• Title/Summary/Keyword: Aeolian Noise

Search Result 19, Processing Time 0.027 seconds

Investigation Into Aeolian Tone Noise by Twin Tandem Square Cylinders in duct Using Lattice Boltzmann Method (격자 볼츠만 방법을 이용한 덕트 내 쌍둥이 직렬배열 사각 실린더에 의한 Aeolian 순음소음 고찰)

  • Lee, Songjune;Cheong, Cheolung
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.24 no.12
    • /
    • pp.962-968
    • /
    • 2014
  • The lattice Boltzmann method(LBM) has attracted attention as an alternative numerical algorithm for solving fluid mechanics since the end of the 90's. In these days, its intrinsic unsteadiness and rapid increase in computing power make the LBM be more applicable for computing flow-induced noise as well as fluid dynamics. The lattice Boltzmann method is a weakly compressible scheme, so we can get information about both aerodynamics and aeroacoustics from single simulation. In this paper, numerical analysis on Aeolian tone noise generated by tandem-twin square cylinders in duct is performed using the LBM. For simplicity, laminar two-dimensional fluid models are used. To verify the validity and accuracy of the current numerical techniques, numerical results for the laminar duct and the cylinder flows are compared with the analytical solution and the measurement, respectively. Then, aerodynamic noise of the twin tandem square cylinders is investigated. It is shown that the aerodynamic noise from the twin tandem square cylinders can be reduced by controlling the distance between the cylinders.

Simulation on the Corona Characteristics of Low Aeolian Noise Conductor Bundles for 765 kV Transmission Line (765kV 송전선로용 저풍소음 복도체 방식의 코로나 특성 모의실험)

  • Ju, M.N.;Yang, K.H.;Shin, K.Y.;Lee, D.I.;Min, S.W.
    • Proceedings of the KIEE Conference
    • /
    • 2000.07a
    • /
    • pp.131-133
    • /
    • 2000
  • Single phase simulations were carried out in order to determine a solutive conductor to the aeolian noise which will be locally applied to 765 kV transmission lines Basic solutive conductors have already been proposed including conductors equipped with spiral rod. low noise conductor of a special shape and others. A low aeolian noise conductor, however, should have excellent corona characteristics in addition to aeolian noise reduction function. In this paper, we compared the performances of the audible noises and radio interferences of 6 candidate conductor bundles by using corona cage. We also developed two programs to need for evaluating environmental effects of each conductor bundle. Those are a program to calculate the conductor surface gradient of various special bundles and a conversion program of single phase data to the model of transmission line. The future determination on the final low aeolian noise conductor will be made through a long-term test to verify environmental impacts at the full-scale Kochang 765 kV test line.

  • PDF

Reduction of Aeolian Noise from Roof Rack Cross Bars Using Asymmetric Section Geometry (비대칭 단면 형상을 이용한 루프랙 크로스바의 윈드노이즈 저감)

  • 이정한;이강덕;정승균
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2001.11b
    • /
    • pp.1406-1412
    • /
    • 2001
  • Roof racks have become a very popular feature of vehicles as the market demand for SUV's and RV's has increased drastically over the years. Aeolian tone from the cross bars however. could be a source of severe discomfort for the passengers. Both experimental and numerical steps are taken to enhance the understanding of the generation mechanism of the wind noise. A successful reduction of the noise is achieved by imposing asymmetry in the section geometry, which reduces the strength of Karmann vortices shed downstream.

  • PDF

Aeolian Noise from High Voltage Insulators (초고압 송전용 애자의 풍소음 특성)

  • Chu, Jang-Hee;Kim, Sang-Beom;Shin, Koo-Yong;Lee, Seong-Doo;Lee, Dong-Il
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2000.06a
    • /
    • pp.1842-1847
    • /
    • 2000
  • In this paper, a review is attempted for understanding of aeolian noise from high voltage insulators and their aerodynamic noise characteristics were investigated using the low noise wind tunnel. The noise from the insulators was dependent upon the wind speed and their orientation relative to the wind direction. The noise spectrum revealed sharp peak which was found the cavity resonance frequency.

  • PDF

Analysis on Electric Field Distributions and Corona Characteristics of Special Conductor Bundles for 765kV Transmission Line (765kV 송전선로용 특수 다중도체 방식의 코로나 잡음특성 및 전계분포 해석)

  • Min, Seok-Won;Kim, Yong-Jun;Sin, Gu-Yong;Lee, Dong-Il;Ju, Mun-No;Yang, Gwang-Ho
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.50 no.12
    • /
    • pp.556-560
    • /
    • 2001
  • To solve aeolian noise, we have tried several special conductor bundles equipped with spiral rod and one kind of low aeolian noise conductor with a special shape. Charge simulation method was applied to analyze electric field distributions of them in transmission line and corona cage for investigating the corona characteristics. This paper describes the electric field distributions and the performances of audible noise and radio interference from the special bundles in 765 kV transmission line by using corona characteristics obtained from corona cage simulation.

  • PDF

3-Dimensional Analysis on Electric Field of Special Conductor Bundle for Reducing Aeolian Noise (풍소음 저감용 특수 다중도체 방식의 3차원 전계해석)

  • Min, Suk-Won;Song, Ki-Hyun
    • Proceedings of the KIEE Conference
    • /
    • 2001.05a
    • /
    • pp.254-258
    • /
    • 2001
  • In this paper, 3-dimensional charge simulation method was developed to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise. When we applied this method to 765 kV double circuit transmission line, we found calculation error of this method was within a reasonable boundary of 1%.

  • PDF

3-Dimensional Analysis II on Electric Field of Special Conductor Bundle for Reducing Aeolian Noise In Corona Cage (코로나 케이지 내부에서의 풍소음 저감용 특수 다중도체 방식의 3차원 전계분포해석 II)

  • Min, Suk-Won;Song, Ki-Hyun
    • Proceedings of the KIEE Conference
    • /
    • 2001.11b
    • /
    • pp.399-402
    • /
    • 2001
  • In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. Comparing electric field distributions of special conductor bundles in 765kV transmission tine with ones in corona case, we decide experimental voltages of special conductor bundles in corona cage.

  • PDF

3-Dimensional Analysis on Electric Field of Special Conductor Bundle for Reducing Aeolian Noise In Corona Cage (코로나 케이지 내부에서의 풍소음 저감용 특수 다중도체 방식의 3차원 전계분포해석)

  • Min, Suk-Won;Song, Ki-Hyun
    • Proceedings of the KIEE Conference
    • /
    • 2001.07a
    • /
    • pp.359-361
    • /
    • 2001
  • In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. We found calculation error of this method was w a reasonable boundary of 0.5%.

  • PDF

Electrical and Mechanical Noise Study of the 765kV Transmission Line (765kV 송전선로의 전기적 및 기계적 소음고찰)

  • Lee,
    • Journal of KSNVE
    • /
    • v.6 no.1
    • /
    • pp.89-95
    • /
    • 1996
  • If the transmission line voltage is greater than 500kV, audible noise (AN) and hum noise (HN) due to corona discharges on the conductor would be an important design factor for the conductor selection of transmission line. Also there is an aeolian noise: wind noise(WN) from the tower and the conductor due to wind. This paper presents the results of a statistical analysis of audible noise, hum noise, aeolian noise of 6-480mm$^{2}$ conductor bundle in KEPRI 765kV Test Transmission Line which was constructed to develop 765kV double circuit AC transmission line for the first time in the world. The result of the analysis shows that 6-480mm$^{2}$ conductor bundle and tower satisfy configuration the audible noise design criterion of 50dB(A).

  • PDF