气流温度传感器时间常数关键影响因素分析

通过对气流温度传感器在热校准风洞上进行动态响应校准,得到不同温度传感器在不同工况条件下的时间常数,并提取焊球直径、偶丝直径、屏蔽罩结构、气流马赫数、气流温度以及温度阶跃量等关键影响因素,对其影响机制进行分析,得到了温度传感器时间常数的影响规律。结果表明:减小焊球直径、偶丝直径、屏蔽罩进出气口面积比和温度阶跃量,增大气流马赫数和气流温度,以及采用进出气口对开结构,均可减小温度传感器的时间常数;其中当偶丝直径由0.8mm减小到0.5mm时,温度传感器的时间常数减小142.9%。研究结果可为气流温度传感器的设计、使用与动态补偿等提供必要的依据。

Analysis of Key Influencing Factors of Time Constant of Gas Flow Temperature Sensors

Dynamic response calibration of gas flow temperature sensors was taken in the hot calibration wind tunnel, through which time constants of various temperature sensors under various working conditions were obtained, and key influencing factors were drawn such as diameter of welding ball, diameter of thermocouple wire, shield structure, gas flow Mach number, temperature and temperature step. Influencing mechanisms were anylised, and influencing laws of time constant were obtained. The results show that time constants can be decreased by decreasing diameter of welding ball, diameter of thermocouple wire, area ratio of shield inlet and outlet and temperature step, increasing gas flow Mach number and gas flow temperature, and using opposite opening structure of inlet and outlet. When diameter of thermocouple wire decreases from 0.8mm to 0.5mm, time constant decreases by 142.9%. The results can provide essential basis for design, use and dynamic compensation of gas flow temperature sensors.