Contribution
A Comparison between Numerical and Experimental Investigations of a Enclosed Centrifugal Fan
* Presenting author
Abstract:
The far-field sound radiation from enclosed centrifugal fans is a complex transmission path, and understanding the underlying mechanisms is the current state of research. The primary sound sources in the system are located directly at the impeller blades. These sources generate sound waves that interact with the interior of the casing wall, causing them to vibrate. In addition, aerodynamic pressure fluctuations within the system cause further excitation of the structure. The vibrating structure excites the air on the outside. This induces sound waves that propagate into the far field. In order to improve the physical understanding of this fluid-structure-acoustic interaction, a public benchmark case was set up with an enclosed centrifugal fan. The system was characterized by experiments including flow field, far field acoustics, casing vibration and aerodynamic pressure measurements. The experimental data not only provide insight into the interaction mechanisms, but also serve as validation data for high-resolution flow simulations of the whole system. The data from the flow simulations are used in a hybrid approach to calculate the sound sources inside the flow field and to perform fluid-structure-acoustic simulations. The geometries, measurements and simulation results will be published with open-access.