Sport Aviation of the Future. Possible Concepts for Future Sport Aircraft Using Different Environmental Friendly Propuls

1. Sport Aviation of the Future.Possible Concepts for Future Sport Aircraft Using Different Environmental Friendly Propulsion Concepts Patrick Berry Fluid and Mechatronic Systems

2. Introduction • A new generation of sport aircraft will require radical changes to the propulsion system • Why? • In the future fossile fuel will be scarce or at least limited and too expensive • Fossile fuel is bad for the environment and might also be prohibited to use in the future because of its environmental impact • So what are the options?! • 1) Use bio fuels • 2) Go electric ICAS 2010

3. Introduction • This study will focus on electric propulsion and what this means for the design and use of such aircraft • Different power sources like the sun, batteries and fuel cells will be covered ICAS 2010

4. Solar powered aircraft • Sources of inspiration: • Human powered aircraft Daedalus (MIT) Gossamer Albatross ICAS 2010

5. Solar powered aircraft • Sources of inspiration: • Solar powered aircraft Powered configuration Configured as a glider Solair 2 ICAS 2010

6. Questions • Is it possible to design something like this which is commercially viable? • …. and to which category do we certify it? • Is there a market? • Will the market accept it? ICAS 2010

7. Solar powered aircraft • The Sun peaks at 1000 W/m2 (in summertime, at noon on a clear day) • An average of 800 W/m2 can be expected (in southern Europe) • This indicates flight times around 7 hrs on pure solar power • But the aircraft won´t be able to take-off and climb on solar power, so it needs to be a hybrid using batteries to assist • Batteries are an additional dead weight which needs to be minimised, so we are looking for a battery with high energy density (Wh/kg) ICAS 2010

8. Battery trends in energy density ICAS 2010

9. Quinetic Zephyr using Li-S (350 Wh/kg)Endurance: 2 weeks ICAS 2010

10. Solar powered aircraft • Affordable solar cells are in the range of 15-20% in efficiency. We need to work with the most efficient ones in order to reduce size, weight and stay reasonable in cost • Essential to minimise losses in the overall power chain ICAS 2010

11. Solar powered aircraft • How would you use such a plane? • Due to its low power-to-weight ratio it´s more suitable as a powered glider, i.e. a glider with self launch capability ICAS 2010

12. Specification for a solar powered aircraft • Average solar radiation = 800 W/m2 • Max. sink rate in glider configuration: less than 0.7 m/s • Cruise speed in solar powered mode: 20% higher than stall speed • The aircraft shall be a hybrid, i.e. battery power for take-off and climb, solar power for cruise • Min. climb speed: 2m/s • Single seater or two seater • Pilot or passenger weight: 90 kg (+7 kg for parachute) • Certification: CS 22, motorgliders ICAS 2010

13. Typical sizing diagram for solar powered flight ICAS 2010

14. Solar powered aircraft • Two configurations are presented: • Conventional layout • Canard configuration ICAS 2010

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17. 2014-07-15 Sid 17 Linköpings universitet ICAS 2010

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21. Typical V-n diagram for a solar powered aircraft ICAS 2010

22. Problem areas • Requires skilled pilot due to lack of excess power • Solar cell integration on wing and stabilizer • Solar cell integration requires stiff surfaces (brittle cells) • Solar cells need to be embedded for low drag (without too much energy losses) • Aircraft limited in use as to where and when you can operate it • Big question= Maintenance of solar cells!! ICAS 2010

23. Problem areas ICAS 2010

24. Battery powered aircraft Source of inspiration: PC Aero Electra One ICAS 2010

25. Battery powered aircraft • Battery powered aircraft are based on the sun powered configurations shown previously • Main difference: Wing loading can be increased since sun power is eliminated (saves weight) • Since battery weight will be even more dominant in this case, we need to decrease structure weight as much as possible (wing essentially) • No sun power means no need for non-tapered wings any more, i.e. weight potential • Aspect ratio can be reduced (weight saver), which means somewhat reduced soaring performance, ICAS 2010

26. Specification for a battery powered aircraft Maximize range/endurance Min. cruise speed : 20% higher than stall speed Min. climb speed: 2m/s Single seater or two seater Pilot or passenger weight: 90 kg (+7 kg for parachute) Certification: CS 22, motorgliders 2014-07-15 Sid 26 Linköpings universitet ICAS 2010

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29. 2014-07-15 Sid 29 Linköpings universitet ICAS 2010

30. 2014-07-15 Sid 30 Linköpings universitet ICAS 2010

31. Pros and cons • Battery powered aircraft are probably the easiest way to replace current combustion engine types (except for bio fuels) • Battery powered aircraft have power to spare, thus easier to fly, require ”normal skilled pilots” • Might be more interesting for the market since range of speed is greater • Big pro = existing infrastructure! • Limited use in terms of over the year useage • Batteries don´t work that good in a cold environment ICAS 2010

32. Fuel cell powered aircraft DLR Antares Source of inspiration: 2014-07-15 Sid 32 Linköpings universitet ICAS 2010

33. Fuel cell powered aircraft compared to battery powered ICAS 2010

34. Fuel cell powered aircraft • The DLR Antares is a derivative of an existing aircraft. It carries two external wing pods. One is the hydrogen tank the other is the fuel cell • In a blank paper design you would probably try to integrate the tank and fuel cell more • One big problem is to house the large pressurised tank (45 MPa), needs to be placed close to the C of G • Suggestion: place it in the main spar! ICAS 2010

35. Fuel cell powered aircraft • The fuel cell powered aircraft concepts are based on the battery powered concepts previously shown • Same specification • Battery weight exchanged for fuel cell + tank weight • Only differrence is in endurance ICAS 2010

36. 2014-07-15 Sid 36 Linköpings universitet ICAS 2010

37. 2014-07-15 Sid 37 Linköpings universitet ICAS 2010

38. Pros and cons • Technology seems promising • Still in early development stage, not mature • Lack of infrastructure!! • Use is limited by the same reason as battery powered aircraft: • Gas performance degrade with lower temperature ICAS 2010

39. How we prepared the study We used an in-house design program, which we rearranged The rearrangement included: Adding solar power model Adding electric motor model Adding battery model Adding fuel cell model Rearranged weight equations in weight module The electric motor model and weight equations were trimmed against published Solair 2 data We benchmarked against existing aircraft in the category and found good relevence 2014-07-15 Sid 39 Linköpings universitet ICAS 2010

40. Conclusions • This study has shown that it´s quite possible to design electric aircraft with different power sources, even using today´s technology • The ability to design light and with low drag is emphazised more than ever • ”Green aircraft” won´t be any high speed machines • Live ”green”= eat ”slow food” • Fly ”green”= fly slowly • Will the market accept slow flight? • Personal view: the market might digest battery powered aircraft in the very near future, but the other variants will probably have to wait for a while ICAS 2010

41. Questions? ICAS 2010