Since you are trying to reduce level flight stall speed, the wing's lift must remain constant until it exceeds the critical angle of attack and it stalls. [&:]

The "Lift Equation" that gives the amount of lift generated by a wing is:

L= 1/2 * air density * velocity (squared)* wing area * Lift Coefficient


It is worth noting that the lift generated depends directly on each of the terms (air density, velocity, wing area and lift coefficient) - that if any one increases, lift will increase, and that if any one of the terms decreases, lift will decrease. One final observation is that if you want to decrease speed, but hold lift constant, we can increase CL by increasing the wing's angle of attack, which is what we do when we enter level slow flight.

Lift Coefficient (CL) is an adjustment factor for the airfoil section being used and the angle of attack being flown. CL increases with more cambered airfoil sections, extension of flaps, slats, etc, and increasing the angle of attack.

Using the lift equation, if we wish to slow the airplane below its "normal" level flight stall speed, the air density is fixed and we want a lower velocity, so we must either increase wing area or CL.

If we increase the thickness of a non-symmetrical airfoil, we increase the airfoil's average camber. Increasing camber causes a small increase in CL (on the order of less than one tenth of a CL unit or so - depending on the change imposed and the airfoil section chosen). As I recall, normal CLs for "clean" wings are in the range of 1.2 - 1.5 or so, so it is easy to see that getting a large increase in lift from increasing camber alone is difficult. while increasing wing area will increase lift directly (meaning a 10% increase in wing area will increase lift by 10%), so it will do so more efficiently than increasing camber for most airfoil sections.

BTW - those are some COOL Mo-Fokkers!!

HTH

Jim