News:



  • November 28, 2020, 01:33:49 AM

Login with username, password and session length

Author Topic: AIRFOIL Integral Vs Flat Flap .  (Read 365 times)

Online Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4070
AIRFOIL Integral Vs Flat Flap .
« on: January 04, 2020, 07:16:30 PM »

  Wottle happen integral Vs flat plate flaps ?

If one did the forward part of the wing , say the spars forward , identical .
Obviously the curve would fall away to the centerline sharper on the flat plate flap version .

i.e. Weve got a flat sheet flap version , If we change it aft of the spar only , will the sky fall in .

We would assume the center of lift , and other things , would be different , thus the C G also .

Then theres getting a workable tidy simple ? hinge line set up on the integral flap version .


Advertise Here

Offline Howard Rush

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 7085
Re: AIRFOIL Integral Vs Flat Flap .
« Reply #1 on: January 05, 2020, 04:11:28 PM »
We would assume the center of lift , and other things , would be different , thus the C G also .

The stability won't change, so the CG won't need to change for stability.
The Jive Combat Team
Making combat and stunt great again

Offline Dennis Toth

  • 2020 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2771
Re: AIRFOIL Integral Vs Flat Flap .
« Reply #2 on: January 11, 2020, 10:48:13 AM »
AM,
Al Rabe is some work with the integral flap airfoil, for him it did not work as good as the smooth shape airfoil flap on the end of the flow shaped wing airfoil (see his Mustunt, Mustang and Bearcat airfoils). He did some crude airflow tests with a unit he attached to the hood of his car. Al did a lot of tests of different approaches starting with the basic Nobler (which he found was a pretty good airfoil) to some asymmetrical airfoils he used on one of the ships. He then thought he would do the integral flap and originally thought this would be the greatest. He found out to his surprise and disappointment it wasn't that good. Granted this was not total scientific approach but since no one had a true wind tunnel and the time and money to run model airplane wing test, this was as close as we could come. If you search for Al's articles I think they might be on this forum.
 
Now contrary to Al's work, Keith Trostel used the IFA on several ships and did just fine. Keith's trailing edge hinge is a work of art. It is fully mated and uses pin hinges to recess the elevator pivot point into the hinge circle centerline. Could be that Al needed more lift and although the IFA worked other shapes met his needs better.

Best,    DennisT

 

Offline Serge_Krauss

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1262
Re: AIRFOIL Integral Vs Flat Flap .
« Reply #3 on: January 12, 2020, 10:21:11 AM »
You might try some searches here and on Stuka Stunt for previous discussions. The one NACA report I found indicated that they preferred the contoured flap only because it had lower drag. I believe their test showed a slight lift advantage to the flat (planar) flaps. I don't think we need to worry about profile drag in stunters.

SK

Online Brett Buck

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 11267
Re: AIRFOIL Integral Vs Flat Flap .
« Reply #4 on: January 12, 2020, 10:11:10 PM »
You might try some searches here and on Stuka Stunt for previous discussions. The one NACA report I found indicated that they preferred the contoured flap only because it had lower drag. I believe their test showed a slight lift advantage to the flat (planar) flaps. I don't think we need to worry about profile drag in stunters.\

   I would also note that all the NACA data appears to show a smooth hinge line, more like the Yatsenko Shark than a convention stunt-type wedge.

   Brett

Online Air Ministry .

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 4070
Re: AIRFOIL Integral Vs Flat Flap .
« Reply #5 on: January 14, 2020, 07:40:46 PM »
Thanks . Considering really only for the ' semi scale ' appearance prospects .

A W W II Fighter would look a bit more sale with the continuous curve to the airfoil / wing ,
rather than the hump & flat ! . Tho I cant say you really pick it up looking at a ' flat flap ' job .

This Photo is probly the culprit .



A right bitch to do a concealed hinge , The ' V ' flap leading edge is conspicuous with the extra depth . surface gap .

Theres a few with say 1/2 span flaps were its senseable to continue the conture / airfoil full span .
Had wondered re ' the efficancy , as you could say the ' V ' flap

has to move ' half the V ' extra to get the same top surface  load ,
and the outer sides more pulled out by a extra ' half the V ' ( angle ) also .

The few ive done with the intregal flap have had relitively narrow chord flaps .
Sounds like wider chord flaps would be preferable with this set up .
Thogh have wondered abot a wing with the whole area aft of the high point pivoting , as per a flap .
Thing the ' T E  deflection , say 2 inch arbitary would be comparable ish to the Std T E flap deflection .
Definately not the Angle .  :-\


Advertise Here
Tags: