Analytical Methodology for Early-Stage Design and Stability Assessment of V-Tail Class-I UAVs

Abstract

Unmanned Air Vehicles (UAVs) are becoming increasingly popular and widely used in a variety of industries such as agriculture, construction, delivery, surveillance, rescue operations, mapping, wildlife tracking and many more. With the advancements in technology, UAVs are becoming more autonomous and able to perform tasks with minimal human intervention, rendering their use indispensable for military and law enforcement purposes. In terms of control surfaces, V-tail configurations are commonly used on UAVs due to their advantages in control and stability performance, as well as their ability to reduce drag and improve overall efficiency. However, research on V-tail design and sizing is limited, particularly for Class I mini-UAVs. The objective of this paper is to identify a methodology for the Conceptual and Preliminary sizing and design of a V-tail of a Class I Mini UAV (NATO classification). The methodology follows the design of a V-tail from the characteristics of the conventional tail of the UAV. Once the characteristics of the conventional tail are extracted, V-tail geometric characteristics are computed. The stability derivatives of the V-tail are then calculated. The methodology for the analytical aerodynamic characteristics and stability derivatives is a combination of two existing methodologies: one methodology for V-tail stability and control derivatives, which refers to the Preliminary or Detailed Design of an aircraft, and one methodology for a conventional tail design, which refers to the Conceptual and Preliminary design of an aircraft. With this combination, a V-tail Preliminary design methodology was achieved. Furthermore, the aerodynamic characteristics and stability derivatives of the designed V-tail were verified by Low Fidelity Aerodynamics simulation, and then by High Fidelity Aerodynamics by means of Computational Fluid Dynamics (CFD).