The intrinsic acoustic properties of porous materials are expressed in terms of complex characteristic impedance Zm and wave number km. Various theoretical models have been proposed which allow the prediction of Zm and km on the basis of the knowledge of few non-acoustic parameters. It is not easy to measure all the needed parameters, so one must resort to some technique to fit measured acoustic data to corresponding data calculated with the selected theoretical model. The authors used a little-modified Optimization Tool found in the MATLAB@ library for searching non-acoustic parameters of a class of loose gravel which had been already studied. The goal function was the input impedance of layers of gravel on a hard backing which had been measured with an impedance tube. Two theoretical models for Zm and km have been considered. The first one requires the airflow resistivity, the porosity and the structure factor of the porous material. The second one is a four-parameter model. The values of these parameters found with the modified Optimization Tool are in good agreement with those already known.

The use of an optimization tool to search non-acoustic parameters of porous materials / Dragonetti, Raffaele; Ianniello, Carmine; Romano, ROSARIO ANIELLO. - ELETTRONICO. - (2004), pp. 1-7. (Intervento presentato al convegno 33rd International Congress and Exposition on Noise Control Engineering INTER-NOISE 2004 tenutosi a Praga nel 22-25 Agosto 2004).

The use of an optimization tool to search non-acoustic parameters of porous materials

DRAGONETTI, RAFFAELE;IANNIELLO, CARMINE;ROMANO, ROSARIO ANIELLO
2004

Abstract

The intrinsic acoustic properties of porous materials are expressed in terms of complex characteristic impedance Zm and wave number km. Various theoretical models have been proposed which allow the prediction of Zm and km on the basis of the knowledge of few non-acoustic parameters. It is not easy to measure all the needed parameters, so one must resort to some technique to fit measured acoustic data to corresponding data calculated with the selected theoretical model. The authors used a little-modified Optimization Tool found in the MATLAB@ library for searching non-acoustic parameters of a class of loose gravel which had been already studied. The goal function was the input impedance of layers of gravel on a hard backing which had been measured with an impedance tube. Two theoretical models for Zm and km have been considered. The first one requires the airflow resistivity, the porosity and the structure factor of the porous material. The second one is a four-parameter model. The values of these parameters found with the modified Optimization Tool are in good agreement with those already known.
2004
8001030555
The use of an optimization tool to search non-acoustic parameters of porous materials / Dragonetti, Raffaele; Ianniello, Carmine; Romano, ROSARIO ANIELLO. - ELETTRONICO. - (2004), pp. 1-7. (Intervento presentato al convegno 33rd International Congress and Exposition on Noise Control Engineering INTER-NOISE 2004 tenutosi a Praga nel 22-25 Agosto 2004).
File in questo prodotto:
File Dimensione Formato  
The use of an optimization tool to search non-acoustic parameters of porous materials.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: Accesso privato/ristretto
Dimensione 271.27 kB
Formato Adobe PDF
271.27 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11588/201789
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact