WINGLET EFFECT ON WING-TIP VORTEX FLOW AT LOW REYNOLDS NUMBER

Winglets are special kinds of wing tip devices used to decrease the induced drag.They are usually connected to wing tip with a specific angle to horizontal surface.The winglet's main task is to decrease wing tip vortex magnitude and to limit thevortex zone made due to the pressure differences between upper and lower surfacesof the wing. In order to examine the effect of using winglet on wing-tip vortex flow atlow Reynolds numbers, a numerical study was performed in the range of Reynoldsnumbers below 30000. In this study, the influences of varying the winglet connectionangle to the wing body on vorticity and circulation magnitude were studied in thevortex flow zone. Six connection angles including 20°, 30°, 40°, 50°, 60° and 70°were considered; their negative values were also studied. To solve the flow indifferent geometries, a 3D unsteady pressure based solver working based on thefinite volume method was used to satisfy the incompressible Navier-Stokesequations. In all cases, the obtained results for models with winglet were comparedwith the solution of the base wing model (without winglet).

Keywords:

Winglet , Wing-tip , Reynolds , Vortex , Circulation