How far are we from the perfect electric "homebuilt" ?

Discussion in 'Hangar Flying' started by Speedboat100, Aug 20, 2019.

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  1. Aug 27, 2019 #161

    stanislavz

    stanislavz

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    Pods are not problematic. Biggest problem is pilot itself in small airplane.

    And more on topic - for motor glider conversion leaf batteries are better suited. Less energy density, but best power. And safe.. Do survive without active thermal management till 40kwh size.
     
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  2. Aug 27, 2019 #162

    Speedboat100

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    Ok...do you understand why it is crucial to get airborne with a minimal power in a fixed pitch propeller aircraft ?
     
  3. Aug 27, 2019 #163

    stanislavz

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    Yes, with case of water or snow start. But this is tiny percent in total power used for take off, i do gues..
     
  4. Aug 27, 2019 #164

    Speedboat100

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    Yes...but you can use higher pitched propeller to reach better speed at lower rpm. Usually the take off is the hardest part that actually defines the prop too....as we dont have infinitely long aerodromes available.
     
  5. Aug 27, 2019 #165

    stanislavz

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    it does not matter as much in energy wise.. Accelerating from 0 to 60 km/h is much lower in energy requirement, than climbing from 0 to 1000 meters or so..
     
  6. Aug 27, 2019 #166

    Speedboat100

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    But you have the friction from the wheels.
     
  7. Aug 27, 2019 #167

    stanislavz

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    No. Only rolling resistance.
     
  8. Aug 27, 2019 #168

    Speedboat100

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    Yes rolling resistance. It is very low with trains.
     
  9. Aug 27, 2019 #169

    stanislavz

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  10. Aug 27, 2019 #170

    Speedboat100

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    I'll make the 1/3 scale model first.
     
  11. Aug 27, 2019 #171

    stanislavz

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    Just please remember, all in aerodynamic is already known.. It is not 1920, when all was learned hard ways..
     
  12. Aug 27, 2019 #172

    Aerowerx

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    I wish we still had a ROFL emoji!

    Hold on a bit...my side is still hurting from the laugh.

    OK that's better....

    If everything is already known, then why is NASA still in business????
     
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  13. Aug 27, 2019 #173

    stanislavz

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    Have your seen any new radical design in shape ? Any new foils ? All progredd is done by new possible materials. Not new shapes.
     
  14. Aug 27, 2019 #174

    henryk

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    Last edited: Aug 27, 2019
  15. Aug 27, 2019 #175

    litespeed

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    Yeah,

    What happened to the old emojs, it was a nice addition to provide some with a message. It also could demonstrate sarcasm.
     
  16. Aug 27, 2019 #176

    Aerowerx

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    Large lifting body airliners??? PRANDTL-D??? B-2 bomber??? F-22?? This thing from NASA???

    You said that EVERYTHING was already known. Then why do we not have bird-like morphing wings?

    All the equations and simulations are just APPROXIMATIONS, not reality.

    See that air particle that just went past your nose? If you can tell me where it is in 10 minutes, then I will believe we know everything about air flow! <sarcasm>

    And remember that new materials allow for the new shapes!
     
    Last edited: Aug 27, 2019
  17. Aug 28, 2019 #177

    Topaz

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    >squints<

    This is the sort of commentary that got you tossed out of HBA before. You opened this thread with a request for opinions. You're getting them. Refuting every one with irrelevant replies is going to go in a very predictable direction. Please stop.

    As for the posts #171 and onwards, let's keep it civil, gentlemen. Please.
     
    Last edited: Aug 28, 2019
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  18. Aug 28, 2019 #178

    Speedboat100

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    Aerodynamics may have reached the half way point of its developement...but aeroplane designing has just begun...especially for electric aeroplanes.

    We have few good examples so far:

    1. Elektra One
    2. Solar Impulse
    3. EADS demostrator
    4. Pipistrel Apha Electro

    https://en.wikipedia.org/wiki/PC-Aero_Elektra_One

    They all seem to have some similarities...extreme light weight...by reducing LG weight and by having clean shapes...and composite materials.

    More here:
     
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  19. Aug 28, 2019 #179

    Speedboat100

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    There is something remakable here...46 kg/m2 wingloading plane flies at 3 KW.

    https://en.wikipedia.org/wiki/PC-Aero_Elektra_One

    The Elektra One was test flown in March 2011, using 3 kW of power. In August 2011, the Elektra One won the Lindbergh electric aircraft prize presented at the EAA AirVenture airshow in July 2011.[3]
     
  20. Aug 28, 2019 #180

    stanislavz

    stanislavz

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    Ok. agree.
    In de page, more info is provided :

    Leermasse
    (max. Batteriemasse) 100 kg (ohne Batterien)
    100 kg
    Nutzlast 100 kg
    max. Startmasse 300 kg

    100 kg airframe, 100kg batteries, and 100kg load..
     

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