A thermoacoustic-Stirling heat engine: detailed study
26 May 2000-Journal of the Acoustical Society of America (Acoustical Society of America)-Vol. 107, Iss: 6, pp 3148-3166
TL;DR: 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.
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TL;DR: A review of the state of the art and on-going developments of these five kinds of cryocoolers can be found in this paper, where the general trend of new research on these three types is also presented.
Abstract: Cryocooler performance and reliability are continually improving. Consequently, they are more and more frequently implemented by physicists in their laboratory experiments or for commercial and space applications. The five kinds of cryocoolers most commonly used to provide cryogenic temperatures for various applications are the Joule-Thomson, Brayton, Stirling, Gifford-McMahon, and pulse tube cryocoolers. Many advances in all types have occurred in the past 20 years that have allowed all of them to be used for a wide variety of applications. The present state of the art and on-going developments of these cryocoolers are reviewed in this paper. In the past five years new research on these cryocoolers has offered the potential to significantly improve them and make them suitable for even more applications. The general trend of this new cryocooler research is also presented.
269 citations
01 Jan 2009
TL;DR: A review of the state of the art and on-going developments of these five kinds of cryocoolers can be found in this paper, where the general trend of new research on these three types is also presented.
Abstract: Cryocooler performance and reliability are continually improving. Consequently, they are more and more frequently implemented by physicists in their laboratory experiments or for commercial and space applications. The five kinds of cryocoolers most commonly used to provide cryogenic temperatures for various applications are the Joule-Thomson, Brayton, Stirling, Gifford-McMahon, and pulse tube cryocoolers. Many advances in all types have occurred in the past 20 years that have allowed all of them to be used for a wide variety of applications. The present state of the art and on-going developments of these cryocoolers are reviewed in this paper. In the past five years new research on these cryocoolers has offered the potential to significantly improve them and make them suitable for even more applications. The general trend of this new cryocooler research is also presented.
233 citations
TL;DR: The Los Alamos thermoacoustics code, available at www.lanl.gov/thermoACoustics/, has undergone extensive revision this year, and a Python-based graphical user interface wrapped around that core provides improved usability as discussed by the authors.
Abstract: The Los Alamos thermoacoustics code, available at www.lanl.gov/thermoacoustics/, has undergone extensive revision this year. New calculation features have been added to the original Fortran computational core, and a Python‐based graphical user interface wrapped around that core provides improved usability. A plotter routinely displays thermoacoustic wave properties as a function of x or tracks results when a user‐specified input variable, such as frequency or amplitude, is varied. The Windows‐like user interface provides mouse‐based control, scrolling, and simultaneous displays of plots and of several categories of numerical values, in which color indicates important features. Thermoacoustic phenomena can be calculated with superimposed steady flow, and time‐averaged pressure gradients are calculated. In thermoacoustic systems with toroidal topology, this allows modeling of steady flow caused by gas diodes (with or without time‐averaged heat transfer) and Gedeon streaming. Thermoacoustic mixture separation is included, also with superimposed steady flow. The volume integral of the complex gas momentum is available, so vibrations of thermoacoustic systems can be analyzed.
188 citations
Cites background or methods from "A thermoacoustic-Stirling heat engi..."
..., TASHE [40, 5]), we suppress Gedeon streaming, or account for it with nonzero _ N ....
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...In toroidal TASHEs [40, 5], we might include almost a dozen MINOR segments....
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...[5, 40], will be used to illustrate the use of DeltaEC to design a toroidal thermoacoustic apparatus without Gedeon streaming [41]....
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...7: Thermoacoustic-Stirling hybrid engine [5]....
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TL;DR: In this article, a review of the research development of Stirling cycle engines for recovering low and moderate temperature heat is presented, which includes four types of engines: kinetic, thermoacoustic, free-piston, and liquid piston types.
