David Ullman, IDEAL using electric ducted fans in battery or hybrid electric planes

Discussion in 'Aircraft Design / Aerodynamics / New Technology' started by sotaro, Oct 14, 2018.

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  1. Oct 14, 2018 #1

    sotaro

    sotaro

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    I am interested to hear what others think of Dr. Ullman and his research on using ducted fans to increase lift with the Coanda affect. His goal is to allow near VTOL with diminished induced drag and less wing area.

    https://docs.wixstatic.com/ugd/20f020_a8d0b9e4bac14d59acb710f79fc1e3ab.pdf

    Integrated Distributed Electric-Augmented Lift

    Distributed Electric Propulsion using electric ducted fans

    Dr. David Ullman Vincent Homer





    NASA, with the X-57 is similar but not using ducted fans and according to Ullman giving up the reduction in induced drag.

    Thanks
     
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  2. Oct 14, 2018 #2

    pictsidhe

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Dr Ullman would benefit form an aerodynamics 101 course.
     
  3. Oct 14, 2018 #3

    lr27

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    I'm skeptical. However, amazing things have been done with powered lift.

    https://en.wikipedia.org/wiki/Hunting_H.126#Specifications_(H.126)

    I expect something that looks like what Dr. Ullman is writing about could cause dramatic increases in lift, but a CL of 10 seems a bit far fetched. And although I think it would probably make measuring induced drag very tricky, I doubt that there would be a reduction.
     
    Last edited: Oct 14, 2018
  4. Oct 14, 2018 #4

    markaeric

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    If the paper is wrong, it means that the authors are either cranks, con-artists or they interpreted the data in their experiments incorrectly (or failed to account for some other factors). I don't suspect the first two to be the case, and I'll give them the benefit of the doubt on the last one. Having just skimmed through the paper, I'm not sure how they're figuring CL, as I didn't see any AoA vs CL graph going anywhere near 10. I suspect that they could produce a difference in CL for a given AoA and airspeed with upper surface blowing turned on and off. I wouldn't say their design is completely novel as we've seen quite a bit of similar research, especially as of late, and the results appear promising. I don't think they need to achieve an extraordinary CL to be worthwhile, but I'll be ecstatic if they do with such a fairly simple configuration.
     
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  5. Oct 14, 2018 #5

    pictsidhe

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    You don't produce lift by blowing on a surface. You produce lift by moving air in the opposite direction to the lift required. That requires significant energy.
    I don't know why the authors haven't worked this out yet, it is very simple to demonstrate. With the mechansim described in the paper, doesn't need a wind tunnel to do.

    TANSTAAFL.
     
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  6. Oct 14, 2018 #6

    markaeric

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    And how is air moved in the direction opposite of lift? Or for that matter, under what condition does air move in any situation? Anything that can be reduced to something other than pressure differentials? Downwash is an effect of wing lift generation, not the cause.
     
  7. Oct 14, 2018 #7

    blane.c

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    I am confident it will work when the fuselage is of adequate size and filled with hydrogen.
     
  8. Oct 14, 2018 #8

    BBerson

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Correct.
    I think he is a Custer Channel wing enthusiast.
     
  9. Oct 14, 2018 #9

    henryk

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    -russian experiments with oscillatin wing blower upon airfoil was generate Cl=6 !

    (Boldyrev)...

    https://dic.academic.ru/dic.nsf/ruwiki/679568
     
  10. Oct 14, 2018 #10

    pictsidhe

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Boundary layer control can achive huge Cl by maintaining attached flow at large angles of attack and/or with extreme airfoils. Cl of around 10 has been achieved. But this paper isn't talking about boundary layer control. It talking about using the bernoulli effect to generate lift.

    Get a nice power ful fan, blow air radially over a flat disc. According to Ullman, this should generate large amounts of lift.
    It doesn't.

    Go on, try it if you don't believe me. A leaf blower, cardboard, tape and a bit of your time is enough.

    There is a small amount of lift from air being moved downwards to be blown out radially, but it tiny compared to the calculated 'bernoulli lift' that Ullman believes in and is trying to get funding for...
     
  11. Oct 14, 2018 #11

    Vigilant1

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Wow, a "flapping slat" instead of a propeller. I'd never heard of that. I'm not surprised it broke down mechanically, but it is interesting.

    Regarding the OP: Something like the Fanwing seems to be a more elegant way to push a large volume of air smoothy over the top of the wing. The problem with the Fanwing is its high drag at higher airspeeds. I don't think all those bumps and other stuff on the IDEAL wing are going to be much better. Also, the total exit area of those ducted fan units looks considerably smaller than the disc area of the prop they replace, so we can expect them to be less efficient at producing thrust from a given amount of power.

    When the paper says "Cl", I do wonder how they are deriving that--based on the lift produced by a particular >vehicle< airpseed, or do they use the airspeed over the blown wing? If it is the vehicle airspeed, then a hovering helicopter has an infinite Cl?
     
