Computational Fluid Dynamics Simulation of a Thermoacoustic Refrigerator

El-Rahman, Ahmed I. Abd; Abdel‐Rahman, Ehab

doi:10.2514/1.t4150

Cited by 18 publications

(6 citation statements)

References 17 publications

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“…The simplest is a harmonic pressure or velocity boundary condition [96,98]. Another method, more expensive in terms of computational costs, is the use of a dynamic mesh with a prescribed reciprocating velocity to simulate the membrane displacement of a speaker or a piston [99]. Namdar et al [100] highlighted that, for a specific hot-cold temperature difference, the right choice of the drive ratio as input is needed to allow the HXs to work correctly according to their thermodynamic role and therefore guarantee a positive coefficient of performance (COP).…”

Section: Single Tacmentioning

confidence: 99%

CFD Modeling of Thermoacoustic Energy Conversion: A Review

Meglio

Massarotti

2022

Energies

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In this article, a comprehensive review of the computational fluid dynamics (CFD)-based modeling approach for thermoacoustic energy conversion devices is proposed. Although thermoacoustic phenomena were discovered two centuries ago, only in recent decades have such thermoacoustic devices been spreading for energy conversion. The limited understanding of thermoacoustic nonlinearities is one of the reasons limiting their diffusion. CFD is a powerful tool that allows taking into consideration all the nonlinear phenomena neglected by linear theory, on which standard designs are based, to develop energy devices that are increasingly efficient. Starting from a description of all possible numerical models to highlight the difference from a full CFD method, the nonlinearities (dynamic, fluid dynamic and acoustic) are discussed from a physical and modeling point of view. The articles found in the literature were analyzed according to their setup, with either a single thermoacoustic core (TAC) or a full device. With regard to the full devices, a further distinction was made between those models solved at the microscopic scale and those involving a macroscopic porous media approach to model the thermoacoustic core. This review shows that there is no nonlinear porous media model that can be applied to the stack, regenerator and heat exchangers of all thermoacoustic devices in oscillating flows for each frequency, and that the eventual choice of turbulence model requires further studies.

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Section: Single Tacmentioning

confidence: 99%

CFD Modeling of Thermoacoustic Energy Conversion: A Review

Meglio

Massarotti

2022

Energies

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“…1. The two-dimensional model inspired by El-Rahman and Abdel-Rahman [24] is used in this study to save computing costs associated with three-dimensional simulation. Fig.…”

Section: Device Descriptionmentioning

confidence: 99%

Numerical study on a thermoacoustic refrigerator with continuous and staggered arrangements

Liu

2022

THERM SCI

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Thermoacoustic devices require heat exchangers with oscillating flow, but there is currently no viable design approach for them. A heat exchanger with a staggered structure can efficiently improve the velocity disturbance and promote heat transfer in steady flow. The flow and heat transfer characteristics of a standing-wave thermoacoustic refrigerator and an ambient heat exchanger with staggered parallel plates under the oscillating flow condition are investigated in this study, primarily focusing on the geometric influences and differences between staggered and non-staggered (continuous) arrangements. Computational fluid dynamics simulation is a mainstream tool for the numerical simulation of complex thermoacoustic phenomena. The flow field around the stack and heat exchanger plate is simulated by introducing the dynamic mesh boundary conditions. Through numerical simulation, the flow field characteristics of nonlinear vortices generation around the heat exchanger are presented. By changing the staggered column number in the ambient heat exchanger, it is observed that the larger the column number of staggered parallel plates, the more significant the refrigeration effect through the thermoacoustic effect.

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“…Equation 30is adequate for most purposes, but a number of investigators are now using CFD to examine the thermoacoustic characteristics of stacks without any explicit boundary layer approximation. 79 Again in the limit of diameters of channels much larger than the penetration depth, and for a short stack (Áx in length) subjected to a standing-wave in an inviscid gas, Swift 77 has shown that…”

Section: Heat Transfer In Regenerators and Stacksmentioning

confidence: 99%

Common features in the thermoacoustics of flames and engines

Lawn

Pénelet

2017

International Journal of Spray and Combustion Dynamics

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Thermoacoustic phenomena generated inadvertently during combustion, and those produced by heating and cooling material to generate a temperature gradient, have mostly been studied independently. Indeed, researchers of one phenomenon are seldom familiar with the literature on the other. This paper seeks to remedy this by reviewing the two subjects alongside one another, by comparing and contrasting them where possible. There is a brief account of the historically important papers in the development of both subjects, followed by a description of the nature of the phenomena. A selective number of papers is called upon to illustrate these principles. Techniques for handling the pure acoustics in the two subjects are addressed, before an outline is given of the modelling of the two thermoacoustic systems. Non-linear phenomena in the two systems are then explored. Finally, methods of 'control', of changing the system characteristics, are briefly discussed.

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Computational Fluid Dynamics Simulation of a Thermoacoustic Refrigerator

Cited by 18 publications

References 17 publications

CFD Modeling of Thermoacoustic Energy Conversion: A Review

CFD Modeling of Thermoacoustic Energy Conversion: A Review

Numerical study on a thermoacoustic refrigerator with continuous and staggered arrangements

Common features in the thermoacoustics of flames and engines

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