Physics Letters A 381 (2017) 177–183
Contents lists available at ScienceDirect
Physics Letters A
Fluid dynamic analysis and experimental study of a low radiation error temperature sensor
Jie Yang a,b,lowast;, Qingquan Liu c,d, Wei Dai a,b, Renhui Ding e
a Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044, China
b School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China
c Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing 210044, China
d Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology, Nanjing 210044, China
e Jiangsu Meteorological Observation Center, Nanjing 210008, China
a r t i c l e i n f o a b s t r a c t
Article history:
Received 19 May 2016
Received in revised form 10 November 2016 Accepted 15 November 2016
Available online 18 November 2016 Communicated by R. Wu
Keywords:
Radiation error
Surface air temperature Temperature sensor Computational fluid dynamics
To improve the air temperature observation accuracy, a low radiation error temperature sensor is proposed. A Computational Fluid Dynamics (CFD) method is implemented to obtain radiation errors under various environmental conditions. The low radiation error temperature sensor, a naturally ventilated radiation shield, a thermometer screen and an aspirated temperature measurement platform are characterized in the same environment to conduct the intercomparison. The aspirated platform served as an air temperature reference. The mean radiation errors of the naturally ventilated radiation shield and
the thermometer screen are 0.57 ◦C and 0.32 ◦C, respectively. In contrast, the mean radiation error of the
low radiation error temperature sensor is 0.05 ◦C. The low radiation error temperature sensor proposed in this research may be helpful to provide a relatively accurate air temperature measurement result.
2016 Elsevier B.V. All rights reserved.
Introduction
Near surface air temperature is a type of fundamental infor- mation of climate change forecasting, data assimilation of satel- lite, weather forecasting, meteorological disaster warning. In recent years, a number of research projects has been focused on the sur- face air temperature [1–6]. Haines et al. [7] concluded that the air temperature increased 0.09 ◦C per decade by analyzing the data of
satellite observation, and concluded that the air temperature in- creased 0.17 ◦C per decade by researching the data of weather sta- tions. Dillon et al. [8] concluded that the air temperature increased
-
- ◦C and 0.95 ◦C in tropical and northern hemisphere areas, re-
spectively, by analyzing the data in the period 1961–2009, of 3186 weather stations throughout the world. In conclusion, the magni- tude of air temperature change is on the order of 0.1 ◦C per decade.
In order to observe the global, large scale and local climate change accurately, to study the influence of aerosol and the solar radiation on the climate, and to research the change of content of water va- por, CO2, methane and other greenhouse gases quantitatively, the
* Corresponding author at: Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044, China.
E-mail addresses: yangjie396768@163.com (J. Yang), andyucd@163.com (Q. Liu), daiweiilove@163.com (W. Dai), drhabcd@sina.com (R. Ding).
measurement accuracy of the air temperature observation on the order of or less than 0.01 ◦C would be desired.