Abstract: A review is presented for the research development of Stirling cycle engines for recovering low and moderate temperature heat. The Stirling cycle engines are categorized into four types, including kinetic, thermoacoustic, free-piston, and liquid piston types. The working characteristics, features, technological details, and performances of the related Stirling cycle engines are summarized. Upon comparing the available experimental results and the technology potentials, the research directions and the possible applications of different Stirling cycle engines are further discussed and identified. It is concluded that kinetic Stirling engines and thermoacoustic engines have the greatest application prospect in low and moderate temperature heat recoveries in terms of output power scale, conversion efficiency, and costs. In particular, kinetic Stirling engines should be oriented toward two directions for practical applications, including providing low-cost solutions for low temperatures, and moderate efficient solutions with moderate costs for medium temperatures. Thermoacoustic engines for low temperature applications are especially attractive due to their low costs, high efficiencies, superior reliabilities, and simplicities over the other mechanical Stirling engines. This work indicates that a cost effective Stirling cycle engine is practical for recovering small-scale distributed low-grade thermal energy from various sources.
166 citations
TL;DR: In this article, the authors proposed a traveling-wave thermoacoustic electricity generator, which employs a looped-tube travelling-wave engine to convert thermal energy into acoustic power, an ultra-compliant alternator within the engine loop to extract and convert the engine acoustic power to electricity, and an acoustic stub matching technique to match the alternator to the engine.
158 citations
Cites background or methods from "A thermoacoustic-Stirling heat engi..."
...Swift [1] designed and tested a large scale standing-wave thermoacoustic engine, which uses 13.8 bar helium as the working gas and can deliver 630 W of acoustic power to the external acoustic load, converting the heat (thermal) energy into acoustic power at a thermal efficiency of 9%....
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...Much later, based on a compact acoustic network, Backhaus and Swift [3] proposed a new type of thermoacoustic engine which employs an inherently reversible Stirling cycle in the regenerator and utilised a high acoustic impedance to suppress the high acoustic loss....
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...Torus type travelling wave engines have high thermal efficiencies [3,9], and the generator based on this type of engine has shown a high generator efficiency [9]....
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...U1 leads p1 at the cold end and U1 lags p1 at the hot end [3])....
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...The regenerator has a cross sectional area A much larger than that of feedback pipe, in order to improve the generator performance by having |Z| qMa/A [3]....
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References
More filters
Book•
01 Jan 1950
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.
Abstract: Fundamentals of Vibration. Transverse Motion: The Vibrating String. Vibrations of Bars. The Two--Dimensional Wave Equation: Vibrations of Membranes and Plates. The Acoustic Wave Equation and Simple Solutions. Reflection and Transmission. Radiation and Reception of Acoustic Waves. Absorption and Attenuation of Sound. Cavities and Waveguides. Pipes, Resonators, and Filters. Noise, Signal Detection, Hearing, and Speech. Architectural Acoustics. Environmental Acoustics. Transduction. Underwater Acoustics. Selected Nonlinear Acoustic Effects. Shock Waves and Explosions. Appendices. Answers to Odd--Numbered Problems. Index.
4,047 citations
2,697 citations
Book•
01 Jan 1973
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.
Abstract: This introductory text emphasizes the physical concepts of fluid mechanics and methods of analysis, beginning from first principles. In helping readers develop a more orderly approach to problem solving, the book starts from basic equations, states all assumptions clearly, and relates results to expected physical behavior with the aid of 103 example problems. The third edition features the use of SI units in approximately 70% of the more than 1,100 problems, 500 of which are new.
2,344 citations
Book•
01 Jan 1986
TL;DR: In this paper, pertes de : charge, frottement, incompressible, ecoulement, interne reference record created on 2005-11-18, modified on 2016-08-08
Abstract: Keywords: pertes de : charge ; frottement ; ecoulement : incompressible ; ecoulement : interne Reference Record created on 2005-11-18, modified on 2016-08-08
1,253 citations
Proceedings Article•
01 Jan 1991TL;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.
Abstract: Thermoacoustic engines (TAEs) can be used to pump heat using a sound wave or pump a sound wave using a temperature gradient. The basic arrangement is a gas-filled acoustic resonator with appropriately positioned thermoacoustic elements. Two types of thermoacoustic elements are used in these engines: (1) heat exchangers used to communicate heat between the gas and external heat reservoirs; and (2) the TAE, also known as a stack. The TAEs are sections of porous media that support the temperature gradient, transport heat on the acoustic wave between the exchangers, and produce or absorb acoustic power. Previous results have been developed for TAEs with circular or parallel slit pore geometries. The theory is extended for gas-filled TAEs to include pores of arbitrary cross-sectional geometry. An approximate analysis of energy flow and acoustical measurements of a thermoacoustic prime mover are given. >
821 citations