The transmission spectrum of sound through a phononic crystal subjected to liquid flow

Declercq, Nico F.; Chehami, Lynda; Moiseyenko, Rayisa P.

doi:10.1063/1.5017168

Cited by 7 publications

(2 citation statements)

References 11 publications

(6 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In their experiment, as the filling rate of the periodic structure and the inflow rate of the background flow increased, the reflectance of the bandgap frequency range decreased. Declercq et al 14 demonstrated through experiments that the bandgap of the periodic structure exhibits negligible change when the flow velocity of water increases. However, the flow rate considered in the experiment was too low (7.2 mm/s); therefore, it failed to conclusively demonstrate the background flow effect on the bandgap.…”

Section: Introductionmentioning

confidence: 99%

Analysis of noise attenuation for offshore platform silencer in duct with flow

Kim

Hong

Song

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part M:

View full text Add to dashboard Cite

Recently, the NORSOK standards, which regulate noise and vibration on offshore platforms, were strengthened by prohibiting the use of glass wool for environmental and safety reasons. In addition, the use of sound-absorbing materials in panels and silencers was prohibited. Therefore, developing a silencer that does not use sound-absorbing materials is necessary. In this study, a bandgap expressed by acoustic characteristics of a periodic structure was applied to develop a silencer without sound-absorbing materials. The bandgap is formed in a frequency range in which propagation of acoustic waves is suppressed by setting a specific distance between single units based on periodic structural theory. The designed silencer evaluates the noise attenuation effect of the periodic structure based on a fluid-structure coupling finite-element equation for a plane wave in a stationary medium. In addition, the silencer model was selected by analyzing the regenerated noise originating from the periodic structure in the flow duct. This flow noise is used to analyze the propagation of sound waves based on the FW-H equation. This is achieved by employing the Lighthill acoustic analogy to predict the flow-induced sound pressure. Furthermore, compressed air was injected at the end of the duct in the flow noise experiment to perform measurements. The results from the acoustic and flow noise experiments were compared to confirm the effect of the flow in the duct on noise generation. Moreover, the flow noise analysis based on the flow velocity elucidated the effect of the periodic structure on the flow. In addition, the analysis results were used to investigate its performance of the silencer with the periodic rod arrangement considering the flow noise in the duct and predict its acoustic characteristics in the bandgap frequency range.

show abstract

Section: Introductionmentioning

confidence: 99%

Analysis of noise attenuation for offshore platform silencer in duct with flow

Kim

Hong

Song

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part M:

View full text Add to dashboard Cite

show abstract

“…The modification of the density, elastic parameters, and hylemorphic features, such as the size, shape, and arrangement of scatterers in the PnC strongly changes the behavior of transient mechanical or acoustic waves through the crystal. Controlling any of the properties enables functional material systems that may behave as filters, 1 cloaks, 2 negative index lenses, 3 and negative mass density 4 amongst other unique behaviors. 5…”

Section: Introductionmentioning

confidence: 99%

Tunable Hybrid Phononic Crystal Lens Using Thermo-Acoustic Polymers

Walker¹,

Reyes-Contreras

Jin

et al. 2019

ACS Omega

View full text Add to dashboard Cite

Solid phononic crystal (PnC) lenses were made active on infiltration with thermosensitive polymers to produce a thermoactuated hybrid solid lens with variable focusing. Acoustic lenses, both solid state and PnCbased, are passive elements with a fixed focal length. Their focal characteristics are functions of the lens structure or the arrangement of the PnC unit cell. Dispersion effects, liquid-filled membranes, and phase delay in a multi-element emitter have been used for variable focusing. The high thermal, electric, and electromagnetic sensitivity of the elastic properties of poly(vinyl alcohol) (PVA) poly(N-isopropylacrylamide) (PNIPAm)-based hydrogels enable them to operate as tunable solids. However, these solids do not have strong enough contrast with water or well-controlled shape parameters to function as standalone lenses. Here, a tunable hybrid solid ultrasonic lens is realized by combining a PnC lens with PVA-PNIPAm thermoacoustic hydrogel to modify the transmission and dispersion properties of transient acoustic waves. Variable focusing is demonstrated from 40 to 50 mm using the anomalous thermosensitivity of the elasticity and speed of sound of the hydrogel.

show abstract