Perspectives of China’s Wind Energy Development

Wind energy is a kind of clean renewable energy, which is also relatively mature in technology, with large-scale development conditions and prospect for the commercialization. Wind energy’s development and utilization is an important measure to increase energy supply, adjust energy structure, ensure energy security, protect the ecological environment, reduce greenhouse gas emission and build a harmonious society. Wind energy is a kind of clean renewable energy, which is also relatively mature in technology, with large-scale development conditions and prospect for the commercialization. The development of wind energy is a systematic project, involving policy, law, technology, economy, society, environment, education and other aspects. The relationship among all the aspects should be well treated and coordinated. This paper has discussed the following relationships which should be well coordinated: relationship between wind resources and wind energy development, relationship between the wind turbine generator system and the components, relationship between wind energy technology and wind energy industry, relationship between off-grid wind power and grid-connected wind power, relationship between wind farm and the power grid, relationship between onshore wind power and offshore wind power, relationship between wind energy and other energies, relationship between technology introduction and self-innovation, relationship among foreign-funded, joint ventured and domestic-funded enterprises and relationship between the government guidance and the market regulation, as well as giving out some suggestions.     

物理模拟虚功和余虚功原理及它们在金属成形工艺中的应用

在文[1]的基础上,本文建立了金属成形工艺非耦联系统和相似非耦联系统的物理模拟虚功原理及余虚功原理,并从该两原理出发导出了文[1]所建立的物理模拟变分原理。上述诸原理共同组成物理模拟能量原理。而物理模拟虚功原理及余虚功原理是物理模拟能量原理的统一理论。同时,给出了模拟虚功原理的应用。     

风电项目中的土木工程问题及有关研究的思考和发展展望

从配套工程建设、风况数据的搜集、整理及分析、预测等角度,探讨了促进我国风电事业的发展方式;指出关注风电建设中的土木工程问题,编制有关规范或指导手册等文件,做好风资源的普查、评估和风电场发电量预测,并在这些技术领域做到专业化、规范化,形成可靠的、成熟的、具有自主知识产权的技术体系对我国的风电发展至关重要。最后探讨了需要进行研究的方向,并结合中国国情对风电的发展做了展望。     

Analysis and Assessment of Wind Energy Potential of Al-Hodeidah in Yemen

Renewable energy is one of the essential elements of the social and economic development in any civilized country. The use of fossil fuels and the non-renewable form of energy has many adverse effects on the most of ecosystems. Given the high potential of renewable energy sources in Yemen and the absence of similar studies in the region, this study aimed to examine the wind energy potential of Hodeidah-Yemen Republic by analyzing wind characteristics and assessment, determining the available power density, and calculate the wind energy extracted at different heights. The average wind speed of Hodeidah was obtained only for the data currently available for the five years 2005–2009 (due to the current economic and the political situation in Yemen). The results show that the average wind speed in the five years is (25.2 W/m2 at 10 m, 93.9 W/m2 at 30 m, and 173.5 W/m2 at 50 m). The average yearly wind power density (25.2 W/m2 at 10 m, 93.9 W/m2 at 30 m and 173.5 W/m2 at 50m), and the average yearly energy density (220.8 KWh/m2/year at 10 m, 822.6 KWh/m2/year at 30 m and 1519.9 KWh/m2/year at 50 m). This research is a preliminary assessment of the potential of wind energy in Hodeidah, which provides useful information for developing wind energy and an efficient wind approach. According to the International Wind Energy Rating criteria, the region of Hodeidah falls under ‘Class 2’ and is classified as ‘Marginal’ for most of the year.     

复杂体型高层建筑表面风压及周围风环境的数值模拟

采用离散化的数值模拟方法对一幢复杂体型高层建筑及其裙房的表面风压与周围风环境进行了模拟计算,并在边界层风洞中进行了模型试验测定。数值模拟基于Reynolds时均方程,分别采用了两种湍流封闭模型:标准k?ε模型和重整化群k?ε模型。通过将两种模型的风压计算结果与风洞试验结果进行比较,获得了该类建筑物表面风压的分布特性,并对建筑周围的风环境作了分析和评价,为结构设计和建筑覆面设计提供了依据。     

