Research Fellows Directory
Dr Paul Hopewell
Europe’s Advisory Council for Aerospace Research has set targets for aircraft to reduce CO2 emissions by 50%, with 15-20% to come from the engines. Modern gas turbines are vastly more efficient and over 75% quieter than their predecessors. As further improvement gets progressively more difficult it is necessary to exploit synergies between the sub-systems to give an optimised overall system and this Industrial Fellowship proposal is investigating the scope for such optimisation of aircraft electrical power systems.
Aircraft use electrical power for many things, such as environmental control, avionics, de-icing, lighting and passenger services. Power is provided by generators driven by the engines and, as the electrical power consumed has risen, it now forms a growing proportion of engine load during much of a typical flight.
The main objective of this Fellowship is to accurately model the generation/load system to identify an optimum operating strategy, demonstrated at a unique test facility within the University of Manchester. The IEPNEF facility simulates an aircraft electrical system. Power is distributed via a DC bus to a number of power electronics-based load emulators, to replicate the dynamic behaviour of real hardware.
A feature unique to some Rolls-Royce engines is that they have independent high- and intermediate-pressure shafts which may be used to drive generators. No other aero-engine in the world has this capability. Sharing loads between such generators has implications on an engine’s operating point and efficiency. However, the appropriate sharing is dependent upon the electrical power required, the desired engine thrust and the speed and altitude of the aircraft. Initial investigations suggest that this arrangement is highly beneficial for reducing fuel usage in a more-electric aircraft. IEPNEF is probing the inter-relations between the generators and the engine and seeking optimum control strategies to maximise fuel and emissions saving.