A methodology for vehicle and mission level comparison of More Electric Aircraft subsystem solutions: Application to the flight control actuation system

Abstract

As part of the More Electric Initiative, there is a significant interest in designing energy-optimized More Electric Aircraft, where electric power meets all non-propulsive power requirements. To achieve this goal, the aircraft subsystems must be analyzed much earlier than in the traditional design process. This means that the designer must be able to compare competing subsystem solutions with only limited knowledge regarding aircraft geometry and other design characteristics. The methodology presented in this work allows such tradeoffs to be performed and is driven by subsystem requirements definition, component modeling and simulation, identification of critical or constraining flight conditions, and evaluation of competing architectures at the vehicle and mission level. The methodology is applied to the flight control actuation system, where electric control surface actuators are likely to replace conventional centralized hydraulics in future More Electric Aircraft. While the potential benefits of electric actuation are generally accepted, there is considerable debate regarding the most suitable electric actuator – electrohydrostatic or electromechanical. These two actuator types form the basis of the competing solutions analyzed in this work, which focuses on a small narrowbody aircraft such as the Boeing 737-800. The competing architectures are compared at both the vehicle and mission levels, using as metrics subsystem weight and mission fuel burn, respectively. As shown in this work, the use of this methodology aids the decision-making process by allowing the designer to rapidly evaluate the significance of any performance advantage between the competing solutions.