CN109768474A - The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength - Google Patents
The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength Download PDFInfo
- Publication number
- CN109768474A CN109768474A CN201811346715.7A CN201811346715A CN109768474A CN 109768474 A CN109768474 A CN 109768474A CN 201811346715 A CN201811346715 A CN 201811346715A CN 109768474 A CN109768474 A CN 109768474A
- Authority
- CN
- China
- Prior art keywords
- whirlpool
- lightning rod
- vibration
- steel pipe
- order
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Landscapes
- Wind Motors (AREA)
Abstract
This hair proposes a kind of Karman vortex street phenomenon to the influence calculation method of steel pipe lightning rod mechanical strength；And it proposes that Karman vortex street is avoided to act on the Vortex-excited vibration phenomenon to be formed to the method for steel pipe lightning rod intensity effect.Method includes the following steps: one, calculating lightning rod whirlpool shakes fatigue life；Step are as follows: (1) estimate vibration critical wind speed；(2) it calculates whirlpool and swashs power；(3) it calculates whirlpool and swashs fatigue stress；(4) steel pipe lightning rod fundamental frequency is calculated；(5) fatigue life is swashed in estimation whirlpool；Two, according to existing 220kV, 330kV, 500kV, 750kV transformer substation framework lightning rod structural parameters, possible single order, second order vibration critical wind speed are estimated using above-mentioned calculation method；Three, according to calculated result, in the appearance of free-standing steel pipe lightning rod, arrange that rectangle spoiler, winding screw line or package have the coat of spiral ribs item, and the staggered fin plate of setting.
Description
Technical field
The invention belongs to electricity fields, and in particular to a kind of that Vortex-excited vibration is avoided to influence steel pipe lightning rod mechanical strength
Method.
Background technique
A kind of important direct lightning strike safeguard of the lightning rod as electric system and industrial and agricultural production, various structures, rule
Lattice are different.In the super of electric system, ultra-high voltage transformer station, to prevent lightning surge from damaging transformer equipment and its attached setting
It applies, a kind of universal method is to prevent from attacking lightning overvoltage directly using lightning rod and lightning conducter.
Into in the past few years, with the continuous expansion of power grid scale, a large amount of steel pipe type framework lightning rod is largely used power transformation
It stands in power plant, many advantages such as this steel pipe lightning rod is simple, easy for installation with its design, operation and maintenance amount is small are fast
Speed is in newly-built super, the universal use of extra-high voltage power transformation engineering.
With the continuous accumulation of operating experience, there has also been considerable degree of to the lightning rod of this structure specific by people
Solution, but since in May, 2015, two steel pipe frameworks occur in succession for the domestic 750kV substation in the Xinjiang and Gansu of the Northwest
Lightning rod is broken fallen accident from flange in the bottom junction in strong wind weather, and accident investigation is analyzed to think: on the accident same day
Strong wind weather under, the design mechanical strength of the steel pipe lightning rod of this variable cross-section is fully able to meet the requirements, and also there are appropriate
Nargin, but from the lightning-arrest skill of handling needles downlink connection bolt fracture cross-section observation of the fracture at scene, find there are 3 planes of disruption in 8 bolts
60% corrosion is had more than, remaining bolt is unable to satisfy lightning rod intensity requirement in strong wind weather.Therefore, preliminary to exclude design original
Cause.
On the other hand, the wind speed considered when design is 100 years one Limit of Wind Speed met, and is changed by extremum I distributing model
Maximum mean wind speed is obtained after calculation, then the maximum wind velocity of different height is found out at corresponding height by formula conversion, as
Design considerations.This method is always the common practice of domestic major electric survey design industry unit.But why pass through this side
Other ground do not break down the steel pipe lightning rod that method designs at home, but only occur in the Northwest, pass through fluid force
Content and crash analysis are learned, finally found that, influence of the Karman vortex street to lightning rod, Karman vortex street are had ignored when designing lightning rod
It acts on steel pipe lightning rod, in the effect of certain wind speed, causes lightning rod Vortex-excited vibration, lightning rod oscillation at this time is the most acute
Strong, amplitude is maximum, and resonance causes screw cross-section part to be cut, and mechanical strength reduces, and is then broken in failure day, therefore, must
Must take measures influence of the Vortex-excited vibration to lightning rod mechanical strength caused by eliminating Karman vortex street, just can guarantee by original design
The lightning rod intensity of method design is met the requirements.
