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广东沿海近地层大风特性的观测分析 被引量:81
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作者 宋丽莉 毛慧琴 +1 位作者 汤海燕 刘爱君 《热带气象学报》 CSCD 北大核心 2004年第6期731-736,共6页
根据广东沿海岸边3个测风梯度塔实测资料及18个沿海气象站历史资料,普查出该地历史上各个8级以上大风个例,并针对各类天气系统造成的大风过程,对比分析其在近地层的阵性特征、演变规律、垂直切变和空间分布等特征。还根据实际观测事实,... 根据广东沿海岸边3个测风梯度塔实测资料及18个沿海气象站历史资料,普查出该地历史上各个8级以上大风个例,并针对各类天气系统造成的大风过程,对比分析其在近地层的阵性特征、演变规律、垂直切变和空间分布等特征。还根据实际观测事实,针对结构工程抗风设计的需求,分析指出了目前我国相关的国家规范中存在的风参数误差,提出了在热带气旋影响的沿海地区,结构工程抗风设计中风参数取值的具体依据。 展开更多
关键词 大风特性 近地层 广东沿海
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台风影响下上海近海风场特性的数值模拟分析 被引量:24
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作者 徐家良 穆海振 《热带气象学报》 CSCD 北大核心 2009年第3期281-286,共6页
选择近年来影响上海最严重的不同路径台风个例,首先利用TAPM数值模式对出现最大风速过程期间,海岸线的风速变化作了数值模拟计算,然后与海岸测风梯度塔的同步观测数据进行对比,在验证了模式计算结果的准确性和可靠性基础上,对台风影响... 选择近年来影响上海最严重的不同路径台风个例,首先利用TAPM数值模式对出现最大风速过程期间,海岸线的风速变化作了数值模拟计算,然后与海岸测风梯度塔的同步观测数据进行对比,在验证了模式计算结果的准确性和可靠性基础上,对台风影响下上海近海区域最大风速的分布特征、不同高度风速变化规律进行分析评估。同时采用海上测风平台的观测数据,对近海海面上的湍流强度作了计算。结果表明:当台风影响上海地区时,上海近海海上的最大风速有较明显的梯度变化;海面上风速随高度变化远比陆上小,各高度层风速如用指数律公式计算,幂指数可取0.09~0.10;海面上的湍流强度亦较小,基本上在0.10以下范围内波动。 展开更多
关键词 应用气象学 大风特性 数值模式 台风 近海 湍流强度
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Morphological Characteristics Analysis of 11 Broom Sorghum Varieties 被引量:1
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作者 乌艳红 李志明 +8 位作者 辛晓平 孙德欣 吕宁 乌仁图亚 娜日娜 赵建平 王军 韩晓华 李峰 《Agricultural Science & Technology》 CAS 2009年第1期15-18,42,共5页
[Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of b... [Objective] To provide a theoretical basis for high-yield breeding of broom sorghum.[Method] Using 11 kinds of broom sorghum collected at home as research objects, the differences in morphological characteristics of broom sorghum were compared through the survey of some indicators, such as plant height, tillering, inflorescence, stem node, stem-leaf ratio, yield, and so on. [Result] The 11 kinds of broom sorghum were different in morphological characteristics with large amplitude of plant height; zygl-1, zygl-6, zygl-8 and zygl-9 were appropriate for fixed broom type; zygl-9 had the highest integrated production. [Condusion] The study laid the foundation for further exploring breeding, cultivation and promotion of broom sorghum. 展开更多
关键词 Broom sorghum Morphological characteristic ANALYSIS
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Characteristics for wind energy and wind turbines by considering vertical wind shear 被引量:8
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作者 郑玉巧 赵荣珍 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第6期2393-2398,共6页
The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm,... The probability distributions of wind speeds and the availability of wind turbines were investigated by considering the vertical wind shear. Based on the wind speed data at the standard height observed at a wind farm, the power-law process was used to simulate the wind speeds at a hub height of 60 m. The Weibull and Rayleigh distributions were chosen to express the wind speeds at two different heights. The parameters in the model were estimated via the least square(LS) method and the maximum likelihood estimation(MLE) method, respectively. An adjusted MLE approach was also presented for parameter estimation. The main indices of wind energy characteristics were calculated based on observational wind speed data. A case study based on the data of Hexi area, Gansu Province of China was given. The results show that MLE method generally outperforms LS method for parameter estimation, and Weibull distribution is more appropriate to describe the wind speed at the hub height. 展开更多
关键词 Weibull distribution wind power vertical wind shear power-law process parameter estimation
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Study on the Rotor Design Method for a Small Propeller-Type Wind Turbine
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作者 Yasuyuki Nishi Yusuke Yamashita Terumi Inagaki 《Journal of Thermal Science》 SCIE EI CAS CSCD 2016年第4期355-362,共8页
Small propeller-type wind turbines have a low Reynolds number,limiting the number of usable airfoil materials.Thus,their design method is not sufBciently established,and their performance is often low.The ultimate goa... Small propeller-type wind turbines have a low Reynolds number,limiting the number of usable airfoil materials.Thus,their design method is not sufBciently established,and their performance is often low.The ultimate goal of this research is to establish high-performance design guidelines and design methods for small propeller-type wind turbines.To that end,we designed two rotors:Rotor A,based on the rotor optimum design method from the blade element momentum theory,and Rotor B,in which the chord length of the tip is extended and the chord length distribution is linearized.We examined performance characteristics and flow fields of the two rotors through wind tunnel experiments and numerical analysis.Our results revealed that the maximum output tip speed ratio of Rotor B shifted lower than that of Rotor A,but the maximum output coefficient increased by approximately 38.7%.Rotors A and B experienced a large-scale separation on the hub side,which extended to the mean in Rotor A.This difference in separation had an impact on the significant decrease in Rotor A's output compared to the design value and the increase in Rotor B's output compared to Rotor A. 展开更多
关键词 Wind Turbine Propeller-Type Horizontal Axis Blade Element Momentum Theory Rotor Design Method
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