Evaluation of the relationship between exhaust gas temperature and operational parameters in CFM56-7B engines

Abstract

This study presents the relationship between exhaust gas temperature (EGT) and engine operational parameters at two different power settings, including maximum continuous and take-off, in the CFM56-7B turbofan engine. The ground measurements of engine operational parameters including net thrust, fuel flow, low rotational speed, core rotational speed, pressure ratio, air temperature at engine fan inlet, take-off margin temperature, and thrust-specific fuel consumption of 51 different CFM56-7B engines are used to find the relationship mentioned in the study. This engine type is selected due to its common use by the civil aviation sector. In accordance with the results of multiple linear regression analysis, it was shown that EGT is affected by the engine operational parameters in different rate. The relationship between EGT and the operational parameters used in the maximum continuous power setting is slightly stronger than that of take-off power setting, R2=0.73 and 0.69, respectively. The fuel flow, thrust-specific fuel consumption, and take-off margin temperature are determined to be the most significant operational parameters in the correlations used to predict the EGT of 51 CFM56-7B turbofan engines in maximum continuous and take-off power settings, R2=0.28, 0.23, and 0.35 and R2=0.27, 0.14, and 0.60, respectively. It is found that there are good agreements between the predicted and measured values of EGT in the study. It can be concluded that the proposed technique is an effective tool for the EGT estimation of the turbofan engine.