Paper submitted as part of the special session for the ALPES Aircraft Loads Prediction Using Enhanced Simulation Project.The main objective of this paper is to present a new methodology to correct the air loads computed with traditional potential flow models by means of linearised frequency domain analysis. The correction will be compared with the reference accurate steady and unsteady aeroelastic calculations performed with an OpenFSI methodology which strongly couples the structural solver MSC Nastran and the CFD code DLR TAU. This framework has demonstrated the capability to perform static and gust calculations for the FFAST wing, which is representative of a modern civil transport wing. An updated version of the framework will allow rigid body modes of heave and pitch to be included in the analysis. The linearised frequency domain solver has shown higher computational performance compared to unsteady time accurate simulation, hence will allow a reduction in the time necessary to compute the necessary corrections.

A multiphase fluid-structure interaction (FSI) framework using open-source software has been developed, utilising components able to run on high-performance computing platforms. A partitioned approach is employed, ensuring a separation of concerns (fluid, structure, and coupling), allowing design flexibility and robustness while reducing future maintenance effort. Multiphase FSI test cases have been simulated and compared with published results and show good agreement. This demonstrates the ability of this multiphase FSI framework in simulating complex and challenging cases involving a free liquid surface.

This paper presents a new methodology to increase the accuracy of gust loads analysis, evaluated by means of traditional potential flow models. Linearised frequency domain aerodynamic loads have been used to estimate the correction factors necessary to update the Aerodynamic Interference Coefficients matrices for gust and mode shapes deformation. The results, obtained using a corrected doublet-lattice method, are presented and compared to the fully coupled CFD/FEM results computed with a Fluid Structure Interaction interface. The application of this technique to a wing model, representative of a general single aisle civil aircraft, has shown an excellent agreement to the fully coupled results, both for rigid and flexible aerodynamic loads in the transonic regime.

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