• Wind and Structures
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• 제5권1호
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• pp.61-80
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• 2002

Wind tunnel aeroelastic model tests of the Commonwealth Advisory Aeronautical Research Council (CAARC) standard tall building were conducted using a three-degree-of-freedom base hinged aeroelastic(BHA) model. Experimental investigation into the effects of coupled translational-torsional motion, cross-wind/torsional frequency ratio and eccentricity between centre of mass and centre of stiffness on the wind-induced response characteristics and wind excitation mechanisms was carried out. The wind tunnel test results highlight the significant effects of coupled translational-torsional motion, and eccentricity between centre of mass and centre of stiffness, on both the normalised along-wind and cross-wind acceleration responses for reduced wind velocities ranging from 4 to 20. Coupled translational-torsional motion and eccentricity between centre of mass and centre of stiffness also have significant impacts on the amplitude-dependent effect caused by the vortex resonant process, and the transfer of vibrational energy between the along-wind and cross-wind directions. These resulted in either an increase or decrease of each response component, in particular at reduced wind velocities close to a critical value of 10. In addition, the contribution of vibrational energy from the torsional motion to the cross-wind response of the building model can be greatly amplified by the effect of resonance between the vortex shedding frequency and the torsional natural frequency of the building model.

• Wind and Structures
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• 제1권1호
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• pp.1-23
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• 1998

This paper describes wind investigations for the Leaning Tower of Pisa which were conducted as part of an overall evaluation of its behaviour. Normally a short, stiff and heavy building would not be a candidate for detailed wind analyses. However, because of extremely high soil pressures developed from its inclination, there has been increasing concern that environmental loading such as wind actions could combine with existing conditions to cause the collapse of the tower. The studies involved wind assessment at the site as a function of wind direction, analysis of historical wind data to determine extreme wind probabilities of occurrence, estimation of structural properties, analytical and boundary layer wind tunnel investigations of wind loads and evaluation of the response with special concern for loads in the direction of inclination of the tower and significant wake effects from the neighboring cathedral for critical wind directions. The conclusions discuss the role of wind on structural safety, the precision of results attained and possible future studies involving field measurements aimed at validating or improving the analytical and boundary layer wind tunnel based assessments.

• 한국항행학회논문지
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• 제26권6호
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• pp.393-403
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• 2022

도심지역 교통문제의 해결책으로 제시되고 있는 UAM의 초기 운영 형태는 다양한 연구에서 현재 항공기 중 VTOL 기체와 유사 할 것으로 제시되고 있다. 고정익 항공기가 이·착륙하는 활주로의 방향 결정과 유사한 형태로 VTOL 기체의 이착륙이 이루어지는 버티포트는 기체의 이·착륙 과정의 출발 및 도착의 비행 방향을 바람의 방향을 고려하여 정하도록 하고 있다. 일반적으로 공항이 건설되는 지역과 다르게 도심지의 경우 새로운 건물의 건축 등 지형 또는 장애물 변화 환경에 따라 바람의 특성이 지속적으로 변화될 수 있는 여건이 예상된다. 본 연구에서는 버티포트의 위치가 예상되는 도심 위치에서 이착륙 방향 검토를 위한 장기간의 실제 관측 데이터를 풍배도를 사용하여 비교 후 관측 기간 및 관측 위치에 따라 지상 바람의 특성과 주 바람의 방향이 변화 가능성을 확인하였다.

• 환경영향평가
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• 제21권3호
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• pp.417-429
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• 2012

In this study, a diagnostic wind model, CALMET and a micrometeorological numerical model, ENVI-MET were used to analyze the wind field in and out of the site designated for the industrial complex around Buron-myeon, Wonju, Gangwon-do. The results of modeling with CALMET showed that the air flow in industrial complex was little affected by the surrounding terrain. And the result of wind field analysis with ENVI-MET showed there are turbulent air flows such as cavity and wake around structures in the industrial complex, which can cause high-air pollution. Therefore, it is necessary to design the industrial complex considering the wind path according to wind directions.

• Wind and Structures
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• 제18권1호
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• pp.21-35
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• 2014

The latest developments in topology optimization are integrated with Computational Fluid Dynamics (CFD) for the conceptual design of building structures. The wind load on a building is simulated using CFD, and the structural response of the building is obtained from finite element analysis under the wind load obtained. Multiple wind directions are simulated within a single fluid domain by simply expanding the simulation domain. The bi-directional evolutionary structural optimization (BESO) algorithm with a scheme of material interpolation is extended for an automatic building topology optimization considering multiple wind loading cases. The proposed approach is demonstrated by a series of examples of optimum topology design of perimeter bracing systems of high-rise building structures.