  12. Oct 14, 2018 #12

    jedi

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    It is an interesting proposal and should produce promising results. I was not aware that the YC-14 project went as far back as the 1960s. The YC-14 was flown in the late 70s I believe. I worked at Boeing Flight Test at the time the YC-14 was being tested and results were promising. The conversion to distributed electric power should solve one of the major problems, that is, how to handle the engine out condition. Their proposal should do much better than the X-57.

    For what it's worth, Whitold Kasper (who claimed to have worked on the YC-14 aerodynamics) thought his Vortex Lift Theory had much greater potential. Perhaps that was because it worked as a glider and did not depend on power systems that can fail.

    Henryk: Very interesting paper in post #9 even if I can not understand the language.

    Lets assume the project is completed and is successful in developing a two seat PAV/AT (Personal Air Vehicle / Air Taxi) with STOL capabilities and it is based on the Jabiru J230 airframe and specifications. How would such an Air Vehicle (AIRV) be operated? Let's assume it is a two seat autonomous vehicle (ATOMV) with a 25 mph Vso, 100 kt max cruise speed and 120 mile range with exterior dimensions of the J230.

    It appears to me that it would not be able to operate from the roadways and if it were to operate from airports we already have that capability and it is not used or commercially viable. I am trying to be positive here but I can not envision a market for the product, in today's environment, as presented.
     
    Last edited: Oct 14, 2018
  13. Oct 14, 2018 #13

    henryk

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    " a "flapping slat" instead of a propeller."

    -flapping slat or flap give us much better capebility=drag REDUCTION,
    ANIHILATION and at the end=THRUST force(negative drag, Cx<0) !!!

    =lower drag=lower power for fly...

    https://www.youtube.com/watch?v=g7ZM6wKY3lA

    =modell tests...
     
    Last edited: Oct 14, 2018
  14. Oct 14, 2018 #14

    Sockmonkey

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    I have to agree with you on that one. A cross-flow fan may be less efficient at moving air, but it moves it as a continuous sheet over the wing and has a low parts count. At higher speeds perhaps an auxiliary prop or adjustable intake slots might help.
    The main issue with a cross-flow fan seems to be that the airflow over each blade has to be reversed between the time it acts as an intake blade at the front of it's travel, and the time it has to act as a thrust blade at the rear.
    Shaping the blades so a vortex is formed around each individual one might solve this, but that's speculation on my part.
    With setups like the Voith-Schnider drive units they solve the problem by having the blades change AOA relative to the airflow as they spin, but that's kind of complex and would be hard to make light enough for an aircraft.
     
  15. Oct 14, 2018 #15

    jedi

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    But why not flap the whole wing. Much better power density. Then VTOL (humming bird) is possible.
     
  16. Oct 14, 2018 #16

    sotaro

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    I meant to add more last night before I posted, but didn't. Here are some related material and links.
    Patent application
    https://patentimages.storage.googleapis.com/a1/93/38/380dec936ec375/US20170190436A1.pdf

    BIOGRAPHY
    Dr. David G. Ullman is Emeritus Professor of Design from Oregon State University and an active electric aircraft designer. He holds an MS in Aerospace Engineering and a PhD in Mechanical Engineering. He is a Life Fellow in ASME and is the author of “The Mechanical Design Process” 6th edition. He is a current pilot (since 1988) who has built two airplanes, a Velocity and a Jabiru, and is currently completing wind tunnel testing for his forth-coming electric airplane. Past president of EAA 292, currently trustee. Lives in Independence, Oregon USA

    Vincent Homer is the current patent application assignee and co investigator with Dr. Ullman. Lives in Independence, Oregon USA

    NASA X-57
    https://www.nasa.gov/centers/armstrong/news/FactSheets/FS-109.html

    Coanda effect
    https://en.wikipedia.org/wiki/Coandă_effect

    Custer channel wing
    http://sustainableskies.org/hopflyt-channels-custer-channel-wing/

    The YC-14 used upper surface blowing

    https://en.wikipedia.org/wiki/Boeing_YC-14

    Upper surface blowing (USB)
    https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19760003953.pdf
     
    Last edited: Oct 14, 2018
  17. Oct 14, 2018 #17

    pictsidhe

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Hmmm, maybe he's just trying to patent USB with added bullpoop.
     
  18. Oct 14, 2018 #18

    henryk

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  19. Oct 14, 2018 #19

    pictsidhe

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Ball-Bartoe_Jetwing

    CL of about 7.

    I've read a lot of stuff on boundary layer control. Suction produces a lower lift increment, but is more power efficient. Seems preferable for e-power. The suction required pressure varies across the chord and span, further complicating an efficient design. Delft University has been playing with suction more recently. Frequent undergraduate and graduate work going on there.

    The MSU Marvel program was an interesting effort at BLC suction STOL plane. Ullman should note that Raspet died in an experimental BLC plane crash...

    I have no idea how Ullman thinks induced drag wil be reduced.
     
  20. Oct 14, 2018 #20

    Bill-Higdon

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    Re: David Ullman, IDEAL using electric ducted fans in battery or hybrid electric plan

    Don't forget the Antoov An-72 & An-74 they both is blown flaps like the Boeing YC-14
     
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