• Title, Summary, Keyword: 풍속

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A Study on the Application ratio of Directional wind speeds Characteristics by Gumbel Model Simulation Using Directional wind Patterns (풍향패턴에 따른 굼벨 모델 시뮬레이션에 의한 풍향풍속성의 적용율 평가에 관한 연구)

  • Chung, Yung-Bea
    • Journal of Korean Society of Steel Construction
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    • v.22 no.6
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    • pp.573-580
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    • 2010
  • In this study, an assessment method that considers the effects of directional wind speeds on buildings or structures that are sensitive to wind is proposed. Also, the basic characteristics of directional wind speeds were assessed by means of local annual maximum wind speeds. From the method of assessment of the characteristics of directional wind speeds, their goodness-of-fit was verified by applying extreme value distribution to the data on annual maximum wind speeds from the Korea Meteorological Administration. To consider the characteristics of directional winds, an assessment method is suggested that divides the directional wind pattern of each directional wind speed into four groups. From the study results, all the data on directional wind speeds based on the Gumbel distribution were examined using data on annual maximum wind speeds from Seoul, Tongyung, and Incheon. Since the Gumbel model of all directional wind speeds has independent probability characteristics that govern the 4 directional wind pattern groups, the application ratio proposed was based on the assessment of these four groups. According to the goodness-of-fit of the data on the annual maximum wind speeds based on the Gumbel distribution, new application ratios were proposed that consider the directional wind speeds in Seoul, Tongyung, and Incheon.

Characteristic Analysis on the Distribution of Wind Speed in the Korean and Japanese West Coast (우리나라와 일본 서해안의 풍속 분포 특성 분석)

  • Seol, Dong-Il
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.11-12
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    • 2017
  • 최근 20년간(1996년 12월~2016년 2월)의 자료를 사용하여 우리나라와 일본 서해안의 풍속 분포 특성을 분석하였다. 우리나라 서해안의 관측점 3곳 중에서 2곳(군산, 목포)의 풍속은 시간의 흐름과 함께 약해지는 추세를 보인다. 풍속이 약해지는 추세는 목포보다 군산이 더 크다. 일본 서해안의 관측점 3곳 중에서 1곳(Akita)의 풍속은 시계열 분포 상 큰 변화 없이 일정한 상태를 유지하나 2곳(Kanazawa, Tottori)은 풍속이 시간의 흐름과 함께 약해지는 추세를 보인다. 관측점별로 차이는 있으나 전체적으로 풍속이 시간의 흐름과 함께 약해지는 추세가 있음을 확인하였다. 특히, 우리나라 서해안의 경우가 일본 서해안의 경우보다 그 추세의 정도가 더 크다. 일본 서해안의 풍속은 우리나라 서해안의 풍속보다 강한 특성을 보인다. 이는 겨울철 동해의 해상이 서해보다 더 거칠고 그에 따라 선박 운항 상의 위험도가 더 높다는 것을 의미한다.

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A Study on the Change of Wind Speed in South Korea: In Case of January and August (한국에서 풍속 변화에 관한 연구 -1월과 8월을 대상으로-)

  • Lee, Seung-Ho
    • Journal of the Korean Geographical Society
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    • v.47 no.3
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    • pp.347-358
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    • 2012
  • This study aimed to investigate the change of wind speed during winter and summer seasons for 50 years(1961-2010). It were analyzed the mean wind speed, maximum wind speed, windy days and storm days on January and August of 13 weather stations in South Korea. The mean wind speed was decreased in the coastal region(Busan, Jeju, Ulsan, Pohang) in winter and summer seasons. Also it was similar to windy day. The relationship between wind speed and mean temperature has negative correlation in winter season. The relationship is low in summer season. The number of windy day and storm day has negative relation with monthly mean temperature.

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Analysis of Wind Velocity Profile for Calculation of Wind Pressure on Greenhouse (온실의 풍압력 산정을 위한 풍속의 수직분포 분석)

  • Jung, Seung-Hyeon;Lee, Jong-Won;Lee, Si-Young;Lee, Hyun-Woo
    • Protected Horticulture and Plant Factory
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    • v.24 no.3
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    • pp.135-146
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    • 2015
  • To provide the data necessary to determine the design wind speed for calculating the wind load acting on a greenhouse, we measured the wind speed below 10m height and analyzed the power law exponents at Buan and Gunwi. A wind speed greater than $5m{\cdot}s^{-1}$ is appropriate for calculating the power law exponent necessary to determine the wind speed distribution function according to height. We observed that the wind speed increased according to a power law function with increased height at Buan, showing a similar trend to the RDC and JGHA standards. Therefore, this result should be applied when determining the power law function for calculating the design wind speed of the greenhouse structure. The ordinary trend is that if terrain roughness increases the value of power law exponent also increases, but in the case of Gunwi the value of power law exponent was 0.06, which shows contrary value than that of the ordinary trend. This contrary trend was due to the elevations difference of 2m between tower installed and surrounding area, which cause contraction in streamline. The power law exponent started to decrease at 7 am, stopped decreasing and started to increase at 3 pm, and stopped increasing and remained constant at 12 pm at Buan. These changes correspond to the general change trends of the power law exponent. The calculated value of the shape parameter for Buan was 1.51, confirming that the wind characteristics at Buan, a reclaimed area near the coast, were similar to those of coastal areas in Jeju.

