CN107490344A - A kind of testpieces free end deformation method for real-time measurement of wind tunnel test - Google Patents
A kind of testpieces free end deformation method for real-time measurement of wind tunnel test Download PDFInfo
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- CN107490344A CN107490344A CN201710550042.6A CN201710550042A CN107490344A CN 107490344 A CN107490344 A CN 107490344A CN 201710550042 A CN201710550042 A CN 201710550042A CN 107490344 A CN107490344 A CN 107490344A
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- testpieces
- video camera
- free end
- wind
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
- G01B11/00—Measuring arrangements characterised by the use of optical techniques
- G01B11/16—Measuring arrangements characterised by the use of optical techniques for measuring the deformation in a solid, e.g. optical strain gauge
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
- G01M9/00—Aerodynamic testing; Arrangements in or on wind tunnels
- G01M9/06—Measuring arrangements specially adapted for aerodynamic testing
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- General Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Aerodynamic Tests, Hydrodynamic Tests, Wind Tunnels, And Water Tanks (AREA)
Abstract
The invention discloses a kind of testpieces free end of wind tunnel test to deform method for real-time measurement, is related to aircraft technical field of aeroelasticity.The testpieces free end of the wind tunnel test deforms method for real-time measurement, reference point is chosen in the free end of testpieces, the first video camera and the second video camera are installed respectively with reference to side wall of the reference point in wind-tunnel and top, and set the first mark patch to be pasted with the second mark respectively in the side wall relative with the first video camera and the second video camera；Then apply external force to testpieces, make testpieces that vertical deformation and horizontal distortion occur respectively, record is through the reference point that the first video camera and the second video camera are seen in the position that the first mark patch and the second mark are sticked；Testpieces is blowed experiment, measure reference point by screenshotss marks the relative position sticked in the first mark patch and second, calculates the practical distortion of testpieces.The advantage of the invention is that：This method is simple to operate, easy to use, and measurement accuracy can meet engine request.
Description
Technical field
The present invention relates to aircraft technical field of aeroelasticity, and in particular to a kind of testpieces free end deformation of wind tunnel test
Method for real-time measurement.
Background technology
In the wind tunnel test of routine, the deformation seldom to testpieces free end measures；Even if there is larger deformation
Amount is also simply assessed simply by range estimation, and error is larger.For big flexibility test part, how much wing tip deflection is that it enters
The important indicator of row nonlinear analysis.The skyborne large deformation situation of aircraft must be simulated in advance in ground experiment, found out winged
Inherent characteristic of the machine under large deformation state, it is ensured that flight safety.
The content of the invention
It is an object of the invention to provide a kind of wind tunnel test testpieces free end deform method for real-time measurement, with solve or
At least mitigate background technology in the presence of at least one at the problem of.
To achieve these goals, the technical solution adopted by the present invention is：The testpieces for providing a kind of wind tunnel test is free
End deformation method for real-time measurement, reference point is chosen in the free end of testpieces, with reference to side wall peace of the reference point in wind-tunnel
The first video camera is filled, and the first mark patch is set in the side wall relative with first video camera；Exist with reference to the reference point
The second video camera is installed at top in wind-tunnel, and the second mark patch is set on the ground relative with second video camera；So
Apply external force to testpieces afterwards, make testpieces that vertical deformation and horizontal distortion occur respectively, record is seen through the first video camera
The reference point the first position for sticking of mark and through the reference point that the second video camera is seen in the second mark patch
On position；Testpieces is blowed experiment, by screenshotss measure the reference point on testpieces in the first mark patch and
The relative position that second mark sticks, calculate the practical distortion of testpieces.
Preferably, the height and position for the first video camera installed in the side wall in wind-tunnel is consistent with the zero-bit of testpieces, institute
State zero-bit refer to testpieces installed in wind-tunnel after position under non-stress；Second video camera of the top installation in wind-tunnel
The surface of the reference point on the testpieces.
Preferably, the testpieces free end deformation method for real-time measurement of the wind tunnel test further becomes parameter comprising foundation
Line is examined, the reference line sticked is marked for side wall first, applies external force to testpieces and records what is seen through the first video camera
The reference point is parallel with the both ends line that testpieces projects through the position point-rendering behind the position that the first mark sticks
Side wall reference line, repeat said process and draw a plurality of side wall reference line；The reference line sticked for the second mark, is applied to testpieces
Add external force and record through the reference point that the second video camera is seen behind the position that the second mark sticks, through the position point-rendering
The reference line parallel with the projection sideline of testpieces, repeat said process and draw a plurality of ground reference line.
