Hybrid cooling of a high performance electric propulsion system for aircraft

Abstract: Efficient cooling of electric motors

Electric powered aerobatic aircraft are not yet available on the market. Considering the high noise emissions of conventionally powered aerobatic aircraft and the specific possibilities of electric propulsion, MSW Aviation Services GmbH sees a significant market potential for aerobatic aircraft equipped with a high performance electric motor.

On the basis of the development work by the Bern University of Applied Sciences and by MSW aviation on a high performance electric motor for the Votec 221 aerobatic aircraft, this project is dedicated to researching new and more efficient possibilities of propulsion system cooling which are adequate for aerobatics.

Project Description

The integration of a high performance electric propulsion system in an aerobatic aircraft is new and involves numerous challenges, such as system cooling with the help of the propeller and the very diverse and partially contrasting tendencies typical of aerobatics. For example, maximum power – and therefore maximum cooling effectiveness – is required at high angle of attack and low speed; such a condition would not be relevant for a touring aircraft.

To meet such extreme demands, different cooling concepts have been developed and analysed in this project. In particular, the inflow in the cowling to the components of the propulsion system and the outflow from the fuselage have been conceived to limit the need of external cooling to a minimum. It is necessary to develop cooling channel arrangements that allow the best possible functioning of the hybrid cooling system. The most promising concepts will be tested in real scale in the RUAG large wind tunnel facility.

 

The results from this project will form the basis for future applications on training and touring aircraft.