航空发动机热电偶传感器稳态测温偏差分析

Analysis of steady-state temperature measurement deviation of thermocouple sensors on aeroengine

为了满足航空发动机上高温、高压、高来流马赫数的恶劣工作环境下的使用需求,对某型航空发动机上选用的低压涡轮后热电偶传感器开展热风洞校准试验及测温准确性分析,明确热电偶传感器测温偏差的影响因素,并通过一种基于表面传热系数推导公式的测温偏差修正方法对校准结果进行计算验证,结果表明,计算方法合理可行,计算结果与测量结果一致性良好,在全部试验点偏差量均小于0.6%。针对现有校准设备无法完全模拟航空发动机真实工况的问题,对校准结果进行修正计算,修正计算结果与真实气流温度偏差在0.7%以内,传感器的稳态测温偏差能够满足在该型航空发动机上的使用需求。

In order to meet the application requirements of the aeroengines under harsh working environment of high temperature, high pressure and high incoming Mach number, the hot wind tunnel calibration and temperature measurement accuracy analysis were carried out for the low-pressure turbine rear thermocouple sensor selected for an aeroengine,and the influencing factors of temperature measurement deviation of the thermocouple sensors were identified. A temperature measurement deviation correction method based on the derivation formula of convective heat transfer coefficient was used to validate the calibration results. The results showed that the modified method was reasonable and feasible,and the calculation results were in good agreement with the measurement results,the deviation was less than 0. 6% in all test sites. Considering the problem that the hot wind tunnel cannot fully simulate the real operating conditions of aeroengines,the modified method was used to correct the calibration results,the deviation between the correction results and the real air temperature was less than 0. 7%, so the low-pressure turbine rear thermocouple sensors can meet the application requirements of this type of aeroengine.