But currently, lightning rod design does not consider this influence also, this patent will consider this influence, and corresponding work is unfolded
Make.
Summary of the invention
It is an object of the present invention to propose a kind of Karman vortex street phenomenon to the influence calculating side of steel pipe lightning rod mechanical strength
Method；And it proposes that Karman vortex street is avoided to act on the Vortex-excited vibration phenomenon to be formed to the method for steel pipe lightning rod intensity effect.
Method includes the following steps:
One, lightning rod whirlpool is calculated to shake fatigue life；Step are as follows: (1) estimate vibration critical wind speed；(2) it calculates whirlpool and swashs power；
(3) it calculates whirlpool and swashs fatigue stress；(4) steel pipe lightning rod fundamental frequency is calculated；(5) fatigue life is swashed in estimation whirlpool；
Two, according to existing 220kV, 330kV, 500kV, 750kV transformer substation framework lightning rod structural parameters, above-mentioned meter is utilized
Calculation method estimates possible single order, second order vibration critical wind speed；
Three, according to calculated result, in the appearance of free-standing steel pipe lightning rod, arrange rectangle spoiler, winding screw line or
Package has the coat of spiral ribs item, and the staggered fin plate of setting.
Further, step is calculated in step 1 are as follows:
(1) vibration critical wind speed is estimated
Take steel pipe air terminal length l be 27m, with intermediate cross-section characterization total calculating section, outer diameter D 0.47m,
Radius of gyration ixFor 0.164m, lightning rod slenderness ratio λ=l/ixIt is 164, cantilever constraint, single order vibration critical wind speed are as follows:
vα1=0.41 × 105λ-2
Second order vibration critical wind speed
vα1=2.54 × 105λ-2
(2) whirlpool is swashed power and is calculated
It is assumed that the intermediate position that power acts on 27m long lightning rod with concentrated force is swashed in whirlpool, power is swashed in single order whirlpool and torque is swashed in whirlpool:
Power is swashed in second order whirlpool and torque is swashed in whirlpool:
(3) Fatigue stress calculation is swashed in whirlpool
After socket mode, the curved scissors stress under the sharp power effect in whirlpool is born in the entire ring section of substrate jointly, and substrate is cut
Face outer diameter is 0.8m, and internal diameter 0.78m, annular cross-sectional area A are 0.0992m2, ring section bending resistant section coefficient
Each rank whirlpool vibration curved scissors Stress calculation
(4) steel pipe lightning rod fundamental frequency calculates
Under field conditions (factors), when whirlpool vibration occurs, mostly take place frequently with the single order of structure and divalent radical raw locking, i.e., whirlpool vibration frequency with
Single order, the second order fundamental frequency of structure are consistent；Estimate the whirlpool vibration accumulation frequency, need first to structure one, second order fundamental frequency counts
It calculates；In view of analysis object is variable-section steel pipe structure, general reduced mechanical model can not obtain accurate frequency, therefore establish
Finite element model carries out model analysis and has obtained the fundamental frequency and second order frequency of steel pipe lightning rod；
(5) estimation of fatigue life is swashed in whirlpool
According to Code for design of steel structures, aeolian vibration steel tube component allowable stress range of fatigue value is calculated
It connects and considers by the 5th class, the value of C is 1.47x1012, β 3；Greater than the wind of single order vibration critical wind speed 1.52m/s
Speed is almost all occurring all the time, then the frequency of single order whirlpool vibration can be calculated as follows:
n1=365 × 24 × 3600 × 1.04=3.27 × 107
It shakes, is calculated under the reciprocating of second order fatigue stress maximum value for second order whirlpool, the maximum tolerance fatigue of structure
Number is as follows:
Wherein σ2maxFor second order fatigue stress maximum value, can be inquired by preliminary examination design data；It is assumed that whole day 24 hours
In the case where the vibration of uninterrupted generation whirlpool, maximum tolerance number of days are as follows:
Detailed description of the invention
Karman vortex street under Fig. 1 different Reynolds number；
Fig. 2 interlocks fin plate.