新型斜拉桥与摩天轮复合结构流场数值模拟与风洞试验研究

为研究天津慈海桥的压强分布系数,建立了新型斜拉桥与摩天轮复合结构有限元模型,采用了RANS的RNGk-ε模型作为慈海桥进行数值分析的湍流模型,采用非平衡壁面函数模拟壁面附近复杂的流动现象。运用数值风洞法对斜拉桥部分周围流场进行数值模拟,得到斜拉桥周围流场的速度分布和斜拉桥表面的压强系数。通过风洞试验进行测量,介绍了风洞试验的风洞和试验模型,得出了32个测点不同方向的压强系数。把其中具有代表性的测点数值风洞理论值与风洞试验结果进行比较分析,结果对比说明:理论与试验数据一致,所得到的压强分布系数可以用于工程实际。同时证明该文所采用的数值模拟方法来预测斜拉桥表面的平均压强分布情况可以推广应用。     

基于能量传递模型的永磁直驱变桨变速风电机组功率特性测试方法

风电机组功率特性现场测试存在效率低、条件要求高、结果不准确等问题,已成为当前行业关注的热点。为有效解决风电机组功率特性工程测试工作中存在的效率偏低等问题,提出一种基于能量传递模型的功率特性测试方法。以永磁直驱机组为研究对象,围绕永磁直驱机组能量捕捉、传递、转化过程,结合机组风能捕捉系数与桨距角、叶尖速比之间的关系,从机理角度进行定量分析,构建典型机组的能量传递模型,对比实测数据进行调整;在同类机组上进行应用验证,取得了预期的效果,验证了该方法的有效性,研究结果具有重要参考意义。     

体育场主看台悬挑屋盖表面风压的数值模拟

采用数值模拟方法对体育场主看台悬挑屋盖结构的表面风压分布进行了预测和分析。为验证数值模拟的准确性,首先对一具有风压风洞试验结果的主看台平屋盖结构进行了计算,计算结果与风洞试验结果作了比较。然后对浙江温州地区一主看台悬挑屋盖结构进行了数值模拟,考虑了屋盖倾角为0°和16°两种情况;通过对两个最不利风向角0°和180°的模拟结果的分析和比较,提出了这类屋盖表面风压的简化分布规律和计算方法,并与国外相关规范建议的公式作了比较。该简化计算方法可直接供同类结构抗风设计参考和应用。     

曲壳裙房对球形高层建筑风荷载影响的数值研究

对一球形高层建筑在有和没有曲壳裙房情况下的表面风压分布进行了数值模拟和分析。结果表明,曲壳裙房对主体高层建筑的风荷载有着较显著的影响。裙房缩小了球形建筑迎风面和背风面的正风压区域,最大正风压略有减小;裙房较大程度地提高了球形建筑侧风面和顶面的负风压数值,整体结构的风荷载趋于增大,风压分布趋于不均匀。由于裙房的影响,在球面背风区下侧还观察到了明显的对称涡列。在对不同风向角下的风压分布规律进行分析的基础上,还给出了建筑物在最不利风向角下的最不利剖面上的风压系数分布曲线。     

Hybrid energy cell for simultaneously harvesting wind,solar, and chemical energies

We report a hybrid energy cell that can simultaneously or individually harvest wind, solar, and chemical energies to power some electronic devices. By utilizing the wind driven relative rotations between a polytetrafluoroethylene film and an etched A1 film attached on two acrylic tubes, the fabricated triboelectric nanogenerator （TENG） can deliver an open-circuit voltage of about 90 V, a short-circuit current density of about 0.5 mA/m2, and a maximum power density of 16 mW/m2, which is capable of directly lighting up 20 blue light- emitting-diodes （LEDs）. By integrating a TENG, a solar cell, and an electrochemical cell, a hybrid energy cell has been fabricated to simultaneously scavenge three different types of energies. As compared with the individual energy units, the hybrid energy cell exhibited much better performance in charging a capacitor. Moreover, we also demonstrated that the hybrid energies generated can be stored in a Li-ion battery for powering a commercial wind speed sensor and a temperature sensor. This work represents significant progress toward practical applications of hybrid energy cells, providing potential solutions for simul- taneously scavenging wind, solar, and chemical energies.     

