Abstract
Resonators designed in spiral and helical shapes exhibit sound absorption performance in the lower frequency band. The absorption characteristics including frequency range and acoustical impedance can be controlled by adjusting the permittivity and permeability are dependent on the length or dimensions of the resonator. As the helical structure is added, the absorption performance can deteriorate due to the change in the resonator geometry. The compliant wall trembles in response to changes in waveguide pressure, generating dissipation of sound energy. The resonator is surrounded by a compliant wall to compensate for the absorption effect of the resonator. Acoustic properties were obtained using the equivalent impedance concept consisting of the acoustic surface impedance of the cavity, the helical structure, and the soft wall. The theoretical scattering coefficients were compared with measurements obtained with the 4-microphone method using impedance tubes. In this study, the tunability of the length extension ratio of the helical structure was investigated by controlling geometric parameters (or boundary conditions of the outer wall of the resonator). Keywords: scattering coefficients; compliant wall; helical structure
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: INTER-NOISE and NOISE-CON Congress and Conference Proceedings
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
