Turbulators, are they supposed to stick up from ribs or be even?
 

Just wondering some things about turbulators....

On my 1 other glider build I did I sanded them down smooth with the wing ribs or are they supposed to stick up above them?

Also what do they really do? or are they just support?

Thanks!

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

I have never used them but I do believe they are supposed to stick up above the surface of the wing. From what I understand, they break the air from the wing to change the performance of the wing. They are a fix for design flaw in the airfoil, from what I hear.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Flush with the rib top but the covering tightens down between the ribs and takes on the edges of the turbulators to give an angle change between them instead of a smooth contour. Most of the time they stick up a bit on mine because I don't sand the notches deep enough.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

They slow the wing down and are usually at the leading edge of the wings. Makes up for the lack of washout at the tips. Airplanes will fly more stable in this condition. More appropriately they interrupt the spanwise flow at high angle of attack and turn it into a big vortex that allows the plane to fly slower by preventing tip stall to a higher AoA.

Most commonly found on power planes.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Turbulators and turbulator spars are sort of the same and sort of different. True turbulators are strips, saw teeth or other outside surface mountedelementswith their sole purpose being to generate a controlled amount of turbulence. On the other hand turbulator spars are used more for structure and covering support to try to generate a more accurate airfoil profile and perhaps to aid to some extent in generating a tubulent boundry layer.

the supportive stripsin thewing structure thatwe call turbulator spars are typically sanded down flush with the wing surface. And in truth they are primarily support for the covering to try to avoid some of the typical mid rib sag. But at the same time these spars produce a bit of a ridge that can also aid in generating some turbulence. If you use enough close spaced turbulator spars your airfoil becomes primarily a series of flat facets or tangents that form the airfoil since the spars themselves have more effect on supporting the covering than the ribs do. In such a case making the spars high enough to sit slightly above the wing is an option but it's not normally done that way by most builders nor is it shown that way on the big majority ofplans.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

I'm talking about turbulator spars then...

so how do you sand them down without sanding the curvature of the ribs out that is between the turbulator spars?

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Um... ... carefully?  :D 

When I do such wings I cut the spar slots a hair deeper than they need to be.  Then I push the turbulator spar strips in using a piece of balsa until they are just flush and then glue them in place.  No or very little sanding needed.

If yours are sticking up then just go easy and check your progress.  Use a fresh piece of sandpaper and don't push down on it.  Just glide the sanding block back and forth and let the fresh sharp grains and weight of the block do the cutting while you keep a close eye on the progress.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

The longer the sanding block the easier the job.

Stick-on sandpaper is magic stuff. I make all manner of special sanding blocks for all manner of tasks. I had a length of hardwood scrap that does an excellent job after attaching stick-on to it. It spans about 3 bays and really helps keep me from dishing where I don't want dishing.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Does anyone have pics?

Alas, I am almost done building my 70" Bocian SZD 9 and didn't build any washout. I just read in this thread that turbulators help with tip stall. Perhaps I should add these to the Bocian. 3degree dihedral each wing.

Any thoughts?

Here is the Bocian, I am waiting on the paint to gas off, its been 5 days, so I am ready to start painting again and adding stripes and details.

http://lh3.ggpht.com/_RCNadMKspOE/TP...cian%20006.jpg

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Nice Bocian nhogberg,
Since you are past the building the wing stage, turbulator spars are no longer possible. There are possible ways to add turbulance generating features though. Tape strips such as pin striping would work. But I have to say your bird is looking pretty good and if it were mine I would NOT add the turbulator strips now.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

You'd be surprised at what some careful application of steam can do for warping the wings to add washout.  Get one of the whistling kettles and get it up on song with a good jet of steam coming out.  Hold some washout twist in the wing while passing it through the jet of steam long enough and close enough to get the covering and wood under it quite warm.  WHen you think it's gotten some warp into it remove and hold for a couple of minutes until cool.  Check for the amount of warp and do again if needed until you've got your washout.

If you find that you still need it turbulator strips made from a stacked layer of two strips of automotive pin striping tape will do the job.  Locate this strip at around the 20% chord point.

RE: Turbulators, are they supposed to stick up from ribs or be even?
 

Hi guys.
Take a look of what I did on both Fly-Fly DG-1000 and Discus CS from Jamara, following some advise from French magasine RCM. From many forum, it seem to work and even transform the gilder, especially the DG which is sensitve to tip stall.