The paper addresses the simulation of turbulent wind gusts hitting rigid and flexible
structures. The purpose is to show that such kind of complex fluid–structure interaction
(FSI) problems can be simulated by high-fidelity numerical techniques with reasonable
computational effort. The main ingredients required for this objective are an efficient
method to inject wind gusts within the computational domain by the application of
a recently developed source-term formulation, an equally effective method to prescribe
the incoming turbulent flow and last but not least a reliable FSI simulation methodology
to predict coupled problems based on a partitioned solution approach combining an LES
fluid solver with a FEM/IGA solver for the structure. The present application is concerned
with a rigid and a membranous hemisphere installed in a turbulent boundary layer
and impacted by wind gusts of different strength. The methodology suggested allows
to inject the gusts in close vicinity of the object of interest, which is typically well
resolved. Therefore, the launch and transport of the wind gust can be realized without
visible numerical dissipation and without large computational effort. The effect of the
gusts on the flow field, the resulting forces on the structure and the corresponding
deformations in case of the flexible structure are analyzed in detail. A comparison
between the rigid and the flexible case makes it possible to work out the direct reaction
of the deformations on the force histories during the impact. Furthermore, in case of the
flexible structure the temporal relationships between local or global force developments
and the local deformations are evaluated. Such predictions pinpoint the areas of high
stresses and strains, where the material is susceptible to failure.