scholarly journals Convergence of transonic wind tunnel test results of the AGARD-B standard model

2020 ◽  
Vol 48 (4) ◽  
pp. 761-769
Author(s):  
Dijana Damljanović ◽  
Đorđe Vuković ◽  
Goran Ocokoljić ◽  
Boško Rašuo
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Test Results ◽  
Aerodynamic Coefficients ◽  
Supersonic Wind Tunnel ◽  
Mean Values ◽  
Wide Range ◽  
Production Technologies ◽  
Mach Numbers

AGARD-B is a widely-used configuration of a standard wind tunnel model. Beside its originally intended application for correlation of data from supersonic wind tunnel facilities, it was tested in a wide range of Mach numbers and, more recently, used for assessment of wall interference effects, validation of computational fluid dynamics codes and validation of new model production technologies. The researchers and wind tunnel test engineers would, naturally, like to know the "true" aerodynamic characteristics of this model, for comparison with their own work. Obviously, such data do not exist, but an estimate can be made of the dispersion of test results from various sources and of the probable "mean" values of the aerodynamic coefficients. To this end, comparable transonic test results for the AGARD-B model at Mach numbers 0.77, Mach 1.0 and Mach 1.17 from six wind tunnels were analyzed and average values and dispersions of the aerodynamic coefficients were computed.

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 Wind Tunnel Test Investigation on Unsteady Aerodynamic Coefficients of Iced 4-Bundle Conductors

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Mengqi Cai ◽  
Linshu Zhou ◽  
Hang Lei ◽  
Hanjie Huang
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Aerodynamic Characteristics ◽  
Critical Parameters ◽  
Torsional Motion ◽  
Aerodynamic Coefficients ◽  
Unsteady Aerodynamic ◽  
Wind Velocities ◽  
Aerodynamic Instability ◽  
Test Investigation

Iced conductor motion is induced by the aerodynamic instability of these conductors. The unsteady aerodynamic characteristics are different from the steady aerodynamic characteristics. The unsteady aerodynamic coefficients of typical iced conductors’ models under torsional motion are measured by the unsteady wind tunnel test. The unsteady aerodynamic coefficients of crescent-shape and sector-shape iced 4-bundle conductors under different torsional motion frequencies, wind velocities, and ice thicknesses are obtained. Wind test results show that there are significant differences between the unsteady and steady aerodynamic coefficients. The unsteady aerodynamic coefficients curve is a loop which is different from the steady aerodynamic coefficients. In addition, the obvious differences exist between unsteady aerodynamic coefficients of crescent-shape and sector-shape iced bundle conductors. Critical parameters, including torsional motion frequencies, wind velocity, ice shape, and ice thickness, have significant influences on unsteady aerodynamic coefficients. It shows that the wind tunnel experiment results are able to provide necessary data for the investigation of iced bundle conductor motion and their prevention techniques.

Supersonic Wind Tunnel Experiment on Aerodynamic Characteristics and Winglets Effects of the Tapered Supersonic Biplane

2011 ◽  
Author(s):  
Takashi Fujisono ◽  
Hiroshi Yamashita ◽  
Atsushi Toyoda ◽  
Hiroki Nagai ◽  
Keisuke Asai ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
High Speed ◽  
Type A ◽  
Aerodynamic Characteristics ◽  
Type B ◽  
Supersonic Wind Tunnel ◽  
Wing Model ◽  
Mach Numbers ◽  
The Difference ◽  
Wing Tip

The aerodynamic characteristics and the effects of tip plates of a tapered supersonic biplane wing during the starting process have been investigated through Experimental and Computational Fluid Dynamics (EFD/CFD). Three types of the wing model were used: without tip plate (type-N); with the tip plate which covers only the aft-half of the wing tip (type-A); with the tip plate which covers the entire wing tip (type-B). Experiment was conducted in the supersonic blowdown wind tunnel with 600 mm × 600 mm cross section located at the High-speed Wind Tunnel Facility of Institute of Space and Astronautical Science (ISAS/JAXA). The flow conditions covered from M∞ = 1.5 to 1.9 with increments of 0.1. Pressure-Sensitive Paint was applied to measure pressure distributions on the surface of the wing. CFD simulations were conducted to compare with experiments and to investigate effects of the Mach numbers in detail. The tapered biplane wing without the tip plate was found to start between M∞ = 1.8 and 1.9. The difference of the starting Mach numbers between type-N and type-A was small. On the other hand, the starting Mach number of type-B was about 0.05 higher than that of type-N.

