Electric and Counter Rotation

Discussion in 'Electric Propulsion' started by RonL, Apr 2, 2019.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Apr 2, 2019 #1

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    A very informative interview with some good visual display that should get anyone's mind seeing clearly and their just scratching the surface. :)



    Thanks for watching.
     
    blane.c likes this.
  2. Apr 2, 2019 #2

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland
    -for comparation,see reactonless drive,

    CR FLIGHT...

    https://www.crflight.com/analysis
     
  3. Apr 3, 2019 #3

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    Not sure I see your thoughts in connecting CR-Flight and reactionless drive, I did a search and reactionless drive seems to go more to quantum electrodynamics, some really interesting things,but I couldn't quite make the connection to current general aviation.
    James Ritchey seemed to go silent after our conversations here a few months ago when I mentioned an idea of a three part motor/generator design that powered a prop and the reaction driving a generator section instead of a second &reverse prop. My big question is, would I rather have more prop power or recover some of what energy has been supplied to the motor ?
    With that in mind here is a picture I captured off u-tube that generated the thought of a shroud around a propeller and how much power could be generated if electronics provided a very well managed power/glide cycle ?

    upload_2019-4-3_10-26-8.png
     
  4. Apr 3, 2019 #4

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland
    "reactionless drive seems......"

    =I mean reaction momentum from propellers to the stator or frame of flying device...

    iff reduction is "i", the reaction momentum is multipled by "i"'

    F=m*a (second Nevton law) is working normally.
     
  5. Apr 4, 2019 #5

    Sockmonkey

    Sockmonkey

    Sockmonkey

    Well-Known Member

    Joined:
    Apr 24, 2014
    Messages:
    1,657
    Likes Received:
    431
    Location:
    Flint, Mi, USA
    So the idea is to counter the gyroscopic effect of the prop by by having the IC engine spin the generator in the opposite direction?
     
  6. Apr 4, 2019 #6

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland


    ="hard" CR gear...



    ="soft" CR system=NO fuselage reaction !

    (electric is much simpler).

    PS=in both cases NO gyroscopic momentum!



    =example...
     
    Last edited: Apr 4, 2019
  7. Apr 4, 2019 #7

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    The gyroscopic effect of a propeller would be a bit different than the torque resistance of a generator rotor, because of mass and diameter of rotation.
     
  8. Apr 4, 2019 #8

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    Something I found that should be of interest to a few people on HBA. The first link is a e-book details of how the flyer was made (a $14.00 purchase if anyone is really interested), the second is first flight trials, and the last is a combination of flying and assembly, with mechanical peeks.
    I find that selecting the closed caption box (on u-tube) helps with understanding everything he says.
    The four rings do involve counter rotating sets and as he says, are critical to location.

    http://www.amazingdiyprojects.com/multirotors.html



     
  9. Apr 4, 2019 #9

    Sockmonkey

    Sockmonkey

    Sockmonkey

    Well-Known Member

    Joined:
    Apr 24, 2014
    Messages:
    1,657
    Likes Received:
    431
    Location:
    Flint, Mi, USA
    Ah, I didn't bother watching the video initially.
     
  10. Apr 4, 2019 #10

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland
    RonL

    "With that in mind here is a picture "

    =any moore info?
     
  11. Apr 4, 2019 #11

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    A clip from an aviation site to start....


    "Relative to MAV, as opposed to large scale rotors:

    Compared to the baseline open rotor, the shrouded rotors showed increases in thrust by up to 94%, at the same power consumption, or reductions in power by up to 62% at the same thrust.

    At rotor collectives above 10°, all shrouded-rotor models showed improvements in performance over the isolated (‘open’) rotor — that is, higher thrusts and lower power requirements. At the same power consumption, increases in thrust over the open rotor by up to 94% were observed, or, conversely, up to 49% reductions in power at the same thrust, for the condition where the open and shrouded rotors are required to have the same tip speed. If, instead, the rotor disk areas are required to be the same, then up to 90% increases in thrust at the same power.

    The effects of changing any one of the four parameters (tip, rlip, d, Ld) on the shrouded-rotors’ performance became more pronounced as the other three parameters were changed to degrade the performance. It is therefore not possible to categorically state that any one particular parameter has a greater effect on performance than any other, since the amount of influence of any parameter depends on the values of the other parameters. The exception to this seems to be the lip radius, changes in which had almost same effect no 258 matter what the values of the other parameters are. Thus, in general, it would seem that changing the value of any shroud parameter so as to improve performance results in less sensitivity of the performance to changes in any of the other parameters; similarly, improving the efficiency of the rotor itself would seem to result in less of a performance benefit from the presence of a shroud.

