CN109649642B - Control device for inhibiting shear flow density pulsation - Google Patents
Control device for inhibiting shear flow density pulsation Download PDFInfo
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- CN109649642B CN109649642B CN201811573585.0A CN201811573585A CN109649642B CN 109649642 B CN109649642 B CN 109649642B CN 201811573585 A CN201811573585 A CN 201811573585A CN 109649642 B CN109649642 B CN 109649642B
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C21/00—Influencing air flow over aircraft surfaces by affecting boundary layer flow
- B64C21/10—Influencing air flow over aircraft surfaces by affecting boundary layer flow using other surface properties, e.g. roughness
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C23/00—Influencing air flow over aircraft surfaces, not otherwise provided for
- B64C23/06—Influencing air flow over aircraft surfaces, not otherwise provided for by generating vortices
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/10—Drag reduction
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- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The utility model provides a restrain control device that shear flow density pulsated, includes that the baffle surface at two air currents sets up rough area, produces the flow direction wake vortex, promotes shear flow to transition fast, restraines shear flow's density pulsation intensity, reinforcing flow field homogeneity. Compared with the prior art, the invention can be suitable for supersonic or hypersonic flow, is beneficial to generating control effect in a wider Mach number range due to the structural characteristics, has larger applicable Mach number range, and can effectively inhibit density pulsation in a flow field and improve the quality of the flow field under the conditions of hardly changing the appearance, applying no extra energy and not increasing additional equipment.
Description
Technical Field
The invention relates to a control device for inhibiting shear flow density pulsation, in particular to a partition plate arranged on two air flows, which can introduce beneficial three-dimensional disturbance, so that transition is accelerated, high turbulence intensity and strong density pulsation in free shear or limited shear flow are reduced, the flow field quality is improved, and the flow field density is homogenized.
Background
Free or limited shear flow is a common flow type in engineering applications, often found in fuel mixing inside engines and other fields. The shear flow formed by two air flows with different speeds passing through the partition plate is easy to form a large-scale vortex structure in the flow field due to Kelvin-Helmholtz instability, the secondary instability in the shear layer makes the flow unstable in the expansion direction, and the flow forms a process of being laminar flow, unstable and transition into turbulent flow. So that the density distribution in the flow field is not uniform, and the combustion efficiency and the heat release effect of the fuel are also influenced for the mixing of the fuel and the air.
As shown in fig. 6, which is a flow field characteristic diagram of free shear flow, in order to make shear flow mixing more sufficient and reduce density unevenness in the flow field, a flow control means must be adopted for control. Common flow control techniques include active control, mainly of blowing and sucking air, zero mass jet, etc., and passive control, including changing the shape of the baffles, arranging projections, etc. According to the invention, a passive coarse belt is arranged at the upstream of the partition plate of the two air flows, so that the shear flow behind the partition plate is in a fully developed turbulent flow state, and the density pulsation in a flow field is effectively inhibited.
Disclosure of Invention
The technical problem solved by the invention is as follows: the control device for inhibiting the shear flow density pulsation overcomes the defects of the prior art, and can promote the rapid transition of the shear flow formed by two air flows by utilizing the three-dimensional disturbance caused by the isolated rough unit which is easy to process and has a simple geometric shape and the rough belt formed by the isolated rough unit, and realize the functions of reducing the density pulsation in the flow field and improving the uniformity of the flow field in a wide Mach number flow range.
The technical solution of the invention is as follows: the utility model provides a restrain control device that shear flow density pulsated, includes that the baffle surface at two air currents sets up rough area, produces the flow direction wake vortex, promotes shear flow to transition fast, restraines shear flow's density pulsation intensity, reinforcing flow field homogeneity.
The rough belt is embedded or adhered on the surface of the aircraft through screws or adhesives.
The rough belt comprises a plurality of rough elements which are arranged at equal intervals along the direction vertical to the flow direction.
The rough element and the rough belt base are integrally processed, or the rough belt base and the rough element are respectively processed, and then the rough element is fixed on the rough belt base.
The rough element is in the shape of a sweepback slope diamond-like column, wherein the top view of the sweepback slope diamond-like column is in the shape of a diamond, and the section in the height direction is in the form of beveling.
The inclined plane formed by beveling the sweepback slope diamond-like column faces to the incoming flow direction, and the beveling angle is less than or equal to 45 degrees.
The maximum height h of the coarse units is more than or equal to 0.3 delta, and delta is the thickness of the local boundary layer.
