Research and Verification of Dynamic Modification Algorithm for Aeroengine Exhaust Gas Temperature

Accurate measurement of dynamic exhaust gas temperature (EGT) in Aeroengine is a challenging task. The most common, and also the most practical, method of measurement is to insert a physical probe, for example, a thermocouple sensor, directly into the exhaust flow. The structure principle of the sensor determines there are temperature measurement lags when the EGT changes dynamically. A theoretical model of the heat transfer phenomena that take place in the exhaust flow has been developed to decrease the dynamic error of measuring the exhaust gas temperatures with the thermocouple sensor. And a wind tunnel experiment had been done to obtain the actual time constant of the EGT sensor in variety of dynamic conditions. The theoretical time constant model was compared with the actual time constant to prove its effectiveness. In this work, the authors introduce a new temperature compensation algorithm that can modify the dynamic response errors introduced during the measurement. The algorithm was designed and verified on a real Aeroengine bench test. The fact that the dynamic modified values of EGT obtained in the real engine test are basically consistent with the theoretical values, proves the accuracy of the dynamic modification algorithm of the EGT.