Design of a Flying Wing to Convert an Existing Multirotor UAV into a VTOL Aircraft

• Autor(a) principal: Marques, Ricardo Jorge Rodrigues
• Data de Publicação: 2023
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/14097
• topic: Falha em Compósitos; Análise de Estabilidade; Análise por Elementos Finitos; Cad de- Sign; Design Aerodinâmico de Asas; Estruturas em Compósito; Seleção de Perfís Alares; Sequência de Empilhamento; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

This dissertation contributes to one of the projects being developed by the Advanced Air Mobility (AAM) business unit of the Portuguese Centre of Engineering and Product Development (CEiiA). The project’s objective is to develop a modular vertical takeoff and landing (VTOL) unmanned aerial vehicle (UAV) capable of performing long-range missions and operating in urban environments through a removable wing system. The present work details the preliminary aerodynamic and structural development of a wing that can be integrated with the multirotor developed by the AAM business unit. A literature review was conducted on topics such as aircraft design, aircraft structures, composite structures, and VTOL UAV technologies. This was followed by the conceptual design of the wing, which takes into account the requirements of the business unit and the constraints imposed by the multirotor’s geometry to create several different configurations. The feasible configurations were evaluated and subsequently narrowed down until a baseline design was established. An airfoil selection, an assessment of the component’s arrangement, the design of an aerodynamic wing model, and a stability analysis were performed using the Flow5 software. All of these parameters were determined and evaluated based on examples or typical restrictions found in the literature, with the exception of the wing design, which required an iterative method that was defined specifically for this case. A thrust-to-weight ratio constraint analysis was employed to select an appropriate motor and propeller for the forward flight propulsive system (FFPS). Additionally, a performance analysis was conducted considering the aerodynamic characteristics of the wing, the mission profile, the selected battery, and the characteristics of the FFPS to determine the range and endurance of the UAV. A computer-aided design model of the wing and its internal structure was developed using SolidWorks, based on the dimensions of the aerodynamic wing model and the structural requirements of the wing. A material selection, an assessment of the stacking sequence of the component’s laminates, and a structural analysis of the wing’s structure were performed using Ansys. The structural analyses were conducted using Finite Element Analysis and using the Composite Failure tool to obtain solutions. The research conducted in this dissertation led to the development of a six-meter wingspan flying wing, primarily made of carbon fiber and foam-cored carbon fiber sandwiches, specifically designed to be integrated with a multirotor. The structure of the wing has a total mass of approximately 8.5 kg and is capable of withstanding an ultimate load factor 6.75 times greater than the vertical aerodynamic force exerted on the wing during normal cruise conditions. With the wing attached and disregarding the drag of the exposed frame, the UAV is theoretically capable of performing 82.97 km missions over a duration of 0.92 h when fully loaded, and 105.13 km missions over a duration of 1.32 h when empty.