The maximum size L of the rough element along the spanwise direction1Satisfies 0.3 delta<L1<1.8δ。
The width L of the trailing edge of the rough element2Satisfies 0.1 delta<L2<0.8δ。
The span-wise distance W between the rough element and the adjacent rough element satisfies 0.3 delta < W <1.8 delta.
Compared with the prior art, the invention has the advantages that:
(1) according to the invention, the isolated rough elements arranged on the surfaces of the partition plates of the two air flows are used for generating stable flow and introducing three-dimensional disturbance to the wake vortex, and the three-dimensional disturbance is used for promoting the nonlinear action of shear flow formed by the two air flows and promoting the rapid transition of the shear flow;
(2) according to the invention, the isolated rough elements arranged on the surfaces of the partition plates of the two air flows are used for reducing the density pulsation intensity in the flow field, enhancing the uniformity of the density of the flow field and realizing the function of improving the quality of the flow field;
(3) the invention can be suitable for supersonic/hypersonic flow, is beneficial to generating control effect in a wider Mach number range due to the structural characteristics, has larger applicable Mach number range, and can effectively inhibit density pulsation in a flow field and improve the quality of the flow field under the conditions of hardly changing the appearance, applying no extra energy and adding no additional equipment.
Drawings
FIG. 1 is a schematic view of the installation position of a control device for suppressing shear flow density pulsations;
FIG. 2 is a schematic of a coarse band of a control device for suppressing shear flow density pulsations;
FIG. 3 is a schematic diagram of a slope-shaped roughness dimension parameter and a slope angle;
FIG. 4 is a three-dimensional view of a rough belt;
fig. 5 is a numerical calculation result after the rough bands are arranged on the partition wall surfaces when the inflow conditions are Ma 6/Ma 3, respectively;
FIG. 6 is a flow field signature for free shear flow;
fig. 7 is a flow field image, i.e., a spatial distribution diagram of the wavefront distortion amount average wavefront, obtained explicitly from the flow field in the FD-20 wind tunnel of the research institute of aerospace aerodynamic technology in china when the incoming flow conditions are respectively Ma 6/Ma 3, (a) is an uncontrolled diagram, and (b) is a diagram with the control device of the present invention;
fig. 8 is a test verification result of the density pulsation improving effect obtained by an optical test in the FD-20 wind tunnel of the research institute of aerospace aerodynamic technology in china when the inflow conditions are respectively Ma 6/Ma 3, that is, a spatial distribution diagram of the wavefront distortion amount average wavefront, (a) is without a control device; (b) for arranging the control device of the invention;
fig. 9 shows a control device for suppressing the shear flow density pulsation.
Detailed Description
According to the characteristic that the isolated rough elements flow in the boundary layer, the invention provides a flow direction wake vortex generated by the isolated rough elements on the partition plates of the two air flows, and promotes the rapid transition of the shear flow; the wake vortex generated by the device can realize the suppression of the density pulsation intensity of the shear flow, thereby improving the flow field quality. A control device that suppresses shear flow density pulsation is proposed based on this principle. The concrete expression is as follows: the prism-like body can generate a stable wake vortex configuration, and the height of the isolated rough element is not less than 0.3 time of the nominal thickness of the local boundary layer, so that the two functions are realized, and the purposes of reducing density pulsation and enhancing the uniformity of a flow field are further achieved.
As shown in FIG. 1, the present invention proposes a control device for suppressing shear flow density pulsation, in which a rough belt 1 is provided on the surface of a partition plate of two air flows to reduce the intensity of shear flow density pulsation. The rough strip 1 can be embedded or bonded to the aircraft part surface by means of screws or also by means of an adhesive.
As shown in fig. 1, the roughened band is provided on the surface of the separator for both air streams, i.e., region 1 in fig. 1.
As shown in fig. 2, the roughness tape 1 is composed of a plurality of roughness elements arranged at equal intervals in a direction perpendicular to the flow direction.
The shape of the single rough element is a sweepback slope diamond-like column; the slope diamond-like column means that the shape of the top view of the column is diamond-like, and the section form in the height direction of the column is oblique cutting. The inclined plane formed by beveling faces the incoming flow direction, and the beveling angle is less than or equal to 45 degrees.
The rough element and the rough belt base can be integrally processed, namely the rough belt base and the rough element are integrated, or the rough belt base and the rough element can be respectively processed and then fixed on the rough belt base.
As shown in fig. 3, five parameters of the roughness elements are defined, namely, the width of the leading edge, the width of the trailing edge, the height and the expansion angle of the roughness elements, and the spanwise spacing between the roughness elements. The maximum height h of the rough element is more than or equal to 0.3 delta, delta is the thickness of a local boundary layer, and the maximum size of the rough element in the spanwise direction meets the relation of 0.3 delta<L1<1.8 delta, and the spacing between two adjacent rough elements along the spanwise direction satisfies the relation of 0.3 delta<W<1.8δ。
As shown in FIG. 3, the slope angle θ of the slope-shaped roughness element is not more than 45 degrees, and the slope surface is in the surface flow field direction.