Specific embodiment
When Karman vortex street phenomenon refers to permanent incoming flow under certain condition around certain objects, object two sides can be periodically
Ground falls off, and direction of rotation is opposite out and is arranged in well-regulated biserial line vortex.When beginning, this two alignments whirlpool keeps itself respectively
Movement is advanced, and then they are interfered with each other, and is attracted each other, and interferes increasing, the nonlinear so-called vortex street of formation.Toll bar
Vortex street is a kind of phenomenon that viscous incompressible fluid dynamics are studied.Fluid winding flow chimney stalk, skyscraper, electric wire,
Karman vortex street can be all generated when the tube bank of oil-piping and heat exchanger, the Karman vortex street under different Reynolds number is shown in Fig. 1.Karman vortex street is made
With on steel pipe lightning rod, in the effect of certain wind speed, causing lightning rod Vortex-excited vibration, lightning rod oscillation at this time is the most violent,
Amplitude is maximum, and resonance causes lightning rod fixing bolt cross-section parts to be cut, and mechanical strength reduces, final fracture.
Therefore, it is wanted to guarantee that lightning rod meets design in the various weather conditions especially mechanical strength when there is wind weather
It asks, it is necessary to this Karman vortex street phenomenon acted on lightning rod is studied, to determine the condition of Vortex-excited vibration generation,
It is taken in design, avoids failure.
For Karman vortex street phenomenon to the influence calculation method of steel pipe lightning rod mechanical strength
One, lightning rod whirlpool vibration Calculation of Fatigue Life
Also with real whirlpool vibration occurs for randomness in view of fatigue cracking and non-linear relatively strong, accurate fatigue life prediction
Number is closely related, and existing theoretical calculation is only capable of being calculated for the sharp power in cross-section steel pipe whirlpool, and variable-section steel pipe is lightning-arrest
The vibration research of needle whirlpool is insufficient, therefore is currently only capable of estimating that the following are specific to the whirlpool vibration fatigue life of socket steel pipe lightning rod
Calculating process.
(1) vibration critical wind speed is estimated
Take steel pipe air terminal length l be 27m, with intermediate cross-section characterization total calculating section, outer diameter D 0.47m,
Radius of gyration ixFor 0.164m, lightning rod slenderness ratio λ=l/ixIt is 164, cantilever constraint, single order vibration critical wind speed are as follows:
vα1=0.41 × 105λ-2 (1)
Second order vibration critical wind speed is shown in formula (2).
vα1=2.54 × 105λ-2 (2)
By calculating, single order vibration critical wind speed is 1.52m/s, and second order vibration critical wind speed is 9.41m/s.
(2) whirlpool is swashed power and is calculated
It is assumed that the intermediate position that power acts on 27m long lightning rod with concentrated force is swashed in whirlpool, power is swashed in single order whirlpool and torque is swashed in whirlpool
Formula (3), (4) are seen respectively.
Power is swashed in second order whirlpool and whirlpool swashs torque and sees formula (5), (6) respectively:
By calculating, it is 140.43N, 1895N.m that the sharp torque of power and whirlpool is swashed in single order whirlpool, and the sharp power in second order whirlpool and whirlpool swash torque and be
3337N、 45053N.m。
(3) Fatigue stress calculation is swashed in whirlpool
After socket mode, the curved scissors stress under the sharp power effect in whirlpool is born in the entire ring section of substrate jointly, and substrate is cut
Face outer diameter is 0.8m, and internal diameter 0.78m, annular cross-sectional area A are 0.0992m2, and ring section bending resistant section coefficient is shown in formula (7).
Each rank whirlpool vibration curved scissors Stress calculation is shown in formula (8).
By calculating, single order and second order whirlpool vibration curved scissors stress are respectively 0.394MPa, 9.3Mpa.
