate has a plurality of circumferentially distributed perforations, and the plurality of rectifier plates are respectively sleeved in the cone assembly along the axial direction of the cone assembly.

[0008] Preferably, the rectifier plate comprises: a 0.5D rectifier plate with a distance of 0.5 times the diameter of the nozzle outlet from the nozzle outlet end face, a 1D rectifier plate with a distance of 1 times the diameter of the nozzle outlet from the nozzle outlet end face, a 1.5D rectifier plate with a distance of 1.5 times the diameter of the nozzle outlet from the nozzle outlet end face, a 2.0D rectifier plate with a distance of 2 times the diameter of the nozzle outlet from the nozzle outlet end face, a 3.0D rectifier plate with a distance of 3 times the diameter of the nozzle outlet from the nozzle outlet end face, a 4.0D rectifier plate with a distance of 4 times the diameter of the nozzle outlet from the nozzle outlet end face, and a 5.0D rectifier plate with a distance of 5 times the diameter of the nozzle outlet from the nozzle outlet end face.

[0009] Preferably, the 0.5D rectifier plate is installed on the small end face of the cone assembly, and the 5.0D rectifier plate is installed on the large end face of the cone assembly.

[0010] Preferably, each rectifier plate comprises an inner ring rectifier plate and an outer ring rectifier plate, the edge of the center hole of the outer ring rectifier plate has a mounting hole connected with the inner ring rectifier plate through threads, and the inner ring rectifier plate has the flow passage hole.

[0011] Preferably, the center holes of all the outer ring rectifier plates are of the same size.

[0012] Preferably, the perforation diameter of the outer ring rectifier plate is 0.04-0.18D1, and the perforation diameter of the inner ring rectifier plate is 0.04D1, wherein D1 is the diameter of the engine nozzle gas flow field beam at the position corresponding to the rectifier plate.

[0013] Preferably, the depth of the inner ring rectifier plate inserted into the engine nozzle gas flow field beam is 0.04-0.11D1.

[0014] Preferably, the 0.5D rectifier plate and the 5.0D rectifier plate are connected with the cone flange at the end face of the cone assembly through bolts.

[0015] Preferably, a plurality of inner thread holes with axis perpendicular to the wall surface of the cone assembly are circumferentially distributed at the edge of the rectifier plate installed on the inner wall of the cone assembly, and the bolts have through holes connected with the inner thread holes.

[0016] The advantages of the present application include: the invented noise reduction device is a separate structural system from the test bench, and does not need to modify the test bench; the noise reduction device does not occupy the test bench resources and has simple structure and is easy to operate; the noise reduction device can be applied to open-air jet noise reduction of whole machine and components, support model development and test task implementation; the noise reduction device has small flow resistance and small influence on the nozzle aerodynamic performance. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 is a schematic diagram of a low-flow-resistance / high-noise-reduction open-air bench jet noise reduction device;

[0018] Figure 2 is Figure 1 a schematic diagram of a partial IV;

[0019] Figure 3 is Figure 1 a schematic diagram of a partial V;

[0020] Figure 4 is Figure 1 a schematic diagram of a partial I;

[0021] Figure 5 is Figure 1 a schematic diagram of a partial II;

[0022] Figure 6 is Figure 1 a schematic diagram of a partial III;

[0023] Figure 7 is a schematic diagram of a 0.5D rectifier plate;

[0024] Figure 8 is Figure 7 an AA section view of

[0025] Figure 9 is a schematic diagram of an outer ring rectifier plate;

[0026] Figure 10 is a schematic diagram of an inner ring rectifier plate;

[0027] Figure 11 is Figure 10 an AA section view of

[0028] Figure 12 is a schematic diagram of a rectifier plate installed on the inner wall of a cone cylinder assembly;

[0029] Figure 13 is Figure 12 an AA section view of DETAILED DESCRIPTION

[0030] In order to make the technical solutions of the present application and the advantages thereof clearer, the technical solutions of the present application will be further clearly and completely described below in conjunction with the drawings. It should be understood that the specific embodiments described herein are only some of the embodiments of the present application, which are used to explain the present application, but not to limit the present application. It should be noted that, for the purpose of description, only parts related to the present application are shown in the drawings, and other related parts can be referred to the general design. In the case of no conflict, the embodiments in the present application and the technical features in the embodiments can be combined to obtain new embodiments.