• 신재생에너지
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• 제7권2호
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• pp.51-58
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• 2011

Saemankeum is well known for its high speed wind, and it is known that the blueprint of a future city around Saemankeum, including new industrial complex, has been planned. As a result, large-scale offshore wind farm, on the basis of the measurement of wind resource for a long time, can be considered, so that generated electricity can be used to meet the energy demand near the wind farm. Wind speed in Kokunsando of Saemankeum is measured and analyzed with its statistical distribution and wind directions. The probability of wind power resource over Kokunsando of Saemangeum is reviewed with the measured data in one island of Kokunsando. According to measured data, the shape and scale factor of Weibull distribution of wind speed are obtained, and then power density is analyzed as well. Through this study, it is clear that the Saemangeum area has a fluent and abundant wind power source to develop the wind farm in Korea.

• 한국조경학회지
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• 제31권5호
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• pp.43-57
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• 2003

This paper presents the air corridor planning strategy based on simulation with MUKLMO_3 (Micro-scale Urban Climate Model) to investigate the wind field and air corridor caused by the land-use change of the New Town Development Area in Pan-Gyo. In the first part, the most frequently observed wind field in the New Town Development Area was measured and used as an initial value to simulate a more realistic wind field and air corridor. Several experiments with different initial values of wind fields were carried out to investigate the wind field change affected by the New Town Development. The results show the features of the wind field of the neutral stability condition in the urban canopy layer with a high resolution near the ground. The wind speed is weakened at this level due to the New Town Development. It was found that the wind field and air corridor are influenced by the land-use change. After the development of the New Town, the speed of the wind field decreased and the main wind directions and air corridor changed. In this study, this model is found to be a useful tool for evaluating air corridor and change of wind field in speed and direction.

• 한국해안해양공학회지
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• 제15권2호
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• pp.138-142
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• 2003

이어도 해양과학기지가 주변의 바람장에 미치는 영향을 풍동실험을 통하여 검토하였다. 이어도 해양과 학기지에서 관측한 바람자료는 구조물로 인하여 풍속과 풍향의 왜곡이 발생하므로 정확한 풍속과 풍향을 알기 위해서는 관측자료에 구조물의 영향을 보정하여야 한다. 풍속비는 접근풍속의 크기보다는 풍속의 방향과 풍속 관측위치에 민감한 것으로 나타났다. 과학기지 옥상에 설치된 주 관측탑에서의 풍속은 모든 방향에서 접근풍속보다 크며 풍향 왜곡도는 6$^{\circ}$이내로 나타났다.

• Wind and Structures
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• 제11권2호
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• pp.153-178
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• 2008

Based on the empirical formulas for power spectra of generalized modal forces and local fluctuating wind forces in across-wind and torsional directions, the wind-induced lateral-torsional coupled response analysis of a representative rectangular tall building was conducted by setting various parameters such as eccentricities in centers of mass and/or rigidity and considering different torsional to lateral stiffness ratios. The eccentricity effects on the lateral-torsional coupled responses of the tall building were studied comprehensively by structural dynamic analysis. Extensive computational results indicated that the torsional responses at the geometric center of the building may be significantly affected by the eccentricities in the centers of mass and/or rigidity. Covariance responses were found to be in the same order of magnitude as the along-wind or across-wind responses in many eccentricity cases, suggesting that the lateral-torsional coupled effects on the overall wind-induced responses can not be neglected for such situations. The calculated results also demonstrated that the torsional motion contributed significantly to the total responses of rectangular tall buildings with mass and/or rigidity eccentricities. It was shown through this study that the framework presented in this paper provides a useful tool to evaluate the wind-induced lateral-torsional coupled responses of rectangular buildings, which will enable structural engineers in the preliminary design stages to assess the serviceability of tall buildings, potential structural vibration problems and the need for a detailed wind tunnel test.

• Wind and Structures
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• 제21권2호
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• pp.119-158
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• 2015

The characteristics of the coherence functions of X axial, Y axial, and RZ axial (i.e., body axis) wind forces on the Shanghai World Trade Centre - a 492 m super-tall building with section varying along height are studied via a synchronous multi-pressure measurement of the rigid model in wind tunnel simulating of the turbulent, and the corresponding mathematical expressions are proposed there from. The investigations show that the mathematical expressions of coherence functions in across-wind and torsional-wind directions can be constructed by superimposition of a modified exponential decay function and a peak function caused by turbulent flow and vortex shedding respectively, while that in along-wind direction need only be constructed by the former, similar to that of wind speed. Moreover, an inductive analysis method is proposed to summarize the fitted parameters of the wind force coherence functions of every two measurement levels of altitudes. The comparisons of the first three order generalized force spectra show that the proposed mathematical expressions accord with the experimental results well. Later, the influences of coherence functions on wind-induced dynamic responses are analyzed in detail based on the proposed mathematical expressions and the frequency-domain method of random vibration theory.