(4) steel pipe lightning rod fundamental frequency calculates
Under field conditions (factors), when whirlpool vibration occurs, mostly take place frequently with the single order of structure and divalent radical raw locking, i.e., whirlpool vibration frequency with
Single order, the second order fundamental frequency of structure are consistent.Estimate the whirlpool vibration accumulation frequency, need first to structure one, second order fundamental frequency counts
It calculates.In view of analysis object is variable-section steel pipe structure, general reduced mechanical model can not obtain accurate frequency, therefore establish
Finite element model carries out model analysis and has obtained the fundamental frequency of steel pipe lightning rod to be 1.04Hz, second order frequency 4.94Hz.
(5) estimation of fatigue life is swashed in whirlpool
According to Code for design of steel structures, formula (9) are shown in the calculating of aeolian vibration steel tube component allowable stress range of fatigue value.
It connects and considers by the 5th class, the value of C is 1.47x1012, β 3.Greater than the wind of single order vibration critical wind speed 1.52m/s
Speed is almost all occurring all the time, then the frequency of single order whirlpool vibration can be calculated as follows:
n1=365 × 24 × 3600 × 1.04=3.27 × 107
Allowable stress amplitude is then shaken for 35.5Mpa by the single order whirlpool that formula (9) calculate.It is provided according to the initial designs of lightning rod
The fatigue stress maximum value of steel pipe lightning rod known to related content is lower than above formula calculated result in material, illustrates that the vibration of single order whirlpool will not draw
Play the fatigue rupture of lightning rod.
It shakes, is calculated under the reciprocating of second order fatigue stress maximum value for second order whirlpool, the maximum tolerance fatigue of structure
Number is as follows:
Wherein σ2maxFor second order fatigue stress maximum value, can be inquired by preliminary examination design data.It is assumed that whole day 24 hours
In the case where the vibration of uninterrupted generation whirlpool, maximum tolerance number of days are as follows:
It is the calculating step by simplified steel pipe lightning rod Vortex-excited vibration fatigue life above.
Two, Karman vortex street is avoided to act on the Vortex-excited vibration phenomenon to be formed to the method for steel pipe lightning rod intensity effect
1, each voltage class substation framework lightning rod starting of oscillation wind speed estimation
Existing 220kV, 330kV, 500kV, 750kV transformer substation framework lightning rod structural parameters that foundation designing institute provides,
Calculated result is as shown in table 1 to be estimated to possible single order, second order vibration critical wind speed using above-mentioned calculation method.
2, the improvement of pneumatic control measure
Influence of the Karman vortex street to steel pipe lightning rod mechanical strength is mainly manifested on Vortex-excited vibration, is in wind field windward side
The steel pipe lightning rod of most upstream, in the lower flow field of turbulence intensity and under suitable wind friction velocity, it may occur that Vortex-excited vibration；And
Under the continuous action of Vortex-excited vibration Cyclic Loading, fatigue cracking easily occurs for steel pipe lightning rod bottom flange dish connection bolt, makes
The effective work area of bolt constantly reduces, until impaired operation bolt is thoroughly broken, finally when certain gale weather process occurs
The entirety of steel pipe lightning rod is caused to be toppled over.Therefore, the influence by Karman vortex street to lightning rod is reduced to minimum, just must the side of thinking
Try to avoid occurring Vortex-excited vibration, existing corrective measure is that whirlpool is avoided to swash by the improvement to lightning rod pneumatic control measure
The generation of resonance.
Pneumatic control measure is by the aerodynamic configuration of change steel pipe lightning rod, and the rule for upsetting whirlpool falls off, to avoid
The generation of whirlpool vibration is the effective measures for fundamentally solving steel pipe lightning rod whirlpool vibration fatigue.Main implementation include:
The appearance of free-standing steel pipe lightning rod, interval and spacing are along pipe shaft arrangement rectangle spoiler, winding screw line at an angle
Or package has the coat of spiral ribs item, and the staggered fin plate (as shown in Figure 2) of setting.Above-mentioned pneumatic control measure is specific
Structural parameters (arrangement spacing, height, spiral line footpath etc.), closely related with outer diameter of steel pipes, various sizes of lightning rod needs
Design different structural parameters.
Each voltage class framework lightning rod critical wind velocity of table 1
Finally, it should be noted that the foregoing is only a preferred embodiment of the present invention, it is not intended to restrict the invention,
Although the present invention is described in detail referring to the foregoing embodiments, for those skilled in the art, still may be used
To modify the technical solutions described in the foregoing embodiments or equivalent replacement of some of the technical features.
