A hybrid CFD/BEM method for the calculation of aeroacoustic noise from a radial fan
* Presenting author
In this work, a hybrid numerical simulation for the aeroacoustic noise of a radial fan will be presented. The geometry of the problem is in compliance with the “In-Duct” experimental technique according to the industrial norm DIN EN ISO 5136, where the far-field noise levels are monitored inside a circular duct using three probe-type microphones. A radial fan with a diameter of 140 mm and eight backward-curved blades is used. Since direct fluid dynamics simulations for the whole system are computationally expensive, a hybrid approach is employed where the near field pressure and velocity values are computed with CFD (using ANSYS software), and the far field acoustic pressure is evaluated using the direct boundary element (BEM) formulation. In particular, the Detached Eddy Simulation (DES) and the Scale Adaptive Simulation (SAS) are employed in CFD computations. A virtual interface near the beginning section of the duct is used for the data exchange. The acoustic pressure is then computed at the locations of probe microphones in the far-field using BEM. Upon timely completion of experimental measurements, comparison of the numerical results with the experimental values will be shown.