This paper develops the modeling of wind speed by Weibull distribution in the intention to evaluate wind energy potential and help for designing small wind energy plant in Batouri in Cameroon. The Weibull distribution...This paper develops the modeling of wind speed by Weibull distribution in the intention to evaluate wind energy potential and help for designing small wind energy plant in Batouri in Cameroon. The Weibull distribution model was developed using wind speed data collected from a metrological station at the small Airport of Batouri. Four numerical methods (Moment method, Graphical method, Empirical method and Energy pattern factor method) were used to estimate weibull parameters K and C. The application of these four methods is effective using a sample wind speed data set. With some statistical analysis, a comparison of the accuracy of each method is also performed. The study helps to determine that Energy pattern factor method is the most effective (K = 3.8262 and C = 2.4659).展开更多
Combining the computational fluid dynamics-based numerical simulation with the forced vibration technique for extraction of aerodynamic derivatives, an approach for calculating the aerodynamic derivatives and the crit...Combining the computational fluid dynamics-based numerical simulation with the forced vibration technique for extraction of aerodynamic derivatives, an approach for calculating the aerodynamic derivatives and the critical flutter wind speed for long-span bridges is presented in this paper. The RNG k-ε turbulent model is introduced to establish the governing equations, including the continuity equation and the Navier-Stokes equations, for solving the wind flow field around a two-dimensional bridge section. To illustrate the effectiveness and accuracy of the proposed approach, a simple application to the Hume Bridge in China is provided, and the numerical results show that the aerodynamic derivatives and the critical flutter wind speed obtained agree well with the wind tunnel test results.展开更多
利用RHtest提供的两种检验方法:惩罚最大T检验(The Penized Maximal T Test,PMTT)和惩罚最大F检验(The Penized Maximal F Test,PMFT),对新疆大风区域13个国家级气象站点建站至2014年逐年平均风速资料进行了均一性检验和订正;通过在新...利用RHtest提供的两种检验方法:惩罚最大T检验(The Penized Maximal T Test,PMTT)和惩罚最大F检验(The Penized Maximal F Test,PMFT),对新疆大风区域13个国家级气象站点建站至2014年逐年平均风速资料进行了均一性检验和订正;通过在新疆地区特定环境下对该两种误报率分布相对均匀且微小偏移检测能力较高的方法进行评估,找出每种方法在新疆地区实际应用当中的适用性,最终通过订正改善新疆风要素年值历史序列的均一性,结果表明:(1)站址迁移、仪器换型、测风手段变化及台站环境变化等非气候变化因素均对13个待检站点年平均风速序列的均一性产生显著影响,其中仪器换型造成的影响尤为突出。(2)当参考站均一性较好时,PMTT方法检测结果与台站元数据一致性较好,反之则存在虚假跳变点或漏检。(3)PMFT方法因为不依靠参考站,能很好的弥补新疆大风区域站点稀疏、参考站点筛选困难和元数据不完整等弊端,该方法对迁站和仪器换型的检测能力较强。(4)数据订正后,总体变化趋势没有大的改变,呈现下降趋势,符合风要素在全国范围的总体变化趋势,数据的均一性得到很大改善。展开更多
文摘This paper develops the modeling of wind speed by Weibull distribution in the intention to evaluate wind energy potential and help for designing small wind energy plant in Batouri in Cameroon. The Weibull distribution model was developed using wind speed data collected from a metrological station at the small Airport of Batouri. Four numerical methods (Moment method, Graphical method, Empirical method and Energy pattern factor method) were used to estimate weibull parameters K and C. The application of these four methods is effective using a sample wind speed data set. With some statistical analysis, a comparison of the accuracy of each method is also performed. The study helps to determine that Energy pattern factor method is the most effective (K = 3.8262 and C = 2.4659).
基金National Natural Science Foundation of China Under Grant No. 50278029
文摘Combining the computational fluid dynamics-based numerical simulation with the forced vibration technique for extraction of aerodynamic derivatives, an approach for calculating the aerodynamic derivatives and the critical flutter wind speed for long-span bridges is presented in this paper. The RNG k-ε turbulent model is introduced to establish the governing equations, including the continuity equation and the Navier-Stokes equations, for solving the wind flow field around a two-dimensional bridge section. To illustrate the effectiveness and accuracy of the proposed approach, a simple application to the Hume Bridge in China is provided, and the numerical results show that the aerodynamic derivatives and the critical flutter wind speed obtained agree well with the wind tunnel test results.
文摘利用RHtest提供的两种检验方法:惩罚最大T检验(The Penized Maximal T Test,PMTT)和惩罚最大F检验(The Penized Maximal F Test,PMFT),对新疆大风区域13个国家级气象站点建站至2014年逐年平均风速资料进行了均一性检验和订正;通过在新疆地区特定环境下对该两种误报率分布相对均匀且微小偏移检测能力较高的方法进行评估,找出每种方法在新疆地区实际应用当中的适用性,最终通过订正改善新疆风要素年值历史序列的均一性,结果表明:(1)站址迁移、仪器换型、测风手段变化及台站环境变化等非气候变化因素均对13个待检站点年平均风速序列的均一性产生显著影响,其中仪器换型造成的影响尤为突出。(2)当参考站均一性较好时,PMTT方法检测结果与台站元数据一致性较好,反之则存在虚假跳变点或漏检。(3)PMFT方法因为不依靠参考站,能很好的弥补新疆大风区域站点稀疏、参考站点筛选困难和元数据不完整等弊端,该方法对迁站和仪器换型的检测能力较强。(4)数据订正后,总体变化趋势没有大的改变,呈现下降趋势,符合风要素在全国范围的总体变化趋势,数据的均一性得到很大改善。
