Joint Model of Wind Speed and Corresponding Direction Based on Wind Rose for Wind Energy Exploitation

As a common and extensive datum to analyze wind,wind rose is one of the most important components of the meteorological elements.In this study,a model is proposed to establish the joint probability distribution of wind speed and direction using grouped data of wind rose.On the basis of the model,an algorithm is presented to generate pseudorandom numbers of wind speed and paired direction data.Afterward,the proposed model and algorithm are applied to two weather stations located in the Liaodong Gulf.With the models built for the two cases,a novel graph representing the continuous joint probability distribution of wind speed and direction is plotted,showing a strong correlation to the corresponding wind rose.Moreover,the joint probability distributions are utilized to evaluate wind energy potential successfully.In cooperation with Monte Carlo simulation,the model can approximately predict annual directional extreme wind speed under different return periods under the condition that the wind rose can represent the meteorological characters of the wind field well.The model is beneficial to design and install wind turbines.

Design and Data Analysis of a New Type of Antifreezing Cup-Type Wind Velocity Sensor

In most areas of China, affected by the environment of low temperature and high humidity, the wind speed sensor and wind direction sensor are frozen and cannot output data in autumn, winter or the alternation of winter and spring. In order to solve the freezing situation of the wind sensor, this paper designs a new type of antifreeze wind speed sensor. After meteorology performance testing and field observation tests, the correlation coefficient of the observation data is demonstrated, and the data curve is fitted. The result shows the sensor is stable, and has a good antifreeze effect, the data output is reliable.

The Change in the Maximum Wind Speed and the Impact of it on Agricultural Production

Using the data on the maximum wind speed within ten minutes every month in the period 1971-2009 in Zhucheng City of Shandong Province, we conduct statistical analysis of the maximum wind speed in Zhucheng City. The results show that over thirty-nine years, the annual maximum wind speed in four seasons in Zhucheng City tends to decline. The annual maximum wind speed declines at the rate of 1.45 m/s every 10 years. It falls fastest in winter, with decline rate of 1.73 m/s every 10 years; it is close to the average annual maximum wind speed in spring and autumn, with decline rate of 1.44 m/s and 14.8 m/s every 10 years, respectively; it falls slowest in summer, and the extreme value of the maximum wind speed occurs mainly in spring. The curve of changes in the monthly maximum wind speed in Zhucheng City assumes diminishing shape of "two peaks and one trough". We conduct preliminary analysis of the windy weather situation, and put forth specific defensive measures against the hazards of strong winds in the different periods.

Multi-hazard joint probability distribution model for wind speed,wind direction and rain intensity

Multiple disasters such as strong wind and torrential rain pose great threats to civil infrastructures.However,most existing studies ignored the dependence structure between them,as well as the effect of wind direction.From the dimension of the engineering sector,this paper introduces the vine copula to model the joint probability distribution(JPD)of wind speed,wind direction and rain intensity based on the field data in Yangjiang,China during 1971–2020.First,the profiles of wind and rain in the studied area are statistically analyzed,and the original rainfall amounts are converted into short-term rain intensity.Then,the marginal distributions of individual variables and their pairwise dependence structures are built,followed by the development of the trivariate joint distribution model.The results show that the constructed vine copula-based model can well characterize the dependence structure between wind speed,wind direction and rain intensity.Meanwhile,the JPD characteristics of wind speed and rain intensity show significant variations depending on wind direction,thus the effect of wind direction cannot be neglected.The proposed JPD model will be conducive for reasonable and precise performance assessment of structures subjected to multiple hazards of wind and rain actions.

新型多普勒测风激光雷达Windcube的风参数观测与验证

2007年12月11～14日,中国科学院大气物理研究所与法国Leosphere公司在该研究所位于北京市北三环和北四环之间的325m气象塔试验场内联合开展了一次测风激光雷达Windcube的外场演示试验。Wind-cube观测数据随后与325m气象塔上的风杯风速仪测得的风速资料进行了对比,结果是:由两种手段获得的所有6层匹配高度(63m、80m、100m、120m、160m和200m)上的10min风速平均值一致性很好,相关系数都达到或超过0.98。使用矢量法对6层高度上的风向资料进行平均,得到风向的10min平均值,两者的相关系数均达到0.99。与国产测量低层大气风廓线的高精度多普勒激光雷达相比,Windcube的风速测量精度稍优,风向表现相当。验证结果表明,该型多普勒测风激光雷达是一款观测结果可靠、机动性能良好的低层大气风廓线测量仪器。