Rancang Bangun Piranti Lunak Pengolah Data Pasca Pengujian Terowongan Angin Kecepatan Rendah Indonesia

2016 ◽  
Vol 7 (2) ◽  
pp. 131-138
Author(s):  
Ivransa Zuhdi Pane
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Effective Solution ◽  
Post Processing ◽  
Prototype Development ◽  
Design Activities ◽  
Index Terms ◽  
Test Objects ◽  
Processing Requirement

Data post-processing plays important roles in a wind tunnel test, especially in supporting the validation of the test results and further data analysis related to the design activities of the test objects. One effective solution to carry out the data post-processing in an automated productive manner, and thus eliminate the cumbersome conventional manual way, is building a software which is able to execute calculations and have abilities in presenting and analyzing the data in accordance with the post-processing requirement. Through several prototype development cycles, this work attempts to engineer and realize such software to enhance the overall wind tunnel test activities. Index Terms—software engineering, wind tunnel test, data post-processing, prototype, pseudocode

scholarly journals Investigation of the Time Dependence of Wind-Induced Aeroelastic Response on a Scale Model of a High-Rise Building

2021 ◽  
Vol 11 (8) ◽  
pp. 3315
Author(s):  
Fabio Rizzo
Keyword(s):  
Wind Tunnel ◽  
Time Dependence ◽  
Wind Tunnel Test ◽  
Structural Response ◽  
Cumulative Distribution ◽  
Scale Model ◽  
Acquisition Time ◽  
Test Results ◽  
High Rise ◽  
High Rise Building

Experimental wind tunnel test results are affected by acquisition times because extreme pressure peak statistics depend on the length of acquisition records. This is also true for dynamic tests on aeroelastic models where the structural response of the scale model is affected by aerodynamic damping and by random vortex shedding. This paper investigates the acquisition time dependence of linear transformation through singular value decomposition (SVD) and its correlation with floor accelerometric signals acquired during wind tunnel aeroelastic testing of a scale model high-rise building. Particular attention was given to the variability of eigenvectors, singular values and the correlation coefficient for two wind angles and thirteen different wind velocities. The cumulative distribution function of empirical magnitudes was fitted with numerical cumulative density function (CDF). Kolmogorov–Smirnov test results are also discussed.

scholarly journals Gust Alleviation Control using Prior Gust Information: Wind Tunnel Test Results

2019 ◽  
Vol 52 (12) ◽  
pp. 128-133
Author(s):  
Yoshiro Hamada ◽  
Kenichi Saitoh ◽  
Noboru Kobiki
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Gust Alleviation

scholarly journals Galloping Stability and Wind Tunnel Test of Iced Quad Bundled Conductors considering Wake Effect

2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Xiaohui Liu ◽  
Ming Zou ◽  
Chuan Wu ◽  
Mengqi Cai ◽  
Guangyun Min ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Transmission Lines ◽  
Degrees Of Freedom ◽  
Wind Tunnel Test ◽  
Aerodynamic Coefficients ◽  
Wake Effect ◽  
Aerodynamic Coefficient ◽  
Set Up ◽  
The Stability ◽  
Three Degrees Of Freedom

A new quad bundle conductor galloping model considering wake effect is proposed to solve the problem of different aerodynamic coefficients of each subconductor of iced quad bundle conductor. Based on the quasistatic theory, a new 3-DOF (three degrees of freedom) galloping model of iced quad bundle conductors is established, which can accurately reflect the energy transfer and galloping of quad bundle conductor in three directions. After a series of formula derivations, the conductor stability judgment formula is obtained. In the wind tunnel test, according to the actual engineering situation, different variables are set up to accurately simulate the galloping of iced quad bundle conductor under the wind, and the aerodynamic coefficient is obtained. Finally, according to the stability judgment formula of this paper, calculate the critical wind speed of conductor galloping through programming. The dates of wind tunnel test and calculation in this paper can be used in the antigalloping design of transmission lines.

scholarly journals Observations on some transonic wind tunnel test results of a standard model with a T-tail

2016 ◽  
Vol 66 (4) ◽  
pp. 34-39 ◽  
Author(s):  
Dijana Damljanovic ◽  
Djordje Vukovic ◽  
Aleksandar Vitic ◽  
Jovan Isakovic ◽  
Goran Ocokoljic
Keyword(s):  
Wind Tunnel ◽  
Standard Model ◽  
Wind Tunnel Test ◽  
Test Results ◽  
Transonic Wind Tunnel

Galloping response of sector-shape iced eight bundle conductors

2020 ◽  
Vol 47 (10) ◽  
pp. 1201-1213
Author(s):  
Meng-qi Cai ◽  
Lin-shu Zhou ◽  
Qian Xu ◽  
Xiao-hui Yang ◽  
Xiao-hui Liu
Keyword(s):  
Transmission Lines ◽  
Theoretical Basis ◽  
Wind Tunnel Test ◽  
Dynamic Responses ◽  
Test Results ◽  
The Finite Element Method ◽  
Aerodynamic Coefficients ◽  
Aerodynamic Loads ◽  
Natural Modes ◽  
Wind Velocities

Wind tunnel test results of the aerodynamic coefficients of sector-shape iced eight bundle conductors varying with wind attack angles are presented. Then, by means of the user-defined cable elements, the aerodynamic loads are applied on the cable elements of each sub-conductor through the finite element method (FEM). In addition, the galloping responses of sector-shape iced eight bundle conductors are discussed. Finally, galloping responses, including dynamic responses (natural modes and frequencies), galloping orbits, and amplitudes of typical sector-shape iced eight bundle conductor transmission lines in the cases of different span lengths, wind velocities, and angles of wind attack are studied, respectively. These results provide useful references for a theoretical basis for the study of galloping and the technique of anti-galloping in cold regions.

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