Analysis of the Application of Distributed Propulsion to the AOS H2 Motor Glider

Abstract

The paper describes the selection of a distributed propulsion for the AOS H2 motor glider (selection of engines, their number, and propellers) and determination of its performance. This analysis is related to the research conducted on environment friendly and hybrid propulsions in various research centres. The main aim of the analyses conducted is to increase the performance of vehicles powered by electric motors. The batteries have a low density of energy, i.e. the ratio of mass to cumulated energy. Instead of a battery set, it is possible to apply a hybrid-electric system, where the combustion engine works as a generator or an electric-hydrogen generator, where the hydrogen cell supports a small set of batteries. One of such flying vehicles, fitting in this trend, is the AOS H2 motor glider built at the Rzeszow University of Technology in cooperation with other universities. It is a hybrid aircraft, equipped with a hydrogen cell, which together with a set of batteries is a source of electricity for the Emrax 268 electric motor. To increase the vehicle's performance (the range and flight duration), it is possible to use a distributed propulsion. This type of propulsion consists in placing many electric motors along the wingspan of the aircraft. Appropriate design of such a system (propeller diameters, engine power, number of engines) can improve the aerodynamic and performance parameters of the airframe. An analysis of the performance for the selected flight trajectory for this propulsion variant was conducted and compared to the performance of the AOS H2 motor glider equipped with traditional propulsion. The consumption of hydrogen was also determined for both systems. The results obtained were presented in the diagrams and discussed in the conclusions.

3E – A new paradigm for the development of civil aviation

“…In this case, the role of the range extender can be taken over by a fuel cell, e.g. a hydrogen fuel cell, as in the AOS H2 motor glider [20].…”

“…Properly designated flight path can significantly affect the performance of the aircraft and the propulsion system, such as fuel consumption or pollutants emission, as shown in [24][25][26][27][28][29]. On the other hand, the optimized mass of the aircraft significantly reduces fuel consumption, which is associated with lower power and thrust required for an aircraft's steady flight at a certain speed [20,31]. Such an approach to aircraft design is inline with the '3E' paradigm.…”

“…The application of distributed propulsion can significantly improve the performance of the aircraft. In [20], the authors presented a proposal for the use of distributed propulsion for a hybrid glider based on a hydrogen fuel cell. Calculations showed that it is possible to reduce hydrogen consumption by 3 kg, which will increase flight duration by 26.5%.…”

“…They are usually placed on the wing leading edge or at the fuselage. This division and location of the propulsion is aimed at improving the propulsion efficiency, improving the aerodynamic parameters of the aircraft and a better balance of energy consumption during the flight [7,11,20].…”

Effect of Energy Consumption Reduction on the Decrease of CO2 Emissions during the Aircraft’s Flight

“…Another way to reduce pollutants emissions is to modify the structure of the aircraft or propulsion-e.g., the use of a hybrid propulsion (combination of internal combustion and electric propulsion) [14][15][16][17]. Development of new technical solutions, new aerodynamic systems, new materials, and new propulsion-these are challenges for aviation industry and scientists for the next several years [18][19][20][21].…”