{"title":"Natural Convection Immersion Cooling of the Cylinders in Nanofluids: Developing a New Nusselt Number Correlation","authors":"","doi":"10.1007/s40997-024-00759-w","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <p>This study focuses on exploring the natural convection heat transfer within water-alumina nanofluids and its practical applications in immersion cooling. The aim is to improve the efficiency of this cooling method by utilizing fluids with improved thermal properties. The selected geometry is a vertical cylinder, which is of great significance in engineering applications and academic research. The used nanofluid consists of <span> <span>\\({{\\text{Al}}}_{2}{{\\text{O}}}_{3}-{\\text{water}}\\)</span> </span> nanofluid, with varying volume fractions (0.1, 0.2, and 0.5%). Experimental assessments were carried out using a steady-state methodology. Numerical simulations employ the single-phase and two-phase mixture approaches. The results of this research reveal the impressive accuracy of the mixture method in simulating external natural convection when compared to concurrently obtained experimental data. Furthermore, in the present paper, the single-phase method has yielded results deemed acceptable and closely aligned with the outcomes from the two-phase method. This alignment was achieved through the utilization of appropriate relationships, ensuring the accurate estimation of thermophysical properties. Notably, it becomes evident that established correlations for the Nusselt number correlation of natural convection designed for conventional fluids and the mere incorporation of the thermophysical properties of nanofluids are insufficient for the accurate prediction of the Nusselt number for nanofluids. In response to this challenge, a novel Nusselt correlation is introduced, comprehensively considering the thermophysical properties of <span> <span>\\({{\\text{Al}}}_{2}{{\\text{O}}}_{3}-{\\text{water}}\\)</span> </span> nanofluids, nanoparticle transport mechanisms, geometric attributes of the studied object, and nanoparticle volume fraction. Comparative assessments with previous correlations emphasize the enhanced predictive accuracy of the proposed innovative correlation.</p>","PeriodicalId":49063,"journal":{"name":"Iranian Journal of Science and Technology-Transactions of Mechanical Engineering","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Iranian Journal of Science and Technology-Transactions of Mechanical Engineering","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1007/s40997-024-00759-w","RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
引用次数: 0
Abstract
This study focuses on exploring the natural convection heat transfer within water-alumina nanofluids and its practical applications in immersion cooling. The aim is to improve the efficiency of this cooling method by utilizing fluids with improved thermal properties. The selected geometry is a vertical cylinder, which is of great significance in engineering applications and academic research. The used nanofluid consists of \({{\text{Al}}}_{2}{{\text{O}}}_{3}-{\text{water}}\) nanofluid, with varying volume fractions (0.1, 0.2, and 0.5%). Experimental assessments were carried out using a steady-state methodology. Numerical simulations employ the single-phase and two-phase mixture approaches. The results of this research reveal the impressive accuracy of the mixture method in simulating external natural convection when compared to concurrently obtained experimental data. Furthermore, in the present paper, the single-phase method has yielded results deemed acceptable and closely aligned with the outcomes from the two-phase method. This alignment was achieved through the utilization of appropriate relationships, ensuring the accurate estimation of thermophysical properties. Notably, it becomes evident that established correlations for the Nusselt number correlation of natural convection designed for conventional fluids and the mere incorporation of the thermophysical properties of nanofluids are insufficient for the accurate prediction of the Nusselt number for nanofluids. In response to this challenge, a novel Nusselt correlation is introduced, comprehensively considering the thermophysical properties of \({{\text{Al}}}_{2}{{\text{O}}}_{3}-{\text{water}}\) nanofluids, nanoparticle transport mechanisms, geometric attributes of the studied object, and nanoparticle volume fraction. Comparative assessments with previous correlations emphasize the enhanced predictive accuracy of the proposed innovative correlation.
期刊介绍:
Transactions of Mechanical Engineering is to foster the growth of scientific research in all branches of mechanical engineering and its related grounds and to provide a medium by means of which the fruits of these researches may be brought to the attentionof the world’s scientific communities. The journal has the focus on the frontier topics in the theoretical, mathematical, numerical, experimental and scientific developments in mechanical engineering as well
as applications of established techniques to new domains in various mechanical engineering disciplines such as: Solid Mechanics, Kinematics, Dynamics Vibration and Control, Fluids Mechanics, Thermodynamics and Heat Transfer, Energy and Environment, Computational Mechanics, Bio Micro and Nano Mechanics and Design and Materials Engineering & Manufacturing.
The editors will welcome papers from all professors and researchers from universities, research centers,
organizations, companies and industries from all over the world in the hope that this will advance the scientific standards of the journal and provide a channel of communication between Iranian Scholars and their colleague in other parts of the world.