Interaction of two micro-propellers in coplanar and coaxial arrangement for UAV application

In the present work, we have focused on the understanding of the effect of gap between micro propellers in coplanar and in coaxial arrangements on the thrust generation experimentally. In a way it’s a preliminary optimization of the spacing and placement of the micro propellers in a multirotor UAV system. APC 12-inch diameter (D) (12X8 E) and Master air screw (MAS) 11-inch diameter (11X6) propellers each 2 in numbers were considered in the study. A static testing rig was built with a provision to mount the propellers in coplanar and in coaxial arrangements. A thrust was measured using a single component load cell. Parameters like current consumption by BLDC motors and propeller RPM were also monitored. For coplanar arrangement, there is no influence of gap (G) between the propellers on the coefficient of thrust (CT). However, for G/D<0.2 random variation in CT is observed. Similarly, for propellers in coaxial arrangement, for smaller gap between the propellers along the axis is found to generate higher thrust. This optimization of the gap between the propellers may be lead to a compact multi-rotor UAV system having higher payload carrying capacity or higher endurance