Experimental and Numerical Investigations of Thermal Characteristics of Heat Exchangers in Oscillatory Flow

Olusegun M. Ilori, Artur J. Jaworski, Xiaoan Mao

Research output: Contribution to journalArticle

Abstract

Heat exchangers under oscillatory flow conditions constitute a critical component of thermoacoustic engines and coolers for which effective design methodologies are not yet available. In this study, the thermal and pressure drop performance of compact Tube Heat Exchanger (T-HEX) under oscillatory flow conditions is investigated using experimental and numerical methods. A standing wave experimental set-up, driven by the Q-drive linear alternator, and a measurement technique were developed to measure the temperature and acoustic pressure near the T-HEX simultaneously. The symmetric arrangement of three identical heat exchangers, one ‘hot’ heat exchanger, centrally placed between two ‘cold’ heat exchangers, is employed for an improved thermal analysis. Furthermore, aerodynamic shape is used on the heat exchangers gas channels to improve flow conditions associated with a sudden change in the cross-section. Experimental results are found to agree well with the predictions from three-dimensional Computational Fluid Dynamics (CFD) models. The Nusselt number and pressure drop due to minor losses show dependency on the drive ratio (measured maximum oscillating pressure to the system mean pressure), the edge shape and hot heat exchanger temperature. At a high amplitude, the edge shape significantly minimises the minor loss pressure difference, with negligible effect on the thermal performance. The results reported in this study will benefit the development of compact heat exchangers for the thermoacoustic engines/refrigerators or Sterling engines/coolers in cryogenic applications.

LanguageEnglish
Pages910–925
Number of pages16
JournalApplied Thermal Engineering
Volume144
Early online date17 Jul 2018
DOIs
Publication statusPublished - 5 Nov 2018

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Heat exchangers
Thermoacoustic engines
Tubes (components)
Pressure drop
Refrigerators
Nusselt number
Hot Temperature
Cryogenics
Thermoanalysis
Dynamic models
Numerical methods
Aerodynamics
Computational fluid dynamics
Acoustics
Engines
Temperature
Gases

Cite this

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title = "Experimental and Numerical Investigations of Thermal Characteristics of Heat Exchangers in Oscillatory Flow",
abstract = "Heat exchangers under oscillatory flow conditions constitute a critical component of thermoacoustic engines and coolers for which effective design methodologies are not yet available. In this study, the thermal and pressure drop performance of compact Tube Heat Exchanger (T-HEX) under oscillatory flow conditions is investigated using experimental and numerical methods. A standing wave experimental set-up, driven by the Q-drive linear alternator, and a measurement technique were developed to measure the temperature and acoustic pressure near the T-HEX simultaneously. The symmetric arrangement of three identical heat exchangers, one ‘hot’ heat exchanger, centrally placed between two ‘cold’ heat exchangers, is employed for an improved thermal analysis. Furthermore, aerodynamic shape is used on the heat exchangers gas channels to improve flow conditions associated with a sudden change in the cross-section. Experimental results are found to agree well with the predictions from three-dimensional Computational Fluid Dynamics (CFD) models. The Nusselt number and pressure drop due to minor losses show dependency on the drive ratio (measured maximum oscillating pressure to the system mean pressure), the edge shape and hot heat exchanger temperature. At a high amplitude, the edge shape significantly minimises the minor loss pressure difference, with negligible effect on the thermal performance. The results reported in this study will benefit the development of compact heat exchangers for the thermoacoustic engines/refrigerators or Sterling engines/coolers in cryogenic applications.",
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Experimental and Numerical Investigations of Thermal Characteristics of Heat Exchangers in Oscillatory Flow. / Ilori, Olusegun M.; Jaworski, Artur J.; Mao, Xiaoan.

In: Applied Thermal Engineering, Vol. 144, 05.11.2018, p. 910–925.

Research output: Contribution to journalArticle

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