Evaluation of Wing Gap Variation on Box Wing UAV with Computational Fluid Dynamics

Closed-loop wing design improves aerodynamic performance by suppressing vortices at the wingtips. This allows the reduction of drag and improvement in stall performance. The non-planar geometry of this configuration opens many possibilities for its development. To properly optimize this design, it is necessary to explore which parameter affects the performance of this configuration. This study investigates the effects of varying the gap between the wings in a closed-loop configuration on the aerodynamic performance of the test model. The test model was based on an existing Dara Aviation D-1 UAV wing design. A total of three variations were made from the base model, with a wing gap of 0.5, 0.75, and 1 mean aerodynamic chord. These models were analyzed using Computational Fluid Dynamics, employing the Reduced Averaged Navier Stokes method and the K-Epsilon turbulence model. The angle of attack varied from -4 to 20 degrees and the flow velocity was 25 m/s. The result of this analysis indicates that increasing the wing gap in a closed-loop wing configuration resulted in greater lift and stall resistance.