Journal ArticleDOI
A thermoacoustic-Stirling heat engine: detailed study
Scott Backhaus,Gregory W. Swift +1 more
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A new type of thermoacoustic engine based on traveling waves and ideally reversible heat transfer is described and data are presented which show the nearly complete elimination of the streaming convective heat loads.Abstract:
A new type of thermoacoustic engine based on traveling waves and ideally reversible heat transfer is described. Measurements and analysis of its performance are presented. This new engine outperforms previous thermoacoustic engines, which are based on standing waves and intrinsically irreversible heat transfer, by more than 50%. At its most efficient operating point, it delivers 710 W of acoustic power to its resonator with a thermal efficiency of 0.30, corresponding to 41% of the Carnot efficiency. At its most powerful operating point, it delivers 890 W to its resonator with a thermal efficiency of 0.22. The efficiency of this engine can be degraded by two types of acoustic streaming. These are suppressed by appropriate tapering of crucial surfaces in the engine and by using additional nonlinearity to induce an opposing time-averaged pressure difference. Data are presented which show the nearly complete elimination of the streaming convective heat loads. Analysis of these and other irreversibilities show which components of the engine require further research to achieve higher efficiency. Additionally, these data show that the dynamics and acoustic power flows are well understood, but the details of the streaming suppression and associated heat convection are only qualitatively understood.read more
Citations
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Journal ArticleDOI
Optimization of thermoacoustic refrigerators using second law analysis
TL;DR: In this article, a simplified two-dimensional computational method for studying the entropy generation characteristics inside the core porous structures of a thermoacoustic refrigerator is presented, where the model integrates the equations of the standard linear thermo-acoustic theory into an energy balance-based numerical calculus scheme.
Journal ArticleDOI
Lattice Boltzmann simulations of attenuation-driven acoustic streaming
David Haydock,Julia M. Yeomans +1 more
TL;DR: In this article, lattice Boltzmann simulations are used to model the attenuation-driven acoustic streaming produced by a travelling wave and the streaming pattern produced by an imposed body force approximating the Reynolds stresses.
Journal ArticleDOI
A method of characterising performance of audio loudspeakers for linear alternator applications in low-cost thermoacoustic electricity generators
TL;DR: In this paper, the feasibility of using commercially available loudspeakers as low-cost linear alternators for thermo-acoustic applications, to convert acoustic power to electricity, is investigated, in which a high intensity acoustic wave is induced by using a high power woofer, while a pair of microphones and a laser displacement sensor are used to enable acoustic power measurements.
Journal ArticleDOI
Working-fluid selection and performance investigation of a two-phase single-reciprocating-piston heat-conversion engine
Oyeniyi A. Oyewunmi,Christoph J.W. Kirmse,Andrew J. Haslam,Erich A. Müller,Christos N. Markides +4 more
TL;DR: In this article, the Up-THERM heat converter, a two-phase unsteady heat engine that belongs to a class of innovative devices known as thermofluidic oscillators, was investigated with respect to working-fluid selection for its prospective applications.
Journal ArticleDOI
Stationary velocity and pressure gradients in a thermoacoustic stack.
TL;DR: The second-order time-averaged acoustics of a viscous, thermally conducting gas between closely spaced parallel plates is studied by expanding the equations of fluid dynamics and heat transfer to second order in Mach number.
References
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Book
Fundamentals of acoustics
TL;DR: In this article, the authors present a two-dimensional wave equation and simple solutions for the wave equation with respect to the two dimensions of the wave and the two types of vibrations.
Book
Introduction to Fluid Mechanics
Robert W. Fox,Alan T McDonald +1 more
TL;DR: In this article, the physical concepts of fluid mechanics and methods of analysis, beginning from first principles, are discussed, and a more orderly approach to problem solving is presented, starting from basic equations, states all assumptions clearly, and relates results to expected physical behavior with the aid of 103 example problems.
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Handbook of hydraulic resistance
TL;DR: In this paper, pertes de : charge, frottement, incompressible, ecoulement, interne reference record created on 2005-11-18, modified on 2016-08-08
Proceedings Article
Thermoacoustic engines
W. P. Arnott,R. Raspet,H.E. Bass +2 more
TL;DR: In this paper, an approximate analysis of energy flow and acoustical measurements of a thermoacoustic prime mover with arbitrary cross-sectional geometry is given. But this analysis is restricted to the case of TAEs with circular or parallel slit pore geometry.