• Title/Summary/Keyword: wind tunnel investigation

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Comparison of finite element analysis with wind tunnel test on stability of a container crane (컨테이너 크레인의 안정성에 대한 풍동실험과 유한요소해석의 비교)

  • Han, D.S.;Lee, S.W.;Han, G.J.
    • Journal of Power System Engineering
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    • v.12 no.6
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    • pp.29-35
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    • 2008
  • This study is conducted to provide the proper analysis method to evaluate the stability of a container crane under wind load. Two analysis method, namely structure analysis and fluid-structure interaction, are adopted to evaluate the stability of a container crane in this investigation. To evaluate the effect of wind load on the stability of the crane, 50-ton class container crane widely used in container terminals is adopted for analysis model and 19-values are considered for wind direction as design parameter. We conduct structure analysis and fluid-structure interaction for a container crane with respect to the wind direction using ANSYS and CFX. Then we compare the uplift forces yielded from two analysis with it yielded from wind tunnel test. The results are as follows: 1) A correlation coefficient between structure analysis and wind tunnel test is lower than 0.65(as $0.29{\sim}0.57$), but between fluid-structure interaction and wind tunnel test is higher than 0.65(as $0.78{\sim}0.86$). 2) There is low correlation between structure analysis and wind tunnel test but very high correlation between fluid-structure interaction and wind tunnel test.

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Wind tunnel investigation on wind characteristics of flat and mountainous terrain

  • Li, Jiawu;Wang, Jun;Yang, Shucheng;Wang, Feng;Zhao, Guohui
    • Wind and Structures
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    • v.35 no.4
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    • pp.229-242
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    • 2022
  • Wind tunnel test is often adopted to assess the site-specific wind characteristics for the design of bridges as suggested by current design standards. To investigate the wind characteristics of flat and mountainous terrain, two topographic models are tested in a boundary layer wind tunnel. The wind characteristics, including the vertical and horizontal mean wind speed distributions, the turbulence intensity, and the wind power spectra, are presented. They are investigated intensively in present study with the discussions on the effect of wind direction and the effect of topography. It is indicated that for flat terrain, the wind direction has negligible effect on the wind characteristics, however, the assumption of a homogenous wind field for the mountainous terrain is not applicable. Further, the non-homogeneous wind field can be defined based on a proposed approach if the wind tunnel test or on-site measurement is performed. The calculated turbulence intensities and wind power spectra by using the measured wind speeds are also given. It is shown that for the mountainous terrain, engineers should take into account the variability of the wind characteristics for design considerations.

The Wind Pressure Evaluation on Exterior Wall for High-rise Buildings (고층구조물 외벽의 내풍설계를 위한 풍압평가)

  • Lee Kyu-Ung;Kim Jae-Ung
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.63-70
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    • 2005
  • For using narrow site effectively, recently constructions of high-rise buildings have been increased. High-rise buildings are mainly governed by wind loads. Since wind flow Is vaned irregularly, the experimental method such as wind tunnel test is used to evaluate real wind loads. In this study, it is intended to estimate design wind pressure and amounts of material of cladding by AIK recommendations and wind tunnel test. Also, this study includes the investigation of reliability, suitability and economical efficiency in design of cladding of buildings by AIK recommendations and wind tunnel test by comparing and examining various results. Finally, it is concluded that not only AIK recommendations but also wind tunnel test should be considered to get the reasonable wind pressure acting on the cladding of high-rise buildings.

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Investigation on vortex-induced vibration of a suspension bridge using section and full aeroelastic wind tunnel tests

  • Sun, Yanguo;Li, Mingshui;Liao, Haili
    • Wind and Structures
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    • v.17 no.6
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    • pp.565-587
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    • 2013
  • Obvious vortex induced vibration (VIV) was observed during section model wind tunnel tests for a single main cable suspension bridge. An optimized section configuration was found for mitigating excessive amplitude of vibration which is much larger than the one prescribed by Chinese code. In order to verify the maximum amplitude of VIV for optimized girder, a full bridge aeroelastic model wind tunnel test was carried out. The differences between section and full aeroelastic model testing results were discussed. The maximum amplitude derived from section model tests was first interpreted into prototype with a linear VIV approach by considering partial or imperfect correlation of vortex-induced aerodynamic force along span based on Scanlan's semi-empirical linear model. A good consistency between section model and full bridge model was found only by considering the correlation of vortex-induced force along span.

Examination of experimental errors in Scanlan derivatives of a closed-box bridge deck

  • Rizzo, Fabio;Caracoglia, Luca
    • Wind and Structures
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    • v.26 no.4
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    • pp.231-251
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    • 2018
  • The objective of the investigation is the analysis of wind-tunnel experimental errors, associated with the measurement of aeroelastic coefficients of bridge decks (Scanlan flutter derivatives). A two-degree-of-freedom experimental apparatus is used for the measurement of flutter derivatives. A section model of a closed-box bridge deck is considered in this investigation. Identification is based on free-vibration aeroelastic tests and the Iterative Least Squares method. Experimental error investigation is carried out by repeating the measurements and acquisitions thirty times for each wind tunnel speed and configuration of the model. This operational procedure is proposed for analyzing the experimental variability of flutter derivatives. Several statistical quantities are examined; these quantities include the standard deviation and the empirical probability density function of the flutter derivatives at each wind speed. Moreover, the critical flutter speed of the setup is evaluated according to standard flutter theory by accounting for experimental variability. Since the probability distribution of flutter derivatives and critical flutter speed does not seem to obey a standard theoretical model, polynomial chaos expansion is proposed and used to represent the experimental variability.

