This paper details five aeroelastic modelling methods applied to the study of an example high aspect ratio wing subject to high loads resulting in large structural deformations. Each method is discussed in turn and example static results from each are compared. Overall agreement is illustrated between the methods for key quantities of interest although aerodynamic modelling choices regarding the orientation of aero forces is observed to play a significant role in the agreement between predicted distributed loads and deflections. Quantitative differences resulting from linearisation of the wing model are also presented and discussed. It is found that by linearising the problem, wing deflection, aerodynamic forces and root bending are all over-estimated. Large differences are also observed between linear and nonlinear predictions of root twist, however the modelling of drag effects is deemed important to the exact nature of the observed discrepancy. Altogether, linearised assumptions are shown to have a noticeable impact on the accuracy of predicted results for the considered wing test case and are deemed unsuitable in isolation for the analysis of this class of flexible problem.

In recent years, significant resources have been invested to further improve the efficiency and environmental sustainability of modern aircraft. A possible strategy consists of reducing the induced-drag contribution (40% of total drag) by means of wing tip devices, e.g. winglets. However, these solutions have a negative impact on structural sizing, requiring reinforcements, and aeroelastic stability, requiring mass balancing. The subject of this study is the numerical study of an alternative wing tip device. In particular, two different design concepts are presented, namely discrete and raked options. These solutions improve the aerodynamic efficiency by extending the wing span and feature an integrated aeroelastic passive load alleviation capability. The design of the wing tip devices follows a multi-fidelity approach, closely matching today's best practices in the aerospace industry. In the first part of the study, the design phase is carried out with lowfidelity very efficient tools. In the second part, the most promising solutions are verified with high-fidelity more expensive tools, within the framework of computational aeroelasticity.

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The reduced weight and improved efficiency of modern aeronautical structures (as a consequence of e.g. MDO, composite materials) result in a smaller and smaller separation of rigid and elastic modes frequency ranges. Therefore the availability of an integrated environment for aeroservoelastic analysis is mandatory from the very beginning of the design process. Together with the availability of more and more powerful computing resources, current trends pursue the adoption of high fidelity tools and state-of-the-art technology within the very active and fruitful research fields of Computational Structural Dynamics (CSD), Multibody System Dynamics (MSD) and Computational Fluid Dynamics (CFD). This choice is somehow obliged when dealing with non-linear aeroservoelastic phenomena, such as in the transonic regime. In this paper we illustrate the implementation of a platform for solving multidisciplinary non-linear Fluid-Structure Interaction (FSI) problems coupling high-fidelity CSD and CFD tools by means of a robust interface scheme. We deal with mesh deformation by means of a novel hierarchical strategy particularly suited for aeroelastic simulation of free flying aircraft. The credibility of the developed set of analysis procedures is assessed by tackling the non-linear aeroelastic trim problem for a free-flying aircraft taking into account different design configurations and maneuvers. The results are compared with the outputs of classical linear(ized) methods.

University of Bristol -Explore Bristol Research General rightsThis document is made available in accordance with publisher policies. Please cite only the published version using the reference above. showing the effectiveness and efficiency of the methodology.