• Title/Summary/Keyword: Wind pressure measurement

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The Study of Correlation between Pattern Identification of Stroke Patients and Meteorological Elements (중풍 환자 변증과 기후 요소와의 상관성에 관한 연구)

  • Ma, Mi-Jin;Han, Chang-Ho
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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    • pp.200-211
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    • 2009
  • There are many reports about correlations between meteorological elements and stroke. In Oriental medicine, it is recognized that the weather affects the human body and diseases, but there are few studies about the correlation between meteorological elements and pattern identification of stroke. 105 stroke patients classified into fire-heat pattern or dampress-phlegm pattern were registered during the study period. We took the measurement of each meteorological element (atmospheric pressure, temperature, humidity, wind speed) according to pattern identification and analyzed pattern identification into two groups according to mean of each meteorological element during the study period. Mean temperature was higher with the heat-fire pattern than with the dampness-phlegm pattern. Heat-fire pattern also had higher frequency when temperature was higher than mean temperature. There was no correlation between atmospheric pressure, relative humidity, or wind speed and pattern identification.

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Aerodynamic measurements of across-wind loads and responses of tapered super high-rise buildings

  • Deng, Ting;Yu, Xianfeng;Xie, Zhuangning
    • Wind and Structures
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    • v.21 no.3
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    • pp.331-352
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    • 2015
  • A series of wind tunnel tests were conducted on tapered super high-rise buildings with a square cross section by applying synchronous pressure measurement technology. The effects of global strategy of chamfered modification on aerodynamic loads and wind-induced responses were investigated. Moreover, local aerodynamic strategies of opening a ventilation slot in the corner of equipment and refuge floors were carried out. Results show that the global strategy of tapered elevation increased the vortex shedding frequency, but reduced vortex shedding energy, leading to reduction of across-wind aerodynamic loads and responses. Chamfered modification suppressed the across-wind vortex shedding effect on tapered buildings. Opening the ventilation slot further suppressed the strength of vortex shedding and reduced the residual energy related to vortex shedding in aerodynamic loads of chamfered buildings. Finally, the optimized locations of local aerodynamic strategies were suggested.

Field Test and Evaluation of Noise from Wind Turbine Generators at Yongdang and Hangwon in Jeju Island (제주도 용당/행원 풍력발전기 현장 소음 실증)

  • Cheong, Cheol-Ung;Jeong, Sung-Su;Cheung, Wan-Sup;Shin, Su-Hyun;Jeon, Se-Jong;Lee, Saeng-Hui
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.818-821
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    • 2005
  • The sound measurement procedures of IEC 61400-11 are applied to field test and evaluation of noise emission from 1.5 MW wind turbine generator (WTG) at Yongdang and 660 kW WTG at Hangwon in Jeju Island. Apparent sound power level, wind speed dependence and third-octave band levels are evaluated for both of WTGs. 1.5 MW WTG at Yongdang is found to emit lower sound power than 660 kW one at Hangwon, which seems to be due to lower rotating speed of the rotor of WTG at Yongdang. Equivalent continuous sound pressure levels (ECSPL) of 660 kW WTG at Hangwon vary more widely with wind speed than those of 1.5 MW WTG at Yongdang. The reason for this is believed to be the fixed blade rotating speed of WTG at Yongdang. One-third octave band analysis of the measured data show that the band components around 400-500 Hz are dominant for 1.5 MW WTG at Yongdang and those around 1K Hz are dominant for 660 kW WTG at Hangwon.

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The Developement of a Wind Direction/Speed Measurement Equipment Using RTD or Piezo Sensors (RTD 및 피에조 센서를 활용하는 풍향/풍속 측정장치 개발)

  • Joo, Jae-Hun;Kim, Dong-Hyun;Gong, Byung-Gunn;Lee, Jin-Ho;Choi, Jung-Keyng
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2011.05a
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    • pp.827-830
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    • 2011
  • In this paper, a wind speed & direction module and the DSP(Digital Signal Processor) sensor interface circuit board are proposed. This DSP system accepts and process the informations from a wind speed & direction module, the atmospheric pressure sensor, the ambient air temperature sensor and transfers it to the PC monitering system. Especially, a wind speed & direction module and a DSP hardware are directly designed and applied. A wind speed & direction module have a construction that it have four film type RTD(Resistive Temperature Detectors) or film type Piezo sensors adhered around the circular metal body for obtaining vector informations about wind. By this structure, the module is enabled precise measurement having a robustness about vibration, humidity, corrosion. A sensor signal processing circuit is using TMS320F2812 TI(Texas Instrument) Corporation high speed DSP.