Wind-tunnel study of wake galloping of parallel cables on cable-stayed bridges and its suppression

  • Li, Yongle;Wu, Mengxue;Chen, Xinzhong;Wang, Tao;Liao, Haili
    • Wind and Structures
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    • v.16 no.3
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    • pp.249-261
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    • 2013
  • Flexible stay cables on cable-stayed bridges are three-dimensional. They sag and flex in the complex wind environment, which is a different situation to ideal rigid cylinders in two-dimensional wind flow. Aerodynamic interference and the response characteristics of wake galloping of full-scale parallel cables are potentially different due to three-dimensional flows around cables. This study presents a comprehensive wind tunnel investigation of wake galloping of parallel stay cables using three-dimensional aeroelastic cable models. The wind tunnel study focuses on the large spacing instability range, addressing the effects of cable separation, wind yaw angle, and wind angle of attack on wake galloping response. To investigate the effectiveness of vibration suppression measures, wind tunnel studies on the transversely connected cable systems for two types of connections (flexibility and rigidity) at two positions (mid-span and quarter-span) were also conducted. This experimental study provides useful insights for better understanding the characteristics of wake galloping that will help in establishing a guideline for the wind-resistant design of the cable system on cable-stayed bridges.

Study of wind tunnel test results of high-rise buildings compared to different design codes

  • Badri, Abdulmonem A.;Hussein, Manar M.;Attia, Walid A.
    • Wind and Structures
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    • v.20 no.5
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    • pp.623-642
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    • 2015
  • Several international codes have been developed for evaluating wind loads on structures; however, the wind structure interaction could not be accurately captured by these codes due to the gusty nature of wind and the dynamic behavior of structures. Therefore, the alternative wind tunnel testing was introduced. In this study, an introduction to the available approaches for wind load calculations for tall buildings was presented. Then, a comparative study between different codes: the Egyptian code, ECP 201-08, ASCE 7-05, BS 6399-2, and wind tunnel test results was conducted. An investigation has been carried out on two case studies tall buildings located within the Arabian Gulf region. Numerical models using (ETABS) software were produced to obtain the relation between codes analytical values and wind tunnel experimental test results for wind loads in the along and across wind directions. Results for the main structural responses including stories forces, shears, overturning moments, lateral displacements, and drifts were presented graphically in order to give clear comparison between the studied methods. The conclusions and recommendations for future works obtained from this research are finally presented to help improving Egyptian code provisions and show limitations for different cases.

Computational Investigation of Similarity Law and Wind Tunnel Testing for Side Jet Influence on Supersonic Missile Aerodynamics (초음속 유도탄의 측추력기 작동시 풍동실험을 위한 CFD 해석 연구)

  • Hong S. K.;Sung W. J.
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.87-90
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    • 2002
  • Computational study has been undertaken to investigate the aerodynamic influence of side jet on a supersonic missile and to find a similarity condition between the flight condition and the wind tunnel testing. Tasks were performed to validate the existing Raytheon test body with side jet, to simulate the flow inside the supersonic wind tunnel, and to compare the flow fields between the missile in free flight and that in the wind tunnel. Then sub-scale model of body-tail configuration was analyzed to estimate the influence of the side jet on the missile components. It Is found that the influence of side Jet is not as significant on the tail region as on the body surface and a simple algebraic formula for aerodynamic coefficients accounting for the side jet as a point force may be cautiously utilized in setting up control logic.

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Investigation into the Hysteretic Behaviors of Shock Wave in a Supersonic Wind Tunnel (초음속 풍동에서 발생하는 충격파 히스테리시스 현상의 연구)

  • Lee, Ik In;Kim, Heuy Dong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2017.05a
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    • pp.609-611
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    • 2017
  • The hysteresis phenomena are frequently encountered in the wide variety of fluid flow systems of industrial and engineering applications. Hysteresis mainly appears during the transient change of pressure ratios, and this, in turn, influences the performance the supersonic wind tunnel. However, investigations on the hysteresis phenomenon particularly inside the supersonic wind tunnel are rarely studied. In the present study, numerical simulations are carried out to investigate hysteresis phenomenon of the shock waves inside the Supersonic Wind Tunnel. The unsteady, compressible flow through the supersonic wind tunnel is computationaly analyzed with an symmetric model. The Navier-Stokes equations are solved with Spalart-Allmaras turbulence model using a fully implicit finite volume scheme. The variaton in the flow field between the starting pressure ratio and operating pressure ratio of a supersonic wind tunnel is investigated in terms of hysteresis phenomenon.

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A Study on Wind-Driven Ventilation Performance According to Opening Types in Basement Parking Lots of Apartment - Investigation of Wind Pressure Coefficient by Wind Tunnel Test - (공동주택 지하주차장의 개구유형에 따른 풍력환기 성능에 관한 연구 - 풍동실험에 의한 풍압계수 검토 -)

  • Roh, Ji-Woong
    • KIEAE Journal
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    • v.11 no.6
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    • pp.37-42
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    • 2011
  • This Paper aims for analyzing the effect of opening types on wind-driven ventilation performance in basement parking lots of apartment. The scale model of basement parking lot was made, wind tunnel tests conducted. Wind pressure of three opening types was measured, wind pressure coefficient calculated. As the result, it showed that the air flow pattern of stack type opening was strongly changed by wind direction, but it was almost not at scuttle vent type. But, as for the difference of wind pressure coefficient, stack type opening was more than the other two types.