Can I measure induced drag with a simple wind tunnel test? Device can measures total drag force  and lift of wing for given AoA and airflow speed.
Wing both wingtips are far away from side walls.
Airflow speed is constant all the time:50m/s
TOTAL DRAG=MEASURED DRAG
TOTAL DRAG =ZERO LIFT DRAG + INDUCED DRAG
TOTAL DRAG=PROFILE DRAG +INDUCED DRAG
profile drag=skin friction drag + pressure drag
Step 1.
•First I put  wing at zero-lift angle: it show 500N drag force
Step 2.
•Then I put wing at 15° AoA:it show 700N drag force
Results:
So for 15° AoA and 50m/s:
&quot;Profile drag&quot;(Skin friction + pressure drag) is 500N and induced drag is 200N(700-500).
Is this correct calculation?
Yes, by the textbook definition $C_D=C_{D_0}+KC_L^2$.
Your measurement at AoA=0° gives $C_{D_0}$, 500 N.
Your measurement at another AoA=15°, by subtraction, gives $KC_L^2$, the induced drag at that AoA, 200 N.
If measurements at many AoA's yield a consistent $K$ and $C_L$,
then you gain confidence in those values.
If the airfoil is strongly cambered, a better fit to the equation is made if you add another term proportional to $C_L$ (not squared).