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Study of a Photovoltaic System as an Emergency Power Supply for Offshore Plant Facilities (해양플랜트 설비의 비상전원공급을 위한 태양광 발전시스템 연구)

  • Choi, Gun Hwan;Lee, Byung Ho;Jung, Rho-Taek;Shin, Kyubo
    • Journal of Ocean Engineering and Technology
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    • v.32 no.4
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    • pp.279-286
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    • 2018
  • The use of eco-friendly energy in the offshore plant system is expanding because conventional generators are operated by fossil fuel or natural gas. Eco-friendly energy, which replaces existing power generation methods, should be capable of generating the power for lighting protection equipment, airborne fault indication, parameter measurement, and others. Most of the eco-friendly energy used in offshore plant facilities is solar and wind power. In the case of using photovoltaic power, because the structure must be constructed based as flat solar panels, it can be damaged easily by the wind. Therefore, there is a need for a new generation system composed of a spherical structure that does not require a separate structure and is less influenced by the wind. Considering these characteristics, in this study we designed, fabricated, and tested a unit that could provide the most efficient spherical photovoltaic power generation considering wind direction and wind pressure. Our test results indicated that the proposed system reduced costs because it did not require any separate structure, used eco-friendly energy, reduced carbon dioxide emissions, and expanded the proportion of eco-friendly energy use by offshore plant facilities.

Wind tunnel tests for analyzing noise generation from the inter-coach spacing of a high-speed train (풍동을 이용한 고속철의 차간 공간에서의 공력 소음 측정 및 특성 분석)

  • Park, Ki-Hyoung;Song, Si-Mon;Kim, Tae-Ho;Lee, Taek-Jin;Choi, Sung-Hoon;Park, Jun-Hong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2006.11a
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    • pp.65-68
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    • 2006
  • Experiments were performed to investigate the effects of mud-flap width on the aeroacoustic noise generation inside high-speed trains. The open-circuit type wind tunnel was used. The measurement setup was custom-built to simulate intercoach spacing. From the measurements, the characteristics of the turbulent flow after the intercoach spacing and consequent generation of aeroacoustic noise inside the cabin was investigated. Especially the effects of mud flap length on the characteristics of the characteristics of the turbulent flow were identified. The mechanism of noise generation by analyzed interactions with structure vibration characteristics and generation characteristics of blocked pressure was investigated.

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Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer (난류 경계층에서 컴플라이언트 코팅과 점탄성 벽면의 방사 소음에 관한 실험적 연구)

  • Lee Seungbae;Lee Chang-Jun;Kwon O-Sup;Jeon Woo-Pyung
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.779-782
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    • 2002
  • We examine the problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick, open-cell foam with fabric covering and a viscoelastic painted plate of 1mm thick over an acoustic board of 4m thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber ($k_{ch}$) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

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Radiated Sound from Compliant and Viscoelastic Plates in a Turbulent Boundary Layer (난류 경계층에서 컴플라이언트 코팅된 벽면과 점탄성 벽면의 방사 소음에 관한 실험적 연구)

  • Lee, Chang-Jun;Lee, Seung-Bae;Kwon, O-Sup;Jun, Woo-Pyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.3
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    • pp.294-301
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    • 2003
  • We examine a problem in which porous/viscoelastic compliant thin plates are subject to pressure fluctuations under transitional or turbulent boundary layer. Measurements are presented of the frequency spectra of the near-field pressure and radiated sound by compliant surface. A porous plate consisting of 5mm thick. open-cell foam with fabric covering and a viscoelastic-painted plate of 1mm thick over an acoustic board of 4mm thick were placed over a rigid surface in an anechoic wind tunnel. Streamwise velocity and wall pressure measurements were shown to highly attenuate the convective wall pressure energy when the convective wavenumber (k$_{c}$h) was 3.0 or more. The sound source localization on the compliant walls is applied to the measurement of radiated sound by using an acoustic mirror system.

A Study on the Measurement of Aerodynamic Load of Aircraft Wing (항공기 날개의 공력하중 측정 기법 연구)

  • Kang, Seung-Hee;Lee, Jong-Geon;Lee, Seung-Soo;Ahn, Seung-Ki
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.30 no.4
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    • pp.38-43
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    • 2002
  • A study on the test, design and fabrication of wind tunnel model for measurement of air load distribution on wing surfaces is presented. 447 pressure taps are installed normal to the wing surfaces, and measured by PSI-8400 system using total 8 ESPs modules installed in the model. The test was performed at 50 m/sec constant speed in the low speed wind tunnel of Agency for Defense Development. Tests were carried out to determine effects of angle of attack, angle of sideslip and flap and stores for the load distribution of wing. The test results in this paper can be applied to the design optimization of structure and validation of computational fluid dynamics.

Aspects of the use of proper orthogonal decomposition of surface pressure fields

  • Baker, C.J.
    • Wind and Structures
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    • v.3 no.2
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    • pp.97-115
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    • 2000
  • The technique of proper orthogonal decomposition is potentially useful in specifying the fluctuating surface pressure field around structures. However there has been a degree of controversy over whether or not the calculated modes have physical meanings. This paper addresses this issue through consideration of the results of full scale experiments, and through an analytical investigation. It is concluded that the lower, most energetic modes are likely to reflect different fluctuating flow mechanisms, although no mode is likely to be associated with just one flow mechanism or vice versa. The higher, less energetic modes are likely to represent interactions between different flow mechanisms, and to be significantly affected by the number of measurement points and measurement errors. The paper concludes with a brief description of the application of POD to the problem of building ventilation, and the calculation of cladding pressures.