electric idea and need help?

Discussion in 'Electric Propulsion' started by Ethan Appleton, Sep 24, 2019.

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  1. Sep 24, 2019 #1

    Ethan Appleton

    Ethan Appleton

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    So I here is the general aspect to my idea. Using two small maybe 8hp motors spinning a compressor blade, collect blead air off those compressor blades run them through an aircycle machine (such as how you get A/C on turbin powered aircraft) - Using this now cooled (forget the actual amount but its cold enough to cause ice on pipes) blow that over a primary electric motor (maybe the tesla model 3 ones or the chevy volts) My primary questions include 1. would I need a gear reduction if om looking to off the master engine run a counter rotating prop assembly each with large 4 blade props? second with the cooled air blowing over the motors from the air cycle machine that should lower cool my motor and increase the efficiency of the system? 3. my base frame idea for the design is the bell "P-39" aircrobra just a smaller version excluding my wing will be composite and one solid structure with just removable panels to install controls and batteries? Does this idea make any sense and where are my gaps at to the overall idea??? still saving to by a good computer to run the cad programs to properly draw it up my had drawing sucks!! Any help thanks!
     
  2. Sep 24, 2019 #2

    pictsidhe

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    Your cooling scheme does not make engineering sense. Cool your motor conventionally, or the system will be heavy and inefficient. There is a reason that things are doen the way they are. Without being a gifted engineer, you are unlikely to come up with something better. Plagiarism should be your best friend.
    Geared motors can be a lot lighter than direct drive motors.
     
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  3. Sep 24, 2019 #3

    Ethan Appleton

    Ethan Appleton

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    I understand that but if you super cool the motor you lower the resistence and a simple air cycle machine witch ways little less then I think like 50 pounds can super cool bleed air and I could use that air. the only thing id need in piping and the mount points per what my plane is set up like the engineering side would be the numbers I need to prove my scheme to show it works on paper when I have the money ill just scrap build something and see how well it works but id like to in my mind come to the perfect idea to build- with two conpressors running if I can make them work off a simple electric motor and be able to run efficiently then they can use bleed air and run the aircycle machine cooling the main and themselves with the now -temp air those things produce- tore apart the one to an 86 g2 and the things not that complex but the condut is heavy and takes space I need to srink it and I need numbers for that or money to waste experimenting
     
  4. Sep 24, 2019 #4

    pictsidhe

    pictsidhe

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    50 pounds and 12kW to add how much efficiency to your main motor?
    If you do the math, I can guarantee that this idea will lose all its appeal.
     
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  5. Sep 24, 2019 #5

    Ethan Appleton

    Ethan Appleton

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    how does the math work in sense? im still trying to figure our how to choose an electric motor im not trying to exceed 1,000 pounds in the overall empty weight I need to figure how much the wing and batteries will be.. that's still a problem I know the tesla batteries work really well but I was watching some stuff on the different batteries and just got lost.. and with the motor if I can with the aircycle machine I want to try and chill the system down to - temps to increase the efficenci so I can run more current and not burn the **** thing up...conventional cooling wouldn't work to do that less I carry liquid nitrogen and freeze the main engine at intervials but that adds more complexity in my head.. explain more why you think it wont work
     
  6. Sep 24, 2019 #6

    pictsidhe

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    Your cooling idea will use more power than the main motor will save from the extra cooling. Stir in the fact that magnetic losses will increase below around 100C, it's not an improvement on conventional motors. That's not even considering the extra complexity and the fact that a failure is going to a bad thing.
    Go find a conventional motor of the correct size. Trust me, trying to design your own high efficiency motor is not easy. I've done it.
     
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  7. Sep 24, 2019 #7

    henryk

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    -CR FLIGHT system (conter rotating propellers,no gear) can divide motor RPM by circa 2...
    -or motor + differential gear =by circa 3.

    20190503_132318.jpg

    BTW= high RPM motors are lighter and cheaper,as low RPM,big momentum ones !
     
    Last edited: Sep 24, 2019
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  8. Sep 24, 2019 #8

    Hot Wings

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    Pictsidhe is correct. The efficiency gained from the cooling is not a good trade for the weight and complexity. If you are planning a trans Atlantic flight in an electric plane it had better be amphibious with some ships stationed along your route for a recharge or two!

    Electric flight technology just isn't developed enough for that project to even be considered 'edge of the envelope'.
     
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  9. Sep 24, 2019 #9

    BJC

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    Ethan:

    Keep dreaming up ideas. Then, learn how to do a high-level sanity check. Where there are multiple energy conversions in a scheme, knowing the overall efficiency will indicate whether or not the scheme is viable. Study, learn about energy and energy conversion processes, and then calculate energy into and out of each component. Total the work done (useful energy out), divide by the energy in, multiply by 100 and you will have the overall energy efficiency.

    Note that getting a good working understanding of physics is a long, on-going process.


    BJC
     
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  10. Sep 24, 2019 #10

    Aerowerx

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    And don't forget the tank of DRY Nitrogen gas you have to carry!

    Why? Because I can pretty much guarantee that you will have frost build up which will block the cooling ducts. And you will need a shroud over the motor itself to contain the dry nitrogen and prevent frost on the motor.
     
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  11. Sep 25, 2019 #11

    Ethan Appleton

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    more info regarding what you mean and what is that thing??
     
  12. Sep 25, 2019 #12

    Ethan Appleton

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    I was planning to mimic the same a/c system used in the g2 just smaller and rather then using it for cool air use it to cool and maintain the motors tempt I saw a video online where a guy put a dc motor in liquid nitrogen and it worked better and was faster then what he was able to get via the same input soo that's what got me on the way to think I could use the cold air produced by and air cycle machine to cool down the motor possible enough to mimic that tho I did think that building a plane with a single set of batteries not more then a max of an hour flight then using an external tank flush the liquid nitrogen over the engine cooling it down then running it till the batteries where dead but im broke in school and cant afford to waste money and my understanding of the physics is only well if I can see and have someone show me how to work the formules in a real world example problem not on just paper
     
  13. Sep 25, 2019 #13

    henryk

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  14. Sep 25, 2019 #14

    stanislavz

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    That is your mission ? On aircraft, all counts - not only motor efficiency, but energy/mass for all system. And it is better sometimes to take 90% eff motor, if it weights 5 kg, than 98%, weighting 20 kg.. Active cooling for motor - yes. Water cooling - maybe if it fits. Superconductor - absolutely yes, if you can make them in your kitchen laboratory.
     
  15. Sep 25, 2019 #15

    Dan Thomas

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    Liquid nitrogen is at -320°F. An air cycle machine is just a glorified air conditioner and won't produce temperatures anywhere near that low. You can't expect any lower than about -20°F from the machine. And the 8 hp motors are going to consume an awful lot of battery capacity as well.

    The laws of physics tend to correct wishful thinking real quick.
     
  16. Sep 25, 2019 #16

    RonL

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    I'm not sure why henryk put the picture in his post, but I think it is a gyrocopter, less the rotor mast section.

    Another thing you might want to learn about is why ice balls (hail) fall out of the sky in the near vicinity of tornados. (search vortexes)
    You might not need a heavy air machine to make cold air. ;)
     
  17. Sep 26, 2019 #17

    henryk

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    =it is KASPERWING cage with conter rotating differential gear=moore thrust,no gyroscopic momentum...
     
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