reason for mirage 2000 slat angle

[litzj]

mirage 2000 has differential slat angle when they flight at high aoa as shown in this pic.

Do the differential slat has effect on flow field? like dog-tooth or notch of the wing?


I have search papers or report to find effect of this design, however I caanot find.

If someone knows about this design, please let me know about that.

 

[ScrutorAudax]

I know this is a bit late, but I suspect it is due to the local angle of attack. The differential spanwise slat actuation itself doesn't appear to be for vortex control, as the difference in deflection is very small and there are no visible vortices that would be affected by this method of slat control. It seems more likely that this is a product of the flow conditions (large vortical flow at the wings resulting in downwash at the root of the wing and upwash at the tip) of the delta wing planform.

This is what I can infer from the picture you provided; I hope it helps.

 

[Machdiamond]

Highly swept wing or delta wing tend to stall outboard first and this induces a pitch up at stall, making things worse.

So here the outboard wing section can reach a higher AoA than the inboard section, so the inboard stalls first and pitches the aircraft down.

The generally preferred method is to leave a section of the wing leading edge near the wing root without slat, so you need only one slat per side and the stall starts at the root.

 

[TomcatViP]

The ratio b/w wing chord and slat length is variable with the position on the wing. Because delta have large chord and low thickness, the percentage of lenght in the slat that is deflected vary greatly.
Now, slat angle increases curvature that increases local AoA
A 10% slotted section, won't reach same AoA than one at a 20% ratio. Hence the discretisation of the wing LE.

The F4 has the same arrangement.