It is all within the contents of the present invention and principle, any modification, equivalent replacement, improvement and so on should be included in of the invention
Within protection scope.
Claims (2)
1. the method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength, which is characterized in that this method includes following step
It is rapid:
One, lightning rod whirlpool is calculated to shake fatigue life；Step are as follows: (1) estimate vibration critical wind speed；(2) it calculates whirlpool and swashs power；(3) it counts
It calculates whirlpool and swashs fatigue stress；(4) steel pipe lightning rod fundamental frequency is calculated；(5) fatigue life is swashed in estimation whirlpool；
Two, according to existing 220kV, 330kV, 500kV, 750kV transformer substation framework lightning rod structural parameters, above-mentioned calculating side is utilized
Method estimates possible single order, second order vibration critical wind speed；
Three, rectangle spoiler, winding screw line or package are arranged in the appearance of free-standing steel pipe lightning rod according to calculated result
Coat with spiral rib, and the staggered fin plate of setting.
2. the method according to claim 1 for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength, feature exist
In,
Step is calculated in step 1 are as follows:
(1) vibration critical wind speed is estimated
Taking steel pipe air terminal length l is 27m, with the calculating section of intermediate cross-section characterization total, outer diameter D 0.47m, revolution
Radius ixFor 0.164m, lightning rod slenderness ratio λ=l/ixIt is 164, cantilever constraint, single order vibration critical wind speed are as follows:
vα1=0.41 × 105λ-2
Second order vibration critical wind speed
vα1=2.54 × 105λ-2
(2) whirlpool is swashed power and is calculated
It is assumed that the intermediate position that power acts on 27m long lightning rod with concentrated force is swashed in whirlpool, power is swashed in single order whirlpool and torque is swashed in whirlpool:
Power is swashed in second order whirlpool and torque is swashed in whirlpool:
(3) Fatigue stress calculation is swashed in whirlpool
After socket mode, the entire ring section of substrate bears whirlpool jointly and swashs curved scissors stress under power effect, outside substrate section
Diameter is 0.8m, and internal diameter 0.78m, annular cross-sectional area A are 0.0992m2, ring section bending resistant section coefficient
Each rank whirlpool vibration curved scissors Stress calculation
(4) steel pipe lightning rod fundamental frequency calculates
Under field conditions (factors), when whirlpool vibration occurs, mostly take place frequently with the single order of structure and divalent radical raw locking, i.e. whirlpool vibration frequency and structure
Single order, second order fundamental frequency it is consistent；Estimate the whirlpool vibration accumulation frequency, need first to structure one, second order fundamental frequency calculates；It examines
Considering analysis object is variable-section steel pipe structure, and general reduced mechanical model can not obtain accurate frequency, therefore establish limited
Meta-model carries out model analysis and has obtained the fundamental frequency and second order frequency of steel pipe lightning rod；
(5) estimation of fatigue life is swashed in whirlpool
According to Code for design of steel structures, aeolian vibration steel tube component allowable stress range of fatigue value is calculated
It connects and considers by the 5th class, the value of C is 1.47x1012, β 3；Wind speed greater than single order vibration critical wind speed 1.52m/s is several
All the time all occurring, then the frequency of single order whirlpool vibration can be calculated as follows:
n1=365 × 24 × 3600 × 1.04=3.27 × 107
It shakes, is calculated under the reciprocating of second order fatigue stress maximum value for second order whirlpool, the maximum tolerance times of fatigue of structure
It is as follows:
Wherein σ2maxFor second order fatigue stress maximum value, can be inquired by preliminary examination design data；It is assumed that whole day 24 hours uninterrupted
In the case where whirlpool vibration occurs, maximum tolerance number of days are as follows:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811346715.7A CN109768474A (en) | 2018-11-13 | 2018-11-13 | The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811346715.7A CN109768474A (en) | 2018-11-13 | 2018-11-13 | The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109768474A true CN109768474A (en) | 2019-05-17 |
