Vortex Generators !!!! for non-flying vehicle :-)

Discussion in 'General Experimental Aviation Questions' started by flywheel1935, Jun 28, 2019.

Help Support HomeBuiltAirplanes Forum by donating:

  1. Jun 28, 2019 #1

    flywheel1935

    flywheel1935

    flywheel1935

    Well-Known Member

    Joined:
    Nov 1, 2018
    Messages:
    52
    Likes Received:
    11
    Location:
    Downham Market, Norfolk, UK.
    Hi guys, here in the the UK I have a Motorhome, you call them RV's. Anyway the overcab is shaped like a aerofoil section, so I'm looking for some Clear Plastic VG's to help flow over the roof and stop dirt ,etc. can get cheap and nasty black ABS/Carbon fibre rubbish off ebay, but like the stuff on Carbon Cubs/ Kitfox etc. any leads ?
     
  2. Jun 28, 2019 #2

    pshadwick

    pshadwick

    pshadwick

    Member

    Joined:
    Jul 23, 2015
    Messages:
    12
    Likes Received:
    1
    Location:
    Carrollton, MS


    Blackmax brakes sell them...
     
  3. Jun 28, 2019 #3

    Wanttaja

    Wanttaja

    Wanttaja

    Well-Known Member

    Joined:
    Sep 15, 2013
    Messages:
    1,185
    Likes Received:
    1,350
    Location:
    Seattle, WA
    Go to your local big-box hardware store and buy the clear plastic angles used to protect wallpaper on corners. They cut nicely on a bandsaw, and are pretty cheap. The Fly Baby community uses them as gap seals.
    [​IMG]


    Ron Wanttaja
     
  4. Jun 28, 2019 #4

    flywheel1935

    flywheel1935

    flywheel1935

    Well-Known Member

    Joined:
    Nov 1, 2018
    Messages:
    52
    Likes Received:
    11
    Location:
    Downham Market, Norfolk, UK.
    Hi Guys, Its the Air Wave ones I was looking for, (clear plastic), I'll get my buddy in CT to buy them, then next time he's in the UK
    I'll collect. :)
     
  5. Jun 28, 2019 #5

    wktaylor

    wktaylor

    wktaylor

    Well-Known Member

    Joined:
    Sep 5, 2003
    Messages:
    86
    Likes Received:
    31
    Location:
    Midwest USA
  6. Jun 28, 2019 #6

    pictsidhe

    pictsidhe

    pictsidhe

    Well-Known Member

    Joined:
    Jul 15, 2014
    Messages:
    6,432
    Likes Received:
    1,670
    Location:
    North Carolina
    Polycarbonate can be bent on a brake. PC and acrylic can be bwnt over a piece of wood if hot. Seems easier than importing?
     
  7. Jun 28, 2019 #7

    Hephaestus

    Hephaestus

    Hephaestus

    Well-Known Member

    Joined:
    Jun 25, 2014
    Messages:
    936
    Likes Received:
    206
    Location:
    YMM
    Have a friend 3d print one of the designs in thingiverse. Diy vacuforming tables are easy to find - super cheap lexan sheets available.

    Heat sheet, vacuform repeat.
     
  8. Jun 28, 2019 #8

    Victor Bravo

    Victor Bravo

    Victor Bravo

    Well-Known Member

    Joined:
    Jul 30, 2014
    Messages:
    5,882
    Likes Received:
    4,704
    Location:
    KWHP, Los Angeles CA, USA
    Airwave and STOLSpeed are both available through Aircraft Spruce, and I believe they have an office in England.
     
  9. Jun 28, 2019 #9

    Hephaestus

    Hephaestus

    Hephaestus

    Well-Known Member

    Joined:
    Jun 25, 2014
    Messages:
    936
    Likes Received:
    206
    Location:
    YMM
    Of course I'm thinking airtabs not the double break style.
     
  10. Jun 29, 2019 #10

    Rockiedog2

    Rockiedog2

    Rockiedog2

    Well-Known Member

    Joined:
    Dec 12, 2012
    Messages:
    2,214
    Likes Received:
    1,553
    pic of my POS motorcycle helmet. Had the head wag problem from spill over the windshield. Tried vgs shown here. didn't help. Good luck.
     

