Numerical techniques for near-field acoustic holography

Abusag, NM, 2019. Numerical techniques for near-field acoustic holography. PhD, Nottingham Trent University.

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Abstract

Near-field acoustic holography (NAH) has proved to be an enormously successful sound source identification technique, which is widely used in field of acoustics and noise control. The work presented in this thesis aims at developing a novel method for modelling near-field acoustic holography, where the particle velocity on the surface of a vibrating structure is recovered from measurements taken in the exterior field. The model developed will form a powerful predictive tool for identifying sources of acoustic radiation for applications in mechanical and audio engineering.

Inspired by advances in the solution of ill-posed problems in imaging science using the so-called compressed sensing, we seek to develop new compressed or sparse reconstruction methods for the NAH problem. A sparse superposition method will be developed and implemented based on the inverse method of superposition (MoS), or equivalent source method as it is often known. The method should be able to reconstruct the normal velocity of a vibrating object using a very small number of charge points. Two primary reasons this is beneficial are; one can potentially reduce the amount of measured data required, and one could also detect sources of noise when small clusters of charge points are identified. The sparse inverse MoS will then be applied to reconstruct the surface velocity of a loudspeaker from measurements of the sound pressure field taken in a semi-anechoic chamber. The development of the new sparse inverse MoS and its experimental verification form the primary contributions to knowledge of this thesis.

Item Type:	Thesis
Creators:	Abusag, N.M.
Date:	September 2019
Rights:	This work is the intellectual property of the author. You may copy up to 5% of this work for private study, or personal, non-commercial research. Any re-use of the information contained within this document should be fully referenced, quoting the author, title, university, degree level and pagination. Queries or requests for any other use, or if a more substantial copy is required, should be directed in the owner(s) of the Intellectual Property Rights.
Divisions:	Schools > School of Science and Technology
Record created by:	Linda Sullivan
Date Added:	01 Apr 2020 09:04
Last Modified:	01 Apr 2020 09:04
URI:	https://irep.ntu.ac.uk/id/eprint/39526

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