Abstract :
This research aimed to investigate the effects of winglets adding
modification on the wing T-34C-1 Charlie aircraft with winglets variation design.
Wingtip vortices reduced the wing efficiency due to its vortices. Basically, the
vortices could be overcome by increasing the available power from the engine to
balance the induced drag so it made the fuel more consumptive.
In this research, the specimens were the miniature of T-34C-1 Charlie
aircraft wing with 1:40 ratio with four specimens wings made of balsa wood. The
three specimens; the winglet blended, winglet upswept and winglet twisted were
measured from zero relative. Another wing was the original one (without winglet)
The experiment was conducted in a wind tunnel at Gadjah Mada University
by measuring the lift and drag, each of them was varied in terms of the angle of
attack and the air flow velocity. The result of this research was the best
performance in the form of lift and drag coefficient ratio (CL/CD)max. The best
performance (CL/CD)max was 3,790 at the wing with the addition of winglets
blended. The original winglets performance (CL/CD)max was 2,445 while at the
other wings with the addition of winglets performance (CL/CD)max was less than
the winglet blended. The addition of winglets blended showed 55,01% increase
performance compared to the original one (without winglet).
With the addition of winglets blended, the airflow from the lower surface
encouraged the winglet surface thus the pressure distribution moved evenly and
the vortices bending moment at the root chord of the wing was higher, therefore
the generated vortex at the wingtips was reduced