    Attached Files:

  11. Jun 29, 2019 #11

    BBerson

    BBerson

    BBerson

    Well-Known Member HBA Supporter

    Joined:
    Dec 16, 2007
    Messages:
    11,665
    Likes Received:
    2,188
    Location:
    Port Townsend WA
    Might want to try dimples (like a golf ball) instead of VG's on a semi-round object. The idea of dimples is to turbulate instead of add energy as with VG's, I think. (or is it just a guess? :D)
     
  12. Jun 29, 2019 #12

    flywheel1935

    flywheel1935

    flywheel1935

    Well-Known Member

    Joined:
    Nov 1, 2018
    Messages:
    52
    Likes Received:
    11
    Location:
    Downham Market, Norfolk, UK.
    Hi Guys, thanks for all the info, but the air-wave ones I had in mind, as you can see I plan to fit about 12"
    aft of the leading edge
     

    Attached Files:

  13. Jun 29, 2019 #13

    Hephaestus

    Hephaestus

    Hephaestus

    Well-Known Member

    Joined:
    Jun 25, 2014
    Messages:
    936
    Likes Received:
    206
    Location:
    YMM
    https://www.thingiverse.com/thing:858621

    At my cost for PETG using the typical material cost *5 most smaller hobbiest 3d printing companies would charge you about $0.30 each.

    Then buy 3m tape and apply.
     
  14. Jul 3, 2019 #14

    dougbush

    dougbush

    dougbush

    Member

    Joined:
    Nov 23, 2014
    Messages:
    5
    Likes Received:
    4
    Location:
    NW FL
    Before you guess where the VGs should go, aren't you going to attach tufts to your motorhome and film them while driving to see where the flow separates?
     
    Rockiedog2 likes this.
  15. Jul 3, 2019 #15

    TFF

    TFF

    TFF

    Well-Known Member

    Joined:
    Apr 28, 2010
    Messages:
    11,433
    Likes Received:
    3,172
    Location:
    Memphis, TN
    On mc helmets, you want spoilers to stop lift. That camper is better than most in the US. Instead of the front, I think I would be trying to work on the aft.
     
  16. Jul 3, 2019 #16

    Rockiedog2

    Rockiedog2

    Rockiedog2

    Well-Known Member

    Joined:
    Dec 12, 2012
    Messages:
    2,214
    Likes Received:
    1,553
    yeah me too. the suckhole. must take a lotta power to drag that along.
     
  17. Jul 3, 2019 #17

    Hephaestus

    Hephaestus

    Hephaestus

    Well-Known Member

    Joined:
    Jun 25, 2014
    Messages:
    936
    Likes Received:
    206
    Location:
    YMM
    You'd definitely want them not 1' back but definitely before it drops.

    Then look at how airtabs are used on 18wheelers. Back of the cab before the black hole behind.
     
  18. Jul 3, 2019 #18

    Richard6

    Richard6

    Richard6

    Well-Known Member

    Joined:
    Aug 14, 2010
    Messages:
    655
    Likes Received:
    73
    Location:
    Plymouth, MN USA
    You may want to look at this NASA document "tech brief LAR-13768". Deals with blunt front vehicles.

    Go here to find the first page:
    https://ntrs.nasa.gov/search.jsp?R=19900000416#

    Looks like you will have to fill out the form at the bottom of the page to get the whole document:
    For more information or questions about this document, please submit a Document Inquiry

    Richard
     
  19. Jul 4, 2019 #19

    flywheel1935

    flywheel1935

    flywheel1935

    Well-Known Member

    Joined:
    Nov 1, 2018
    Messages:
    52
    Likes Received:
    11
    Location:
    Downham Market, Norfolk, UK.
    Hi Guys, and thanks for all the input into my thread, many years ago at a Helicopter convention, one dealer used a very square trailer to move his kit, on the back were VG's
    to keep the tail-end clean, and to improve on fuel economy by reducing drag. My RV is a moulded GRP shell thats very curvy, so tufting may well indicate best position.
     
  20. Jul 4, 2019 #20

    Rockiedog2

    Rockiedog2

    Rockiedog2

    Well-Known Member

    Joined:
    Dec 12, 2012
    Messages:
    2,214
    Likes Received:
    1,553
    yes.
    On my 701 I first tried 12% of chord, then 10% then 8%. 12 and 10 were too far back and they didn't do any good. 6% made drag. So there may not be much distance between the right position and the wrong position.

    tufts and a gopro and you'll get it right. I do wonder tho that if it's swoopy and without much of a break that there will be much separation. If not, I wouldn't see much need for vgs
     

Share This Page

arrow_white