Investigations of Helmholtz Resonators with Curved Tapered Embedded Neck Extension

TL;DR

This paper investigates how curved tapered embedded necks in Helmholtz resonators affect their acoustic absorption, using numerical simulations and experiments to optimize low-frequency noise reduction.

Contribution

It introduces a novel curved tapered neck design and provides comprehensive numerical and experimental analysis of its acoustic performance.

Findings

Tapered curved necks lower the absorption frequency.

Longer necks and smaller diameters improve low-frequency absorption.

Experimental results confirm the numerical trends.

Abstract

In this study, the performance of Helmholtz resonators with curved tapered neck extensions was investigated through numerical and experimental methods. A numerical parametric analysis was carried out using the Finite Element Method with COMSOL, while experimental validation was conducted using a two-microphone acoustic impedance tube. The analysis evaluated the effects of neck outlet/inlet diameter ratio, neck length, and diameter of the neck on the absorption coefficients and resonance frequency of the resonators. Results revealed that a tapered curved embedded neck configuration led to a lower absorption frequency as the outlet/inlet ratio increased trend to convergent neck geometry. Furthermore, a longer effective neck length and smaller neck diameter enhanced low-frequency noise absorption. Experimental validation with four 3D-printed samples confirmed these trends.