Transition performance analysis of quadrotor biplane tailsitter using computational fluid dynamics

Major companies start to introduce UAVs for delivering goods to the hands of customers. Tailsitter is a novel airframe configuration for delivering goods through last-mile delivery. It allows the aircraft to land on its tail, take off in rotary-wing configuration, then transition to fixed-wing for forward flight. To create the best design for a tailsitter UAV, understanding the stall performance, as well as the propeller and wing interaction during the transition phase are essential. This research aims to study the performance of a biplane tailsitter during the transition phase. The aircraft is assumed to be in a steady transition; thus, the pitch is always the same magnitude as the angle of attack. The freestream and propellers’ velocities required to hold the position in a balanced force manner are analyzed in four iterations using the analytical approach, then verified using numerical computation. From the study, the results of aerodynamic performances are successfully obtained for the aircraft. The findings also suggest that adverse slipstream effects create sharper changes in performance in high angles of attack relative to the low angles of attack.