As shown in fig. 4, a three-dimensional view of the rough belt.
As shown in fig. 5, numerical verification of the control effect is given. Calculating a rough belt consisting of isolated rough elements in a spanwise arrangement under the condition that the incoming flow Mach number Ma is 6/Ma is 3; the calculations show that the coarse band is effective in promoting rapid development of shear flow.
In order to verify the effect of improving the density pulsation in the flow field, the test verification based on optical measurement is carried out in the research institute of aerospace aerodynamic technology in China. FIG. 6 shows a test model used for the test verification conducted in the FD-20 wind tunnel of the research institute of aerospace aerodynamic technology in China. The figures show physical forms of isolated coarse cells.
As shown in fig. 7, flow field images obtained by the PIV flow field explicit technique are shown with or without a control device, from which it can be qualitatively observed that the present invention can make the flow field more uniform.
Since the density pulsation cannot be directly measured by experiment, it can be verified by optical measurement. The verification principle is that optical distortion occurs after a light beam passes through a flow field, and the more uniform the flow field is, the smaller the optical distortion is. Physical quantities commonly used to characterize optical distortion include the average wavefront, the PV value, and the RMS value. The experimental measurements of the optical transmission measurements with and without the control device are shown in fig. 8, in which the spatial distribution of the average wavefront of the optical distortion is listed. It can be seen from the figure that the optical distortion is significantly reduced after the control device for improving the aerodynamic optical effect is arranged. The statistical average value of the average wave front of the observed flow field is reduced from 1.244 to 0.9652, and the improvement amount is about 22.4%, thus proving the effectiveness of the invention in inhibiting the density pulsation of the shear flow field.
As shown in fig. 9, the present invention provides a control device for suppressing shear flow density pulsation, which is based on a coarse cell to introduce three-dimensional disturbance upstream of shear flow according to engineering requirements, and is capable of: 1) under the laminar flow state, the quick development of the shear flow formed by the two air flows behind the partition plate into a turbulent flow state is effectively promoted; 2) under the turbulent flow condition, strong density pulsation in the shear flow formed by the two air flows behind the partition plate is effectively inhibited, so that the density field is homogenized. According to our numerical simulation and optical test measurement, it can be confirmed that the control device for suppressing the shear flow density pulsation provided by the patent can realize the above two functions.
Those skilled in the art will appreciate that those matters not described in detail in the present specification are well known in the art.
Claims (1)
1. A control device for inhibiting shear flow density pulsation is characterized by comprising a rough belt arranged on the surfaces of partition plates of two air flows to generate a flow direction wake vortex, promote the rapid transition of the shear flow, inhibit the density pulsation intensity of the shear flow and enhance the uniformity of a flow field;
the rough belt is embedded or adhered to the surface of the aircraft through screws or adhesives;
the rough belt comprises a plurality of rough elements which are arranged at equal intervals along the direction vertical to the flow direction;
the rough element and the rough belt base are integrally processed, or the rough belt base and the rough element are respectively processed, and then the rough element is fixed on the rough belt base;
the rough element is in the shape of a sweepback slope diamond-like column, wherein the top view of the sweepback slope diamond-like column is in the shape of a diamond, and the section in the height direction is in a beveling mode;
the inclined plane formed by beveling the sweepback slope rhombic column faces to the incoming flow direction, and the beveling angle is less than or equal to 45 degrees;
the maximum height h of the rough element is more than or equal to 0.3 delta, and delta is the thickness of a local boundary layer;
the maximum size L of the rough element along the spanwise direction1Satisfies 0.3 delta<L1<1.8δ；
The width L of the trailing edge of the rough element2Satisfies 0.1 delta<L2<0.8δ；
The span-wise distance W between the rough element and the adjacent rough element satisfies 0.3 delta < W <1.8 delta.
