机载下投式探空温度传感器设计与实验研究

Design and experimental study of airborne dropsonde temperature sensor

为降低太阳辐射对机载下投式探空仪中温度传感器的影响,设计了一种阵列式NTC珠状热敏电阻探空温度传感器。该传感器阵列通过探头间的太阳辐射误差比值推算大气环境温度的真实值。首先,通过计算流体动力学(computational fluid dynamics, CFD)方法选出传感器探头的最优引线夹角,再对表面涂覆不同太阳辐射反射率涂层的探头进行太阳辐射误差比值计算;然后利用支持向量机(support vector machine, SVM)拟合仿真,得到辐射误差比值拟合模型;最后,搭建低气压风洞以及太阳模拟器实验平台。实验结果表明,该温度传感器阵列可将测量误差降低至0.065℃,均方根误差降至0.078℃,有望将太阳辐射误差对下投式探空仪温度测量的影响降低至0.1℃以内。

In order to reduce the impact of solar radiation on temperature sensors of airborne dropsondes,an array-style NTC bead thermistor temperature sensor for use on board the dropsonde aircraft was designed.The true value of atmospheric temperature was inferred by the ratio of solar radiation error between the probes.Firstly,the radiation error of the different probe lead angles was calculated by computational fluid dynamics(CFD)method,and the probe angle with small and stable radiation error was selected.Then,the solar radiation error ratio of the thermistor probes coated with different solar radiation reflection materials on the surface was calculated.Subsequently,a radiation error ratio correction model was obtained through fitting simulation by support vector machine(SVM).Finally,to verify the measurement accuracy of the array-type NTC bead thermistor temperature sensor,a low-pressure wind tunnel and a solar simulator experiment platform were built.The experimental results indicate that the temperature sensor array can reduce the measurement error to 0.065℃and the root mean square error to 0.078℃,it is expected that the impact of solar radiation errors on temperature measurement of the dropsonde can be reduced to within 0.1℃.