scholarly journals Experimental and Numerical Studies on Static Aeroelastic Behaviours of a Forward-Swept Wing Model

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yan Ouyang ◽  
Kaichun Zeng ◽  
Xiping Kou ◽  
Yingsong Gu ◽  
Zhichun Yang
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Wind Tunnel Test ◽  
Swept Wing ◽  
Lattice Method ◽  
Model Calculations ◽  
Wind Tunnel Tests ◽  
Model Based ◽  
Wing Model ◽  
Fidelity Model

The static aeroelastic behaviours of a flat-plate forward-swept wing model in the vicinity of static divergence are investigated by numerical simulations and wind tunnel tests. A medium fidelity model based on the vortex lattice method (VLM) and nonlinear structural analysis is proposed to calculate the displacements of the wing structure with large deformation. Follower forces effect and geometric nonlinearity are considered to calculate the deformation of the wing by finite element method (FEM). In the wind tunnel tests, the divergence dynamic pressure is predicted by the Southwell method, and the static aeroelastic displacement is measured by a photogrammetric method. The results obtained by the medium fidelity model calculations show reasonable agreement with wind tunnel test results. A high fidelity model based on coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) predicts better results of the wing tip displacement when the freestream dynamic pressure is approaching the divergence dynamic pressure.

Wind Tunnel Experimental Research on Flutter Stability of Liujiaxia Bridge

2013 ◽  
Vol 361-363 ◽  
pp. 1105-1109
Author(s):  
Chun Sheng Shu
Keyword(s):  
Wind Tunnel ◽  
Critical Velocity ◽  
Experimental Research ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Wind Tunnel Tests

Liujiaxia Bridge is a truss stiffening girder suspension bridge which span is 536m, and it is the narrowest suspension bridge with the same scale, so the problems of flutter stability are prominent. Results of wind tunnel test show that its critical velocity cannot meet the requirements without any aerodynamic measures. Based on above considerations, seven kinds of aerodynamic measures are proposed, respectively wind tunnel tests are conducted. The results show that the program, in which the upper central stable board is 1.12m high and the under central stable board is 1.28m high, can meet the requirements. The results of this study provide some references to solving the problem of wind-resistant stability of narrow deck suspension bridge.

Videogrammetric Measurement for Model Displacement in Wind Tunnel Test

2011 ◽  
Vol 130-134 ◽  
pp. 103-107 ◽  
Author(s):  
Zheng Yu Zhang ◽  
Shui Liang Wang ◽  
Yan Sun
Keyword(s):  
Image Processing ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Accurate Data ◽  
Exterior Orientation ◽  
Wind Tunnel Tests ◽  
Key Techniques ◽  
Transonic Wind Tunnel

It is crucial measuring position and attitude of model to gain the precise and accurate data in wind tunnel tests. The model displacement videogrammetric measurement (MDVM) system and its key techniques such as the exterior orientation with big rotation angles and large-overlap, mark points, image processing and calibration based on the known distances are therefore presented. The practice example in Asia's largest (2.4m) transonic wind tunnel has demonstrated the MDVM system and its key techniques are correct and feasible, and they have application value.

Wind Tunnel Test of a Blended Wing Aircraft in Ground Effect With Active Flow Control

2016 ◽  
Author(s):  
Michael Mayo ◽  
Jonathan Carroll ◽  
Nicholas Motahari ◽  
Warren Lee ◽  
Robert Englar
Keyword(s):  
Wind Tunnel ◽  
Active Flow Control ◽  
Wind Tunnel Test ◽  
Ground Effect ◽  
Circulation Control ◽  
Wing Model ◽  
Subsonic Wind Tunnel ◽  
Test Methodology ◽  
Tunnel Floor ◽  
Lift And Drag

This paper describes the test methodology and results for a wind tunnel experiment featuring a blended wing aircraft in ground effect with built-in circulation control. A 82.55cm wingspan blended wing model was tested in a subsonic wind tunnel at velocities ranging from 18m/s – 49m/s and corresponding Reynolds numbers ranging from 130k – 350k. Pitch angle was held constant at 0 degrees and the height above the wind tunnel floor was modified to determine lift and drag modification due to ground effect. At a normalized height (y/bw) of 0.06, ground effect increased lift production by 24% and reduced drag by 22% when compared to a normalized height of 0.5. The addition of the circulation control significantly increased the lift production of the model at a cost of increased drag. At a normalized height of 0.031, the lift production increased by 200% at a blowing coefficient of 0.01, but the drag also increased by 72%, ultimately increasing L/D by 178%. Experimental results also suggest that ground effect and circulation control have a synergistic effect when used simultaneously. The effects of Reynolds number and circulation control slot height are also investigated.