Preferably, during blowing test, the speed of incoming flow stable period is selected as surveying range.
Preferably, when screenshotss measure the deformation under a certain certain wind speed, continuous several times intercept the screen under the certain wind speed
Curtain, takes the average value repeatedly intercepted as the practical distortion under the certain wind speed.
Preferably, when screenshotss measure the deformation under a certain certain wind speed, continuous 5 screens intercepted under the certain wind speed
Curtain.
Preferably, the reference point is chosen for the tip of testpieces free end.
The beneficial effects of the present invention are：
The influence of the deformation size of the part of the invention that is not put to the test, operating process is simple, can guarantee that certain measuring accuracy.Make
With convenient and swift, the reliability of test efficiency and test result can be substantially increased；The measurement apparatus is applicable not only to wind-tunnel examination
The testpieces free end deformation measurement in real time tested, extends also to the deformation measurement of other dynamic cantilever section free ends (such as
In aircraft flight, the measurement of wing tip deformation).
Brief description of the drawings
Fig. 1 is the device used in the testpieces free end deformation method for real-time measurement of the wind tunnel test of one embodiment of the invention
Schematic diagram.
Fig. 2 is the device used in the testpieces free end deformation method for real-time measurement of the wind tunnel test of one embodiment of the invention
Other direction schematic diagram.
Wherein, 1- testpieces, the video cameras of 2- first, 3- reference points, the mark patches of 4- first, the video cameras of 5- second, 6- second
Mark patch, 7- reference lines.
Embodiment
To make the purpose, technical scheme and advantage that the present invention is implemented clearer, below in conjunction with the embodiment of the present invention
Accompanying drawing, the technical scheme in the embodiment of the present invention is further described in more detail.In the accompanying drawings, identical from beginning to end or class
As label represent same or similar element or the element with same or like function.Described embodiment is the present invention
Part of the embodiment, rather than whole embodiments.The embodiments described below with reference to the accompanying drawings are exemplary, it is intended to uses
It is of the invention in explaining, and be not considered as limiting the invention.Based on the embodiment in the present invention, ordinary skill people
The every other embodiment that member is obtained under the premise of creative work is not made, belongs to the scope of protection of the invention.Under
Embodiments of the invention are described in detail with reference to accompanying drawing for face.
In the description of the invention, it is to be understood that term " " center ", " longitudinal direction ", " transverse direction ", "front", "rear",
The orientation or position relationship of the instruction such as "left", "right", " vertical ", " level ", " top ", " bottom " " interior ", " outer " is based on accompanying drawing institutes
The orientation or position relationship shown, it is for only for ease of the description present invention and simplifies description, rather than instruction or the dress for implying meaning
Put or element there must be specific orientation, with specific azimuth configuration and operation, therefore it is not intended that the present invention is protected
The limitation of scope.
As shown in Figure 1 and Figure 2, the testpieces free end deformation method for real-time measurement of a kind of wind tunnel test, in testpieces 1
Reference point 3 is chosen in free end, and the selection of reference point 3 should have the observation beneficial to experiment, and red in the present embodiment, reference point 3 is chosen
It at the tip of the free end of testpieces 1, the advantage is that, not only facilitate observation, additionally it is possible to measure the maximum distortion of testpieces 1.
The first video camera 2 is installed with reference to side wall of the reference point 3 in wind-tunnel, and in the side wall relative with the first video camera 2
Upper to set the first mark patch 4, the first video camera 2 is used to shoot position of the reference point 3 in the first mark patch 4, the first mark patch 4
For recording testpieces 1 in the position of reference point in the state of by different power 3；With reference to top installation of the reference point 3 in wind-tunnel
Second video camera 5, and the second mark patch 6 is set on the ground relative with the second video camera 5, the second video camera 5 is used to shoot
Position of the reference point 3 in the second mark patch 6, the second mark patch 6 are referring to for recording testpieces 1 in the state of by different power
The position of point 3；Then apply external force to testpieces 1, make testpieces 1 that vertical deformation and horizontal distortion occur respectively, record passes through
The reference point 3 that first video camera 2 is seen exists in the reference point 3 that the first mark pastes the position on 4 and seen through the second video camera 5
Position in second mark patch 6；Apply external force for testpieces 1 with reference to the actual loading size of testpieces 1, occur after making its stress
Change, and record position of the reference point 3 under different force effect.