WindSim软件在复杂地形风电场风能资源评估中的应用

复杂地形的风能资源评估研究对于风电事业的发展具有极为重要的意义。作者利用基于计算流体力学(CFD)方法的风能资源评估系统软件WindSim对我国复杂地形新疆托克逊县境内某风电场2007年的风资源情况进行了模拟,并将模拟结果与测风塔观测结果进行对比分析。模拟结果表明,WindSim软件对我国复杂地形地区平均风速的模拟能力比较好,10m、40 m、50 m、70 m高度的月平均风速的平均相对误差分别是12.91%、10.21%、9.68%、12.91%。同时,WindSim软件不仅可以较为准确地模拟出该区域2007年的主导风向,而且对该年的有效风速频率的模拟效果也很好。此风电场风能资源模拟试验说明,该地区具有十分丰富的可供开发利用的风能资源,进一步说明WindSim软件对我国复杂地形地区的风能资源评估工作具有很好的参考和应用价值。

Characteristics of daily extreme wind gusts on the Qinghai-Tibet Plateau, China

Severe wind is a major natural hazard and a main driver of deserdficadon on the Qinghai-Tibet Plateau. Generally, studies of Qinghai-Tibet Plateau＇s wind climatology focus on mean wind speeds and its gust speeds have been seldom investigated. Here, we used observed daily maximum gust speeds from a 95- station network over a 5-year period （2008-2012） to analyze the characteristics of extreme wind speeds and directions by fitting Weibull and Gumbel distributions. The results indicated the spatial distribution of extreme wind speeds and their direction on the Qinghai-Tibet Plateau is highly variable, with its western portion prone to greater mean speeds of extreme wind gusts than its eastern portion. Maximum extreme wind speeds of 30.9, 33.0, and 32.2 m/s were recorded at three stations along the Qinghai Tibet Railway. Severe winds occurred mostly from November to April, caused primarily by the westerly jet stream. Terrain greatly enhances the wind speeds. Our spatial analysis of wind speed data showed that the wind speeds increased exponentially with an increasing altitude. We also assessed the local wind hazard by calculating the return periods of maximum wind gusts from the observational data based on the statistical extreme value distributions of these wind speeds. Further attention should be given to those stations where the yearly maximum daily extreme wind speed increased at a rate greater than that of mean value of daily extreme wind speeds. Severe extreme wind events in these regions of the plateau are likely to become more frequent. Consequently, building structural designers working in these areas should use updated extreme wind data rather than relying on past data alone.

CFD Simulations of Wind Effect on Net Solar Heat Gain of South Walls with Internal Insulation

Computational fluid dynamics( CFD) techniques are used to investigate effects of both wind direction and wind speed on net solar heat gain of south wall with internal insulation in winter.Results show that wind effect has a significant influence on the net solar heat gain,where the impact of wind direction is stronger than that of wind speed. For regions in lower reaches of the Yangtze River,difference of their average net solar heat gains( NSHGS) is about 20% due to various wind speeds and wind directions.Buildings in districts with a dominant wind direction of north achieve the highest solar energy utilization.

基于Microwindows的风向风速传感器研究

风向风速仪是船舶重要的导航设备之一,能够对舰船提供相对和真风向风速信息数据,直接影响舰船的航行安全。而风向风速传感器是气象设备要素的核心,对风向风速信息采集和测量计算的重要组成部分。该文针对采用超声波风向风速传感器技术进行了研究,并利用NI推出的Microwindows图形系统以及基于Cotex-M0核心的飞思卡尔单片机MKL05Z芯片来模拟并研究实现风向风速传感器系统。

多频率组合波形阵风场模拟与测量研究

基于数值模拟方法选取设定FL-51风洞阵风发生器的装置参数,如发生器叶片的数量、展长、弦长及间距等。发生器采用液压摆动缸独立驱动形式,可模拟正弦波、三角波及随机波等多种波形的多频率组合运动,同时能够减少安装传动件,并提升发生器性能。通过阵风场校测结果表明:叶片能够实现摆动频率为0 Hz~15 Hz,在校测范围内发生器产生的正弦流场较均匀;在来流风速40 m/s、叶片摆动频率为10 Hz、摆角为15°时,最大阵风幅值为8.5 m/s。地面测试与流场校测结果表明:该文所提出的阵风场模拟技术可以实现低速风洞多频率多波形组合运动,为风洞试验提供复杂的阵风流场。

