Optimal shaping of acoustic resonators for the generation of high-amplitude standing waves

2014 ◽  
Vol 136 (3) ◽  
pp. 1003-1012 ◽  
Author(s):  
Milan Červenka ◽  
Martin Šoltés ◽  
Michal Bednařík
Keyword(s):  
Standing Waves ◽  
High Amplitude ◽  
Acoustic Resonators

Un-Shocked High Amplitude Standing Waves in Wave-Shaped Resonators

2012 ◽  
Author(s):  
Dion Savio Antao ◽  
Bakhtier Farouk
Keyword(s):  
Numerical Study ◽  
Fluid Dynamic ◽  
Ambient Pressure ◽  
Standing Waves ◽  
High Amplitude ◽  
Prime Mover ◽  
Non Linear ◽  
Resonator System ◽  
Cylindrical Resonators ◽  
Linear Nature

A numerical study of non-linear, high amplitude standing waves in non-cylindrical circular resonators is reported here. These waves are shock-less and can generate peak acoustic overpressures that can exceed the ambient pressure by three/four times its nominal value. A high fidelity compressible computational fluid dynamic model is used to simulate the phenomena in cylindrical and arbitrarily shaped axisymmetric resonators. A right circular cylinder and frustum of cone are the two geometries studied. The model is validated using past numerical and experimental results of standing waves in cylindrical resonators. The non-linear nature of the harmonic response of the frustum of cone resonator system is investigated for two different working fluids (carbon dioxide and argon) operating at various values of piston amplitude. The high amplitude non-linear oscillations demonstrated can be used as a prime mover in a variety of applications including thermoacoustic cryocooling.

Acoustic energy harvesting from vortex-induced tonal sound in a baffled pipe

2011 ◽  
Vol 225 (8) ◽  
pp. 1847-1850 ◽  
Author(s):  
R Hernandez ◽  
S Jung ◽  
K I Matveev
Keyword(s):  
Acoustic Pressure ◽  
Electrical Energy ◽  
High Amplitude ◽  
Acoustic Mode ◽  
Acoustic Energy ◽  
Electric Load ◽  
Mean Flow ◽  
Acoustic Resonators ◽  
Acoustic Energy Harvesting ◽  
Mean Flow Velocity

Energy of high-amplitude sound that often appears in acoustic resonators with mean flow can be harnessed and converted into electricity for powering sensors and other devices. In this study, tests were conducted in a simple setup consisting of a pipe with a pair of baffles and a piezoelement. Tonal sound, corresponding to the second acoustic mode of the resonator, was excited due to vortex shedding/impinging on baffles in the presence of mean flow. Generated sound energy was partially converted into electrical energy by a piezoelement. About 0.55 mW of electric power was produced on a resistive electric load at acoustic pressure amplitudes in the pipe about 170 Pa and mean flow velocity 2.6 m/s.

scholarly journals Temperature Effects in Acoustic Resonators

10.14311/364 ◽  
2002 ◽  
Vol 42 (4) ◽  
Author(s):  
M. Červenka ◽  
M. Bednařík ◽  
P. Koníček
Keyword(s):  
Temperature Effects ◽  
Standing Waves ◽  
Acoustic Resonators ◽  
Mean Temperature ◽  
Nonlinear Standing Waves

This paper deals with problems of nonlinear standing waves in axisymetrically shaped acoustic resonators where a mean temperature is distributed along the axis.

Introduction to Acoustic Compressors

2000 ◽  
Author(s):  
Bart Lipkens ◽  
Fred Lalande ◽  
David Perkins
Keyword(s):  
Fluid Dynamic ◽  
New Technology ◽  
Acoustic Resonance ◽  
High Amplitude ◽  
Transfer Energy ◽  
Acoustic Resonators ◽  
Variable Reluctance ◽  
Low Profile ◽  
Variable Capacity ◽  
Spot Cooling

Abstract The emergence of acoustic compressors has been made possible by the development of a new technology called Resonant MacroSonic Synthesis (RMS). RMS allows the creation of macrosonic standing waves in acoustic resonators. The shape of the resonator controls the nonlinear fluid dynamic processes by which energy is transferred to higher harmonics. Through this process resonators have been designed that allow high-amplitude shock-free waveforms. A variable reluctance driver is used to transfer energy into the resonator. The entire resonator is oscillated along its axis at the fundamental acoustic resonance frequency. This process is called entire resonator drive. The valve technology used in these compressors is similar to that of conventional reciprocating compressors. Acoustic compressors are inherently variable capacity and oil-free. Other unique characteristics are flexible orientation and low profile packaging option. Development focuses on vapor-compression applications. The application discussed here is spot-cooling.

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