Optimization Study of an Intercooled Recuperated Aero-Engine

Preprint, 2011

The design space of an intercooled recuperated aero-engine has been explored with detailed engine performance, weight and dimensions modelling. The design parameters of the engine fan, the core, the intercooler, the recuperator as well as the cooling air ratio and the variable geometry settings in the low pressure turbine have been optimized to minimize the mission fuel burn. Analysis shows that the improvement in engine performance is mainly due to an increase in thermal efficiency. A parametric study has also been carried out around the optimal point to understand the impact of the design parameters on fuel burn. In particular, the analysis shows that the fan design parameters have a more complicated interaction with the engine performance compared to the conventional engine case. It is also found that the resulting optimal pressure ratio between the low pressure and the high pressure compressors closely reproduces the predictions of a previous analytical study. Further analysis reveals that the increasing amount of cooling air is benefical for fuel burn when a hot bleeding concept is adopted. It has been determined that the potential of the variable geometry is limited by the high pressure turbine blade metal temperature.