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1.
设计并实现了一个小型风力发电机的外特性测试平台,平台包括低速开放式风洞、数据采集系统两部分.风洞设计成口径3.5 m的直流式风洞,实验段采用圆形截面,动力段采用多风机提供动力,在风流通过蜂窝器后,大大改善了风流效果并提高了可靠性.数据采集系统通过工业控制数据采集卡对风速、风力发电机转速、输出电压、电流等进行数据采集和处理.通过对某小型风力发电机进行测试的结果表明,平台可满足测试小型风机外特性的实验要求. 相似文献
2.
为确定残积土表面蒸发强度影响因素的敏感程度及其模型,以2种花岗岩残积土为例,采用自制室内蒸发试验,分析了温度、风速、太阳辐射、空气湿度、压实度、含水率对蒸发强度的影响规律,并标定了E0—θ模型的参数．结果表明,土体在高温（40℃）条件下蒸发强度约为低温（5℃）条件下的10-20倍;受太阳辐射时蒸发强度约为相同温度下不受太阳辐射时的1．5～2倍;有风条件下土表蒸发强度约为无风状态下的2～4倍;空气湿度越低蒸发强度越高;随着土壤压实度的增加,土壤蒸发强度逐渐减小,但其影响较小;土体蒸发强度随含水率降低呈减小趋势,并可近似为直线关系．因此,在确定土袁蒸发强度时应重点考虑温度、风速、空气湿度、太阳辐射、含水率的影响;E0-θ蒸发模型适用于花岗岩残积土的蒸发强度模型,相关指数均在0．9以上． 相似文献
3.
探讨了热气候风洞实验台环境测控系统动态工况的误差,对系统各环境参数(温度、湿度、辐射照度和风速)的测量不确定度进行评定。通过分析影响系统控制不稳定的因素,找出其规律性,并给出改善建议。 相似文献
4.
赵红杰 《中国现代教育装备》2012,(9):9-10,14
对低温制冷综合试验台进行了研究,详细说明了该试验台的基本构成和参数控制思路,并对该试验台进行实验项目的探讨。试验台内部最低温度可达-35℃,能提供恒温、恒湿、恒风速实验环境,可进行蒸发器结霜特性、换热器性能等多方面的实验,也可进行其他交叉学科的科学研究,可为教学、科研换热设备的开发、研制提供服务。 相似文献
5.
张世龙 《南通职业大学学报》2021,(1):63-67
利用Excel对空气质量国控点与自建点的"两尘四气"浓度日平均数据进行透视分析,得到二者相对应的变化趋势,发现大部分数据波动比较大;再利用SPSS对"两尘四气"数据与风速、压强、降水量、温度、湿度的相关性进行分析,结果表明,PM2.5、PM10与湿度呈中度相关,SO2与风速、湿度基本不相关;最后以自建点整点时刻"两尘四气"的平均数据与国控点数据的差值为因变量,风速、压强、降水量、温度、湿度为自变量,用MATLAB进行多元线性回归,建立自建点数据的矫正模型,模型校验效果达到预期。 相似文献
6.
文章介绍了一种整体长度为0.64m,重约为4kg,轻巧、便携的烟风洞装置的特点.该装置有着良好的烟气发生装置和烟气流动质量,方便的燃油补充机构和试件磁力固定结构,是流体力学学科中一种较完美的教学工具.轻巧的结构使得这种烟风洞装置可以很方便地携入教室用于教学演示.各种研究对象在风洞中的绕流情况可以很好地用高质量的数字照片显示出来,这些照片如圆柱绕流,平面叶栅的流线分布,都能较好地反映了流体力学流动基本规律;同时,通过对一个模型汽车所进行的流体力学数值计算（FLUENT）与实验对比,其结果显示出它们的流动状态吻合较好,说明这种便携式烟风洞的良好性能. 相似文献
7.
Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake)plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2=0.76, P=0.01 at Hetou and R2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X3 15147X2-1250.7X 2278.4 (R2=0.68; P=0.01) at Hetou and Y=-101.67X3-1.65X2-376.4X 1914.8 (R2=0.40, P=0.05) at Jijia, where Ywas daily SFD, Xwas daily wind speed.Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa,slightly lower under high relative humidity (＞80%) compared with those at the Jijia site; (3) The upper and lower threshold 相似文献
8.
基于暖体假人的低温灾害模拟实验系统设计 总被引：1，自引：0，他引：1
开发了一套利用制冷系统实现最低-18℃低温环境,在其中以暖体假人为核心实验设备的低温灾害模拟实验系统.系统使用压缩机组采用风冷实现降温,并利用微控制器实现系统控制和温度的自动调节;系统使用先进的暖体假人模拟人体发热、发汗等生理活动,配置多点环境温湿度器在线测量室内环境变化.经测试,此实验系统降温速度约1℃/min,同时墙体保温性能以及制冷送风最大风速符合低温环境研究的基本要求.这一低温灾害模拟系统的建立,可为开展围绕低温灾害中人体生理反应的相关研究提供实验条件,为低温环境中防护装备的有效性及舒适性等研究提供有效支撑. 相似文献
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10.
同晓正 《杨凌职业技术学院学报》2011,10(2):1-4,10
水分是制约黄土高原丘陵区植被恢复与重建的主要限制性因子。本研究通过选择陕北黄土高原丘陵区鱼鳞坑、水平沟和天然封育3种不同措施,研究近地表的气温、空气湿度、风速以及地温等小气候特征,揭示不同水保措施下近地表小气候的变化规律。经试验结果综合对比,3种水保措施改善小气候能力的强弱为：水平沟〉鱼鳞坑〉封育草地。 相似文献
11.
We carried out a wind tunnel test to measure cladding loads for a high-rise building of 295 m in height, which would be located in the business center of Chongqing Municipality, P. R. China. The rigid model was used to determine fluctuating local pressures on the exterior surfaces of the building. The wind tunnel test results show the cr/tical zone of wind pressures on building surfaces in both standalone and interference conditions. The computational fluid dynamics （CFD） was conducted by using the FLUENT Code to compare with the wind tunnel test results, and the steady three-dimensional turbulent flow with Realizable k-ε as a turbulence model was used. The CFD results are agree with the wind tunnel test results in regards to distributions of wind pressures over a high-rise building＇s surfaces. 相似文献
12.
2012年9月,全国大学生运动会在天津召开,本文利用天津地区1951年-2010年的气象资料,分析了大运会期间天津的天气气候特征,特别对温度、降水、风和相对湿度这些对运动会比较敏感的气象因素进行了分析,结合一些运动项目给出了气象条件对运动项目的影响分析、建议和应对措施。分析结果表明,体育运动与气象条件息息相关,对此应给予高度关注。 相似文献
13.
Decomposition of dimethyl sulfide （DMS） in air was investigated experimentally by using a wire-cylinder dielectric barrier discharge （DBD） reactor at room temperature and atmospheric pressure. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse-forming network （BPFN） was adopted in our experiments. The maximum power output of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV, respectively. The important parameters affecting odor decomposition, including peak voltage, pulse frequency, gas flow rate, initial concentration, and humidity, which influenced the removal efficiency, were investigated. The results showed that DMS could be treated effectively and almost a 100% removal efficiency was achieved at the conditions with an initial concentration of 832 mg/m3 and a gas flow rate of 1000 ml/min. Humidity boosts the removal efficiency and improves the energy yield （EY） greatly. The EY of 832 mg/m3 DMS was 2.87 mg/kJ when the relative humidity was above 30%. In the case of DMS removal, the ozone and nitrogen oxides were observed in the exhaust gas. The carbon and sulfur elements of DMS were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, sulfur was discovered in the reactor. According to the results, the optimization design for the reactor and the matching of high pulse voltage source can be reckoned. 相似文献
14.
