Transonic Wing and Control Surface Loads Modelling for Aeroservoelastic Analysis

Transonic Wing and Control Surface Loads Modelling for Aeroservoelastic Analysis

Lancelot, P.M.G.J. (TU Delft Aerospace Structures & Computational Mechanics)

Bisagni, C. (promotor)
De Breuker, R. (promotor)

Delft University of Technology

2023-05-08

The exponential growth of the aviation sector combined with environmental and energy supply challenges have led companies to innovate to reduce aircraft fuel consumption. Among the many areas currently under research, this thesis investigates the possibility of making aircraft wings lighter thanks to flight load alleviation systems and more accurate modelling methods.

The development process of an aircraft involves using low-fidelity aerodynamic models at the early stage of the design process to rapidly compute the loads acting on the airframe, and to evaluate the efficiency of wing control surfaces. These models are, however, limited to linear flow conditions, and transonic shock or flow separation cannot be simulated with such methods. This requires important safety factors and leads to generally heavier designs. Computational Fluid Dynamic with Reynolds-Averaged Navier-Stokes (CFD-RANS) analysis is capable of better aerodynamic predictions, but the computational time required for such simulations is too long to be efficiently included in the sizing process of the airframe. The approach proposed in this thesis aims to combine the accuracy of CFD with fast linear loads estimation. This is achieved by deriving reduced-order models (ROM) of the aircraft control surfaces and manoeuvre loads from rigid CFD analysis to improve the accuracy of faster but lower-fidelity results where needed. These fast aerodynamic models for the control surfaces also allow rapid control optimisation to evaluate their load alleviation potential.

The thesis starts by introducing and validating the unsteady and non-linear models with 2D examples. Then, it covers the application of these models to a flexible 3D wing. The models are validated against high-fidelity steady and dynamic Fluid-Structure Interaction simulations and show good agreement with a 5% to 10% error margin in loads and deformations in most of the cases. Finally, a wingbox sizing optimization is performed with active load alleviation. Choosing to either use the linear or the non-linear aileron model for the GLA alone leads to a 2.5% difference in the wingbox structural weight.

Aeroelasticity
Control surfaces
Transonic aerodynamics
Structural optimisation
Load alleviation
Model identification

https://doi.org/10.4233/uuid:e37566e8-cb46-4f90-863d-9cfe0b634507

978-94-6366-679-4

2023-05-08

Institutional Repository

doctoral thesis

© 2023 P.M.G.J. Lancelot