Family
ID=66449563
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811346715.7A Pending CN109768474A (en) | 2018-11-13 | 2018-11-13 | The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109768474A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106300212A (en) * | 2016-09-05 | 2017-01-04 | 中国电力科学研究院 | A kind of steel pipe lightning arrester being controlled based on aerodynamic configuration |
| CN106486892A (en) * | 2016-11-24 | 2017-03-08 | 国网新疆电力公司电力科学研究院 | Mitigate the steel pipe lightning rod of wind-induced vibration |
| CN108563870A (en) * | 2018-04-16 | 2018-09-21 | 中国电力工程顾问集团中南电力设计院有限公司 | The computational methods of steel tube tower rod piece aeolian vibration fatigue life |
-
2018
- 2018-11-13 CN CN201811346715.7A patent/CN109768474A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106300212A (en) * | 2016-09-05 | 2017-01-04 | 中国电力科学研究院 | A kind of steel pipe lightning arrester being controlled based on aerodynamic configuration |
| CN106486892A (en) * | 2016-11-24 | 2017-03-08 | 国网新疆电力公司电力科学研究院 | Mitigate the steel pipe lightning rod of wind-induced vibration |
| CN108563870A (en) * | 2018-04-16 | 2018-09-21 | 中国电力工程顾问集团中南电力设计院有限公司 | The computational methods of steel tube tower rod piece aeolian vibration fatigue life |
Non-Patent Citations (1)
| Title |
|---|
| 孙涛,李玥,温定筠,张广东,朱生鸿: "卡门涡街作用对钢管避雷针机械强度的影响", 《电瓷避雷器》 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Zhao et al. | Comparison of modeling methods and parametric study for a piezoelectric wind energy harvester | |
| CN104406558B (en) | Method for monitoring power transmission line sag | |
| CN101672125B (en) | Device for inhibiting power transmission line steel tube pole tower vortex-induced wind vibration and method thereof | |
| Shi et al. | Flapping dynamics of a low aspect-ratio energy-harvesting membrane immersed in a square cylinder wake | |
| CN106919731B (en) | Method for determining wake flow of wind turbine generator for different wind direction angles | |
| CN109543258A (en) | A kind of tower frame for wind generating set stress state calculation method based on mode superposition method | |
| Kawecki et al. | Cross-wind vibrations of steel chimneys—A new case history | |
| CN109768474A (en) | The method for avoiding Vortex-excited vibration from influencing steel pipe lightning rod mechanical strength | |
| CN107956650A (en) | Building enclosure with vibration inhibiting function and method for inhibiting vibration of building enclosure | |
| Jiang et al. | Research on the along-wind aerodynamic damping and its effect on vibration control of offshore wind turbine | |
| CN108563870B (en) | Method for calculating breeze vibration fatigue life of steel tube tower rod piece | |
| Palanimuthu et al. | A review of recent aerodynamic power extraction challenges in coordinated pitch, yaw, and torque control of large-scale wind turbine systems | |
| CN106592951B (en) | Wind-resistant vibration reduction hanging basket for aloft work | |
| CN202520041U (en) | Special steel tube component for structural steel tube tower | |
| CN109060214B (en) | Wire stress monitoring method under unbalanced tension working condition | |
| Wang et al. | Effects of wind rotor tilt angle on aerodynamic power of wind turbine under typical periodic disturbances | |
| Lu et al. | Hybrid nutation damper for controlling galloping power lines | |
| Henriksen et al. | A model based control methodology combining blade pitch and adaptive trailing edge flaps in a common framework | |
| CN202706638U (en) | Steel tube tower structure capable of effectively controlling breeze vibration | |
| Hassanli et al. | Flow enhancement in tall buildings for wind energy generation | |
| Furlanetto et al. | Design optimization of tapered steel wind turbine towers by QPSO algorithm | |
| Abraham et al. | Investigation of the near-wake behaviour of a utility-scale wind turbine | |
| CN207638243U (en) | Hinged bolt formula spacer pin | |
| Pedersen et al. | Investigation of load reduction possibilities in wind turbines using a fluid power pitch system | |
| Wei et al. | Study of the interference effect of building on the along-wind load of tower crane |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20190517 |
|
| RJ01 | Rejection of invention patent application after publication |