High-fidelity predictions of airfoil noise and its mitigation
Trailing-edge (TE) noise is a dominant contributor to noise produced in many engineering applications featuring flows around lifting surfaces such as wings and rotating blades, for example wind turbines, cooling fans and fans of aero-engines during approach. Previous studies have shown that TE serrations as illustrated in the figure significantly reduce the scattering of noise without adversely affecting the aerodynamic performance.
Recent analytical studies inspired by the silent flight of owls suggest that TE elasticity of the owl wing is one of the reasons why they can hunt in acoustic stealth. Understanding the underlying physical mechanism could lead to new noise reduction devices for the aforementioned applications. Alternatively, design guidelines for lifting surfaces to reduce noise using the same physical mechanism could be developed. Recently, Prof Sandberg has initiated a project to investigate the effect of elasticity on TE noise generation. To that end the in-house DNS code HiPSTAR has been coupled to a structural solver.
This new high-fidelity flow-structure interaction framework serves as the basis for this project. The computational setup will be used to conduct fully-coupled 3D simulations to give additional physical insight into the generation of the excess noise as well as the noise reduction mechanism and potential. Furthermore the effect of the moving body on the hydrodynamic field will be considered.
Leader: Richard Sandberg
Optimisation of resources and infrastructure
aeroacoustics; computational fluid dynamics; fluid structure interactions; turbulence