• Title/Summary/Keyword: summation of loads

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Load Ratio between Two Adjacent Wings of Load Cell Type Anemometer according to Wind Direction (풍향에 따른 로드 셀형 풍향풍속계의 인접한 두 날개 사이의 하중 비)

  • Han, Dong-Seop
    • Journal of Navigation and Port Research
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    • v.36 no.5
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    • pp.357-361
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    • 2012
  • Anemometer is a meteorological instrument that measures wind direction and wind speed in real time, and is mounted to the cranes that are used at ports, shipbuilding yards, off-shore structure, or construction sites that are influenced by wind, and it is used in conjunction with the safety system. Load cell-type anemometer measures the wind direction through the ratio of load between 4 positions by mounting the thin plate to 4 load cells, and measures wind velocity through the summation of loads. In this study, we compared and analyzed the results in the theoretic approach, analytic approach and experimental approach to derive the correlation between load ratio and wind direction. Wind direction was selected as the design variable, and selected 9 wind direction conditions from $0^{\circ}{\sim}90^{\circ}$ with $11.25^{\circ}$ space for analysis, and 10 wind direction conditions with $10^{\circ}$ space for experiment.

Design Methodology on the Steel-type Breakwater I.Design Procedure and Wave Pressure Estimation (철재형 이안제 설계기법 연구 I. 설계 및 파압추정 단계)

  • Kweon, Hyuck-Min;Han, Yu-Shik;Kwon, Oh-Kyun;Ko, Kyoung-Lae
    • Journal of the Korean Society of Hazard Mitigation
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    • v.11 no.3
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    • pp.209-218
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    • 2011
  • The present study proposes a new estimation relationship for the transmission rate of the steel breakwater which is expected to make up for the weakness points in existing hard solution for shore protection. The steel breakwater consists of the wave dissipator of the dual horizontal plates, the supporting columns and their foundations, and thus its respective designs should also be conducted one by one. Furthermore, the breakwater has to ensure both functions of shore protection and structure stabilization. The study produced experimental data for the stability and safety investigation of the steel breakwater. The forces acting on the steel breakwater were classified into two categories, one is vertical up and down loads for the pile resistance and the other was maximum difference of the vertical load acting on horizontally different position for the torsion. The study applied the stability force produced by the summation of maximum pressure at each point and the safety force acting on each point simultaneously. The regular wave corresponding to the significant wave was utilized for measuring wave pressure and force. The study showed the method for the proper position of submerged upper plate by considering occurrence frequency of tide level. The design process finally determined by trial and error is proposed in the present study.

Comparison of Load Ratio of Load-cell type Anemometer with Windswept Shape Variation (수풍부 형상에 따른 로드 셀형 풍향풍속계의 하중 비 비교)

  • Kim, Tae-Hyeong;Han, Dong-Seop
    • Journal of Navigation and Port Research
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    • v.36 no.10
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    • pp.839-844
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    • 2012
  • Anemometer is a meteorological instrument that measures wind direction and wind speed in real time, and is mounted to the cranes that are used at ports, shipbuilding yards, off-shore structure, or construction sites that are influenced by wind, and it is used in conjunction with the safety system. Load cell-type anemometer measures the wind direction through the ratio of load between 4 positions by mounting the thin plate to 4 load cells, and measures wind velocity through the summation of loads. According to previous research, the load ratio between two adjacent windswept with respect to the wind direction has unstable value due to vortex around windswept. This causes the result that increases an error on the wind direction. In this study we compared and analyzed the difference between the load ratio with respect to three type windswept shapes in order to suggest the proper windswept shape to reduce this error. The computational fluid flow analysis is carried out with ANSYS CFX to analyze the load ratio between three windswept shapes. Wind direction was adopted as the design variable, and selected 9 wind direction conditions from $0^{\circ}{\sim}90^{\circ}$ with $11.25^{\circ}$ interval for computational fluid flow analysis.