scholarly journals Aerodynamic study of a suspension bridge deck by CFD simulations, wind tunnel tests and full-scale observations

2021 ◽  
Vol 1201 (1) ◽  
pp. 012007
Author(s):  
I. Kusano ◽  
E. Cheynet ◽  
J. B. Jakobsen ◽  
J. Snæbjörnsson
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Suspension Bridge ◽  
Aerodynamic Characteristics ◽  
Full Scale ◽  
Navier Stokes ◽  
Cfd Simulations ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wide Range

Abstract Assessing the aerodynamic characteristics of long-span bridges is fundamental for their design. Depending on the terrain complexity and local wind conditions, episodes of large angles of attack (AoA) of 15° may be observed. However, such large AoAs ( above 10°) are often overlooked in the design process. This paper studies the aerodynamics properties of a flow around a single-box girder for a wide range of AoAs, from –20° to 20°, using numerical simulations. The simulations are based on a 2D unsteady Reynolds-averaged Navier–Stokes (URANS) approach using the k − ω SST turbulence model with a Reynolds number of 1.6 × 105. Numerically obtained aerodynamic static coefficients were compared to wind tunnel test data. The CFD results were generally in good agreement with the wind tunnel tests, especially for small AoAs and positive AoAs. More discrepancies were observed for large negative AoA, likely due to the limitation of modelling 3D railings with 2D simulations. The simulated velocity deficit downstream of the deck was consistent with the one measured in full-scale using short-range Doppler wind lidar instruments. Finally, the Strouhal number from the CFD simulations were in agreement with the value obtained from the full-scale data.

scholarly journals Desain dan Eksperimen Uji Getaran di Tanah dari Model Separuh Sayap Pesawat N219

WARTA ARDHIA ◽  
2017 ◽  
Vol 42 (3) ◽  
pp. 123
Author(s):  
Sayuti Syamsuar ◽  
Leonardo Gunawan ◽  
Martina Widiramdhani ◽  
Nina Kartika
Keyword(s):  
Wind Tunnel ◽  
Critical Phenomenon ◽  
Damping Ratio ◽  
Wind Tunnel Test ◽  
Ground Vibration ◽  
Parameter Analysis ◽  
Vibration Test ◽  
Software Analysis ◽  
Flutter Speed ◽  
Wing Model

Fenomena flutter merupakan salah satu fenomena yang kritis dan dapat membahayakan pesawat. Ketika, pesawat terbang semakin cepat dan mencapai kecepatan flutter, maka akan terjadi ketidakstabilan struktur. Oleh sebab itu, untuk menjamin keselamatan Pilot saat uji terbang, perlu dilakukan analisis awal pada kecepatan flutter. Uji terowongan angin selalu dilakukan untuk memvalidasi hasil dari analisis numerikal. Penelitian ini meliputi analisis program NASTRAN pada model separuh sayap pesawat N219 saat uji getaran di tanah. Prediksi kecepatan flutter secara analisis hampir sama dengan hasil uji terowongan angin. Parameter modus struktur yang ditemukan, seperti frekuensi natural, modus getar dan rasio redaman, dapat digunakan untuk analisis parameter flutter sebagai metoda analisis baru. [The Design and Experiment of Ground Vibration Test of N219 Aircraft Half Wing Model] Flutter phenomena is a critical phenomenon that can be dangerous for aircraft. When an aircraft fly faster until reach flutter speed, the structure will become unstable. Therefore, it is important to conduct preliminary analysis of flutter speed to ensure the safety of Pilot. Wind tunnel test is necessary to be conducted to validate numerical analysis results. This research consist of NASTRAN software analysis of half wing model of N219 aircraft for ground vibration test. The prediction of flutter speed which is obtained from software analysis is similar with the wind tunnel test result. It is found that the modus parameter of structure like natural frequency, modus of vibration and damping ratio can be used on the parameter analysis as a new analysis method.

