• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.472-475
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• 2014

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.138-139
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• 2012

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2010.05a
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• pp.332-333
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• 2010

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2011.10a
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• pp.623-624
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• 2011

• Wind and Structures
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• v.11 no.2
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• pp.121-135
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• 2008

The paper is concerned with a comparative study of both the along and cross-wind responses of a tall industrial chimney with and without flexibility of soil. The along-wind response has been estimated by means of approaches presented in three Standards: the Polish, the ISO and the Eurocode and by random vibration approach which is outlined below. The cross-wind response has been estimated by means of the three models developed by Vickery and Basu, Ruscheweyh and Flaga and methods presented in Standards: the Polish, the ISO and the Eurocode (Approach 1 and 2). Computer programmes were developed to obtain estimates of responses of a six-flue, 250 m-tall chimney. The analytical results computed according to the methods presented in different standards and random vibration approaches have been compared. Some unexpected conclusions have been observed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.612-618
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• 2008

Microphone array beamforming method has been recognized as an important aeroacoustic research field and become a standard technique in localizing sound sources. This method also used in flight acoustic measurement, and especially, it is very useful when measure sounds inside the wind tunnel. In measuring sound which is inside the wind tunnel by traditional beamforming method, there are some errors caused by airstream. The speed and the propagation path of the sound changes as it travel through the airstream. This makes the error which the position of sound is changed a little bit to the down stream direction. In this paper, validation test has made about the correction equation for this wind effects of previous researches. And beamforming including shear layer correction was performed about a sound source in the anechoic open-jet wind tunnel.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.311-315
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• 2012

In these days, promising renewable energy, wind turbine is clean energy but has an environmental pollutant which is noise. Noise assessment is one of the major performance evaluations for wind turbine and nowadays, developing and research for measurement and method of the assessment considering environmental pollutants is being important. Object in this study is that figuring out sound power characteristic of the gearbox for wind turbine through measuring sound intensity. In back-to-back test, we can figure out the noise characteristic of the gearbox for wind turbine through comparing and measuring sound pressure level, sound power level in operating at the each load condition respectively.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.431-434
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• 2014

Wind turbine industry is the most developing field among other renewable energy industry. As expanding wind farms, noise is the big problem to solve. This study is about wind turbine noise measuring method based on IEC 61400-11. Sound pressure levels, 1/3-octave band levels, and low frequency sound pressure levels of a 3 MW wind turbine were measured and analyzed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.725-730
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• 2012

In this paper, flow noise characteristics of Savonius-type vertical-axis wind turbines are numerically investigated using hybrid CAA techniques. High frequency harmonics as well as BPF components are identified in the predicted noise spectra from a Savonius wind turbine. As the BPF components belong to infrasound, the higher harmonic components affects human response dominantly. Further analysis is performed to investigate the reason causing the higher frequency harmonic noise by changing operational conditions of a Savonius wind turbine. Based on this result, it is revealed that the frequency of higher harmonic components is determined by the radius of blades and angular velocity of Savonius wind turbine.

• Transactions of the Korean Society of Mechanical Engineers
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• v.14 no.5
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• pp.1087-1095
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• 1990

A finite element method is used for analyzing the resonance characteristics of circular wind tunnel. Two-dimensional circular wind tunnel with one and three slots is considered. The wind tunnel resonance characteristics are affected by the number and position of the slots of the wind tunnel. The resonant frequencies for the vertical vibration mode are higher than those for the horizontal vibration mode. The resonance frequencies increase as the open area ratio increases.