UNMANNED AERIAL VEHICLE AERODYNAMICS PERFORMANCE OPTIMIZATION USING VARIABLE SWEEP WING ANGLE

Abstract

The unmanned aerial vehicles (UAVs) can take many forms depending on the type of UAV
duty and condition of flight. In this project, optimization of UAVs aerodynamics property through
the sweep angle of wing (sweepback angle) to reduce wave drag and delay the onset of drag divergence.
therefor models of unmanned aerial vehicles (UAVs) designed with five different sweepback
wing angle (15o, 20o, 25o, 30o, and 35o) and different aspect ratio with constant taper ratio =
0.2 have been used. Every wing was built with airfoil for root and tip chord SD8020, with low
Mach number equal to 0.058 (i.e., Velocity equal to 20 m/s). The whole models of a wing were
plotted for a three-dimensional using the SOLIDWORKS software program, and then the models
of this wing were analyzed employing ANSYS FLUENT. Calculations of the value of lift to drag
ratio were made for deciding which UAV has optimum value of lift and the lowest drag versus the
attack angle (0o, 2o, and 4o). The results Show that the aerodynamics performance changes according
to the value of the sweepback angle and aspect ratio, the maximum lift to drag ratio
achieved at UAV with sweepback angle 15o and the angle of attack is 2o, minimum lift to drag
ratio at UAV with sweepback angle 35o and the angle of attack is 0o. Due to constant taper ratio
which equal to 0.2 the wing area different according to each model. Best model with maximum lift
to drag ratio has wing area equal to 1.68 m2 while model with minimum lift to drag has wing area
equal to 0.65 m2.