why gripen wings look like that

[rcguy01]

Hello folks;

I wonder why the delta wings on the gripen look like that?
Just do not know how to say it properly, please look at
the picture of the Gripen here?

http://www.rcgroups.com/forums/showthread.php?t=308830

The question is what is the purpose of the
outer part of its delta wings? to reduce the stall????

Some other jets like the F4, fantom wings, do have that same odd shape.
And the same with the horizon tail of the F 15? What is it for?

Thanks all.

[raptor22]

It's called "leading edge strakes". They produce a draggy but very high energy vortex at higher angles of attack that energizes the boundary layer to delay stall and produce a more favorable lift distributuion at those high alfas. It enables planes to fly slower and turn sharper.

--Alex

[BMatthews]

Those teeth on the leading edge are not strakes Alex. Strakes as you mention are the leading edge extensions close to the fuselage at the wing roots that do what you say.

The shark teeth on the leading edges of the Grippen and many other planes are flow straighteners to help control the amount of span wise flow in the swept and delta type planforms. The function is similar to the wing fences seen way back when on the Mig15 and other planes of the time and still seen on some modern aircraft. The sharks teeth often have an associated "ditch" extending a short ways on the wing as well. The idea is to catch and funnel the air at that point and then the air around it tends to flow with it. In effect the hook and ditch creates a simulated fence from channeled air.

[raptor22]

Yes, that's right. i didn'tlook at the pic and i wasthinking of teh draken,another swedish fighter.

--Alex