It is understood that the first video camera 2 and the second video camera 5 should select high-definition camera, and can realize same
Time more continuous shootings.
Experiment is blowed to testpieces 1, reference point 3 on testpieces 1 is measured in the first mark patch 4 and the by screenshotss
The reference point locations recorded in relative position in two mark patches 6, the mark of contrast first patch 4 and the second mark patch 6, calculate experiment
The practical distortion of part 1.
In the present embodiment, the height and position for the first video camera 2 installed in the side wall in wind-tunnel and the zero-bit of testpieces 1
Unanimously, the zero-bit refer to testpieces 1 installed in wind-tunnel after position under non-stress；The of top installation in wind-tunnel
The surface for being located at the reference point 3 on testpieces 1 of two video cameras 5.
It is understood that the position of the first video camera 2 and the second video camera 5 can also be set according to actual conditions.Example
Such as, in an alternative embodiment, the zero-bit of a little higher than testpieces 1 of installation site of first video camera 2 in side wall.
In the present embodiment, the testpieces free end deformation method for real-time measurement of the wind tunnel test is further comprising foundation
Reference line 7 is deformed, for the reference line in the mark of side wall first patch 4, applies external force to testpieces 1 and records through the first shooting
Behind position of the reference point 3 that machine 2 is seen in the first mark patch 4, the both ends projected through the position point-rendering and testpieces 1 connect
The parallel side wall reference line 7 of line, the projection refer to projection of the testpieces 1 in side wall, repeat said process and draw a plurality of side
Wall reference line；For the reference line in the second mark patch 6, apply external force to testpieces 1 and record and see through the second video camera 5
Position of the reference point 3 in the second mark patch 6 after, project the parallel ginseng in sideline through the position point-rendering and testpieces 1
Line 7 is examined, said process is repeated and draws a plurality of ground reference line.
It is understood that in order to improve experiment calculation precision, the reference line on reference line and ground in side wall should
More secret agreement is good, i.e., shortens the distance between adjacent two lines as far as possible.
During blowing test, when loading is blowed, wind speed slowly improves, it is necessary to steady after reaching loading and requiring
Determine one end time, after the stabilization of part 1 to be tested, select the speed of incoming flow stable period as surveying range.Its advantage
It is, is advantageous to improve measurement accuracy.
When screenshotss measure the deformation under a certain certain wind speed, continuous several times intercept the screen under the certain wind speed, take more
The average value of secondary interception is as the practical distortion under the certain wind speed.
Specifically, in the present embodiment, when screenshotss measure the deformation under a certain certain wind speed, the spy is intercepted continuous 5 times
Determine the screen under wind speed.If it is understood that when repeatedly intercepting the screen under a certain certain wind speed, one of screen is found
Reference point locations and other positions deviation on curtain are larger, had deviated from theoretical position, then should give up the location point, calculate
The average value of remaining location point.
The influence of the deformation size of the part of the invention that is not put to the test, can guarantee that certain measuring accuracy.It is convenient to use, energy
Substantially increase the reliability of test efficiency and test result；The testpieces that the measurement apparatus is applicable not only to wind tunnel test is free
End deformation in real time measurement, extend also to other dynamic cantilever section free ends deformation measurement (in such as aircraft flight,
The measurement of wing tip deformation).
It is last it is to be noted that：The above embodiments are merely illustrative of the technical solutions of the present invention, rather than its limitations.To the greatest extent
The present invention is described in detail with reference to the foregoing embodiments for pipe, it will be understood by those within the art that：It is still
Technical scheme described in foregoing embodiments can be modified, or which part technical characteristic is equally replaced
Change；And these modifications or replacement, the essence of appropriate technical solution is departed from the essence of various embodiments of the present invention technical scheme
God and scope.
Claims (7)
1. the testpieces free end deformation method for real-time measurement of a kind of wind tunnel test, it is characterised in that in the free end of testpieces
Choose reference point, the first video camera be installed with reference to side wall of the reference point in wind-tunnel, and with the first video camera phase
To side wall on set first mark patch；The second video camera is installed with reference to top of the reference point in wind-tunnel, and with institute
State and the second mark patch is set on the relative ground of the second video camera；Then apply external force to testpieces, testpieces is occurred respectively
Vertical deformation and horizontal distortion, the reference point that record is seen through the first video camera is in the position that the first mark sticks and thoroughly
The reference point that the second video camera sees is crossed in the position that the second mark sticks；Testpieces is blowed experiment, by cutting
Screen measures the relative position that the reference point on testpieces is sticked in the first mark patch and the second mark, calculates the reality of testpieces
Border deforms.
2. the testpieces free end deformation method for real-time measurement of wind tunnel test as claimed in claim 1, it is characterised in that：Wind-tunnel
The height and position for the first video camera installed in interior side wall is consistent with the zero-bit of testpieces, and the zero-bit refers to testpieces in wind
Position after being installed in hole under non-stress；Second video camera of the top installation in wind-tunnel is located at the ginseng on testpieces
The surface of examination point.
3. the testpieces free end deformation method for real-time measurement of wind tunnel test as claimed in claim 2, it is characterised in that：It is described
The testpieces free end deformation method for real-time measurement of wind tunnel test is marked further comprising deformation reference line is established for side wall first
Remember the reference line sticked, apply external force to testpieces and record through the reference point that the first video camera is seen in the first mark
Behind the position sticked, the side wall reference line parallel with the both ends line that testpieces projects through the position point-rendering, repeat above-mentioned
Process draws a plurality of side wall reference line；For the second reference line for sticking of mark, apply external force to testpieces and record through the
The reference point that two video cameras are seen is behind the position that the second mark sticks, through the projection side of the position point-rendering and testpieces
The parallel reference line of line, repeat said process and draw a plurality of ground reference line.
4. the testpieces free end deformation method for real-time measurement of wind tunnel test as claimed in claim 3, it is characterised in that：Blowing
During wind experiment, the speed of incoming flow stable period is selected as surveying range.
5. the testpieces free end deformation method for real-time measurement of wind tunnel test as claimed in claim 4, it is characterised in that：Cutting
When screen measures the deformation under a certain certain wind speed, continuous several times intercept the screen under the certain wind speed, take what is repeatedly intercepted to be averaged
Value is as the practical distortion under the certain wind speed.
6. the testpieces free end deformation method for real-time measurement of wind tunnel test as claimed in claim 5, it is characterised in that：Cutting
When screen measures the deformation under a certain certain wind speed, continuous 5 screens intercepted under the certain wind speed.
7. the testpieces free end deformation method for real-time measurement of the wind tunnel test as described in any one of claim 1 to 6, its feature
It is：The reference point is chosen for the tip of testpieces free end.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710550042.6A CN107490344B (en) | 2017-07-07 | 2017-07-07 | Real-time measuring method for deformation of free end of test piece in wind tunnel test |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710550042.6A CN107490344B (en) | 2017-07-07 | 2017-07-07 | Real-time measuring method for deformation of free end of test piece in wind tunnel test |
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| Publication Number | Publication Date |
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| CN107490344A true CN107490344A (en) | 2017-12-19 |
| CN107490344B CN107490344B (en) | 2020-04-28 |