覃有钧 《中山大学学报论丛》1990,(1)
1986年1月在深圳市罗湖区的南洋大夏(31层),现场监测了塔楼附近风速、风向、温度及汽车尾气污染物浓度随高度的变化,总结了一些规律。在此基础上,用SIMPLE方法模拟了北风、中性大气条件下南洋大厦附近的三维流场,用求对流扩散方程数值解的方法模拟了北风、中性大气条件下南洋大厦附近NOx的浓度分布,并与实测结果相比较。模拟结果表明,塔楼的风影能起到一个相当干烟囱的作用,对减轻街道面的汽车尾气污染有利。 相似文献
15.
Xiao-jun Ma Xu-guang Jiang Yu-qi Jin Hong-mei Liu Xiao-dong Li Tong Chen Jian-hua Yan 《浙江大学学报(A卷英文版)》2012,13(1):69-78
The emission of dioxins from municipal solid waste incinerators (MSWIs) has become a widespread concern. The effect of meteorological
parameters (wind speed, atmospheric stability and mixing height) on the hourly ground level concentration (GLC) of dioxins
was estimated using air dispersion models. Moreover, the health risks of dioxin exposure were evaluated for children and adults
using the Nouwen equation. The total environmental exposure via air inhalation and food ingestion was calculated, based on
linear fit equations. The results indicate that potentially severe pollution from dioxins occurs at a wind speed of 1.5 m/s
with atmospheric stability class F. In addition, local residents in the study area are exposed to severe weather conditions
most of the time, and the risk exposures for children are far higher than those for adults. The total exposure for children
far exceeds the tolerable daily intake of dioxin recommended by the World Health Organization (WHO) of 1–4 pg TEQ/(kg·d) under
severe weather conditions. Results from modeling calculations of health risk assessment were consistent with dioxin levels
obtained during actual monitoring of emissions. 相似文献
16.
张沛宇 《天津职业院校联合学报》2013,(11):100-102
在2012年全国大学生数学建模竞赛的C题中,关于脑卒中疾病受环境影响的因素很多同学都按着多元线性回归分析的模型给出了发病率和温度、湿度、气压等外界环境因素的关系,并通过逐步回归分析得出了温度、湿度、气压的关系系数以及他们的权重因子。但通过对发病率和认为温度、湿度、气压等外界环境因素的关系并非简单的线性关系,而是带有交叉项的回归模型,笔者通过非线性回归分析得到了温度、湿度、气压等外界环境因素的关系,并通过F检验,说明系数的误差。并通过预测得出在未来几年的发病率的大概人数,以供医院对医务人员和器械进行配备。 相似文献
17.
This paper discusses the unsteady aerodynamic behavior of long-span vaulted roofs. First, a forced vibration test in a turbulent boundary layer is conducted in a wind tunnel. The models are force vibrated in the first anti-symmetric mode to investigate the effects of wind speed, rise/span ratio, and the amplitude and frequency of forced vibration on the distributions of wind pressures and unsteady aerodynamic forces. Then, a large eddy simulation (LES) is carried out to clarify the physical mechanism of wind-roof interaction as well as to investigate the influences of a roof’s vibration on the flow field around the roof. From the results of the wind tunnel experiment and the LES, we discuss the characteristics of unsteady aerodynamic forces on a long-span vaulted roof over a wide range of the reduced frequency of vibration. The effect of unsteady aerodynamic forces on the dynamic response of the roof is also discussed. A comparison between the wind tunnel experiment and the LES indicates that the LES can be used effectively to evaluate the unsteady aerodynamic behavior. 相似文献
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19.
杨帆 《成都航空职业技术学院学报》2021,37(1):46-48
自动气象观测系统是专门用于民航机场气象部门进行气象数据的自动采集、计算处理和存储的设备,可以自动连续测量跑道视程、风向、风速、温度、湿度、气压、降水等气象要素。通过青岛流亭机场在一次大雪过后自动气象观测系统测量的跑道视程数值偏低的原因查找和修正过程,希望能够对其他机场遇到雨、雪等特殊天气及数据异常时的自动气象观测系统维护、维修工作提供借鉴。 相似文献
20.
新兴城市深圳对气候的影响日趋明显。旧城区成为高温、低湿、小风的中心,具有城市热岛特征。高层建筑影响气流的运行,已成为城市气候研究中的新课题。 相似文献