Dynamic tests of selected propellers used in micro-class drones

With the widespread use of unmanned aerial vehicles (UAVs) for various purposes and the wide range of components available on the market, the need to use effective and efficient propulsion systems, appropriately selected for the planned performance of the designed aircraft, is crucial. This requires knowledge of the characteristics of both individual components of the propulsion system (e.g., propellers) and the complete propulsion system. However, manufacturers of UAV components rarely publish such data, and even propellers that are similar in appearance and dimensions can have radically different characteristics. This necessitates determining their characteristics through typically costly and time-consuming experimental testing. This paper presents a mathematical model of a brushless DC motor designated 2408 KV 2200, based on which efficiency characteristics were determined as a function of rotational speed and motor current. Next, using the aforementioned motor, experimental testing was conducted on five propellers commonly used in miniature UAVs on a specially constructed thrust stand for the electric motor-propeller system. Experiments were conducted in a wind tunnel at a flow velocity range typical of the aircraft for which the tested propellers were intended. This allowed for the determination and comparison of the most important characteristics of the propellers. The drag coefficient was also determined for the propellers' windmilling range.