Multi-physics modelling and simulation of a distributed electric propulsion system for helicopter anti-torque

Abstract

The flexibility offered by Distributed Electric Propulsion (DEP) has triggered in the recent years a variety of new aircraft demonstrators, showing a way to improve the overall efficiency, capabilities and robustness of the future air-vehicles [1]. In comparison, the conventional helicopter tail rotor, with its vulnerable and complex installation, looks like an example of system application ready to take advantage of DEP, both in terms of redundancy and simplification of the flight control chain. This paper investigates the behavior of a distributed electric anti-torque system, starting from a reference usage spectrum and a fixed-pitch/variable-speed rotor design. The goal is to optimize the key electrical components for steady state operation and to verify the dynamic behavior of the system in healthy as well as in degraded conditions. Following an introduction to the safety requirements and the electrical technology state-of-the-art, all the main components are modelled and combined into a single dynamic network. Simulation results from different testing scenarios are then reviewed (in the mechanical, thermal and electrical domain) to show compliance with the minimum acceptance criteria. Finally, the article discusses the advantages and disadvantages of a distributed versus concentrated electrical solution.