Effect of an expansion chamber on the propagation of sound in circular ducts

Abstract

An analytical and experimental study is presented of sound propagation through a circular duct in the presence of an expansion chamber. Results are presented for various sound frequencies, expansion ratios, and chamber lengths. It is found that the analytical results are in good agreement with the experimental results.

Resonant Properties of Short Expansion Chambers in a Circular Duct: Including Extremely Short Cases and Asymmetric Mode Wave Incidence Cases

“…It is represented by the repeating dome-shaped transmission loss curve, in the case that the plane wave theory can be applied. But when the axial length of the chamber considerably shortens, this property changes remarkably and the chamber begins to act as a resonator mu%er [1].…”

Re-expansion method for circular waveguide discontinuities: Application to concentric expansion chambers

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Modelado analítico-numérico y caracterización experimental de silenciadores de escape híbridos

“…Mediante la aplicación de las condiciones de continuidad de velocidad en las discontinuidades geométricas y empleando las relaciones de ortogonalidad de las funciones de Bessel, Miles obtuvo un sistema de ecuaciones, y por medio de su resolución, determinó las amplitudes de las ondas incidente y reflejada. ElSharkawy y Nayfeh [46] extendieron este análisis en el tratamiento axisimétrico bidimensional en cámaras de expansión simple y compararon sus resultados con medidas experimentales realizadas con prototipos de diferente longitud y radio. Empleando la técnica de Ajuste Modal, Åbom [1] derivó la matriz de cuatro polos en la que incorporó los efectos de los modos de alto orden en cámaras concéntricas, con conductos extendidos de entrada y salida.…”