STI wingtip (stall fence) on a standard wing?

[GMKman]

Does any know of any benefits or drawbacks of putting the STI style wingtip (stall fence)on a standard 7 wing?
I already have vgs and am happy with them! Just wondering how much more slow speed stability you gain with the wingtip fences. I’m curious how much drag penalty there is though.

[jmodguy]

I’m wondering the same thing. I am planning to make some wingtips with fences and a set of fences for my standard wing. I will start with standard wing with vortex generators then change out the wingtips and add fences.
it’s on the back burner right now. Gotta get ‘er flying first

[Shadowrider]

I don’t think the wingtip provides any other benefits other than looks. I was told from the factory the stall fence (not the wingtip) did not change stall speed at least that could be measured. I plan on flying my sti without the stall fence at this point unless we can come up with a way to build a carbon one that is straight. It’s just cut out of wood and warped enough that all I see it doing is providing a lot of drag. I am also curious if the wingtip provides any low speed handling improvement? I think the improvement it adds is the additional wing area. Adds almost 2’ of wing.

[jiott]

I think the main, and maybe only, benefit added by the stall fence and wingtip fence is a LOT of drag during a slip maneuver. Slips are used a lot in short field STOL operations.

[David47]

From memory, wing fences help to prevent spanwise airflow along a wing upper and lower surface. Vortices at the wingtip are primarily caused by (If I recall correctly) an outflow on the lower surface and an inflow on the upper. That's why vortices, when viewed from the front of an aircraft, rotate anticlockwise on the right (port wing) and clockwise on the left (stb'd wing). I think there may also be an affect on stall affects at the tip. I'm not sure what affect, if any, they would have on our wing, other than as Jim describes, added drag in a sideslip. FWIW.