CN108108526A - A kind of undercarriage buffer becomes the discharge coefficient computational methods of oilhole - Google Patents
A kind of undercarriage buffer becomes the discharge coefficient computational methods of oilhole Download PDFInfo
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- CN108108526A CN108108526A CN201711236764.0A CN201711236764A CN108108526A CN 108108526 A CN108108526 A CN 108108526A CN 201711236764 A CN201711236764 A CN 201711236764A CN 108108526 A CN108108526 A CN 108108526A
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/15—Vehicle, aircraft or watercraft design
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- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
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Abstract
The present invention relates to the discharge coefficient computational methods that a kind of undercarriage buffer becomes oilhole, belong to undercarriage Dynamics analysis technology field, including：The discharge coefficient formula for calculating and becoming oilhole is initially set up, equivalent flow coefficient is calculated according to above-mentioned discharge coefficient formula afterwards.Buffer provided by the invention becomes the computational methods of oilhole discharge coefficient, ensure that the accurate foundation of buffer analysis model, and reference is provided for undercarriage buffer model foundation, and computational methods are easy to operate and accurately and reliably.
Description
Technical field
The invention belongs to the streams that undercarriage Dynamics analysis technology field more particularly to a kind of undercarriage buffer become oilhole
The computational methods of coefficient of discharge.
Background technology
Modern combat aircraft land when with larger (downwardly and forwardly) speed, in addition the quality of entire aircraft, can produce
Raw larger kinetic energy.Course speed is tapered by the brake for throwing drag parachute, opening flap and undercarriage wheel.For
Vertical kinetic energy and corresponding shock loading are mainly undertaken by the undercarriage buffer system of aircraft.The undercarriage buffer system of aircraft
System is made of buffer and tire.The essence of buffering be exactly the consumption of the kinetic energy of aircraft in buffer system (tire and buffer) and
In the deformation of aircaft configuration (undercarriage, wing, fuselage).It may also be said that act on undercarriage wheel in aircraft landing impact
On external force (ground reaction force) buffer system is made to deform work done, and the kinetic energy for the aircraft that dissipated.
Cushion performance is carried out at the beginning of Landing Gear Design and calculates analysis, exactly sees whether undercarriage buffer system has and absorbs
The ability of the work(amount of design requirement.There are one important physical parameters, i.e. oilhole flow in undercarriage buffer analysis model
Coefficient is affected to result of calculation, and can not be determined by directly measuring.How to determine discharge coefficient just into slow
Rush the most important thing of device analysis.
The content of the invention
The purpose of the present invention is to solve undercarriage cushion performance analyze in need quickly and accurately provide buffer
Become oilhole discharge coefficient the problem of, and provide it is a kind of become oilhole discharge coefficient computational methods, with traditional " examination is gathered " with
The method of personal experience is compared, not only easy to operate but also accurately and reliably.
In order to achieve the above objectives, the technical solution adopted by the present invention is：A kind of undercarriage buffer becomes the flow system of oilhole
Number calculating method, including：
First：Establish the discharge coefficient formula for calculating and becoming oilhole
In formula, k oilholes change corresponding coefficient, and d is spindle diameter of bore, and l is length of the fluid by spindle, and λ is to rub
Coefficient is hindered, s is draft gear travel；
Second：Equivalent flow coefficient is calculated according to discharge coefficient
In formula, n is change oilhole quantity.
Further, coefficient of friction λ values are 0.015~0.016.
Further, coefficient of friction λ values are 0.0153.
Buffer provided by the invention becomes the computational methods of oilhole discharge coefficient, ensure that the accurate of buffer analysis model
It establishes, reference is provided for undercarriage buffer model foundation, computational methods are easy to operate and accurately and reliably.
Description of the drawings
Attached drawing herein is merged in specification and forms the part of this specification, shows the implementation for meeting the present invention
Example, and the principle for explaining the present invention together with specification.
Figure 1A is buffer reset condition schematic diagram.
Figure 1B is the positive stroke state schematic diagram of buffer.
Fig. 1 C are buffer revesal view.
Fig. 2 is change oilhole spindle structure diagram figure.
Specific embodiment
To make the purpose, technical scheme and advantage that the present invention is implemented clearer, below in conjunction in the embodiment of the present invention
Attached drawing, the technical solution in the embodiment of the present invention is further described in more detail.
If Figure 1A~Fig. 1 C show the buffer structure of three kinds of states, buffer includes outer barrel 2, travelling piston 3, plunger
4th, anti-drag valve 5, become oilhole spindle 1 and piston rod 6, as a result of becoming the design of oilhole spindle 1 in buffer, therefore becoming
1 structure type of oilhole spindle is as shown in Fig. 2, the main oil pocket spindle of undercarriage is to become by stroke segmentation in the hollow pipe of peripheral wall perforate
Oilhole oil area is shown in Table 1.
Table 1 becomes oilhole oil area
Oilhole discharge coefficient controls fluid damping force, directly affects simulation result and (eases up including vertical load, stroke
Efficiency of flushing system etc.), the influence to simulation result is clearly.Oilhole discharge coefficient and fluid damping force relation are as follows：
In formula, Cq is oilhole discharge coefficient, and ρ is fluid density, and A is fluid effective active area, and m is area of orifice and oil
The ratio between liquid effective active area, Ad are area of orifice, and Sh is draft gear travel.
For buffer as a result of the designing scheme for becoming oilhole spindle, the main oil pocket spindle of undercarriage is to be segmented by stroke in week
The hollow pipe of wall perforate becomes oilhole oil area and is shown in Table 1.
