scholarly journals Subsonic Flutter of Cantilever Rectangular PC Plate Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Kemal Yaman
Keyword(s):  
Wind Tunnel ◽  
Modal Analysis ◽  
Simple Structure ◽  
Experimental Investigations ◽  
Flexible Plate ◽  
Test Results ◽  
Plate Structure ◽  
Flutter Analysis ◽  
Solution Methods ◽  
Subsonic Flutter

Flutter characteristics of cantilever rectangular flexible plate structure under incompressible flow regime are investigated by comparing the results of commercial flutter analysis program ZAERO©with wind tunnel tests conducted in Ankara Wind Tunnel (ART). A rectangular polycarbonate (PC) plate, 5 × 125 × 1000 mm in dimension, is used for both numerical and experimental investigations. Analysis and test results are very compatible with each other. A comparison between two different solution methods (g-methodandk-method) of ZAERO©is also done. It is seen that thek-methodgives a closer result than the other one. However,g-method results are on a conservative side and it is better to use conservative results, namely,g-method results. Even if the modal analysis results are used for the flutter analysis for this simple structure, a modal test should be conducted in order to validate the modal analysis results to have accurate flutter analysis results for more complicated structures.

Response and Operational Modal Analysis from Wind Tunnel Test of the EOLO Flexible Aircraft

2021 ◽  
Author(s):  
David F. Castillo Zuñiga ◽  
Alain Giacobini Souza ◽  
Roberto G. da Silva ◽  
Luiz Carlos Sandoval Góes
Keyword(s):  
Wind Tunnel ◽  
Modal Analysis ◽  
Wind Tunnel Test ◽  
Operational Modal Analysis ◽  
Flexible Aircraft

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.

Experimental investigations of flow over NACA airfoils 0021 and 4412 of wind turbine blades with and without Tubercles

2021 ◽  
pp. 0309524X2110071
Author(s):  
Usman Butt ◽  
Shafqat Hussain ◽  
Stephan Schacht ◽  
Uwe Ritschel
Keyword(s):  
Wind Tunnel ◽  
Drag Coefficient ◽  
Wind Turbine ◽  
Critical Region ◽  
Lift Coefficient ◽  
Turbine Blades ◽  
Leading Edge ◽  
Reynolds Numbers ◽  
Experimental Investigations ◽  
Wind Turbine Blades

Experimental investigations of wind turbine blades having NACA airfoils 0021 and 4412 with and without tubercles on the leading edge have been performed in a wind tunnel. It was found that the lift coefficient of the airfoil 0021 with tubercles was higher at Re = 1.2×105 and 1.69×105 in post critical region (at higher angle of attach) than airfoils without tubercles but this difference relatively diminished at higher Reynolds numbers and beyond indicating that there is no effect on the lift coefficients of airfoils with tubercles at higher Reynolds numbers whereas drag coefficient remains unchanged. It is noted that at Re = 1.69×105, the lift coefficient of airfoil without tubercles drops from 0.96 to 0.42 as the angle of attack increases from 15° to 20° which is about 56% and the corresponding values of lift coefficient for airfoil with tubercles are 0.86 and 0.7 at respective angles with18% drop.

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 Inter-Facility Correlations of Transonic Test Results of the AGARD-C Standard Wind-Tunnel Model

2018 ◽  
Vol 5 (13) ◽  
pp. 26476-26481
Author(s):  
Dijana Damljanović ◽  
Jovan Isaković ◽  
Marko Miloš
Keyword(s):  
Wind Tunnel ◽  
Test Results ◽  
Wind Tunnel Model ◽  
Tunnel Model

Dynamic Analysis and Experimental Research of Laser Cutting Machines

2014 ◽  
Vol 915-916 ◽  
pp. 31-34
Author(s):  
Qing Ping Zhang ◽  
Zheng Ru Wang ◽  
Yan Fang Wang
Keyword(s):  
Machine Tool ◽  
Modal Analysis ◽  
Laser Cutting ◽  
Machining Accuracy ◽  
Dynamics Analysis ◽  
Theoretical Base ◽  
Test Results ◽  
Cutting Machine ◽  
Manufacturing Errors ◽  
Theoretical Results

Vibration is one of the most important problems in laser cutting machine tool, which causes the manufacturing errors, also influences the machining accuracy of the parts. Modal analysis can calculate vibration type of structures. The paper presents how to use the powerful FEA software ANSYS to do the modal analysis on laser cutting machine tool and also studies the undamped free vibration on laser cutting machine tool. Finally, the test results and theoretical results were compared to verify the rationality of the modal, these provide theoretical base and conditions for dynamics analysis and optimal design.

A new atmospheric boundary layer wind tunnel simulation methodology for wind effects on large cooling towers considering wind environment variations

2018 ◽  
Vol 22 (5) ◽  
pp. 1194-1210 ◽  
Author(s):  
XX Cheng ◽  
X Chen ◽  
YJ Ge ◽  
H Jiang ◽  
L Zhao
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Atmospheric Boundary Layer ◽  
Model Test ◽  
Test Results ◽  
Wind Effects ◽  
Simulation Methodology ◽  
Codes Of Practice ◽  
Wind Tunnel Simulation ◽  
Tunnel Model

The traditional atmospheric boundary layer wind tunnel model test practice employs wind fields, the flow characteristics of which are in accordance with the empirical formulae of the atmospheric turbulence presented in Codes of Practice and monographs. However, the empirical formulae presented in Codes of Practice and monographs cannot truthfully reflect the high variations of the realistic atmospheric turbulence which sometimes aggravates wind effects on structures. Based on model tests conducted in a multiple-fan actively controlled wind tunnel, it is found that most wind effects on large cooling towers change monotonically with the increase in free-stream turbulence, and the model test results are more unfavorable for a flow field of low turbulence intensity than for a flow field of high turbulence intensity with respect to the measured coherences. Thus, a new atmospheric boundary layer wind tunnel simulation methodology for wind effects on circular cylindrical structures is proposed to overcome the deficiency of the traditional atmospheric boundary layer wind tunnel model tests. The new simulation methodology includes the simulation of two realistic atmospheric boundary layer flow fields with the highest and the lowest turbulence intensities in the wind tunnel and the envelopment of model test results obtained in the two flow fields (e.g. the mean and fluctuating wind pressure distributions, the power spectral density, the coherence function, and the correlation coefficient). The superiority of the new atmospheric boundary layer wind tunnel simulation methodology over the traditional model test practice is demonstrated by comparing the model test results with the full-scale measurement data.

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