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| CN201811573585.0A CN109649642B (en) | 2018-12-21 | 2018-12-21 | Control device for inhibiting shear flow density pulsation |
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| CN201811573585.0A CN109649642B (en) | 2018-12-21 | 2018-12-21 | Control device for inhibiting shear flow density pulsation |
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| CN109649642B true CN109649642B (en) | 2022-04-12 |
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| CN116534246B (en) * | 2023-07-05 | 2023-09-12 | 中国空气动力研究与发展中心计算空气动力研究所 | Flow direction vortex modulation device |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5407153A (en) * | 1991-02-25 | 1995-04-18 | Valsan Partners | System for increasing airplane fuel mileage and airplane wing modification kit |
| DE10052022A1 (en) * | 2000-10-13 | 2002-05-16 | Univ Dresden Tech | Insert for shear layers and vortical structures comprises densely packed flexible smooth hair-like structures of textiles or synthetic fibers of specified diameter length and structural density. |
| CN101959755A (en) * | 2008-02-29 | 2011-01-26 | 空中客车英国有限公司 | Aerodynamic structure with non-uniformly spaced shock bumps |
| US7954767B2 (en) * | 2007-04-25 | 2011-06-07 | The Boeing Company | Laminar flow surfaces with selected roughness distributions, and associated methods |
| CN105307931A (en) * | 2013-01-25 | 2016-02-03 | 彼得·艾瑞兰德 | Energy efficiency improvements for turbomachinery |
| CN106124626A (en) * | 2016-06-30 | 2016-11-16 | 中国航天空气动力技术研究院 | Postpone hypersonic boundary layer material and turn the Study system and experiment research twisted |
| GB2547933A (en) * | 2016-03-03 | 2017-09-06 | Airbus Group Ltd | Aircraft wing roughness strip |
| CN107505117A (en) * | 2017-09-08 | 2017-12-22 | 浙江大学 | A kind of experimental provision and method for measuring flat board turbulent skn friction resistance |
| CN107878728A (en) * | 2016-09-29 | 2018-04-06 | 北京航空航天大学 | Wing structure and aircraft |
| CN107941451A (en) * | 2017-04-10 | 2018-04-20 | 重庆大学 | A kind of wind-tunnel rough element apparatus for being easily installed dismounting |
| CN107972850A (en) * | 2017-11-06 | 2018-05-01 | 中国航天空气动力技术研究院 | A kind of high speed drops hot damping device and method around the passive type of laminar boundary layer |
| GB2559844A (en) * | 2016-12-14 | 2018-08-22 | Airbus Defence & Space Gmbh | A method of preventing separation of a fluid flow and flow body system |
| US10087912B2 (en) * | 2015-01-30 | 2018-10-02 | General Electric Company | Vortex generator for a rotor blade |
-
2018
- 2018-12-21 CN CN201811573585.0A patent/CN109649642B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5407153A (en) * | 1991-02-25 | 1995-04-18 | Valsan Partners | System for increasing airplane fuel mileage and airplane wing modification kit |
| DE10052022A1 (en) * | 2000-10-13 | 2002-05-16 | Univ Dresden Tech | Insert for shear layers and vortical structures comprises densely packed flexible smooth hair-like structures of textiles or synthetic fibers of specified diameter length and structural density. |
| US7954767B2 (en) * | 2007-04-25 | 2011-06-07 | The Boeing Company | Laminar flow surfaces with selected roughness distributions, and associated methods |
| CN101959755A (en) * | 2008-02-29 | 2011-01-26 | 空中客车英国有限公司 | Aerodynamic structure with non-uniformly spaced shock bumps |
| CN105307931A (en) * | 2013-01-25 | 2016-02-03 | 彼得·艾瑞兰德 | Energy efficiency improvements for turbomachinery |
| US10087912B2 (en) * | 2015-01-30 | 2018-10-02 | General Electric Company | Vortex generator for a rotor blade |
| GB2547933A (en) * | 2016-03-03 | 2017-09-06 | Airbus Group Ltd | Aircraft wing roughness strip |
| CN106124626A (en) * | 2016-06-30 | 2016-11-16 | 中国航天空气动力技术研究院 | Postpone hypersonic boundary layer material and turn the Study system and experiment research twisted |
| CN107878728A (en) * | 2016-09-29 | 2018-04-06 | 北京航空航天大学 | Wing structure and aircraft |
| GB2559844A (en) * | 2016-12-14 | 2018-08-22 | Airbus Defence & Space Gmbh | A method of preventing separation of a fluid flow and flow body system |
| CN107941451A (en) * | 2017-04-10 | 2018-04-20 | 重庆大学 | A kind of wind-tunnel rough element apparatus for being easily installed dismounting |
| CN107505117A (en) * | 2017-09-08 | 2017-12-22 | 浙江大学 | A kind of experimental provision and method for measuring flat board turbulent skn friction resistance |
| CN107972850A (en) * | 2017-11-06 | 2018-05-01 | 中国航天空气动力技术研究院 | A kind of high speed drops hot damping device and method around the passive type of laminar boundary layer |
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