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Evaluation of survival stow position and stability analysis for heliostat under strong wind

Journal of Central South University 2016年第11期23卷 3006-3017页

作者：冯煜陈小安单文桃 The State Key Laboratory of Mechanical Transmission (Chongqing University) Chongqing 400044 China College of Mechanical Engineering Jiangsu University of Technology Changzhou 213001 China

Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.

关键词： heliostat survival stow position stability bearing capacity strong wind

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Characteristics of strong winds at the Runyang Suspension Bridge based on field tests from 2005 to 2008

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第7期11卷 465-476页

作者： Hao WANG MOE Key Laboratory of Concrete and Prestressed Concrete Structure Nanjing 210096 China College of Civil Engineering Southeast University Nanjing 210096 China

Field measurement of strong wind characteristics is of great significance for the development of bridge wind engineering. Located in east China, the Runyang Suspension Bridge (RSB) with a main span of 1490 m is the longest bridge in China and the third longest in the world. During the last four years, the RSB has suffered from typhoons and strong northern winds on more than ten occasions. To determine the strong wind characteristics of the RSB, wind measurement data obtained from field tests during strong winds and data from the wind environment monitoring subsystem of the structural health monitoring system (SHMS) of the RSB were combined to analyze the wind speed and direction, variation in wind speed with height, turbulence intensity, turbulence integral length, wind friction speed and the power spectrum. Comparative studies on the characteristics of these different strong winds were carried out based on the current wind-resistant design specification for highway bridges. Results showed that some regularity in wind characteristics can be found in these different typhoons passing through the RSB. The difference between a strong northern wind and a typhoon is relatively clear, and in summer the typhoon is the dominant wind load acting on the RSB. In addition, there were some differences between the measured strong wind characteristics and the values suggested by the specification, especially in respect to turbulence intensity and turbulence integral length. Results provide measurement data for establishing a strong wind characteristic database for the RSB and for determining the strong wind characteristic parameter values of this coastal area in east China.

关键词： Suspension bridge strong wind wind characteristic Field test Structural health monitoring system (SHMS)

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A DYNAMICAL INTERPRETATION OF THE wind FIELD IN TROPICAL CYCLONES WITH THE CONSIDERATION OF OROGRAPHIC FACTORS

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Journal of Tropical Meteorology 2010年第2期16卷 125-133页

作者：郝世峰潘劲松岳彩军崔晓鹏杨诗芳 Zhejiang Meteorology Observatory Shanghai Typhoon Institute of China Meteorological Administration LACS Institute of Atmospheric Physics Chinese Academy of Sciences

Based on the barotropic primitive equation in the polar coordinate system and the appropriate assumption, we obtained the mathematical equation of orographic forcing on unit mass air parcel. With the consideration of the frictional stress of the sea and land, supposing that parcel velocity in tropical cyclones is in linear variation and that the distribution of surface pressure is circular, a set of equations are derived, which describe the impact of orographic slope error, the central pressure error and position error of tropical cyclones on the wind field in the tropical cyclone. Typhoon Wipha (2007) is selected to verify the above interpretation method. The results show that the orographic slope, the frictional coefficient, the intensity and position of the cyclone are the important factors which have great influence on the interpretation of wind information about tropical cyclones. The dynamic interpretation method gives very good results, especially for the coastal area. It is applicable to improving the forecasts of the wind field in tropical cyclones.

关键词： tropical cyclone orographic slope frictional stress strong wind dynamic interpretation

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A DYNAMICAL INTERPRETATION OF THE wind FIELD IN TROPICAL CYCLONES

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Journal of Tropical Meteorology 2009年第2期15卷 210-216页

作者：郝世峰崔晓鹏潘劲松周冠博胡波 Zhejiang Meteorological Observatory LACS Institute of Atmospheric Physics Chinese Academy of Sciences

Based on the primitive equations in polar coordinates and with the supposition that parcel velocity in tropical cyclones is in linear variation and that the distribution of surface pressure agrees with the Fujita formula, a set of equations are derived, which describe the impact of perturbations of central pressure, position of tropical cyclones, direction and velocity of movement of tropical cyclones on the wind field. It is proved that the second order approximation of the kinetic energy of tropical cyclones can be described by the equations under linear approximation. Typhoon Wipha (2007) is selected to verify the above interpretation method, and the results show that the interpretation method of the wind field could give very good results before the landfall of tropical cyclones, while making no apparent improvement after the landfall. The dynamical interpretation method in this paper is applicable to improving the forecasts of the wind field of tropical cyclones close to the coast.

关键词： tropical cyclones strong wind dynamical interpretation

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Damage index estimation by analysis of meteorological disasters on film plastic greenhouses

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International Journal of Agricultural and Biological Engineering 2019年第5期12卷 58-63页

作者： Heeryong Ryu Mankwon Choi Myeongwhan Cho Inho Yu Seungyu Kim Protected Horticulture Research Institute National Institute of Horticultural&Herbal ScienceHaman52054South Korea

This study focuses on the analysis of the effect of meteorological disasters on film plastic greenhouses by typhoons,heavy snow,strong wind,and heavy *** data of meteorological disasters from 1998 to 2015 were analyzed on provincial basis to calculate the damage rate depending on the weather *** cumulative damage area is 20279 *** damage rates of typhoons,heavy snow,strong wind,and heavy rain are 46.4%,47.4%,2.5%,and 3.8%,*** damage index of the greenhouse,which is the ratio of the greenhouse area to the cumulative damage area,was proposed to estimate the disaster risk for 17 administrative *** damage index data and the cumulative damage areas were divided using the Jenks’Natural Breaks *** average damage index is 0.66,and the damage indices are high in the metropolitan cities.

关键词： damage index global warming heavy snow strong wind heavy rain protected horticulture typhoon vinyl house

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The influence of different underlying surface on sand-duststorm in northern China

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Journal of Geographical Sciences 2005年第4期15卷 431-438页

作者： SONG Yang QUAN Zhanjun LIU Lianyou YAN Ping CAO Tong College of Resources Science and Technology Key Laboratory of Environmental Change andNatural Disaster the Ministry of Education of China Beijing Normal University Beijing 100875China

In this paper, a quantitative research on the relationship between different underlying surface and sand-dust storm has been made by using 40 years meteorological data of five different types of underlying surface in northern China, which include farmland, grassland, sandland, gobi and salt crust. These metrological data comprise sand-dust storm days and strong wind days. By analyzing, we can find that there are certain correlations between the days of sand-dust storm and strong wind for different underlying surface, which has great influence on sand-dust storm. But there are pronounced differences in different types of underlying surface. The sand-dust storm days of grassland, gobi and salt crust, with smaller interannual variation are obviously less than strong wind days. On the other hand, the sand-dust storm days of farmland and sandland increase evidently, even in many years, are much more than strong wind days. The differences are mainly induced by the influencing mechanism of different underlying surface on sand-dust storm. Grassland, gobi and salt crust with stable underlying surface are not prone to sand-dust storm under strong wind condition. Whereas, the underlying surface of farmland and sandland is unstable, that is easy to induce sand-dust storm under strong wind condition.

关键词： sand-dust storm underlying surface strong wind northern China

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