Acoustic properties of microperforated panels and their optimizatión by simulated annealing

Ruiz Villamil, Heidi (2012). Acoustic properties of microperforated panels and their optimizatión by simulated annealing. Thesis (Doctoral), E.T.S.I. Industriales (UPM).

Description

Title: Acoustic properties of microperforated panels and their optimizatión by simulated annealing
Author/s:
  • Ruiz Villamil, Heidi
Contributor/s:
  • Cobo Parra, Pedro
Item Type: Thesis (Doctoral)
Date: 2012
Subjects:
Faculty: E.T.S.I. Industriales (UPM)
Department: Ingeniería Mecánica y de Fabricación [hasta 2014]
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

This thesis investigates the acoustic properties of microperforated panels as an alternative to passive noise control. The first chapters are devoted to the review of analytical models to obtain the acoustic impedance and absorption coefficient of perforated panels. The use of panels perforated with circular holes or with slits is discussed. The theoretical models are presented and some modifications are proposed to improve the modeling of the physical phenomena occurring at the perforations of the panels. The absorption band is widened through the use of multiple layer microperforated panels and/or the combination of a millimetric panel with a porous layer that can be a fibrous material or a nylon mesh. A commercial micrometric mesh downstream a millimetric panel is proposed as a very efficient and low cost solution for controlling noise in reduced spaces. The simulated annealing algorithm is used in order to optimize the panel construction to provide a maximum of absorption in a determined wide band frequency range. Experiments are carried out at normal sound incidence and plane waves. One example is shown for a double layer microperforated panel subjected to grazing flow. A good agreement is achieved between the theory and the experiments. RESUMEN En esta tesis se investigan las propiedades acústicas de paneles micro perforados como una alternativa al control pasivo del ruido. Los primeros capítulos están dedicados a la revisión de los modelos de análisis para obtener la impedancia acústica y el coeficiente de absorción de los paneles perforados. El uso de paneles perforados con agujeros circulares o con ranuras es discutido. Se presentan diferentes modelos y se proponen algunas modificaciones para mejorar la modelización de los fenómenos físicos que ocurren en las perforaciones. La banda de absorción se ensancha a través del uso de capas múltiples de paneles micro perforados y/o la combinación de un panel de perforaciones milimétricas combinado con una capa porosa que puede ser un material fibroso o una malla de nylon. Se propone el uso de una malla micrométrica detrás de un panel milimétrico como una solución económica y eficiente para el control del ruido en espacios reducidos. El algoritmo de recocido simulado se utiliza con el fin de optimizar la construcción de paneles micro perforados para proporcionar un máximo de absorción en una banda determinada frecuencias. Los experimentos se llevan a cabo en la incidencia normal de sonido y ondas planas. Se muestra un ejemplo de panel micro perforado de doble capa sometido a flujo rasante. Se consigue un buen acuerdo entre la teoría y los experimentos.

More information

Item ID: 14758
DC Identifier: http://oa.upm.es/14758/
OAI Identifier: oai:oa.upm.es:14758
Deposited by: Archivo Digital UPM
Deposited on: 05 Apr 2013 08:20
Last Modified: 21 Apr 2016 14:34
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