Search Results

This paper describes study for fuel pump system configuration which is suitable for the MEE (More Electric Engine) system. The MEE is a new engine system concept which intends engine efficiency improvement, which results in a reduction of engine fuel burn and CO₂ emissions from aircraft. Final configuration of the MEE will contain various engine systems, such as fuel system, oil system and electric generating system, but we focus on high efficiency fuel systems as a first step of the MEE development. The MEE is an advanced engine control technology utilizing recent innovations in electric motors and power electronics and replacing conventional engine accessories, such as AGB-driven pumps and hydraulic actuators with electric motor-driven pumps and EMAs (Electro-Mechanical Actuators), which are powered by generators. Because fuel pump system configuration is a key for the MEE fuel system, we conducted comparison of several pump systems and adopted a fixed displacement gear pump system.

This paper describes how the MEE (More Electric Engine) system contributes toward an integrated propulsion control system, with a particular focus on commercial aircraft. Current aircraft systems control the engine rotational speed or pressure ratio to control propulsion, but in future aircraft systems, control of the engine thrust itself will be required. Because controlling engine thrust can be used as an effective method of changing the aircraft speed and/or attitude, various approaches to engine thrust control have been investigated and developed. In this investigation, key technical issues have emerged; one is which is the need for an enhanced engine thrust response for stable control of the aircraft. The other is accurate estimation of engine thrust in flight. Incremental data processing capability is also required due to the need for additional monitoring, evaluation and calculation of engine parameters to ensure safe engine operation.

To improve an energy optimization issue of ECS for MEA, we propose our concept in which ACS is replaced with VCS. A VCS is generally evaluated as auxiliary or limited cooling system of an aircraft. Cooling demand of commercial aircraft usually becomes large due to ventilation air at hot day conditions. In case of using conventional VCS for whole cooling demand, the ECS becomes too heavy as aircraft equipment. Though ACS's light weight is advantageous, the issue that VCS will be available for aircraft ECS is important for saving energy. ECS of commercial aircraft should work for three basic functions, i.e. pressurization, ventilation, and temperature control. The three functions of the ECS for bleed-less type of MEA can be distributed among equipment of the ECS. MDFAC works for pressurization and ventilation. Therefore, we should select appropriate system for only temperature control.