Aerodynamic sound contributes significantly to the noise emission of high-speed applications such as trains, aircraft and wind turbines. The rapid growth of the computational power available enables the simulation of increasingly complex systems. In the research field of computational aeroacoustics, the simulation of flexible parts undergoing large deformations has become a key topic. The simulation of such multi-field problems requires a coupling between the scientific branches of fluid dynamics, structural mechanics and aeroacoustics.
To simulate aerodynamic sound radiation from the low Mach number flow over flexible structures, we apply a partitioned computation approach. The structural mechanic problem is solved in the finite element solver CalculiX. The fluid problem is treated with a hydrodynamic/acoustic splitting technique in the finite volume solver FASTEST. Large eddy simulation enables an accurate resolution of large scale turbulent flow structures. Acoustic sources are derived from the incompressible flow field solution. The coupling library preCICE is used to exchange interface data.
In this project phase, we applied the developed computation approach to study the fluid-structure interaction and aerodynamic sound radiation of a membrane airfoil at high incidences. The results suggest a coupling between the membrane oscillation and large scale flow structures. The acoustic results indicate a mix of sound source mechanisms. The membrane oscillation was found to contribute significantly to the radiated sound.
Within this project, the coupling of the scientific branches of fluid dynamics, structural mechanics and aeroacoustics is investigated. The application of the developed approach to a complex problem such as a membrane wing has been demonstrated. We are currently investigating the numerical aspects that influence the quality of the large eddy simulation and their influence on the coupled solution.