Propeller locations study on delta-winged unmanned aerial vehicle (UAV) model

Abstract

Delta wing design is being used in aircraft to obtain high manoeuvre properties. The flow above the delta wing is complicated and dominated by a very complex vortex structure. This research investigates the effects of the propeller locations on the aerodynamic characteristics above a generic 55° sharp-edged non-slender delta wing Unmanned Aerial Vehicle (UAV) model. This research was performed by an experimental method. The experiments were conducted in a closed circuit Universiti Teknologi Malaysia-Low Speed Tunnel (UTM-LST) wind tunnel at wind speed of 20 m/s and 25 m/s respectively. In this project, the propeller was located at three different locations at front, middle and rear of the wing. The experimental data highlights an impact of propeller locations on lift, drag, pitching moment and vortex characteristic of the UAV model. Rear propeller configuration recorded the highest lift generation. Meanwhile, middle propeller configuration has the highest drag with increment by 2% to 15%. The results also show that the propeller advance ratio plays important roles in development of the primary vortex above the delta-winged model. The higher propeller advance ratio would decrease the development of the vortex on the wing, consequently limiting the lift generation and stall condition in which are disadvantageous for aircraft aerodynamic characteristics. The lift coefficients decrease by 7% when the propeller advance ratio is increased from 0.98 to 1.20. Lastly, suction effect from the propeller has improved the vortex properties better than blowing mechanism in which is beneficial for the delta-winged UAV propeller selection.