A Computational Investigation of Broadband Noise Generation in a Low-speed Axial Fan

Kurzfassung

The generation of broadband noise in a lab-scale, low-speed axial fan is investigated computationally. The time-dependent aerodynamic and acoustic fields are computed directly by numerically solving the unsteady compressible Navier-Stokes equations. Through the application of both the Detached Eddy Simulation (DES) and the Large Eddy Simulation (LES) approaches, the larger scale turbulent eddies in the wakes of the rotor- and stator-blades, and the tip-flow regions of the rotors, are resolved directly in the numerical simulations. Alongside assessing the applicability of the applied methods to the modeling of broadband noise sources in turbomachinery, the broadband noise generation processes are investigated, and the results are compared with available hot-wire and surface-pressure data.