Because the temperature stability of the fixed points of water, gallium, indium and mercury can be controlled within the order of 0.0002 ◦C, and because the temperature measurement accuracy of a 1595A super-thermometer from Fluke is up to 0.000015 ◦C,
plusmn;
plusmn;
the accuracy of the platinum temperature sensor probe may be able to reach 0.01 ◦C by utilizing the 1595A super-thermometer and the fixed points of International Temperature Scale of 1990
plusmn;
(ITS-90) [9]. Compared to the radiation error, the error induced by electronic devices and circuit is 1–2 orders of magnitude lower than the radiation error. The radiation error is a dominant er- ror source. To minimize the influence of solar radiation and long wave radiation, a temperature sensor probe needs to be housed in a radiation shield or a thermometer screen. Ideally, the shield and the thermometer screen can prevent the direct solar radia- tion, reflected solar radiation and long wave radiation from heat- ing the probe, and can allow adequate airflow to ventilate the probe. Nevertheless, the reflectivities of the thermometer screen and the shield are incapable of reaching 100%. Solar radiation and long wave radiation cause the air int
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Physics Letters A 381 (2017) 177–183
Contents lists available at ScienceDirect
Physics Letters A
一种低辐射误差温度传感器的流体动力学分析与实验研究
杨杰 a,b,lowast;, 刘清惓 c,d, 戴伟 a,b, 丁仁惠 e
a Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044, China
b School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing 210044, China
c Jiangsu Key Laboratory of Meteorological Observation and Information Processing, Nanjing 210044, China
d Jiangsu Collaborative Innovation Center on Atmospheric Environment and Equipment Technology, Nanjing 210044, China
e Jiangsu Meteorological Observation Center, Nanjing 210008, China
a r t i c l e i n f o 概论
Article history:
Received 19 May 2016
Received in revised form 10 November 2016 Accepted 15 November 2016
Available online 18 November 2016 Communicated by R. Wu
Keywords:
Radiation error
Surface air temperature Temperature sensor Computational fluid dynamics
为了提高大气温度观测精度，提出了一种低辐射误差温度传感器。采用计算流体动力学（CFD）方法计算了不同环境条件下的辐射误差。所述低辐射误差温度传感器、自然通风防辐射罩、百叶箱和吸气测温平台在相同环境下进行对比。吸入平台作为空气温度基准。自然通风防辐射罩和百叶箱的平均辐射误差分别为0.57℃和0.32℃。相比之下，低辐射误差温度传感器的平均辐射误差是0.05℃本研究提出的低辐射误差温度传感器可以提供较为准确的空气温度测量结果
2016 Elsevier B.V. 版权所有
1.介绍
近地表气温是气候变化预报、卫星资料同化、天气预报、气象灾害预警等基本信息的一种。近年来，许多研究项目集中在表面空气温度[1-6]。海恩斯等人。[7]通过分析卫星观测，通过对气象资料的研究，得出气温每十年上升0.17摄氏度的结论。狄龙等人。[8]得出结论，气温升高0.4℃和0.95℃，在热带和北半球地区，RE-通过对全球3186个气象站1961-2009年期间的数据进行分析，可以看出这一点。综上所述，气温变化幅度为每十年0.1摄氏度。为了准确观测全球、大范围和局部气候变化，研究气溶胶和太阳辐射对气候的影响，定量研究水汽、二氧化碳、甲烷和其他温室气体含量的变化。空气温度观测的测量精度应达到或低于0.01 ℃。
* Corresponding author at: Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing 210044, China.
E-mail addresses: yangjie396768@163.com (J. Yang), andyucd@163.com (Q. Liu), daiweiilove@163.com (W. Dai), drhabcd@sina.com (R. Ding).
因为水、镓、铟和汞的固定点的温度稳定性可以控制在0.0002℃左右，而且Fluke1595a超级温度计的温度测量精度高达0.000015℃。通过使用1595a超级温度计和1990年国际温标的固定点，铂电阻传感器探头的精度可达0.01℃。（TITS-90）.与辐射误差相比，电子器件和电路引起的误差比辐射误差低1-2个数量级。辐射误差是主要的误差源。为了尽量减少太阳辐射和长波辐射的影响，温度传感器探头需要安装在防辐射罩或百叶箱上。理想情况下，防辐射罩和百叶箱可防止直接太阳辐射、反射太阳辐射和长波辐射对探头的加热，并允许足够的气流使探头通风。然而，百叶箱和防辐射罩的反射率不能达到100%。太阳辐射和长波辐射使空气进入内部被加热，然后产生辐射误差。此外，百叶箱和防辐射罩的结构对空气循环有害，从而降低了内探头的响应速度[10,11]。
http://dx.doi.org/10.1016/j.physleta.2016.11.020 0375-9601/ 2016 Elsevier B.V. All rights reserved.
