探空湿度传感器太阳辐射误差流体动力学分析与实验研究

The Study on Solar Radiation Error of Radiosonde Humidity Sensor by Fluid Dynamic Analysis and Experiment

针对太阳辐射导致的探空湿度测量偏干问题,本文采用模拟仿真和实验进行相关研究。首先采用流体动力学(CFD)方法模拟仿真了湿度传感器在探空过程中由于太阳辐射导致的温升情况,为了验证仿真的准确性,设计湿度测量电路并搭建实验平台,研究了各种不同条件下的湿度传感器的温升误差,对比结果表明仿真值与实验值吻合度较好,最大相对误差为7.5%。其次,研究了海拔高度、太阳辐射强度、气流流速和防护罩对湿度传感器温升误差的影响,结果表明影响较大的是海拔高度,温度误差随海拔高度明显增加,防护罩的影响较小,此外温度误差与太阳辐射强度呈正相关,与气流流速呈负相关。最后以韩国RSG-20A的湿度测量系统为模型,同时以阳江比对中的一次探空数据记录作为仿真条件,模拟仿真了太阳辐射下的温度误差,再结合饱和水汽压公式计算相对误差,结果表明,32 km的高空由于辐射导致的温度差值达13℃,湿度的相对误差达到70%以上。该研究为探空湿度垂直廓线的辐射误差修正提供一定依据。

To solve the problem of the deviation error of humidity sensor on radiosonde caused by solar radiation,simulations and experiments are used for related research in this paper.First,the method of computation fluid dynamics(CFD)was taken to simulate the temperature rise of the humidity sensor caused by solar radiation in the sounding process.In order to verify the accuracy of the simulation,the system of humidity measurement is designed and the experimental platform is set up to verify and contrast the simulation results under different condition.The results show that the simulation values are in good agreement with the experimental values,and the maximum relative error is 7.5%.Then the effects of altitude,solar radiation intensity,airflow speed and size of the protect shell on the temperature error of the humidity sensor are studied.The result shows that the temperature error increased significantly with altitude,and the influence of the protect shell was small.In addition,the temperature error was positively correlated with the solar radiation intensity and negatively correlated with the airflow speed.Finally the humidity measurement system of RSG-20A from South Korea was used as the model,and a sounding data record in Yangjiang was used as the simulation condition.The temperature error under solar radiation was simulated and the relative error was calculated by the formula of the saturated vapor pressure.The results show that the temperature error due to radiation at a height of 32 km can reach 13℃,and the relative error of humidity can reach more than 70%.This study provides a basis for the radiation error correction of the vertical profile of sounding.