Modal filters for in-duct sound based on the cremer impedance and micro-perforated plates
2016 (English)In: Proceedings of the INTER-NOISE 2016 - 45th International Congress and Exposition on Noise Control Engineering: Towards a Quieter Future, German Acoustical Society (DEGA) , 2016, 3215-3222 p.Conference paper (Refereed)
The design of a new filter-type is presented that allows a sufficient reduction of in-duct aero-acoustic noise. The filter is a hybrid design containing a lined duct section based on the so called Cremer impedance and a section with combinations of micro-perforated plates. The Cremer impedance section strongly damps the zero-order or plane wave mode while the MPP section which breaks the circumferential symmetry of the duct and damps the higher order modes. Different designs are investigated numerically, solving the linearized Navier-Stokes equations in the frequency domain and decomposing the sound-field into its modal components. Both, the transmission loss and the total power loss is calculated and compared for different assemblies and plate impedances.
Place, publisher, year, edition, pages
German Acoustical Society (DEGA) , 2016. 3215-3222 p.
Acoustic fields, Acoustic impedance, Acoustic noise, Acoustic variables control, Acoustics, Aeroacoustics, Bandpass filters, Ducts, Frequency domain analysis, Perforated plates, Frequency domains, Higher-order modes, Hybrid design, Linearized navier-stokes equations, Lined ducts, Modal filters, Total power, Transmission loss, Navier Stokes equations
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-202171ScopusID: 2-s2.0-84994654224OAI: oai:DiVA.org:kth-202171DiVA: diva2:1079261
45th International Congress and Exposition on Noise Control Engineering: Towards a Quieter Future, INTER-NOISE 2016, 21 August 2016 through 24 August 2016
QC 201703082017-03-082017-03-082017-03-08Bibliographically approved