Related papers: Low frequency sound attenuation in a flow duct usi…
An experimental investigation of the acoustical behaviour of a liner in a rectangu- lar channel with grazing flow has been conducted. The liner consists of a ceramic structure of parallel square channels: 1mm by 1 mm in cross section, 65 mm…
Underwater noise pollution caused by anthropogenic activities, such as offshore wind farms, significantly affects marine life, hindering the intra- and inter-specific interactions of many aquatic species. A common strategy to mitigate these…
Viscous dissipation causes significant energy losses in fluid flows; in ducts, laminar flows provide the minimum resistance to the motion, whereas turbulent currents substantially increase the friction at the wall and the energy requirement…
We investigate the influence of realistic sheared grazing flow on acoustic propagation in three-dimensional rectangular ducts. We show that conclusions reached in the literature about the effects of sheared grazing flow on acoustic…
This paper presents a straightforward application of an indirect method based on a three-microphone impedance tube setup to determine the non-acoustic properties of a sound absorbing porous material. First, a three-microphone impedance tube…
Telegraphic noise is one of the most significant problems that arises when making sensitive measurements with lateral electrostatic devices. In this paper we demonstrate that a wafer which had only produced devices with significant…
A modelling of low-frequency sound propagation in slowly varying ducts with smoothly varying lining is proposed leading to an acoustic mild-slope equation analogue to the with mild-slope equation for water waves. This simple 1D Mild Slope…
Sound attenuation and internal friction coefficients are calculated for a realistic model of amorphous silicon. It is found that, contrary to previous views, thermal vibrations can induce sound attenuation at ultrasonic and hypersonic…
Decorated membrane, comprising a thin layer of elastic film with small rigid platelets fixed on top, has been found to be an efficient absorber of low frequency sound. In this work we consider the problem of sound absorption from a…
We predict an existence of an new dissipation channel leading to attenuation of ultrasound in disordered conductors and superconductors with perfect electroneutrality. It is due to slow diffusion of thermal energy. We show that in doped…
A formula for the local acoustical admittance in a conical waveguide with viscous and thermal losses given by Nederveen [(1969) Acoustical Aspects of Woodwind Instruments (Frits Knuf, Amsterdam)] is rewritten as an impedance transmission…
Conventional sound shielding structures typically prevent fluid transport between the exterior and interior. A design of a two-dimensional acoustic metacage with subwavelength thickness which can shield acoustic waves from all directions…
Sound absorption is an important technological task in machine-building and civil engineering. Porous materials are traditionally used for these purposes, as they are neither ignitable nor hygroscopic and thus suitable for noise oppression,…
The unique conduction properties of condensed matter systems with topological order have recently inspired a quest for similar effects in classical wave phenomena. Acoustic topological insulators, in particular, hold the promise to…
The problem of noise control and attenuation is of interest in a broad range of applications, especially in the low-frequency range, below 1000 Hz. Acoustic metamaterials allow us to tackle this problem with solutions that do not…
Understanding thermal transport in silicon nanostructures is crucial for effective thermal management in semiconductor devices. In such nanostructures, boundary scattering can significantly reduce thermal conductivity. Diffusive boundary…
Sound waves are attenuated as they propagate in amorphous materials. We investigate the mechanism driving sound attenuation in the Rayleigh scattering regime by resolving the dynamics of an excited phonon in time and space via numerical…
We propose and demonstrate a system that produces squeezed vacuum using a pair of optical parametric amplifiers. This scheme allows the production of phase sidebands on the squeezed vacuum which facilitate phase locking in downstream…
We investigate the low loss acoustic motion of superfluid $^4$He parametrically coupled to a very low loss, superconducting Nb, TE$_{011}$ microwave resonator, forming a gram-scale, sideband resolved, optomechanical system. We demonstrate…
Sound attenuation in low temperature amorphous solids originates from their disordered structure. However, its detailed mechanism is still being debated. Here we analyze sound attenuation starting directly from the microscopic equations of…