Advanced Fluid-Structure Interaction Modelling and Simulation for Aerospace Applications
Licentiate thesis, 2022
High Reynolds number flows, involving separated flow, are very challenging to simulate. Hybrid Reynolds-averaged Navier-Stokes (RANS)-large-eddy simulation (LES) techniques provide the possibility to simulate such flows for industrial purposes. Hybrid RANS-LES methods are employed in this thesis for two applications which require turbulence-resolving techniques.
First, the effects of elastic walls on the aeroacoustics in transonic cavity flow are investigated. The prediction of structural vibrations is also important since vibrations may endanger the structural integrity, additionally, vibrations may negatively affect other apparatuses. The features of cavity flow appear in weapon bays and landing gear bays in an aircraft. In a deep cavity, the flow constitutes of broadband and tonal noise, referred to as Rossiter modes. The cavity structure is simulated with a modal-based approach and with a non-modal approach where the equation of motion is solved for all degrees-of-freedom of a reduced order finite element model. The results evince that the aeroacoustic field is altered by the elastic walls. For the investigated case, the energy of the 4th Rossiter mode is depleted and a strong tone is induced at a frequency below the 4th Rossiter mode, which is absent in the rigid cavity; these observations are made with both the structural simulation methods. However, with the non-modal approach, a second strong tone is induced at a frequency above the 4th Rossiter frequency.
The second investigated application is the aeroelastic prediction of a wing at Mach numbers ranging from subsonic to supersonic speeds. The viscous effects become significant at transonic speeds and may provoke shock induced flow separation. It is shown that the viscous effects play an important role under such circumstances and that both static and dynamic structural responses differ significantly depending on whether hybrid RANS-LES or unsteady RANS is employed for the flow simulation.
Chalmers, Mechanics and Maritime Sciences (M2), Fluid Dynamics
Effects of Aeroelastic Walls on the Aeroacoustics in Transonic Cavity Flow
Aerospace,; Vol. 9(2022)
Nilsson, S., Yao, H.-D., Karlsson, A., Arvidson, S., Eﬀects of Aeroelastic Walls on the Aeroacoustics in Transonic Cavity Flow, Utilising a non-Modal Approach
Conjunction of Aeroelasticity and Aeroacoustics in Transonic Cavity Flow
Proceedings of the International Forum of Aeroelasticity and Structural Dynamics 2022, IFASD 2022,; (2022)
Paper in proceeding
Effects of Viscosity and Density on the Aeroelasticity of the ONERA M6 Wing from Subsonic to Supersonic Speeds
AIAA AVIATION 2022 Forum,; (2022)
Paper in proceeding
Multidisciplinary advanced computations: Fluid dynamics, Aeroacoustics, Structural dynamics (MultFAS)
VINNOVA (PO1600297547), 2019-11-01 -- 2022-10-31.
Fluid Mechanics and Acoustics
Thesis for the degree of Licentiate – Department of Mechanics and Maritime Sciences