Transmission loss of lined Helmholtz resonator with annular air gap: A Green's function based approach

Veerababu, D. and Venkatesham, B. (2021) Transmission loss of lined Helmholtz resonator with annular air gap: A Green's function based approach. Noise Control Engineering Journal, 69 (2). pp. 112-121. ISSN 0736-2501

Full text not available from this repository. (Request a copy)

Abstract

The present article discusses a Green's function-based semi-analytical method to predict the transmission loss of a lined Helmholtz resonator with annular air gap. In the analysis, the walls of the chamber are assumed to be acoustically rigid except at the neck portion where it is treated as a piston source moving with uniform velocity. The Green's function is developed as the summation of eigenfunctions of the central duct. The cumulative effect of the lined portion and the annular air gap including the perforated screens is incorporated as the reflection coefficient in the eigenfunctions. By using the Kirchhoff-Helmholtz integral equation, the velocity potential generated by the piston inside the chamber is evaluated. A transfer matrix relating the acoustic pressure and volume velocity across the neck in the main duct is formulated. The effect of the neck length is included as an added inertance to the impedance in the transfer matrix. The results obtained from the proposed method are validated with the developed numerical models and the experimental data available in the literature. A parametric study has been conducted to investigate the effect of porosity of the perforated screens, thickness and flow resistivity of the absorptive material on the transmission loss of the chamber.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Venkatesham, B	https://orcid.org/0000-0003-3651-513X

Item Type:

Article

Uncontrolled Keywords:

Absorptive materials; Acoustic pressures; Cumulative effects; Function-based approach; Helmholtz resonators; Kirchhoff-Helmholtz integrals; Semi-analytical methods; Velocity potentials Engineering main heading; Acoustic impedance; Acoustic resonators; Ducts; Eigenvalues and eigenfunctions; Numerical methods; Pistons; Transfer matrix method; Transmissions; Wave transmission

Subjects:

Physics > Mechanical and aerospace
Physics

Divisions:

Department of Mechanical & Aerospace Engineering

Depositing User:

. LibTrainee 2021

Date Deposited:

24 Jun 2021 04:27

Last Modified:

01 Mar 2022 07:07

URI:

http://raiithold.iith.ac.in/id/eprint/7986