• Title/Summary/Keyword: wind velocity

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The Analysis of Wind Data at the Cities in Korea with Meteorological Administration Data -Wind Data Analysis in 32 Cities During 30 Years- (기상청 자료를 이용한 도시의 바람자료 분석 연구 - 32개 도시의 30년간 바람자료 분석 -)

  • Yoon, Jae-ock
    • KIEAE Journal
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    • v.3 no.1
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    • pp.5-12
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    • 2003
  • Using the wind, we can get a thermal comfort in summer. In winter we must shut out the wind. To achieve sustainable environmental building design, especially wind data is very important. The wind direction and wind velocity of 32 cities were analyzed to suggest the wind map of Korea. The weather data which was used in this paper was from National Weather Service(19711.1~2000.12.31). The results of this study are 1) The monthly wind velocity of Seoul is 1.1m/s-3.8m/s. 2) The maximum wind velocity could be estimated from the annual average wind velocity. The regression curve is Y(The maximum wind velocity)=6.369732 X(annual average wind velocity) + 6.391668 (P< 9.66E-12). 3) The wind velocity at the inland area which is far from 25km sea side is smaller than coastal area. The distance from the sea is major index of wind velocity. 4) The monthly wind direction was compared inland area with coastal area. 5) The uniform-velocity line on the Korean map was obtained.

Mouthpiece Modeling of the Electronic Wind Instrument Using a Propeller and Linear Analysis for Fast Tracking Wind Velocity (빠른 바람의 세기 추적을 위한 프로펠러를 사용한 전자 관악기 취구의 선형 모델링)

  • Kwak, Jae-Hyung;Lee, Gang-Seong
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.3C
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    • pp.295-301
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    • 2010
  • In this paper, we propose a new mouthpiece model for the electronic wind instrument using a propeller and linear analysis for fast tracking wind velocity blown. This method is a modification of the velocity anemometer for fast tracking wind velocity by the propeller's angular velocity (speed of revolution). In the case of velocity anemometer, wind velocity is calculated using the property that wind velocity is in proportion to the propeller's angular velocity. However, wind velocity and angular velocity of the propeller are not in one-one correspondence because wind velocity takes some transitional time for the expected wind velocity to be calculated from angular velocity. To resolve this problem, we propose a method for finding the impulse response of the system which can be considered as a linear system, and for estimating the wind velocity by deconvolving the propeller's angular velocity with the impulse response. To experiment and to prove the validity of the proposed system, we designed a mouthpiece model which consists of a motor, a propeller and an encoder. The result of estimated wind velocity in this method showed that this system is about eightfold faster than the method by the conventional velocity anemometer.

Deriving vertical velocity in tornadic wind field from radar-measured data and improving tornado simulation by including vertical velocity at velocity inlet

  • Yi Zhao;Guirong Yan;Ruoqiang Feng;Zhongdong Duan;Houjun Kang
    • Wind and Structures
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    • v.38 no.4
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    • pp.245-259
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    • 2024
  • In a tornadic wind field, the vertical velocity component in certain regions of tornadoes can be significant, forming one of the major differences between tornadic wind fields and synoptic straight-line wind fields. To better understand the wind characteristics of tornadoes and properly estimate the action of tornadoes on civil structures, it is important to ensure that all the attributes of tornadoes are captured. Although Doppler radars have been used to measure tornadic wind fields, they can only directly provide information on quasi-horizontal velocity. Therefore, lots of numerical simulations and experimental tests in previous research ignored the vertical velocity at the boundary. However, the influence of vertical velocity in tornadic wind fields is not evaluated. To address this research gap, this study is to use an approach to derive the vertical velocity component based on the horizontal velocities extracted from the radar-measured data by mass continuity. This approach will be illustrated by using the radar-measured data of Spencer Tornado as an example. The vertical velocity component is included in the initial inflow condition in the CFD simulation to assess the influence of including vertical velocity in the initial inflow condition on the entire tornadic wind field.

The Effect of Layout Type of the Housing on Wind Flow Planning for Healthy Environment in Multi-Family Housing (집합주거단지에서 건강환경 조성을 위한 주거동의 배치유형이 통풍계획에 미치는 영향 분석)

  • Cho, Cheul-Hee;Lee, Teuk-Koo
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.10 no.2
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    • pp.71-82
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    • 2004
  • The purpose of this study is to analyze the wind velocity ratio in respect of layout types of housing in multi-family housing. The wind velocity ratio is a difference of wind velocity between on the leeward and on the windward side of multi-family housing. The layout types of housing are grid layout pattern of linear type, mixture pattern of Linear type + tower type and layout pattern of tower type. The planning of wind flow is an induced technique to increase in wind velocity in the city and multi-family housing. This study investigates wind velocity ratio into layout types of housing. consequently, analysis were basic design data for the planning techique of wind flow suggested.

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Wind Load Assumption of 765Kv Transmission Towers

  • Kim, Jeong-Boo
    • Journal of Electrical Engineering and information Science
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    • v.1 no.1
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    • pp.45-50
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    • 1996
  • This paper mainly describes the wind load assumption of 765kV transmission towers. We analyzed wind velocity data a meteorological observatories to get the wind velocity of 50 years return period by using Gumbel I type extreme value distribution. By multi-correlative regression analysis method, wind velocity at no observation site was obtained. Reference dynamics wind pressure map was obtained from above analysis and the wind pressure was classified as three regio in high temperature season.

