Interpolation Technique for Computational Aeroacoustics and Vibroacoustics
* Presenting author
Since the beginning of computational aeroacoustics, hybrid methodologies have been established as the most practical methods for aeroacoustic computations. These approaches are based on three steps: (1) perform unsteady flow computations on a restricted sub-domain; (2) compute with a conservative algorithm the acoustic sources; (3) compute the acoustic field. It should be noted that analog to aeroacoustics, decoupled vibro-acoustic simulations follow a similar three step approach, aiming to compute the acoustic field due to structural deformations. Both computational schemes require a robust transformation of the discrete fluid field (or in case of vibro-acoustics the discrete mechanical deformations) to the acoustic simulation grid. Based on the framework of radial basis functions, we propose a general method for the computation of the source terms. Compared to different interpolation algorithms, radial basis functions have promising capabilities: (1) local behavior and the computational efficiency, known from nearest neighbor algorithms, is possible; (2) C∞ interpolation functions result in smooth derivatives of the interpolated field; (3) patch search techniques indicate typical flow structures. This method allows us to use primary flow variables velocity, pressure, density as input to compute aeroacoustic sources and mechanical displacement for vibro-acoustic sources. We verify our approach by the “co-rotating vortex pair”.