• Journal of Korean Society of Disaster and Security
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• v.10 no.1
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• pp.75-84
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• 2017

This study is concerned with the estimation of daily instantaneous maximum wind velocity in the meteorological major cities (selected each 17 points) during the yearly 1973-2016. The purpose of this paper is to present the turbulence statistic characteristics (probability distribution, correlation coefficient, turbulency intensity, shear velocity, roughness length, turbulence integral length, skewness, and kurtosis) of the daily instantaneous maximum wind velocity. In the processes of analysis, used observations data obtained at Korea Meteorological Adminstration (KMA). The estimation of non-Gaussian load effects for design applications has often been treated tacitly by invoking a conventional wind design load on the basis of Gaussian processes. This assumption breaks down when the instantaneous wind velocity processes exhibits non-Gaussianity. From the analysis results, the probability distribution of the daily instantaneous maximum wind velocity shows a very closed with non-Gaussian in the ensemble population 748, the correlation coefficient shows larger at inland area more than coastal area.

• Journal of Industrial Technology
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• v.22 no.A
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• pp.49-57
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• 2002

The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several methods on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the Taekwanryung test site are presented using a one-month wind data from a reference meteorological mast and a temporal mast installed at the site of wind turbine. From this analysis, it turns out that the current location of the reference meteorological mast is wrongly determined, and the self-developed codes for the site calibration are working properly. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed.

• Wind and Structures
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• v.23 no.4
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• pp.351-366
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• 2016

Nowadays, wind energy is the most rapidly developing technology and energy source and it is reusable. Due to its cleanliness and reusability, there have been rapid developments made on transferring the wind energy systems to electric energy systems. Converting the wind energy to electrical energy can be done only with the wind turbines. So installing a wind turbine depends on the wind speed at that location. The expected wind power can be estimated using a perfect probability distribution. In this paper Weibull and Weibull distribution with multiple parameters has been used in deriving the mathematical expression for estimating the wind power. Statistically the parameters of Weibull and Weibull distribution are estimated using the maximum likelihood techniques. We derive a probability distribution for the power output of a wind turbine with given rated wind speeds for the regions where the wind speed histograms present a bimodal pdf and compute the first order moment of this distribution.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1271-1279
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• 2013

In this paper, a study on the prediction method of basic wind speed at the construction site of long-span bridge using short-term measurements was conducted. To determine the basic wind speed in the wind resistant design for the long-span bridge away from the weather station, statistical analysis of long-term data at site is required. Wind observation mast was installed at site, and short-term measurements were gathered and the correlation analysis between the site and the station was done using regression analysis and MCP(Measure-Correlate-Predict). The long-term wind data of the site was obtained from correlation formula after topographical revision of long-term data of the station. And basic wind speed could be estimated by extreme probability distribution analysis. The research results show that the wind speed by regression analysis is predicted lower than by MCP and after this study a series of correlation analyses at several sites will show clearly the difference two methods. And also a quality control of long-term wind data is very important in estimation of wind speed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.10
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• pp.833-841
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• 2014

This paper proposes an algorithm to estimate the wind velocity by tracking free flying balloons. Balloons used in this method are expendable but inexpensive, which increases the usefulness of the method. Also we can obtain accurate 3D information by using multiple cameras and estimate the wind velocity of the local field. The proposed system consists of aerodynamic modeling of the balloon, a tracking algorithm using image processing, and the velocity estimation algorithm. We performed unit tests of each algorithm for the verification. The method is validated using a system simulation and sources of error case identified.

• Wind and Structures
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• v.30 no.6
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• pp.559-573
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• 2020

This paper presents a study on the effectiveness of the proper orthogonal decomposition (POD) technique for reconstruction of wind pressure field as applied to a cylindrical shell roof based on simultaneously measured wind pressure data. The influence of wind loading mode truncation on the statistics of dynamic pressures and wind load effects are investigated. The results showed that truncation of higher wind loading modes can have more noticeable influence on the maximum and minimum pressures that the standard derivation (STD) values. The truncation primarily affects the high-frequency content of the pressures. Estimation of background response using wind loading modes is more effective than the use of traditional structural modal analysis.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2250-2257
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• 2004

The accurate wind speed information at the hub height of a wind turbine is very essential to the exact estimation of the wind turbine power performance testing. Several methods on the site calibration, which is a technique to estimate the wind speed at the wind turbine's hub height based on the measured wind data using a reference meteorological mast, are introduced. A site calibration result and the wind resource assessment for the TaeKwanRyung test site are presented using three-month wind data from a reference meteorological mast and the other mast temporarily installed at the site of wind turbine. Besides, an analysis on the uncertainty allocation for the wind speed correction using site calibration is performed.

• Proceedings of the KSME Conference
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• 2001.06e
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• pp.361-366
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• 2001

The present study describes a practical estimation procedure about the pantograph under several severe aerodynamic load conditions. As the operating speed of the Korean Train Express(KTX) reaches 350km/h, structural safety at various conditions should be examined at the design stage. In the present study, a compact and reliable procedure is developed to get aerodynamic loads on each part of the pantograph regarding the typhoon condition, the train/tunnel interaction, the train/train interaction and the side wind condition. In the estimation procedure, 3-dimensional steady and unsteady CFD simulation around the high speed train facilitates assigning the external local flow condition around the pantograph. The procedure is verified using the results of the low speed wind tunnel test at JARI and applied to 7 flow conditions and 4 operation configurations.

• International Journal of High-Rise Buildings
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• v.3 no.4
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• pp.305-310
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• 2014

Wind-induced responses of a structure are often evaluated through dynamic analysis, where measured wind forces obtained from a wind-tunnel test and dynamic properties obtained from a FE (Finite Element) model are utilized. However, the FE model generally shows considerable discrepancies in the estimation of natural frequencies compared to field measurements due to some assumptions and simplifications. In this paper, a calibration method that can improve the estimation of natural frequencies in the FE model is proposed, and specific cases are studied for its validity with comparison to the field measurement results.

• International Journal of High-Rise Buildings
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• v.12 no.4
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• pp.287-297
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• 2023

This paper briefly discusses current issues in wind engineering, including the enhancement of aerodynamic database and AI-assisted design, aerodynamic characteristics of tall buildings with atypical building shapes, application of computation fluid dynamics to wind engineering, evaluation of aerodynamic force coefficients based on a probabilistic method, estimation of tornadic wind speed (JEF scale) and effect of the Ekman Spiral on tall buildings.