Compare total drag of wall to wall wing vs wing(open tips) in wind tunnel,AT SAME AoA.
My first intuition is that wall to wall wing has higher pressure drag at outward parts of wing,because side-walls "act" as big endplates,so that makes difference.Reslut is higher total drag.
If aerodynamic force1 =70N and angle A = 75° Drag1 =cos75 x 70N=18.1N
Aerodynamic force2 has lower magnitude lets say 60N and reduced effective AoA is 1° ,then angle B=74° Drag2= cos 74 x 60N =16.5N
(even if I choose 65N(only 7% reduction in aerodynamic force)drag will be smaller at wing ,cos74 x65N=17.9N)
I think Peter Kampf has best opinion,this can not be prove with data because we dont know how much is magnitude of aerodynamic force at wing is reduced compare to wall to wall wing..
Wing has tilted aerodynamic force back but in same time has lower magnitude ,so it cant be prove is drag higher or lower,it can go in both directions. Vector tilt back at wing is usualy very small,maybe 1°,so my general oppinion is that vector tilt back has less contribution than reduction of aerodynamic force magnitude at wing...
What is your opinion?