This work proposes an experimental method for direct measurement of transfer functions of acoustic tubes. The method obtains a pressure-to-velocity transfer function from measurement of input volume velocity and output pressures of a target tube. Steady sinusoidal waves from 100 Hz to 5 kHz with a 10-Hz increment were used as a source signal. Experimental results compared with transmission line...

Algebraic expressions are given (in FORT•aAN format for convenient use) that accurately approximate the value of the per unit-length acoustic impedance of small tubes (radii less than • acoustic wavelength) including isothermal nd viscous effects. Their accuracy of typically 3% or better was obtained as a result of adding a shunt conductance t rm to the traditional approximations and including ...

Active boundary surfaces intended to control reverberation or other characteristics of enclosed sound fields have often been investigated using plane wave tubes. This paper presents an analysis of actively terminated semi-infinite and finite-length plane wave tubes to provide needed clarification of the effects of these surfaces. By considering relationships between complex pressure-amplitude r...

Abstract Among the acoustic metasurfaces that can control propagation of sound waves with structure far thinner than wavelength at operating frequency, split tube has shown its effectiveness in lower frequency band. Here we focus on multiply layered tubes to broaden absorption spectrum. By numerical analysis, show up-to six-layer possessing wideband (1–1000 Hz) absorption. The absorbing peaks b...

• Capillary tubes & SAW devices used to pattern particles in no-flow flowing setups Rectangular tube: particle lines are parallel tube sidewalls for all directions Circular alignment depends on their position along the height Bottom/mid height: parallel/perpendicular direction Continues flow: always flow Acoustofluidic platforms have great potentials integrate capillary controlling and manipula...

The dynamical response of magnetic flux tubes due to local transverse periodic perturbations is investigated by numericalmeans.Our aimwas to check the applicability of the thin flux tube approximation for vertically oriented flux tubes with moderate magnetic field strength (plasma β = 1) and diameters 100 km, 50 km and 25 km immersed in an otherwise homogeneous nonmagnetic environment. All tube...

This paper did a radial compression fatigue test on glass fiber winding composite tubes, collects acoustic emission signals on different fatigue damages stages, used time frequency analysis techniques of modern wavelet transform, and analyzed the wave form and frequency characteristics of fatigue damaged acoustic emission signals. Three main frequency bands of acoustic emission signal had been ...

A novel linear reservoir-vascular tubes network is presented in this work and the design efficacy explored by testing concrete beams loaded on bending assessing their damage healing mechanical recovery. The system composed of additively manufactured polymer components that appear equally effective compared to conventional ceramic since 3D printed polymer-tubes instantly break upon cracking. It ...