Performance improvement of the CFM56-3 aircraft engine by electric power transfer

Abstract

With the design trends towards the More Electric Engine (MEE) for the More Electric Aircraft (MEA), areas for novel technologies can be pinpointed for multi-spool engines, introducing remarkable improvements to push the boundaries of propulsion technology as it strives to create quieter and more efficient engine. Provided that a multi-spool engine is equipped with electrical machines connected to each of its shafts, using power electronics within a single high-voltage DC bus configuration, it is possible to circulate desired amount of power between the engine shafts independent of their speeds. This paper presents an engine model which has also considered Variable Stator Vanes (VSVs) and Variable Bleed Valves (VBVs) for bleeding in order to investigate the idea of power transfer at low speed settings. Validation with test results from the CFM56-3 engine highlights acceptable level of accuracy of the engine model. Moreover, preliminary results show that the idea of power circulation is highly desirable for low speed settings for the CFM56-3 aircraft engine. The electrical power transfer from the Low Pressure (LP) to the High Pressure (HP) shaft at engine’s low speed settings such as taxi and flight idle, helps to decrease the fuel rate and increase the available surge margin of compressors.