Acoustic performance of different Helmholtz resonator array configurations

Cai, Chenzhi; Mak, Cheuk Ming

doi:10.1016/j.apacoust.2017.09.026

Cited by 68 publications

(31 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The effect of incident acoustic pressure amplitude may be crucial when attempting to extrapolate the transmission loss measured in an experimental setup to that which is estimated for an industrial setting. This paper focuses on the TL of the Helmholtz resonator (HR), a device that is ubiquitous in research because of its geometric simplicity and ability to target low frequencies while maintaining relatively small dimensions [2][3][4]. The HR consists of an enclosed cavity with a protruding neck that connects it to the system of interest.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Incident Acoustic Pressure Amplitude on the Transmission Loss of Helmholtz Resonators

et al. 2020

View full text Add to dashboard Cite

Acoustic transmission loss is a common parameter utilized throughout several studies to evaluate the acoustic characteristics of a given test element. Transmission loss has been frequently referred to as a source independent parameter. However, this work presents evidence that the incident acoustic pressure amplitude does, in fact, have an effect on the measured transmission loss for some passive damping devices. The transmission loss was experimentally measured utilizing the two-source location method and the specimens tested include an expansion chamber, a quarter wave resonator, a Herschel-Quincke tube and various Helmholtz resonators. When varying the power supplied to the acoustic source, it was noted that all the devices exhibited nearly constant values of transmission loss, with the exception of the Helmholtz resonators. The Helmholtz resonators had a significant variance of transmission loss with respect to the acoustic source power. This decrease in performance is caused by the "jet-flow" phenomenon occurring at the Helmholtz resonator neck, which results in increased acoustic losses. The present work illustrates that the assumption of source independence, which is often made when using transmission loss to evaluate damping devices, must be taken with caution, as this assumption is case dependent and may be crucial when scaling experimental studies to an industrial setting.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Measured transmission loss spectra for a 1 L volume HR (l neck = 1.5") for various input source power levels.Vibration 2020,3 40 Measured transmission loss peaks (extracted at 150 Hz) for various HR sizes and input source power levels.…”

mentioning

confidence: 99%

Effect of Incident Acoustic Pressure Amplitude on the Transmission Loss of Helmholtz Resonators

et al. 2020

View full text Add to dashboard Cite

show abstract

“…However, this is often implemented in an active form, meaning it require additional energy and employs secondary acoustic source [17][18][19]. On the other hand, studies on the implementation of geometry or structure-based resonance without the use of active elements has been gaining momentum [20][21][22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Targeted sound attenuation capacity of 3D printed noise cancelling waveguides

Arjunan

2019

Applied Acoustics

View full text Add to dashboard Cite

The study explores the creation of 3D printed sound cancelling waveguides that can be customised for selected frequencies as a function of geometry. The potential for attenuation in these waveguides is characterised through experimentally measured acoustic-absorption () and Transmission Loss (TL). This was done to evaluate the potential of geometry-controlled waveguides in the development of passive sound cancelling structures. Geometrically complex waveguides to exploit the Herschel-Quincke-Arjunan (HQA) waveguide model manufactured in Nylon-12 using Selective Laser Melting (SLM) are presented. The attenuation of the waveguides was compared to the bulk Nylon-12 materials to segregate the material-based influence. The results showed that the performance of HQA waveguides can be controlled as a function of length, diameter and waveguide-tortuosity. Accordingly, under right parameters significant improvement in (0.96, 0.80, 0.61 and 0.98) and TL (65.59%, 30.15%, 53.36% and 95.28%) can be achieved at the design frequency. The proposed methodology can be used to develop customisable waveguides exploiting the principles of acoustic wave interference for a range of application including building walls, noise barriers and absorptive panels.

show abstract

“…Cai and Mak [28] developed numerical and theoretical investigations to determine the acoustic performance of three configurations of a Helmholtz resonator. In the first configuration, two HRs were connected in series (cavityneck-cavity-neck), in the second configuration, two HRs were placed independently in the same transversal section of the tube and in the third configuration, two HRs were connected parallel to the tube, one in front of the other.…”

Section: Introductionmentioning

confidence: 99%

Effects of variable-volume Helmholtz resonator on air mass flow rate of intake manifold

Hanriot

Queiroz

Maia

2019

J Braz. Soc. Mech. Sci. Eng.

View full text Add to dashboard Cite

The application of geometric modifications to the intake manifold to improve engine breathing provides positive results using different strategies. Helmholtz resonators (HR) are one of the most basic acoustic models and are widely used in engineering applications. Most of the works presented in the literature focus on the use of HR in the fields of acoustics. The present work experimentally investigates pulsating flow characteristics of the engine intake manifold and the effects of a Helmholtz resonator with variable internal volume. In this paper, acoustic studies were used to model the intake manifold and to develop a complex expression to determine the natural frequency of the system. The model included the primary and secondary intake pipes and the resonator. Experiments were conducted on a straight intake pipe connected to an engine cylinder head mounted on a test flow bench, especially designed for fluid dynamic studies of engine intake systems with unsteady flow conditions. Using electronic controls, the internal volume of the resonator was varied and adjusted according to the frequency of the valves as well as the natural frequency of the intake manifold. The natural frequency of the system was determined from a numerical model of the intake manifold. The results showed the internal volume of the resonator and frequency tuning affect the intake air mass flow rate at a wide range of camshaft velocities. For a fixed volume, the average increase of the mass flow rate was 17.8%, and when the volume was adjusted according to valve frequency, the average increase was 24.7%. The highest intake air mass flow rate was increased 31.5% when the resonator was tuned to the frequency of the system.

show abstract

Acoustic performance of different Helmholtz resonator array configurations

Cited by 68 publications

References 17 publications

Effect of Incident Acoustic Pressure Amplitude on the Transmission Loss of Helmholtz Resonators

Effect of Incident Acoustic Pressure Amplitude on the Transmission Loss of Helmholtz Resonators

Targeted sound attenuation capacity of 3D printed noise cancelling waveguides

Effects of variable-volume Helmholtz resonator on air mass flow rate of intake manifold

Contact Info

Product

Resources

About