Design and performance analysis of a tail-sitter vtol uav with a closed-wing configuration

The history of aviation, which began with the flight of heavier-than-air vehicles, has seen numerous innovative developments over time. Many of these advancements were resulted from through bold experimentation and the valuable knowledge gained even from failures. Within this context, the present study explores the integration of two historically revisited concepts: the closed-wing configuration and the tail-sitter vertical takeoff and landing concept. This study evaluates the potential aerodynamic efficiency of the closed-wing structure and its applicability to next-generation aerial platforms. It presents a novel unmanned aerial vehicle (UAV) design that combines this configuration with tail-sitter takeoff and landing capability. Although such designs were previously limited by technological constraints, with the evolution of advanced manufacturing methods, especially additive manufacturing, complex and unconventional aerospace designs have become more achievable. In this study, a versatile, four-rotor UAV compatible with additive manufacturing methods and capable of tail-sitter takeoff and landing operations was conceptually and structurally designed. A functional prototype was produced. Throughout the development process, performance data were collected and evaluated, followed by comprehensive flight tests. The resulting analyses provided valuable insights into the system's behavior and viability.