Metric based development of acoustic lenses and waveguides

MacDonald, L; Oclee-Brown, J; Hargreaves, JA

Abstract

This paper investigates and develops an automated design procedure for acoustic waveguides, to modify them to be better at supporting single parameter (1P) wave propagation. The design process is driven by two new performance metrics that are calculated from the solution of Laplace's equation in the waveguide. These highlight regions of error in the relative pathlength (“stretch”) and change in area (“flare”) through the domain. Finite Element Analysis (FEA) is used to calculate these metrics on several test cases. The method of equalising the relative pathlength by distorting regions of a thin domain, as is disclosed in and protected by GP Acoustics patent GB2588142 (Dodd and Oclee-Brown, 2021), is then investigated and combined with FEA analysis to form a design technique. Modified waveguides are then evaluated by FEA simulations of the Helmholtz equation, and the performance is quantified by the uniformity of SPL across the exit of the device.

Citation

MacDonald, L., Oclee-Brown, J., & Hargreaves, J. Metric based development of acoustic lenses and waveguides. Presented at Reproduced Sound 2022, Bristol

• Presentation Conference Type: Other
• Conference Name: Reproduced Sound 2022
• Conference Location: Bristol
• End Date: Nov 17, 2022
• Acceptance Date: Oct 7, 2022
• Publication Date: Nov 17, 2022
• Deposit Date: Mar 6, 2023
• Publicly Available Date: Mar 6, 2023
• Publisher URL: https://www.ioa.org.uk/catalogue/paper/metric-based-development-acoustic-lenses-and-waveguides
• Additional Information: Event Type : Conference