    Extracted from: HOVER AND WIND-TUNNEL TESTING OF SHROUDED ROTORS FOR IMPROVED MICRO AIR VEHICLE DESIGN Jason L. Pereira Doctor of Philosophy, 2008 Dissertation directed by: Professor Inderjit Chopra Department of Aerospace Engineering University of Maryland College Park

    Rotor parameters including tip gaps, tilt and relative wind, collective, and motor characteristics will influence rotor RPM, and are indirectly addressed in Pereira's dissertation. Again, there are very broad assumptions in the OP question, but Pereira substantiates generalized efficiency improvements for specific configurations."


    The "Hover and wind-tunnel testing of shrouded rotors for improved micro air vehicle design" by Jason L. Pererira is quite lengthy and detailed. It is in pdf format.


    My idea of extracting electrical energy in-flight is based on the very large amount of KE in a rotating propeller and a large potential energy of a mass in forward motion as it moves through the air. A generator has the potential of large spikes of production of electrical energy in short time spans that will have almost no affect on RPM or forward velocity.
    In the picture above the ring of electrical coils would be embeded in the shroud and the blade tip would be electro-magnets or permanent magnet as in typical design.
     
  12. Apr 5, 2019 #12

    RonL

    RonL

    RonL

    Well-Known Member HBA Supporter

    Joined:
    Jan 9, 2007
    Messages:
    456
    Likes Received:
    28
    Location:
    Texas
    One more video that demonstrates how well the machine responds, I wonder what wind conditions would make it completely unusable ?

     
  13. Apr 5, 2019 #13

    Sockmonkey

    Sockmonkey

    Sockmonkey

    Well-Known Member

    Joined:
    Apr 24, 2014
    Messages:
    1,657
    Likes Received:
    431
    Location:
    Flint, Mi, USA
    Had to dig this one up.[​IMG]
    The duct is the stator. The innermost ring is just to brace the blade tips.
     
  14. Apr 7, 2019 #14

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland
    =big stator diameter=much copper(or Al) coils weight...

    BTW=electric motors/generators energy density is much greater than aerodynamic devices are.
     
  15. Apr 7, 2019 #15

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,270
    Likes Received:
    560
    Location:
    capital district NY
    Everything that rotates to my understanding has gyroscopic effect. But, the propeller has more effect in "P" factor than in gyroscopic effect regards the engine/motor. The rotational mass of the engine/motor is usually greater than the mass of the propeller and therefore the engine/motor has more effect on gyroscopic force. Also in torque.
     
  16. Apr 7, 2019 #16

    BJC

    BJC

    BJC

    Well-Known Member HBA Supporter

    Joined:
    Oct 7, 2013
    Messages:
    9,580
    Likes Received:
    6,349
    Location:
    97FL, Florida, USA
    Propeller gyroscopic effects dominate on my airplane. 76 inch diameter metal propeller, O-360 Lycoming, 2800 to 3200 RPM.


    BJC
     
    wsimpso1 likes this.
  17. Apr 7, 2019 #17

    blane.c

    blane.c

    blane.c

    Well-Known Member HBA Supporter

    Joined:
    Jun 27, 2015
    Messages:
    3,270
    Likes Received:
    560
    Location:
    capital district NY
    The propeller is heavier than the rest of the rotational mass?
     
  18. Apr 7, 2019 #18

    Sockmonkey

    Sockmonkey

    Sockmonkey

    Well-Known Member

    Joined:
    Apr 24, 2014
    Messages:
    1,657
    Likes Received:
    431
    Location:
    Flint, Mi, USA
    That would be a no, as the coils are just arranged in a more spread out way rather than being clustered at the center.
     
  19. Apr 7, 2019 #19

    henryk

    henryk

    henryk

    Well-Known Member

    Joined:
    Mar 8, 2010
    Messages:
    4,698
    Likes Received:
    448
    Location:
    krakow,poland
    =the moore RPM electric device(motor),
    the greater N/G (power/weight) ...

    =handy tools=big RPM +reductor ...

    f.e.=

    PREDATOR 30/8 =10 kW/1.5 kg (8000 RPM)
    https://www.highadventure.ch/wp-content/uploads/2014/03/emotor_by_flytec.pdf

    =10 kW/4.5 kg...(2000 RPM)

    BTW= CR FLIGHT system=motor works as inner reductor circa 2:1 !

    http://www.electric-flight.eu/

    =much moore...
     
    Last edited: Apr 7, 2019
  20. Apr 7, 2019 #20

    BJC

    BJC

    BJC

    Well-Known Member HBA Supporter

    Joined:
    Oct 7, 2013
    Messages:
    9,580
    Likes Received:
    6,349
    Location:
    97FL, Florida, USA
    Weight of propeller verses crankshaft? I don’t know. But the propeller’s moment of inertia is much greater than the crankshaft’s.


    BJC
     

Share This Page



arrow_white