路堤-桥梁过渡段车辆气动力风洞试验研究

为了探究路堤-桥梁过渡段处车辆的气动力,建立1:50的大比例尺路堤-桥梁过渡段和车辆试验模型,在桥梁和路堤段分别布置两种风屏障,并在车辆模型表面布置多个测压点,以研究不同防风措施下处于不同风向角的路桥过渡段车辆气动力。试验结果表明:与无防风措施相比,布置桥梁风屏障后最不利风向角会从-15°变为0°,此风向下过渡段处车辆的三分力最大;再进一步布置路堤风屏障后最不利风向角不变,但大幅度减小了0°风向角下车辆的侧力系数和力矩系数;布置路堤风屏障能有效减小车辆所受三分力;不同风向角下改变陆地风屏障参数产生的影响不同,针对路堤-桥梁过渡段布置防风措施时,应充分考虑其来流方向,以达到最优效果。

A flutter-effect-based triboelectric nanogenerator for breeze energy collection from arbitrary directions and self-powered wind speed sensor

Triboelectric nanogenerators(TENGs)have been developed rapidly into an efficient wind energy collection equipment.Reducing the frictionwear and energy loss in breeze energy collection is a research direction worthy of attention.Herein,a flutter-effect-based triboelectricnanogen erator(FE-TENG)is designed to collect the breeze energy at low wind speed from arbitrary directions.Distinguishing from previouswind-driven TENGs,the wind-driven part of this device is separated from the TENG units,which not only avoids the wear of friction layerscaused by direct wind contact but also reduces the energy loss,therefore,relatively stable electric outputs are obtained with Voc-281 V,Isc-13.4μA,Qsc-143 nC,and output power-4 mW at the wind speed of 4.5 m/s,respectively.In addition,a real-time wind speed monitoringsystem based on LabVIEW software with high sen sitivity and fast response to wind is achieved relying on the excellent linear relation shipbetween wind speed and electrical output signal.Furthermore,it has been successfully applied as power sources for portable electronics,about 170 commercial light-emitting devices(LEDs)are lighted and a digital watch is successfully driven at the wind speed of 2.9 m/s.This worknot only provides a new structure and idea for the future collection of clean and sustainable breeze energy from arbitrary directions but also hasgreat potential in the field of self-powered systems.

集中绕组模块组合式定子结构对低速大功率永磁电机性能影响

针对集中绕组模块组合式定子结构对低速大功率直驱永磁同步电机性能的影响进行研究。首先介绍了模块化定子的分块规则和分块数。基于绕组函数法推导了单个定子单元模块在不同拆分方式下的绕组函数和电感表达式。基于有限元仿真先分析了仅绕组分块对电机性能影响;然后分析了冲片和绕组都分块对电机性能影响。通过对比空载和负载性能,总结出各种定子模块化拆分方案的优缺点,为大功率低速直驱永磁同步电机的模块化设计与制造建立了基础。

高速列车弓网受流系统放电实验平台设计

为掌握外环境下高速列车的运行特点,开展弓网电弧变化特性研究,该文设计并研制了高速列车弓网受流系统放电实验平台,其风洞系统由风洞结构、风扇转子系统、风洞控制系统、弓网电弧发生系统、观测系统组成。测试结果表明:低速直流风洞风速可达50 m/s,湍流度低于1%,速度不均匀性小于1%,流场稳定性不超过1%,气流偏角不超过0.5°,满足《低速风洞和高速风洞流场品质要求》(GJB 1179A—2012)中所规定的参数指标。该系统为探究强气流场环境下弓网电弧物理特性的变化规律提供了良好的实验环境,可为高速运行环境下列车弓网电弧研究提供参考数据。

