Large Eddy Simulation of Sound Sources on a Cambered Airfoil
With an increased emphasis on reducing the flow-induced wind turbine and airframe noise, the current work focuses on quantifying the turbulent sound sources on a cambered wind-turbine profile namely, DU96-180. Aeroacoustics simulation will be carried out following a hydrodynamic-acoustic splitting method that was also recently extended to include the acoustic feedback onto the flow. Flow is resolved by a Large Eddy Simulation (LES) following a finite-volume, immersed-boundary method on a hierarchical Cartesian mesh using MGLET. Run-time coupled with the LES, Acoustic Perturbation Equations (APEs) will be solved on the same mesh with a coarser time-stepping i.e. a multiple of the time-step used to resolve the flow. The flow parameters specified in the workshop of `Benchmark Problems for Airframe Noise Computations (BANC-II)' will be used for the current study with a free-stream velocity of 60m/s, angle-of-attack of 4° and a chord based Reynolds number of 1.2 Million. A wall model will be employed to alleviate the computational requirement of LES at such high Reynolds numbers. The near-field and far-field dataset generated via industry-ready LES+APE simulations will not only be an addition to the benchmarking exercise of BANC, but also serves as a baseline for future noise reduction studies, e.g., retro-fitted serrations.