In this paper, topology optimisation is applied to the design of the rear fuselage of an unmanned aerial vehicle (UAV). A comparison is drawn between the performance of a design created through evolutionary structural optimisation (ESO) and a baseline design modelled on a manually designed and successfully flow fuselage geometry, for different wing shapes. The loading for each wing shape is determined by full-potential (FP) aerodynamic analysis. A Kriging model is then employed in a multidisciplinary optimisation procedure driving a trade study between aerodynamic efficiency and aircraft structural weight. Using this procedure, a Pareto front is populated to give a set of optimal designs which satisfy maximum aerodynamic efficiency and minimum weight objectives. A wide search of the design space is achieved with little manual intervention, which makes use of the high fidelity weight estimate extracted from topology optimization results.
Nomenclature= element index 0 = initial value = compliance = coefficient of lift = coefficient of drag = Young's modulus f = load vector = landing lift constant = lift force = aircraft mass = element removal rate u = displacement vector = volume * = volume fraction = relative density ̅ = mean von Mises stress Introduction NCREASINGLY, complex design systems are operated from a range of different computational platforms with a number of different design teams. The more complex these systems become, the less likely it is to see effective integration of each of these specialist activities 1 . This often results in the opportunities to change the design decreasing dramatically the further one progresses through the design process, and often this allows imperfections to remain in the design as it is too expensive to go back and correct them 2 . Better integration within the design process can facilitate smaller design organisations with shorter time to manufacture and less human interaction. By more fully exploiting the capabilities of computers in design, search and optimisation, this is an achievable objective. The increasing power of modern computer systems continues to expand the depth of computational analysis that can be afforded within the design process. 3 . The aerodynamic optimisation is carried out using an estimate for the weight of the structure based on previous models. Commonly, statistical models are used to provide weight estimates to inform optimisation decisions, some of which are reviewed in Ref.4. To manually update the internal structure in this model would take many hours of Computer Aided Design (CAD) drawing, carried out by a skilled design engineer. Automation of the internal design definition would permit a high fidelity weight estimation, allowing the designer to conduct a much more accurate search of the design space with little additional manual effort.In the literature, several authors have used higher fidelity geometry-generation methods capable of providing weight estimates and structural analysis for the multidisciplinary optimisation of aircrafts. In...