I'm currently designing an aircraft with the following specifications-
s=1.8m^2, AR=7-8, trapezoidal planform with a taper ratio of about 0.45, a load of 25KGs and a cruising speed of 13-15m/s.
I'm barely getting any improvement in drag reduction or tipstall delay after testing twists upto -4deg. A twist of -3 is delaying tipstall by about 0.7deg while reducing Cl by 0.08 in xflr.
Is a twist even necessary for my model?
Also I've read that a twist optimizes drag reduction and lift distribution for a single aoa in non-elliptical planforms. Should this angle be the aoa for the Cl I get for my cruise speed?
Also how would my planes angle of incidence depend on the twist that I select?