: Investigation on small propeller selection for electrically-powered Unmanned Aerial Vehicle in real life application.

Abstract

Propeller has long been studied in detail as it was propulsion method for aircraft of pioneering days of aviation area. With the advent development to push aircraft to fly faster and higher envelope, the move of propeller to jet engine seems inevitable, thus putting the development of propeller to a complete halt. The re-emergence of propeller aircraft especially in the small electric propulsion Unmanned Arial Vehicle (UAV) has created a renewed interest of small propeller; thus the understanding of small scale propeller. The small propeller operates in low Reynolds Number regime as compares to its counterpart, the large propeller. Couple with the known fact that the aerodynamics performance tends to degrade at low Reynolds Number, scaling down of the data from the large propeller to the small-scale propeller does not provide the correct aerodynamics profile of the small propeller. Therefore, the knowledge gathered in the large propellers cannot be empirically duplicated to the small propellers. By investigation the effect of propeller rotational speed, diameter and pitch, this study has manage to develop an initiative which is called SHAIS protocol to enable designers to determine the most suited propeller configuration for cruising mode based on the specification of the Unmanned Aerial Vehicle such as range, maximum take-off weight and mission time. This real-life parametric relationship focuses on the parametric investigation of small propellers in the range of 9” to 11” deemed suitable for small Unmanned Aerial Vehicle. The result of the study has found that the propeller configuration having a diameter to pitch (D/P) ratio of between 1.3 to 1.4 will yield the maximum efficiency during cruising for small electric powered Unmanned Aerial Vehicle. The above result also tested, compared and verified in the real life flight test using a small UAV as test bed where configured propeller managed to exhibit better propeller efficiency during cruising.