川藏过渡区不同气温和风速下沥青混合料降温与压实特性

川藏过渡区气温和风速复杂多变,在进行沥青混合料摊铺碾压时难以有效控制其压实质量.为此,以川藏过渡区德昌至会理高速公路LM3标段为依托开展现场铺筑试验.首先基于理论分析和现场实测对SMA-13、 AC-20C及AC-20共3种不同沥青混合料在铺筑过程中的降温规律进行分析.然后对气温、风速及混合料类型共3个因素开展SPSS正交分析,从而获得其对有效碾压时间的影响性排序.进一步根据降温规律建立沥青混合料的碾压温度估算模型,同时开展室内变温击实试验对其最佳击实温度进行估算.结果表明:当风速小于6 m/s且气温大于5℃时,AC-20C与AC-20的碾压质量较好;当风速大于3 m/s且气温为5~15℃时,SMA-13的碾压质量欠佳;对有效碾压时间的双因素影响性排序为气温&风速>气温&混合料类型>风速&混合料类型;SMA-13、 AC-20C及AC-20的最佳击实温度分别为169℃,166℃,152℃.最后基于分数阶理论,给出了不同气温、风速下不同类型沥青混合料的现场摊铺和碾压温度建议值.

基于CFD模拟的混合式住宅小区布局对风环境改良的研究

文章旨在探讨衡阳市住宅小区的风环境问题,并提出优化方案。通过对该市不同季节的气象数据和现存建筑的模拟分析,研究发现建筑布局和围合形式对风环境有着显著的影响。因此,作者提出了针对冬季和夏季不同风向的方案,以改善住宅小区内部的风环境。本研究采用计算流体动力学CFD(Computational Fluid Dynamics)模拟技术模拟住宅小区周边的风环境,并控制改良后的模拟方案中的变量,以验证所提出的优化方案的可行性,同时对比分析不同方案的效果。结果表明,合理的调整建筑布局能显著优化其周围的风环境,改善通风并缓解局部风速过快的问题。证明CFD技术在未来住宅小区的规划上能提供更科学合理的方案。希望本研究能为未来同类型研究提供参考。

立式风洞新型方向场动压场组合测量装置

为满足立式风洞方向场动压场测量需求,提出一种双倒“T”型结构的方向场动压场组合测量装置方案。采用电机同步控制实现排管架的水平和垂直方向运动,排管架横截面采用NACA0020对称翼型,将原有直径12 mm的五孔探针优化为8 mm,并进行现场安装调试。检测结果表明,该装置水平和垂直方向的位移同步控制精度为0.2 mm。在立式风洞进行一期方向场动压场测量试验,结果表明:该装置性能较为先进,准确地测得了立式风洞试验段模型区内的方向场和动压场数据,能够作为今后立式风洞流场校测主力装置之一。

实际风况下萨沃纽斯风力机集群性能及布局规律研究

为探究风况条件对萨沃纽斯风力机集群功率输出和安装方向的影响,基于变转速控制策略和计算流体力学仿真结果,获得了集群在我国8个典型站点不同安装方向下的输出功率,分析了集群在实际风况下的最佳布局规律,并验证了规律的普适性。仿真结果表明:在沈阳、厦门、昆明、呼和浩特、青岛、喀什、大连以及郑州8个站点合理安装集群,可使单台机组的输出功率分别提升至原来的1.14、1.23、1.31、1.20、1.21、1.24、1.12、1.11倍;对于有明显单一主风能风向的地区,集群应正对此方向摆放;对于两个主风能风向相位差较大的地区,需选择两者中周围风能更丰富的方向排布集群;对于有3个主风能风向、主风能风向不明显或风能分布比较均匀的地区,应先使机组相互格挡的方位避开风能相对集中区,再选择风能资源较丰富的方向排布集群。该研究可使实际风况下萨沃纽斯风力机集群耦合增益最大化,并为复杂风场条件下集群安装方向的选择提供参考。

改进MUSIC算法的超声波测风方法研究

针对传统超声波测风装置测风精度不高、抗噪声能力弱,提出了一种改进多重信号分类(multiple signal classification,MUSIC)算法的超声波测风方法。采用一种弧形6阵元超声波传感器阵列的测风结构,推导其阵列流型;在此基础上,添加小波阈值降噪算法提高信号信噪比,降低噪声信号协方差矩阵的秩;再使用PHAT加权广义互相关时延估计算法以提高时延估计的准确性,同时根据时延关系对传统MUSIC算法矢量矩阵进行改进;最后通过MUSIC算法实现对风速风向的测量。理论分析与仿真结果表明:改进后的MUSIC算法具有较好的抗噪性能和较高的风参数测量精度,测量风速绝对误差达到0.15 m/s,风向绝对误差达到2°,可以应用于对风参数要求较高的场景。