Review and Analysis of the Reasons Delaying the Entry into Service of Power-by-Wire Actuators for High-Power Safety-Critical Applications

Abstract

This paper deals with safety-critical, high-power actuation in aerospace applications. Using a system-level synthetic view, it identifies, explains and discusses the reasons why electrically supplied, or power-by-wire, solutions have not spread rapidly enough to become a generalized replacement of the conventional, hydraulically supplied ones. Once the actuation needs have been summarized, the drawbacks of conventional actuation and the merits of electrically supplied actuation are listed and analyzed. Then, the challenges to be met in order to mitigate the intrinsic disadvantages of power-by-wire are addressed in detail with a focus on the solutions under development or research. Numerous examples, numerical data and orders of magnitude are provided to support the discussion.

Evaluation of Aircraft Actuator Technologies

“…Even though PbW actuators are becoming more common within the flight control system for many different types of aircraft, it is still not always trivial if, when and why they should be equipped. Although electrification provide many opportunities, there are still many challenges which must be dealt with if electrification shall be seen as the superior alternative for actuation [11]. This chapter will aim to compile some of the most relevant previous research and established theories used within the scope of this work.…”

“…Increase of the aircraft take-off weight will directly impact, for example, the fuel consumption which directly relate to air pollution and operating cost. The main disadvantages with the SHAs are related to their efficiency, the power density of the distribution system and the maintainability [11]. The throttling losses connected to the control of the SHA result in very little of the generated power by the supply system will be used.…”

“…One of the drivers for the implementation of PbW actuators is improved power density of the supply system, where it have previously been shown that overall weight savings are possible for this reason, at least for large conventional aircraft [8] [9] [17] [18]. Also, it is stated that the maintainability is approved with electric supply together with the improved monitoring possibilities, increased efficiency through the equipment of power-on-demand and removal of leakage risk, at least within the supply system [11]. However, there are also some challenges introduced with the equipment of PbW actuators.…”

“…The torque produced by the electric motors in PbW actuators are temperature dependent, where excessive heating can permanently damage them. Second, the mass of electric motors are directly driven by the torque they shall produce, which make it beneficial to equip high speed, low torque motors with reducers, but this also increase the reflected inertia which must be handled by the motor [11]. Third, the local weight may be increased with PbW actuators, not only from the actuators themselves, but also from the introduction of a need for a REU to every actuator.…”

Computational Fluid Dynamics (CFD) Simulation of Mesh Jet Devices for Promising Energy-Saving Technologies

“…The adjustable nozzle structure using a deflector made in the form of a diaphragm is known [31][32][33]. For the known control systems of the thrust vector (velocity vector), the highest deflection angle of the flow, at the exit from the nozzle, can vary in the range from +20° to −20° [34][35][36].…”