Auralisation of outdoor fan noise in shielded areas

In a situation where traffic, railway or aircraft noise sources are not present, as it happens in shielded areas, other sources might become relevant in terms of annoyance. This is the case of typical turbomachinery elements, such as fans, compressors or turbines, where sound is generated aerodynamically. As a part of the Sonorus project, where all noise sources in urban environments are considered, the goal of this research is to develop an auralization tool that generates a time domain signal depending on the fan working conditions and the propagation scenario. In this paper, a computational aeroacoustics (CAA) solver is used to simulate the flow field generated by an axial fan, and the acoustic field is calculated using the Ffowcs-Williams and Hawkings method. The information contained in this acoustic field is used to generate a sound signal for auralisation purposes. The model results are evaluated by comparisons with recordings and measurements.