• Title/Summary/Keyword: Overall Sound Pressure Level(OSPL)

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Characteristics of Low Frequency Aero-acoustic Noise Radiation for a Wind Turbine Generator of NREL Phase VI (NREL Phase VI 풍력발전기 저주파 소음방사 특성)

  • Mo, Jang-Oh;Kim, Byoung-Yun;Ryu, Byeng-Nam;Lee, Young-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.504-507
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    • 2009
  • The purpose of this work is to predict the low frequency aero-acoustic noise generated from the horizontal axis wind turbine, NREL Phase VI using large eddy simulation and Ffowcs-Williams and Hawkings model provided in the commercial code, FLUENT. Calculated aerodynamic performances such as shaft torque and power are compared with experimentally measured value. Performance results show a good agreement with experimental data within about 0.8%. If the distance by two times is changed from 32D to 64D toward the downstream region, sound pressure level is reduced by about 6.4dB.

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A Study on the Optimization of Discharge Grille of Outdoor Unit of Air Conditioner (에어컨 실외기 토출그릴 형상 최적화)

  • Choi, Seok-Ho;Oh, Sai-Kee;Kim, Hyun-Jong;Jin, Geun-Ho;Oh, Si-Young;Kim, Byung-Soon
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.23 no.11
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    • pp.726-732
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    • 2011
  • The aerodynamic and aeroacoustic performance of discharge grille of outdoor unit of air-conditioner was investigated in this study. Discharge grille is one of outdoor unit's important parts to affect the flow rate and Overall Sound Pressure Level(OSPL). New type of discharge grille was suggested based on the results of numerical simulation. To simulate the flow pattern near the propeller fan, commercial flow solver FLUENT was used. Sliding mesh method was used for rotating propeller fan and initial condition for unsteady model was calculated by Multiple Reference Frame(MRF) method. To minimize the interaction noise between fan blade wake and discharge grille, new discharge grille has radial rib which is aligned with trailing edge of fan blade. And inclined radial rib was adopted for reducing flow rate drop in discharge grille. The optimization of inclined angle of radial grille was performed experimentally.