Discharge coefficient is calculated by damping slot hole, and formula is as follows：
In formula：λ is the coefficient of friction resistance, and l is length of the fluid by spindle, and d is spindle diameter of bore.
WhenWhen,Very little can omit, Cq=0.82.
Fluid flows through the length of oilhole and changes with stroke in undercarriage buffer,Value it is larger, can not ignore.It does not go together
The corresponding discharge coefficient formula of journey is as follows：
Wherein：K (s) changes corresponding coefficient for oilhole.
Oilhole changes corresponding coefficient k (s) computational methods：
Wherein：F3--- spindle endoporus area, F2--- area of orifice, s --- draft gear travel, l (s) --- spindle hinder
Buddhist nun's length,L --- buffer total travel.
In the present invention, coefficient of friction λ takes 0.0153.
The average in equivalent flow coefficient Cq rounding strokes can finally be acquired：
The oilhole discharge coefficient under each stroke, which is calculated, using the computational methods of the present invention is shown in Table 2.
2 discharge coefficient of table
Using the present invention carry out simulation analysis, and with the Comparative result with permanent current coefficient of discharge simulation analysis, be shown in Table 3.Using
There are larger differences with test data for the result of permanent current coefficient of discharge simulation analysis.And the discharge coefficient provided using the present invention
The result and drop-test data for carrying out simulation analysis are coincide substantially, and error range achieves ideal within 5%
As a result, demonstrate the correctness of computational methods.
3 result of calculation of table compares
The above is only the optimal specific embodiment of the present invention, but protection scope of the present invention is not limited thereto,
Any one skilled in the art in the technical scope disclosed by the present invention, the change or replacement that can be readily occurred in,
It should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with the protection model of the claim
Subject to enclosing.
Claims (3)
1. a kind of undercarriage buffer becomes the discharge coefficient computational methods of oilhole, which is characterized in that including：
First：Establish the discharge coefficient formula for calculating and becoming oilhole
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In formula, k oilholes change corresponding coefficient, and d is spindle diameter of bore, and l is length of the fluid by spindle, and λ is frictional resistance system
Number, s is draft gear travel；
Second：Equivalent flow coefficient is calculated according to discharge coefficient
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In formula, n is change oilhole quantity.
2. undercarriage buffer according to claim 1 becomes the discharge coefficient computational methods of oilhole, which is characterized in that friction
Coefficient lambda value is 0.015~0.016.
3. undercarriage buffer according to claim 2 becomes the discharge coefficient computational methods of oilhole, which is characterized in that friction
Coefficient lambda value is 0.0153.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711236764.0A CN108108526B (en) | 2017-11-30 | 2017-11-30 | Flow coefficient calculation method for variable oil hole of undercarriage buffer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201711236764.0A CN108108526B (en) | 2017-11-30 | 2017-11-30 | Flow coefficient calculation method for variable oil hole of undercarriage buffer |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN108108526A true CN108108526A (en) | 2018-06-01 |
| CN108108526B CN108108526B (en) | 2021-05-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201711236764.0A Active CN108108526B (en) | 2017-11-30 | 2017-11-30 | Flow coefficient calculation method for variable oil hole of undercarriage buffer |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101012007A (en) * | 2007-02-06 | 2007-08-08 | 南京航空航天大学 | Two-stage series connection two-chamber buffer |
| CN102052422A (en) * | 2010-12-09 | 2011-05-11 | 南京航空航天大学 | Nose landing gear bumper with high-pressure inflatable sudden-extension mechanism |
| CN102338186A (en) * | 2011-09-02 | 2012-02-01 | 北京航空航天大学 | Conical damping hole type buffer for undercarriage of passenger plane |
| CN102494073A (en) * | 2011-11-16 | 2012-06-13 | 南京航空航天大学 | Undercarriage buffer |
| CN203285899U (en) * | 2013-05-30 | 2013-11-13 | 江西洪都航空工业集团有限责任公司 | Variable oilhole structure of undercarriage buffer |
| CN106763424A (en) * | 2016-12-02 | 2017-05-31 | 中国运载火箭技术研究院 | A kind of undercarriage buffer method for designing for becoming oilhole based on oil back chamber |
-
2017
- 2017-11-30 CN CN201711236764.0A patent/CN108108526B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101012007A (en) * | 2007-02-06 | 2007-08-08 | 南京航空航天大学 | Two-stage series connection two-chamber buffer |
| CN102052422A (en) * | 2010-12-09 | 2011-05-11 | 南京航空航天大学 | Nose landing gear bumper with high-pressure inflatable sudden-extension mechanism |
| CN102338186A (en) * | 2011-09-02 | 2012-02-01 | 北京航空航天大学 | Conical damping hole type buffer for undercarriage of passenger plane |
| CN102494073A (en) * | 2011-11-16 | 2012-06-13 | 南京航空航天大学 | Undercarriage buffer |
| CN203285899U (en) * | 2013-05-30 | 2013-11-13 | 江西洪都航空工业集团有限责任公司 | Variable oilhole structure of undercarriage buffer |
| CN106763424A (en) * | 2016-12-02 | 2017-05-31 | 中国运载火箭技术研究院 | A kind of undercarriage buffer method for designing for becoming oilhole based on oil back chamber |
Non-Patent Citations (2)
| Title |
|---|
| 祝世兴 等: "基于磁流变减震器的弹性机体起落架着陆仿真分析", 《液压与气动》 * |
| 雷卫东 等: "直升机起落架着陆载荷及参数影响分析", 《海军航空工程学院学院报》 * |
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| Publication number | Publication date |
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| CN108108526B (en) | 2021-05-25 |
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