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| CN201710550042.6A Active CN107490344B (en) | 2017-07-07 | 2017-07-07 | Real-time measuring method for deformation of free end of test piece in wind tunnel test |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109100112A (en) * | 2018-09-29 | 2018-12-28 | 浙江大学 | A kind of air spring pole wind tunnel test plane wind vibration response test method based on computer vision |
| CN111121658A (en) * | 2019-12-31 | 2020-05-08 | 沈阳航空航天大学 | Blade deformation measuring method under wind turbine aerodynamic performance experiment |
| CN111879494A (en) * | 2020-08-10 | 2020-11-03 | 中国空气动力研究与发展中心超高速空气动力研究所 | Low-density wind tunnel flow field space measuring point position calibration method based on electron beam fluorescence |
| CN112924134A (en) * | 2021-01-25 | 2021-06-08 | 吉林大学 | Portable anti-wind stability test system |
| CN115060455A (en) * | 2022-08-18 | 2022-09-16 | 杭州飞仕得科技有限公司 | Test section structure of radiator test wind tunnel |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1632456A (en) * | 2005-01-04 | 2005-06-29 | 李小路 | Method for real-time measurement of airfoil deformation using dual laser |
| CN1688867A (en) * | 2002-10-12 | 2005-10-26 | 莱卡地球***公开股份有限公司 | Electronic display and control device for a measuring instrument |
| CN101201245A (en) * | 2007-12-24 | 2008-06-18 | 中国人民武装警察部队学院 | Method for measuring deformation of metallic material in hyperthermia mechanical test as well as observation instrument |
| CN101551238A (en) * | 2009-05-13 | 2009-10-07 | 西安交通大学 | Method for measuring the deformation of large-sized workpiece |
| CN101629822A (en) * | 2009-08-10 | 2010-01-20 | 张征宇 | Multi-camera movable photography measuring method in vibration environment |
| CN102494635A (en) * | 2011-12-13 | 2012-06-13 | 中国空气动力研究与发展中心设备设计及测试技术研究所 | Wind tunnel model ice shape measuring method and device |
| CN106323587A (en) * | 2016-08-03 | 2017-01-11 | 中国空气动力研究与发展中心高速空气动力研究所 | Monocular video high precision measuring method for wing wind tunnel test model elastic deformation |
-
2017
- 2017-07-07 CN CN201710550042.6A patent/CN107490344B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1688867A (en) * | 2002-10-12 | 2005-10-26 | 莱卡地球***公开股份有限公司 | Electronic display and control device for a measuring instrument |
| CN1632456A (en) * | 2005-01-04 | 2005-06-29 | 李小路 | Method for real-time measurement of airfoil deformation using dual laser |
| CN101201245A (en) * | 2007-12-24 | 2008-06-18 | 中国人民武装警察部队学院 | Method for measuring deformation of metallic material in hyperthermia mechanical test as well as observation instrument |
| CN101551238A (en) * | 2009-05-13 | 2009-10-07 | 西安交通大学 | Method for measuring the deformation of large-sized workpiece |
| CN101629822A (en) * | 2009-08-10 | 2010-01-20 | 张征宇 | Multi-camera movable photography measuring method in vibration environment |
| CN102494635A (en) * | 2011-12-13 | 2012-06-13 | 中国空气动力研究与发展中心设备设计及测试技术研究所 | Wind tunnel model ice shape measuring method and device |
| CN106323587A (en) * | 2016-08-03 | 2017-01-11 | 中国空气动力研究与发展中心高速空气动力研究所 | Monocular video high precision measuring method for wing wind tunnel test model elastic deformation |
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109100112A (en) * | 2018-09-29 | 2018-12-28 | 浙江大学 | A kind of air spring pole wind tunnel test plane wind vibration response test method based on computer vision |
| CN109100112B (en) * | 2018-09-29 | 2020-01-17 | 浙江大学 | Plane wind vibration response testing method for aeroelastic model wind tunnel test based on computer vision |
| CN111121658A (en) * | 2019-12-31 | 2020-05-08 | 沈阳航空航天大学 | Blade deformation measuring method under wind turbine aerodynamic performance experiment |
| CN111121658B (en) * | 2019-12-31 | 2021-04-20 | 沈阳航空航天大学 | Blade deformation measuring method under wind turbine aerodynamic performance experiment |
| CN111879494A (en) * | 2020-08-10 | 2020-11-03 | 中国空气动力研究与发展中心超高速空气动力研究所 | Low-density wind tunnel flow field space measuring point position calibration method based on electron beam fluorescence |
| CN111879494B (en) * | 2020-08-10 | 2022-05-17 | 中国空气动力研究与发展中心超高速空气动力研究所 | Low-density wind tunnel flow field space measuring point position calibration method based on electron beam fluorescence |
| CN112924134A (en) * | 2021-01-25 | 2021-06-08 | 吉林大学 | Portable anti-wind stability test system |
| CN115060455A (en) * | 2022-08-18 | 2022-09-16 | 杭州飞仕得科技有限公司 | Test section structure of radiator test wind tunnel |
| CN115060455B (en) * | 2022-08-18 | 2022-10-28 | 杭州飞仕得科技有限公司 | Test section structure of radiator test wind tunnel |
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