Guideline for Bridge Design Wind Speed in Coastal Region (해안지역 교량 설계풍속 산정 가이드라인)

  • Lee, Sungsu;Kim, Junyeong;Kim, Young-Min
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.615-623
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    • 2015
  • Estimation of wind load on bridges is one of the most important aspects in designing bridges in coastal region. Various design codes and researches have suggested the procedure to estimate design wind speed; however, they do not match one another due to many reasons such as incomplete data set, ignorance of wind environment and so on. For this reason, the necessity of guideline for estimation procedure of basic wind speed which reflect the roughness of surface and the topographical effect have been increasing. In this study, we have analysed limitations of the basic wind speed of nationwide suggested by Korea Building code(AIK, 2009) and Highway bridge design code(MOLTMA, 2010). In additional, we set forth guidelines considering the roughness of land surface and the topographical effect. Using the procedure, the basic wind speed were estimated for 15 coastal regions in Korea and compared with those listed in the existing codes.

Calibration System for Three-Cup Anemometers (현장용 교정 장치를 이용한 3-컵 풍속계의 교정 방법)

  • Chun, Se-Jong;Lee, Saeng-Hee;Choi, Yong-Moon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.3
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    • pp.325-331
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    • 2010
  • Three-cup anemometers are popular devices for measuring wind speeds in automated weather stations, environmental monitoring systems, and wind turbines. Cup anemometers usually suffer from lack of long-term stability owing to the wear of the bearing systems that support the rotational parts. The bearing systems are susceptible to external pollutants, vibrations, and gusts. Therefore, these anemometers have to be calibrated regularly to maintain the desired characteristics for measuring wind speed. In the present study, a new in-situ calibration system to help reduce cost and save time by calibrating the cup anemometers at the installation site is proposed. A portable in-situ calibrator was fabricated. After the characteristics of this calibrator were verified, it was used to calibrate cup anemometers. Some of the calibration results were compared with the data obtained by wind tunnel testing.

Probability-Based Estimates of Basic Design wind Speeds in Korea (확률에 기초한 한국의 기본 설계풍속 추정)

  • 조효남;차철준;백현식
    • Computational Structural Engineering
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    • v.2 no.2
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    • pp.62-72
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    • 1989
  • This study presents rational methods for probability-based estimates of basic design wind speeds in Korea and proposes a risk-based nation-wide map of design wind speeds. The paper examines the fittings of the extreme Type I mode to largest yearly non-typhoon wind data from long-term records, and to largest monthly non-typhoon wind data from short-term records. For the estimation of the extreme typhoon wins speed distribution, an indirect analytical method based on a Monte-Carlo simulation is applied to typhoon-prone regions. The basic desig wind speeds for typhoon and non-typhoon winds at the sites of concern are made to be obtained from the mixed model given as a product of the two distributions. The results of this study show that the proposed models and methods provide a practicable tool for the development of the risk-based basic design wind speed and the design wind map from short-term station records currently available in Korea.

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The Design and Electrical characteristics of Wind Turbine Blades for Low Wind Speed (저풍속에 적합한 풍력터빈 블레이드의 설계 및 전기적 특성)

  • Lee, Jong-Deok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.513-514
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    • 2007
  • 본 연구는 우리나라와 같은 상대적으로 낮은 풍속에 적합한 6[W]급 풍력터빈의 블레이드를 개발하고자 하였다. 풍력발전기의 출력은 풍속 및 블레이드의 회전수에 매우 의존적으로 풍속이 증가함에 따라 전력도 증가하였다. 또한, 피치각에 따라 블레이드의 회전수도 매우 다르며, 낮은 풍속 상태에서는 공기의 힘을 받는 면적이 클수록 출력특성이 줄게 나타났다. 최대출력은 피치각 $10^{\circ}$, 풍속 5.5[m/s]일 때 3.8[W] 의 출력을 보였다.

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Fabrication and Characteristics of Hot-film Anemometer (열박막 풍속계의 제작 및 특성)

  • Kim, Hyung-Pyo;Cho, Chan-Seob
    • Journal of Sensor Science and Technology
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    • v.9 no.3
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    • pp.190-195
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    • 2000
  • The paper presents the constant temperature digital hot-film anemometer that measures easily a wind velocity at the indoor. The output is linearized using microprocessor and analog-to-digital converter, because the fourth root of the wind velocity is the output voltage of the sensor. The comparison result between fabricated and reference anemometer is less than ${\pm}2%$. In the range of air temperature of $23^{\circ}C{\sim}60^{\circ}C$, the error is about ${\pm}1%$ in wind velocity 10m/sec.

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AWS 데이터를 이용한 부산 해안의 바람분포 특성 해석

  • Seol, Dong-Il
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.265-266
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    • 2009
  • 이 연구에서는 10년간(1997-2006년)의 기상청 AWS(Automatic Weather System) 자료를 이용하여 부산 해안의 바람분포 특성을 분석하였다. 그리고 부산 해안의 바랑분포 특성을 명확히 파악하기 위하여 해륙풍의 영향을 받지 않는 밀양의 바람분포 특성도 해석하여 비교하였다. 부산 해안의 평균풍속은 밀양보다 강하고, 부산 해안 중에서도 성인 영도와 가덕도의 평균풍속은 일광, 해운대 및 대연의 그것보다 약 2.0배 강한 특성을 보인다. 상판분석에 의하여, 부산 해안의 월별 평균풍속은 서로 변화 경향이 매우 유사함을 확인하였다. 부산 해안의 월별 평균풍속의 최대값은 9월에 나타나는데 이는 대풍의 영향과 밀접히 관련되어 있다. 최대순간풍속도 섬인 명도와 가덕도에서 특히 강하고, 부산 해안의 최대순간풍속은 주로 8-9월에 그 최대값이 관측된다. 부산 해안의 풍향별 관측횟수의 백분율을 살펴보면, 겨울은 남서풍-북북동풍이 우세하고 봄은 남서풍과 북동풍이 우세하다. 여름의 풍향 분포는 봄과 비슷하고, 가을의 풍향 분포는 겨울과 유사한 경향을 보인다.

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