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中国物理学会期刊

用于气象观测的阵列式温度传感器流体动力学分析与实验研究

CSTR: 32037.14.aps.65.094209

Fluid dynamic analysis and experimental study of a temperature sensor array used in meteorological observation

CSTR: 32037.14.aps.65.094209
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  • 传统百叶箱和防辐射罩内部的温度传感器受到太阳辐射会导致其温度高于大气真实温度, 升温量可达0.8 K甚至更高. 为提高大气温度观测精度, 本文设计了一种阵列式温度传感器. 利用计算流体动力学方法分析计算该传感器在不同环境条件下的辐射升温量, 采用遗传算法对计算结果进行拟合, 获得辐射升温量修正方程. 为验证阵列式温度传感器的实际性能, 研制了强制通风温度测量平台. 将阵列式温度传感器、配有传统防辐射罩的温度传感器和强制通风温度测量平台置于相同环境下, 进行大气温度观测比对实验. 配有传统防辐射罩的温度传感器辐射升温量平均值为0.409 K; 与前者相比, 阵列式温度传感器的辐射升温量仅为0.027 K. 这种阵列式温度传感器可将辐射升温引起的误差降低约93%. 辐射升温量实验测量值与修正方程修正值之间的平均偏移量为0.0174 K, 均方根误差为0.0215 K, 该结果验证了计算流体动力学方法与遗传算法的准确性. 如果配合计算流体动力学方法与遗传算法, 温度测量精度有进一步提高的潜力.

     

    Until now, the air temperature sensors inside thermometer screens and radiation shields are affected by solar radiation, which causes the measuring result to become greater than the actual temperature. The temperature rise can reach 0.8 K or even higher. In this paper, a temperature sensor array design is established for obtaining high precision measurement results. The temperature sensor array consists of an array of radiation shields which features a tube-shape, a platinum resistance sensor array, an aluminum plate with a silver mirror surface and a temperature measurement module that includes a high accuracy thermometer circuit. There is always at least one radiation shield that supplies relatively good ventilation under any airflow direction. A computational fluid dynamic method is implemented to analyze and calculate the temperature rise induced by radiation under various environmental conditions. A correction equation of the temperature rise is obtained by surface fitting using a genetic algorithm. The measurement accuracy can be further improved by this correction equation. In order to verify the performance of the sensor array, a forced ventilation temperature measurement platform is constructed, which consists of a platinum resistance sensor, an L-shaped radiation shield and an air pump. The airflow rate inside the radiation shield can be up to 20~m/s, and the L-shaped radiation shield can horizontally rotate under the control of a software to minimize the error caused by the heated radiation shield. The temperature sensor array, a temperature sensor with traditional radiation shield, and the forced ventilation temperature measurement platform are characterized in the same environment. To experimentally verify the computational fluid dynamic method and the genetic algorithm, a number of contrast tests are performed. The average temperature rise of sensors equipped with the traditional radiation shields is 0.409 K. In contrast, the temperature rise of the sensor array is as low as 0.027K. This temperature sensor array allows the error caused by solar radiation to be reduced by a percentage of approximately 93%. The temperature rise of temperature sensor array, caused by the angular variation of airflow direction is on the order of several mK. When the solar radiation intensity and the airflow rate are 1000W/m2 and 0.1m/s, respectively, the temperature rise is 0.097 K. The temperature rise is 0.05K, when the airflow rate is greater than 0.4 m/s. The temperature rise can be reduced to 0.01 K, when the airflow rate is greater than 2 m/s. The average offset and root mean square error between the correction equation and experimental results are 0.0174 K and 0.0215 K, respectively, which demonstrates the accuracy of the computational fluid dynamic method and genetic algorithm proposed in this research. The temperature measurement accuracy has the potential to be further improved by utilizing the computational fluid dynamics method and the genetic algorithm.

     

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