Calculation of Duct Flow Noise Using CE/SE Method

Noise generated in flow duct propagates extensively through the connected ductwork. Its propagation through the outlets would contribute to indoor acoustic discomfort and results in environmental problem. Silencers with acoustic lining are commonly adopted for noise mitigation in flow duct. Researchers have been devoting many numerical efforts in assessing the performance of a liner design. In general, numerical studies are performed by either time domain or frequency domain approach. This paper reports a development of calculation method solving Acoustic Perturbation Equations and Time-Domain Impedance Boundary on the Conservation Element and Solution Element (CE/SE) framework to calculate duct noise problem in time domain. In this paper, three benchmark cases are presented to verify the capability of the proposed method on calculating the flow induced acoustic generation, propagation, and the acoustic behavior at the impedance boundaries in the presence and absence of flow.