Abstract:
This report addresses the author’s Group Design Project (GDP) and Individual Research
Project (IRP). The IRP is discussed primarily herein, presenting the actuation
technology for the Flight Control System (FCS) on civil aircraft.
Actuation technology is one of the key technologies for next generation More Electric
Aircraft (MEA) and All Electric Aircraft (AEA); it is also an important input for the
preliminary design of the Flying Crane, the aircraft designed in the author’s GDP.
Information regarding actuation technologies is investigated firstly. After initial
comparison and engineering consideration, Electrohydrostatic Actuation (EHA) and
variable area actuation are selected for further research. The tail unit of the Flying Crane
is selected as the case study flight control surfaces and is analysed for the requirements.
Based on these requirements, an EHA system and a variable area actuation system
powered by localised hydraulic systems are designed and sized in terms of power, mass
and Thermal Management System (TMS), and thereafter the reliability of each system
is estimated and the safety is analysed. These two systems are then compared in fuel
penalty, safety, maintenance and installation, cost, risk and certification. A conventional
Fly-By-Wire (FBW) actuation system is used as the reference case.
The results show that both the EHA system and the variable area actuation system are
feasible for the FCS on civil aircraft. The EHA system is proved to be quite efficient in
power consumption and mass reduction. However, the reliability of EHA needs to be
improved and the TMS of this system may lead to an increase in aircraft drag. The
variable area actuation system demonstrates that it can significantly reduce the system
design point and system size; while the localised hydraulic system is not as efficient as a
centralised hydraulic system. Finally, a variable area actuation system powered by the
centralised hydraulic systems is suggested for the FCS on civil aircraft and the Flying
Crane. A variable area actuation system powered by localised hydraulic systems is
recommended as the first step towards MEA and AEA in the future.