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Nonlinear dynamics and failure wind velocity analysis of urban trees

  • Ai, Xiaoqiu;Cheng, Yingyao;Peng, Yongbo
    • Wind and Structures
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    • v.22 no.1
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    • pp.89-106
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    • 2016
  • With an aim to assess the wind damage to urban trees in more realistic conditions, the nonlinear dynamics of structured trees subjected to strong winds with different levels is investigated in the present paper. For the logical treatment of dynamical behavior of trees, material nonlinearities of green wood associated with tree biomechanics and geometric nonlinearity of tree configuration are included. Applying simulated fluctuating wind velocity to the numerical model, the dynamical behavior of the structured tree is explored. A comparative study against the linear dynamics analysis usually involved in the previous researches is carried out. The failure wind velocity of urban trees is then defined, whereby the failure percentages of the tree components are exposed. Numerical investigations reveal that the nonlinear dynamics analysis of urban trees results in a more accurate solution of wind-induced response than the classical linear dynamics analysis, where the nonlinear effect of the tree behavior gives rise to be strengthened as increasing of the levels of wind velocity, i.e., the amplitude of 10-min mean wind velocity. The study of relationship between the failure percentage and the failure wind velocity provides a new perspective towards the vulnerability assessment of urban trees likely to fail due to wind actions, which is potential to link with the practical engineering.

Analysis of Design Wind Load Level for System Supports Considering Local Basic Wind Velocity and Construction Period (지역별 기본풍속과 공사기간을 반영한 시스템 동바리 설계 풍하중 분석)

  • Lee, Sun-Woo;Won, Jeong-Hun;Mha, Ho-Seong
    • Journal of the Korean Society of Safety
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    • v.29 no.2
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    • pp.53-61
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    • 2014
  • This study evaluated wind loads considering a local basic wind velocity and construction periods to define the level of applied wind loads for system supports. Structural responses of system supports were examined and compared to those of system supports with the level of wind loads following various standards and specifications for permanent and temporary structures. And, the maximum combined stress ratios were estimated to evaluate the structural safety of a considered system support. From results, it was found that the wind load level should be applied in accordance with construction periods when estimating the safety of system supports. Looking into the response by change of the basic wind velocity according to local regions, it is no need to consider wind loads in regions with the basic wind velocity of 30 m/s. However, it was analyzed that wind loads should be considered in the regions with the basic wind velocity of 40 m/s or above. In addition, wind loads should be considered in designing system supports located at the region with the basic wind velocity of 35 m/s starting from construction period of 1.5 years. The standard specification for temporary work was analyzed as an incorrect standard in evaluating wind loads, since it underestimated the response of system supports in accordance with the local basic wind velocity and construction periods.

Study on Basic Wind Speed Suiteable for Wind Power Development (풍력발전에 적합한 기본풍속 연구)

  • Kim, JungHwan;Jeong, HoSeong;Kim, HyeongJun;Han, JungHun;Park, SunKyu;Choi, JinWoong
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.189.1-189.1
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    • 2010
  • The wind farm where the wind velocity condition is excellent and economical can be established to produce power with the multiple wind power turbine. The wind velocity which is suitable to Wind Power Development must be evaluated for searching the economical wind farm on planning the wind farm. In this paper, based on wind speed data at 24 locations in Korea from 1971 through 2009, the basic wind velocity which can be applied to designing wind power development is estimated using the statiscal process. The wind velocity which is measured from observation stations is revised according to wind gauge's height and Circumferential environment. The wind speeds for 200 year's return period in 24 locations are determined using the Gumbel's distribution.

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Characteristic of Wind Flow around Building Structures for Wind Resource Assessment (풍자원 평가를 위한 건축물 주변의 유동특성)

  • Cho, Kang-Pyo;Jeong, Seung-Hwan;Shin, Seung-Hwa
    • The KSFM Journal of Fluid Machinery
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    • v.14 no.3
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    • pp.50-58
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    • 2011
  • To utilize wind resources effectively around buildings in urban area, the magnitudes of wind velocity and turbulence intensity are important, which means the need of the information about the relationship between the magnitude of wind velocity and that of fluctuating wind velocity. In the paper, wind-tunnel experiments were performed to provide the information about Characteristic of Wind flow around buildings with the spanwise distance and the side ratio of buildings as variables. For a single building with the side ratios of one and two, the average velocity ratio was 1.4 and the velocity standard deviation ratio ranged from 1.4 to 2.6 at the height of 0.02m at the corner of the windward side, in which flow separation occurred. For twin buildings with the side ratios of one and two, the velocity ratio ranged from 2 to 2.5 as the spanwise distance varied at the height of 0.02m, and the velocity standard deviation ratio varied near 1.25. For twin buildings with the side ratios of one and two, the maximum velocity ratio was 1.75 at the height of 0.6m, and the maximum velocity standard deviation ratio was 2.1. It was also found from the results of CFD analysis and wind-tunnel experiments that for twin buildings with the side ratios of one and two, the difference between the velocity ratio of CFD analysis and that of wind-tunnel experiments at streamwise distances was near 0.75.

Experimental Study on Heat Flow According to the Wind Velocity in an Underground Life Space (지하생활공간 화재시 풍속에 따른 열유동 특성 연구)

  • Kim, Young-No;Suk, Chang-Mok;Kim, Wha-Jung
    • Fire Science and Engineering
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    • v.21 no.3
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    • pp.61-68
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    • 2007
  • The purpose of this study analyzes heat flows and fire behavior through a reduced-scale model experiments about change of wind velocity in underground life space. When the wind velocity is increased the temperature rise time of the fire room was risen fast. And temperature of fire room was increased. And increase of wind velocity displayed maximum temperature at an opening of the fire room. Heat flows by fire spread increase size of smoke occurrence and flame, and displayed high temperature distribution in passageway than inside of neighborhood department promoting eddy flow spread as wind velocity increases. Finally, heat flows are decided by wind and wind velocity at fire of underground life space, and Wind velocity increases, temperature increase and decrease could confirm that is gone fast.