Acoustic Metamaterials for Electronics Cooling Fan Noise Reduction

Acoustic noise is a significant obstacle that limits the performance of data centre Hard Disk Drive (HDD) storage systems. The primary noise source of these systems has been identified as cooling fans that are used for their thermal management. New acoustic metamaterial (AM) designs can be used as a solution to this problem. AMs can be custom-designed to address specific tonal frequencies that HDD servo systems show high sensitivity to. This paper focuses on developing a 3D-printed annular AM treatment that can be easily attached to the inlet or outlet of an axial fan. Initial design optimization was conducted using the Finite Element Method (FEM). Further FEM simulations were carried out using more realistic fan sources from high-fidelity Computational Fluid Dynamics (CFD) simulations. The AM geometry was tested experimentally with a fan that is commonly used in a data centre storage system, where the fan speed was set to induce an acoustic tone that negatively affects the performance of HDDs. Then a full scale Finite Element Method simulation was ran using fan acoustic source data extracted from a high fidelity CFD simulation. Results indicate significant noise reduction at the targeted frequency.