Study on the Aerodynamic Characteristics and Galloping Instability of Conductors Covered with Sector-Shaped Ice by a Wind Tunnel Test

2020 ◽  
Vol 20 (06) ◽  
pp. 2040016
Author(s):  
Jia-Xiang Li ◽  
Jian Sun ◽  
Ye Ma ◽  
Shu-Hong Wang ◽  
Xing Fu
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Ice Thickness ◽  
Shape Parameters ◽  
Aerodynamic Coefficient ◽  
Wind Tunnel Tests ◽  
And Control

Conductors with sector-shaped ice are susceptible to galloping. To prevent and control galloping, it is necessary to study the conductor aerodynamic characteristics. Wind tunnel tests were performed to study the influence of two shape parameters (ice thickness and ice angle) of a conductor with sector-shaped ice on the aerodynamic characteristics considering the roughness of the surface. In addition, the unstable areas for galloping are discussed according to Den Hartog theory and Nigol theory. The results show that with increasing ice thickness, the aerodynamic coefficient curves fluctuate more strongly, and galloping tends to occur; with increasing ice angle, the unstable area becomes larger according to Nigol theory, and the increasing drag coefficient will suppress the unstable areas according to Den Hartog theory. With the increasing two shape parameters, the most affected ranges of the aerodynamic coefficient curves are 150–180∘.

The Aerodynamic Analysis for Iced Four Bundled Transmission Lines with Typical Crescent

2014 ◽  
Vol 8 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Liu Yuejun ◽  
Tang Ai P. ◽  
Liu Ke T. ◽  
Tu Jie W.
Keyword(s):  
Numerical Simulation ◽  
Wind Tunnel ◽  
Transmission Lines ◽  
Angle Of Attack ◽  
Wind Tunnel Test ◽  
Simulation Method ◽  
Single Wire ◽  
Wind Tunnel Tests ◽  
Absolute Value ◽  
Aerodynamic Test

Despite the fact that the wind tunnel tests have been carried out on iced transmission lines subjected to wind load, it is not practical to do wind tunnel tests due to its high cost. This paper describes a detailed numerical simulation method that can be used to instead of wind tunnel tests. Based on the galloping mechanism of iced transmission lines, the aerodynamic test was simulated with the typical crescent super-large thickness iced four bundled conductors. One of the results highlighted in this study is that the wind angle of attack had significant influence on the aerodynamics of iced conductors. The Den-Hartog and O.Nigol coefficient were calculated to determine galloping of iced transmission lines, comparing with the reference of wind tunnel test in the Zhejiang university, the range of the wind angle of attack to the bundled conductor which can lead to gallop is larger than single wire, but the absolute value of amplitude is less than the single conductor, split conductor is more likely to gallop than single conductor.

Aeroelastic Wind Tunnel Tests of the RIBES Wing Model

2020 ◽  
pp. 9-28 ◽  
Author(s):  
F. Nicolosi ◽  
V. Cusati ◽  
D. Ciliberti ◽  
Pierluigi Della Vecchia ◽  
S. Corcione
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Tests ◽  
Wing Model

Design and Application of an all Moving Wing Model Limiting and Locking Device

2013 ◽  
Vol 753-755 ◽  
pp. 1031-1034 ◽  
Author(s):  
Bo Lu ◽  
Bin Bin Lv ◽  
Li Yu ◽  
Hong Tao Guo ◽  
Yu Yan ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Test Data ◽  
High Speed ◽  
Wind Tunnel Test ◽  
Test Equipment ◽  
Test Model ◽  
Wing Flutter ◽  
Wing Model ◽  
Control Principle ◽  
Design And Application

To effectively excite the all moving wing flutter model and limiting or quick locking model in case of bigger amplitude of the model, an excitation and limiting and locking device is designed for the high-speed wind tunnel flutter test model. This paper introduces the structure arrangement, control principle and strategy of this device. The wind tunnel flutter test indicates that this device can enhance the SNR of the test data, improve the boundary prediction precision of flutter, prevent the model from entering the flutter divergence state and protect the model and wind tunnel test equipment.

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