[0031] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present application should be the general meanings understood by the general technical personnel in the field of the present application. The words indicating the direction or position relationship such as "upper", "lower", "left", "right", "center", "vertical", "horizontal", "inner", "outer" and the like used in the description of the present application are only used to indicate the relative direction or position relationship, and not to imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and the relative position relationship may also change accordingly when the absolute position of the described object changes, therefore it cannot be understood as a limitation on the present application. The "first", "second", "third" and the like used in the description of the present application are only for the purpose of description, to distinguish different components, and cannot be understood as indicating or implying relative importance. The "one", "an" or "the" and the like used in the description of the present application should not be understood as an absolute limitation on the quantity, but should be understood as the existence of at least one. The "including" or "containing" and the like used in the description of the present application means that the elements or objects appearing before the word are covered by the elements or objects listed after the word and their equivalents, and other elements or objects are not excluded.

[0032] In addition, it should be further noted that, unless otherwise specified and limited, the "mounting", "connection", "connection" and the like used in the description of the present application should be understood in a broad sense, for example, the connection can be fixed connection, or detachable connection, or integral connection; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium, or the connection between two elements, the skilled in the art can understand the specific meaning of the present application according to the specific circumstances.

[0033] In order to solve the above problems, the present application provides a low-flow open platform jet flow noise reduction device, comprising:

[0034] A base assembly 5 fixed on the experimental platform;

[0035] The conical cylinder assembly 4 is installed on the base assembly 5 by the support, the small end of the conical cylinder assembly 4 faces the engine nozzle, and the conical cylinder assembly 4 is coaxially arranged with the engine nozzle.

[0036] The fairing plate assembly 1 comprises a plurality of fairing plates with different diameters distributed along the axial direction of the conical cylinder assembly 4, the center of the fairing plate has a flow passage hole for the engine nozzle airflow to pass through, the distance of the flow passage hole gradually increases along the flow direction of the engine nozzle airflow, the flow passage hole of the fairing plate far away from the engine nozzle is larger, the plate surface of the fairing plate has a plurality of circumferentially distributed perforations, and the plurality of fairing plates are respectively sleeved inside the conical cylinder assembly 4 along the axial direction of the conical cylinder assembly 4.

[0037] Preferably, the fairing plate comprises: a 0.5D fairing plate 101 with a distance of 0.5 times the diameter of the nozzle outlet from the nozzle outlet end face, a 1D fairing plate 102 with a distance of 1 times the diameter of the nozzle outlet from the nozzle outlet end face, a 1.5D fairing plate 103 with a distance of 1.5 times the diameter of the nozzle outlet from the nozzle outlet end face, a 2.0D fairing plate 104 with a distance of 2 times the diameter of the nozzle outlet from the nozzle outlet end face, a 3.0D fairing plate 105 with a distance of 3 times the diameter of the nozzle outlet from the nozzle outlet end face, a 4.0D fairing plate 106 with a distance of 4 times the diameter of the nozzle outlet from the nozzle outlet end face, and a 5.0D fairing plate 107 with a distance of 5 times the diameter of the nozzle outlet from the nozzle outlet end face. The noise reduction device has simple structure, convenient installation, and is independent of the test bench structure, without the need to modify the test bench.

[0038] In some optional embodiments, the 0.5D fairing plate 101 is installed on the small end face of the conical cylinder assembly 4, and the 5.0D fairing plate 105 is installed on the large end face of the conical cylinder assembly 4.

[0039] In some optional embodiments, each fairing plate comprises an inner ring fairing plate and an outer ring fairing plate, the edge of the center hole of the outer ring fairing plate has a mounting hole connected with the inner ring fairing plate through threads, the inner ring fairing plate has the flow passage hole, and the inner ring fairing plate can be replaced according to test needs.

[0040] In some optional embodiments, the center holes of all outer ring fairing plates are of the same size, so that the outer diameter of the inner ring fairing plate is the same, facilitating unified installation.

[0041] In some optional embodiments, the perforation diameter of the outer ring fairing plate is 0.04-0.18D1, and the perforation diameter of the inner ring fairing plate is 0.04D1, wherein D1 is the diameter of the engine nozzle airflow flow field beam at the corresponding fairing plate position.

[0042] In some optional embodiments, the depth of the inner ring fairing plate inserted into the engine nozzle airflow flow field beam is 0.04-0.11D1.

[0043] In some alternative embodiments, the 0.5D rectification plate 101 and the 5.0D rectification plate 105 are connected to the conical cylinder flange at the end face of the conical cylinder assembly 4 by bolts.

[0044] In some alternative embodiments, a plurality of axis vertical to the wall surface of the conical cylinder assembly 4 are distributed circumferentially at the edge of the rectification plate installed on the inner wall of the conical cylinder assembly 4, and the through holes of the bolts passing through the cylinder wall of the conical cylinder assembly 4 are connected to the internal threaded holes, as shown in the figure. Figures 12-13 As shown, the rectification plate is connected to the conical cylinder by 8 circumferential bolts.