风荷载测试与模拟技术的回顾及展望

对大跨度桥梁、大跨空间结构、高层建筑、高耸塔桅结构等建筑物和构筑物而言，风荷载是结构抗风设计、防灾减灾分析的控制荷载之一。风与上述结构间的相互作用十分复杂，可通过风洞试验、现场实测、数值模拟等方法获取详细可靠的风荷载数据。本文简要介绍了大气边界层风特性与风荷载作用特点，回顾了结构风工程中风洞试验与现场实测的基本情况，讨论了风荷载时程的各种数值模拟技术，展望了风荷载测试与模拟技术研究的趋向。     

建筑表面风压的三维数值模拟

本文采用数值模拟方法预测由近地三维流动风引起的建筑物的表面风压。文中运用一种扩展的ｋ－ε紊流封闭模型，导得了稳态流动风的统一形式的控制微分方程。采用控制容积法对微分方程作了离散，ＳＩＭＰＬＥＣ压力校正迭代算法实现了非线性离散化方程的求解。实例计算与分析比较表明，本文的模拟方法改善了对建筑物侧风面和顶面风压值的预测     

基于超越阈值概率的行人风环境数值评估

大尺度的建筑物和密集的建筑群都会对其周边的风环境造成较大的影响,并可能引起行人风环境问题。首先阐述了行人风环境评估的超越阈值概率方法,提出了综合考虑平均风和阵风影响的行人风环境评估标准;其次,结合某半开敞式的大跨空间建筑,统计了该地区风速气象观测资料并估计了概率参数;再次,使用计算流体力学数值风洞技术,获得了8个风向下的风场分布;最后,给出了场地全风向超越不舒适风速阈值的概率分布图,评价了该建筑的行人风环境。结果表明:该文所述方法能够给出复杂建筑的行人不舒适度和危险度详实评估结果。     

中国风能发展战略研究

2008年2月中国工程院启动中国能源中长期(2030、2050)发展战略研究重大咨询项目,项目设置6个课题,根据可再生能源课题的安排,风能组的工作是在"中国可再生能源发展战略研究"的基础上,进一步摸清风能资源家底,从战略的角度对风能市场、产业、技术和应用进行综合分析,提出我国风能中长期发展的战略目标、技术路线、发展重点和政策措施。文章简要介绍了研究的结果。     

O_2/Si(100)非重构表面LEPS相互作用势模型

对双原子分子O2与非重构Si（100）表面相互作用的LEPS半经验势模型进行了研究，其中表面作为具有波纹度的刚性表面进行处理。确立了系统的势能超曲面，得到的表面吸附特性与P．V．Smith等人基于ASED－MO方法的研究结果进行了定量对比分析。对不同入射条件下的分子－表面相互作用势也进行了研究。     

Specification of design wind loads in India

Codes in current use in India for specifying design wind loads for structures are analysed, and shown to be inconsistent with available data on extremes. Thus, it is found that while the National Building Code specifies the highest wind loads on the east coast and western Gujarat, the observed extreme winds are highest in the eastern Gangetic valley. As the consequences of under-specification can be serious, a careful re-examination of the code seems called for. It is argued that although the available data on extremes may not be complete, they provide a more rational basis for formulating a building code; as wind loads become more important in construction engineering a serious effort at generating and analysing the required meteorological data seems highly worthwhile. However, procedures followed elsewhere for predicting extreme winds and the nature of gusts need to be validated for the country. In addition there is also a need to study certain meteorological phenomena peculiar to the Indian subcontinent like the duststorms and the nor’westers of north India. The work reported here was carried out under a project “Design, Fabrication and Testing of a 10,000 litres/hour Windpump”, financed and administered by the Karnataka State Council for Science and Technology, Indian Institute of Science, Bangalore. An erratum to this article is available at .     

美国AIAA风洞试验管理标准与从业者标准浅析

本文归纳了风洞试验发展的历史背景,简述了美国AIAA风洞试验管理标准和从业者标准制定的过程和内容,重点阐述了标准中风洞试验的理念、管理和推荐的风洞试验具体做法,分析了标准中映射出的美国风洞试验技术的先进点,探讨了标准对改进国内风洞试验通常做法的启示。     

汽车外表面气动噪声特性分析

以荣威750为研究对象,通过声学风洞实验手段对车辆后视镜表面、侧窗表面及其附近流场,以及外场的气动噪声特性进行测试分析;在对数值计算结果验证分析之后,通过数值计算手段以流场脉动压力标准差为评价指标并结合速度场特征,分析车辆表面的压力脉动特性及其产生的原因,在此基础上对车辆表面的噪声大小和分布以及频率特性进行计算分析。研究表明车辆的气动噪声主要能量集中在中低频,频带较宽,不同部位特性差异较大;表面压力脉动是表面气动噪声产生的根本原因,压力脉动大的地方气动噪声亦大;气动噪声大的位置是发生气流分离,湍流运动比较剧烈的区域。就该款车而言,气动噪声主要出现在汽车头部上方、前后挡风玻璃边沿、车顶、A柱、侧窗、后视镜以及车尾和轮胎部分位置处。