Unsteady convective heat transfer in nanofluids at instantaneous transition to film boiling

Авраменко, А. А.; Shevchuk, Igor V.; Dmitrenko, N.P.; Moskalenko, A. A.; Logvinenko, P. N.

doi:10.1016/j.ijthermalsci.2021.106873

Cited by 16 publications

(2 citation statements)

References 28 publications

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“…However, macro-and micro-sized particles cause poor suspension stability in the mixture, can lead to major problems such as blockage of flow channels, wear of the heat transfer appliance and increase in pressure drop. Recently, with the development of technology, there has been an increased interest in using nano-sized solid particles into the main liquid to raise the heat transfer performance of suspensions (Sözen et al, 2019;Avramenko et al, 2020Avramenko et al, , 2021. The suspension of nanometer-sized particles (less than 100 nm) in the main liquid is called nanofluid.…”

Section: Concentric Heat Exchangermentioning

confidence: 99%

Numerical and experimental investigation for enhancing thermal performance of a concentric heat exchanger using different scenarios

Aytaç

Badali

Tuncer

2023

HFF

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Purpose Heat exchangers (HEs) which provide heat transfer and transfer energy through direct or indirect contact between fluids have an essential role in many processes as a part of various industries from pharmaceutical production to electronic devices. Using nanofluid as working fluid and integrating different types of turbulators could be used to upgrade the thermal effectiveness of HEs. Recently, to obtain more increment in thermal effectiveness, hybrid nanofluids are used that are prepared by mixing two or more various nanoparticles. The purpose of this experimental and numerical study is investigating different scenarios for improving the effectiveness of a concentric U-tube type HE. Design/methodology/approach In the numerical section of this study, different turbulator modifications, including circular and quarter circular rings, were modeled to determine the effect of adding turbulator on thermal performance. In addition, Al2O3/water and SiO2/water single and Al2O3–SiO2/water hybrid nanofluids were experimentally tested in an unmodified concentric U-tube HE in two different modes, including counter flow and parallel flow. Al2O3–SiO2/water hybrid nanofluid was prepared at 2% (wt./wt.) particle ratio and compared with Al2O3/water and SiO2/water single type nanofluids at same particle ratios and with distilled water. Findings Numerical modeling findings exhibited that integrating turbulators to the concentric tube type HE caused to raise in the effectiveness by improving heat transfer area. Also, experimental results indicated that using both hybrid and single type nanofluids notably upgraded the thermal performance of the concentric U-tube HE. Integrating turbulators cannot be an effective alternative in a concentric U-tube type HE with lower diameter because of raise in pressure drop. Numerically achieved findings exhibited that using quarter circular turbulators decreased pressure drop in comparison with circular turbulators. According to the experimental outcomes, using hybrid Al2O3–SiO2/water nanofluid leads to obtain more thermal performance in comparison with single type nanofluids. The highest increment in overall heat transfer coefficient of HE by using Al2O3–SiO2/water nanofluid achieved as 58.97% experimentally. Originality/value The overall outcomes of the current research exhibited the positive impacts of using hybrid nanofluid and integrating turbulators. In this empirical and numerical survey, numerical simulations were performed to specify the impact of applying different turbulators and hybrid nanofluid on the flow and thermal characteristics in a concentric U-tube HE. The achieved outcomes exhibited that using hybrid nanofluid can notably increase the thermal performance with negligible pressure drop in comparison with two different turbulator modifications.

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Section: Concentric Heat Exchangermentioning

confidence: 99%

Numerical and experimental investigation for enhancing thermal performance of a concentric heat exchanger using different scenarios

Aytaç

Badali

Tuncer

2023

HFF

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“…A description of the laboratory thermo-acoustic system for determining the cooling properties of quenching media is given in [13].…”

Section: Installation and Techniquementioning

confidence: 99%

Oligomer-containing Aqueous Quench Media Based on Polyethylene Glycol Esters of Oleic Acid

Petro¹,

Anatolii²,

Larisa³

et al. 2022

IJFMTS

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The results of studies of the cooling capacity, rheological and surface-active properties of aqueous solutions of oligomers: mono-and dipolyethylene glycol esters of oleic acid are presented. The availability of these oligomeric surfactants and the complex of their physicochemical properties make it possible to obtain, by varying the concentration of components, the compositions of hardening media (QM) with the required indicators. The process of cooling in oligomeric solutions depends on the concentration and stereochemistry of surfactant molecules. An increase in the content of oligomers is accompanied by a decrease in the rate and a shift in the maxima of the cooling rate curves towards low temperatures. As a result of comprehensive studies, a substantiated version of the heat transfer mechanism during cooling of a metal sample in aqueous micellar solutions of oligomeric surfactants was proposed. The stereochemistry of surfactant molecules, the shape of micelles, their strength, and ability to rearrange determine the complex mechanism of adsorption interaction with the metal surface, thus affecting the stages of shock boiling, vapor film, and nucleate boiling, and, ultimately, the intensity of heat transfer and the magnitude of the heat flux.

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Instantaneous Transition to Film Boiling in Ordinary Fluids and Nanofluids on a Vertical Surface

Авраменко

Shevchuk

2022

Mathematical Engineering

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Unsteady convective heat transfer in nanofluids at instantaneous transition to film boiling

Cited by 16 publications

References 28 publications

Numerical and experimental investigation for enhancing thermal performance of a concentric heat exchanger using different scenarios

Numerical and experimental investigation for enhancing thermal performance of a concentric heat exchanger using different scenarios

Oligomer-containing Aqueous Quench Media Based on Polyethylene Glycol Esters of Oleic Acid

Instantaneous Transition to Film Boiling in Ordinary Fluids and Nanofluids on a Vertical Surface

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