Projects

It is an observed trend that the sound absorption of a fibrous material increases as the size of the fibres decreases. For conventional sound absorbers the diameter of these fibres can be as low as the micron range, but little is known about the mechanisms present for fibres much finer than this with key reason behind this being the breakdown of continuum assumptions for gas near nanoscale features. As these very fine fibres have a characteristic dimension less than one micron they are classified as nanomaterials. Due to the fine scale of nanomaterials visual inspection requires the use of electron microscopy, which is incompatible with monitoring the rapid interactions which occur with acoustic waves.

It is for this reason that this project aims to focus on the modelling of these interactions, with experimental results for the acoustic absorption of nanomaterial samples being used for verification purposes. Molecular dynamics has previously been found to be the modelling technique most suitable for modelling the interactions between acoustic waves and nanomaterials, however, hardware limitations have thus far prevented the audible frequency range from being investigated in these models, with current capabilities in the gigahertz range. Various modifications, including hybridisation, are possible for molecular dynamics models and are being investigated to produce a molecular dynamics based system able to simulate a lower frequency range.

The intent of this project is to develop a sufficiently fast model to allow the interactions between nanomaterials and audible frequencies to be simulated and, hence, produce a greater understanding of the acoustic absorption mechanisms of nanomaterials at this frequency range.