We look at lift,drag and L/D at multi element wing with slots and same wing shape just without slots.
wing without slots:
Completly top side is stalled, so here is all low pressure(blue at picture),more low pressure area then on wing with slots
bottom side= pressure more higher then on wing with slots
Lift and drag higher, L/D lower ..compare to wing with slots (that is how I think, maybe I wrong)
With slots:
top side= less area with lower pressure compare to wing without slots
botttom side= reduction in high pressure compare to wing without slots
Lift and drag lower, L/D higher... compare to wing with slots (just my oppinion, maybe wrong)
My conclusion:
Wing with slots is more efficient in producing lift(better L/D) compare to same shaped wing without slots, but that doesnt mean it produce higher lift at same fixed AoA compare to same wing without slots.(maybe wrong)
Main question: Does wing without slots has lower lift and higher drag compare to wing with slots? (Confirm your answer with pressure distribution arund wing for both cases, CFD would be ideally)
If answer is yes, we have situation Lift down=drag up,isnt that brake rule for induced drag which in short tell: Lift up = drag up, Lift down=drag down,
Notes before answer:
This is case where lift dont have to be equal weight
Stall is caused by closing slots,not by increasing AoA, AoA is fixed in both case, so we basicaly just change pressure distribution around wing.