I am in the process of designing a small wing (Re ~ 50-100k) and was planning to "un-twist" the tip of the foil by -5°. This corresponds to the 5° aoa where the center part of the wing has the highest Cl/Cd.
I am aware that wash-out is mostly about keeping the wing tips out of stall longer than the rest of the wing, but intuitively having the wing tips at 0° aoa during normal operations should reduce the amount of "redirected air" at the wing tips. This in turn should reduce the strength of the wing tip vortices, which in turn should reduce drag?
edit for clarification: I intent to have the tip of the wing be at 0° aoa with an airfoil that does not generate any lift during normal working conditions.