178 J. Yang et al. / Physics Letters A 381 (2017) 177–183
许多调查研究了自然通风防辐射罩和百叶箱的性能。Erell等人通过一系列对比测量得出自然通风防辐射罩的平均辐射误差可达0.8℃。风、辐射和不同涂层对自然通风防辐射罩的能量平衡影响显著，这可能导致2–8°C的辐射误差。在风速为1 m/s、太阳辐射强度为800 W/㎡的不利条件下[17–20]。Brock等[21]发现当风速为小于0.2 m/s。Hubbart[22]提出了一种新的自然通风辐射防护罩，并在温室中进行了测试。新防护罩的平均辐射误差为2.84 摄氏度。Lopardo 等人[23]表明老化的防护罩可能导致测量误差。由于太阳和天气的影响，防护罩的老化和涂层颜色从明亮的反射白色变为浅米色。用旧防护罩测得的温度较大，最大瞬时差为1.63 ℃。（0-5年比较）白天。由于新防护罩也有辐射误差，旧防护罩的辐射误差大于1.63 ℃。一般来说，由于平均风速大于1 m/s，并且防护罩定期清洗，自然通风防护罩和百叶箱的典型辐射误差范围为至2.5 ℃[24–29]。总之，自然通风半径-防护罩和温度计屏幕可能无法满足目前的空气温度测量精度要求。
由于流动的空气有利于辐射热的扩散，通过防护罩的风速越大，辐射误差越小。因此，高性能的防护罩需要机械吸气来提高风速。例如，杨荣荣制造的43502吸气防护罩的风速范围为5–11 m/s。当风速和太阳辐射强度分别为11 m/s和1000 w/m2时，太阳辐射引起的辐射率为0.2 ℃。托马斯和斯莫特[30]提出了一种新的吸气式防护罩。新型吸气式防护罩的辐射误差约为0.2℃，难以满足高精度观测的要求-如果辐射误差为0.1C或更低。但是，电源要求这些系统的维护成本限制了吸气式防辐射罩的应用。气象站的太阳能供电系统大多不能满足电力需求，而灰尘、雪、昆虫等环境因素可能会保证风机的长期可靠性。综上所述，吸气式辐射防护罩在未来很难被气象站广泛应用。
世界气象组织的一份报告[31]指出，利用计算流体动力学（CFD）方法对冯衰减率建模进行研究和对辐射误差的估计都是必要的。Richardson利用CFD软件Fluent模拟了通过罩内的气流。该模型相对简单，仿真结果仅能提供罩内风速和风向。由于成熟度有限，20世纪90年代和21世纪初的CFD技术无法建立防辐射罩和百叶箱的传热模型。因此，温度分布和辐射误差的数值计算结果是不可能得到的。用于气候观测的温度传感器的良好设计应将尽量减少辐射到达探测器。另一方面，最大限度地提高探测器周围的风速是必不可少的。如果不降低探测器附近的风速，防辐射罩就不能阻挡所有不希望的太阳辐射和长波辐射。将这两种设计方法融合到传统的自然通风防辐射罩和百叶箱的设计中是很困难的。本文提出了一种低辐射误差温度传感器。
CFD方法对低辐射采用CFD方法对低辐射温度传感器的误差进行精确定量。利用遗传算法（GA）对CFD结果进行拟合，得到肤色和误差方程。通过大量实验比较，验证了低辐射误差温度传感器的实际性能和辐射误差修正方程。
1.低辐射误差温度传感器的设计
-
- 计算流体动力学模型
低辐射误差温度传感器由温度传感器探头、温度测量模块组成，温度测量模块包括高精度温度计电路和防辐射罩。防护罩由两块带银色镜面的铝板、四根塑料支柱、两个金属吊杆、一根塑料固定柱和两个金属紧固件组成。为温度传感器探针制造了一个具有银镜表面的每个球壳。用导热硅胶将铂电阻探针固定在铜球壳的中心位置。采用密封剂防止水分进入铜球壳的内部。铜球壳的直径、厚度和反射系数分别为8 mm、0.5 mm和95%。为了消除直接太阳辐射、反射太阳辐射和长波辐射引起的误差，Alanod公司生产的4270 Ag铝板安装在温度传感器探头的上方和下方。镀银镜面的反射率为98%。为了减少铝板内表面对探头的反射太阳辐射和长波辐射，铝板内表面涂上一层黑色油漆。内表面的折射率可在10%以内降低。铝板的尺寸为60 mm 60 mm 15 mm。支柱的直径和长度分别为5 mm和40 mm。由于支撑柱的导热系数相对较低，且支撑柱的涂层为白色，因此支撑柱的辐射热相对较小。为了稳定地固定探头，探头被固定在固定柱上，固定柱安装在下铝板的中心。固定柱的直径和长度分别为5 mm和10 mm。支撑柱和固定柱由一种低导热材料制成，在提供机械支撑时可防止铝板的辐射热污染。温度测量模块放置在保护壳内。为了提高长期的可靠性，在气象站安装了低辐射误差温度传感器，采用金属紧固件（图1）。
采用网格软件ICEM-CFD对CFD模型进行网格化。采用非结构化网格技术生成了一个四面体网格。采用CFD软件FLUENT对CFD模型进行计算。利用太阳光线跟踪模型对太阳辐射进行了加载。数值计算采用标准的epsilon模型、简单的算法和标准的初始化方法。为了求解动量、能量和湍流参数，才CFD模型中采用了一阶迎风方法。CFD模型的边界条件根
J. Yang et al. / Physics Letters A 381 (2017) 177–183 179
Fig. 1. Schematic of the low radiation error temperature sensor.
Table 1
Material properties of the low radiation error te
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