[0045] In the specific implementation process, according to the size and working condition of the nozzle, the temperature field and pressure field at the nozzle outlet are calculated, and the size and slope of the cylinder of the noise reduction device are confirmed;

[0046] According to the nozzle outlet diameter and the simulation results of the nozzle outlet flow field, the characteristic dimensions such as the position of the nozzle rectification plate, the size of the perforation and the insertion depth of the plate are given;

[0047] According to the insertion depth of the rectification plate into the main flow and the simulation results, the strength of the support structure is verified, and appropriate anchor bolts and connecting bolts are selected;

[0048] According to the centerline height of the nozzle outlet and the position of the nozzle outlet, the central position of the noise reduction device and the axial position of the noise reduction device are given.

[0049] The advantages of the present application include: the noise reduction device of the application is a separate structure system with the test bench, without the need to modify the test bench; the noise reduction device does not occupy the test bench resources and the device structure is simple and easy to operate; the noise reduction device can be applied to open-air jet flow whole machine and component noise reduction, support model development and test task development; the noise reduction device has small flow resistance and small influence on the aerodynamic performance of the nozzle.

[0050] The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical range disclosed in the present application can be easily thought by those skilled in the art, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A low flow resistance open platform jet stream noise reduction device, characterized by, The utility model relates to a kind of engine nozzle flow field straightener, including: Base assembly (5) fixed on experimental platform; Cone cylinder assembly (4) is installed on base assembly (5) by support, and the small mouth end of cone cylinder assembly (4) is towards engine nozzle, and cone cylinder assembly (4) is coaxially arranged with engine nozzle; Rectifier plate assembly (1) includes multiple rectifier plates of different diameters distributed along the axial direction of cone cylinder assembly (4), the center of rectifier plate has flow passage hole for engine nozzle airflow to pass through, the flow passage hole of rectifier plate farther from engine nozzle is larger, and the plate surface of rectifier plate has multiple perforations distributed in circumferential direction, and multiple rectifier plates are respectively sleeved inside cone cylinder assembly (4) along the axial direction of cone cylinder assembly (4).

2. The low flow resistance open air deck jet stream noise reducing device of claim 1, wherein, Rectifier plate includes: 0.5D rectifier plate (101) with the distance of nozzle outlet end face is 0.5 times nozzle outlet diameter, 1D rectifier plate (102) with the distance of nozzle outlet end face is 1 times nozzle outlet diameter, 1.5D rectifier plate (103) with the distance of nozzle outlet end face is 1.5 times nozzle outlet diameter, 2.0D rectifier plate (104) with the distance of nozzle outlet end face is 2 times nozzle outlet diameter, 3.0D rectifier plate (105) with the distance of nozzle outlet end face is 3 times nozzle outlet diameter, 4.0D rectifier plate (106) with the distance of nozzle outlet end face is 4 times nozzle outlet diameter, 5.0D rectifier plate (107) with the distance of nozzle outlet end face is 5 times nozzle outlet diameter.

3. The low flow resistance open deck jet stream noise abatement device of claim 2, wherein, 0.5D rectifier plate (101) is installed on the small mouth end face of cone cylinder assembly (4), and 5.0D rectifier plate (105) is installed on the large mouth end face of cone cylinder assembly (4).

4. The low flow resistance open deck platform stream injection noise abatement device of claim 1, wherein, Each rectifier plate includes inner ring rectifier plate and outer ring rectifier plate, and the edge of central hole of outer ring rectifier plate has mounting hole connected with inner ring rectifier plate by thread, and inner ring rectifier plate has the flow passage hole.

5. The low flow resistance open deck platform jet stream noise abatement device of claim 4, wherein, The size of central hole of all outer ring rectifier plates is same.

6. The low flow resistance open deck platform jet stream noise abatement device of claim 4, wherein, The diameter of perforation of the outer ring rectifier plate is 0.04-0.18D1, and the diameter of perforation of inner ring rectifier plate is 0.04D1, wherein D1 is the diameter of engine nozzle airflow flow field beam at corresponding rectifier plate position.

7. The low flow resistance open deck jet stream noise abatement device of claim 6, wherein, The depth of inner ring rectifier plate inserted into engine nozzle airflow flow field beam is 0.04-0.11D1.

8. The low flow resistance open platform jet stream noise abatement device of claim 2, wherein, 0.5D rectifier plate (101) and 5.0D rectifier plate (105) are connected with the flange of cone cylinder assembly (4) at end face by bolt.

9. The low flow resistance open platform jet stream noise abatement device of claim 1, wherein, Multiple inner thread holes with axis perpendicular to the wall surface of cone cylinder assembly (4) are distributed in circumferential direction at the edge of rectifier plate installed on the inner wall of cone cylinder assembly (4), and the through hole of bolt passing through the cylinder wall of cone cylinder assembly (4) is connected with the inner thread hole.

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