Effect of inclination angle on the thermal-hydraulic characteristics and entropy generation of Al2O3–water nanofluid for in-tube turbulent flow

IF 1.4 Q2 ENGINEERING, MULTIDISCIPLINARY

World Journal of Engineering Pub Date : 2023-04-04 DOI:10.1108/wje-12-2022-0487

Chinedu Chinakwe, A. Adelaja, Michael O. Akinseloyin, O. T. Olakoyejo

{"title":"Effect of inclination angle on the thermal-hydraulic characteristics and entropy generation of Al2O3–water nanofluid for in-tube turbulent flow","authors":"Chinedu Chinakwe, A. Adelaja, Michael O. Akinseloyin, O. T. Olakoyejo","doi":"10.1108/wje-12-2022-0487","DOIUrl":null,"url":null,"abstract":"\nPurpose\nInclination angle has been reported to have an enhancing effect on the thermal-hydraulic characteristics and entropy of some thermal systems. Therefore, this paper aims to numerically investigate the effects of inclination angle, volume concentration and Reynolds number on the thermal and hydraulic characteristics and entropy generation rates of water-based Al2O3 nanofluids through a smooth circular aluminum pipe in a turbulent flow.\n\n\nDesign/methodology/approach\nA constant heat flux of 2,000 Watts is applied to the circular surface of the tube. Reynolds number is varied between 4,000 and 20,000 for different volume concentrations of alumina nanoparticles of 0.5%, 1.0% and 2.0% for tube inclination angles of ±90o, ±60o, ±45o, ±30o and 0o, respectively. The simulation is performed in an ANSYS Fluent environment using the realizable kinetic energy–epsilon turbulent model.\n\n\nFindings\nResults show that +45o tube orientation possesses the largest thermal deviations of 0.006% for 0.5% and 1.0% vol. concentrations for Reynolds numbers 4,000 and 12,000. −45o gives a maximum pressure deviation of −0.06% for the same condition. The heat transfer coefficient and pressure drop give maximum deviations of −0.35% and −0.39%, respectively, for 2.0% vol. concentration for Reynolds number of 20,000 and angle ±90o. A 95%–99.8% and 95%–98% increase in the heat transfer and total entropy generation rates, respectively, is observed for 2.0% volume concentration as tube orientation changes from the horizontal position upward or downward.\n\n\nOriginality/value\nResearch investigating the effect of inclination angle on thermal-hydraulic performance and entropy generation rates in-tube turbulent flow of nanofluid is very scarce in the literature.\n","PeriodicalId":23852,"journal":{"name":"World Journal of Engineering","volume":" ","pages":""},"PeriodicalIF":1.4000,"publicationDate":"2023-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"World Journal of Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1108/wje-12-2022-0487","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MULTIDISCIPLINARY","Score":null,"Total":0}

引用次数: 1

Abstract

Purpose Inclination angle has been reported to have an enhancing effect on the thermal-hydraulic characteristics and entropy of some thermal systems. Therefore, this paper aims to numerically investigate the effects of inclination angle, volume concentration and Reynolds number on the thermal and hydraulic characteristics and entropy generation rates of water-based Al2O3 nanofluids through a smooth circular aluminum pipe in a turbulent flow. Design/methodology/approach A constant heat flux of 2,000 Watts is applied to the circular surface of the tube. Reynolds number is varied between 4,000 and 20,000 for different volume concentrations of alumina nanoparticles of 0.5%, 1.0% and 2.0% for tube inclination angles of ±90o, ±60o, ±45o, ±30o and 0o, respectively. The simulation is performed in an ANSYS Fluent environment using the realizable kinetic energy–epsilon turbulent model. Findings Results show that +45o tube orientation possesses the largest thermal deviations of 0.006% for 0.5% and 1.0% vol. concentrations for Reynolds numbers 4,000 and 12,000. −45o gives a maximum pressure deviation of −0.06% for the same condition. The heat transfer coefficient and pressure drop give maximum deviations of −0.35% and −0.39%, respectively, for 2.0% vol. concentration for Reynolds number of 20,000 and angle ±90o. A 95%–99.8% and 95%–98% increase in the heat transfer and total entropy generation rates, respectively, is observed for 2.0% volume concentration as tube orientation changes from the horizontal position upward or downward. Originality/value Research investigating the effect of inclination angle on thermal-hydraulic performance and entropy generation rates in-tube turbulent flow of nanofluid is very scarce in the literature.

查看原文本刊更多论文

倾斜角度对管内湍流Al2O3-水纳米流体热工水力学特性和熵产生的影响

目的研究了倾角对某些热系统的热液特性和熵的增强作用。因此，本文旨在数值研究倾角、体积浓度和雷诺数对水基Al2O3纳米流体在湍流中通过光滑圆形铝管的热水力特性和熵产率的影响。设计/方法/方法在管的圆形表面施加2000瓦的恒定热流。当氧化铝纳米颗粒体积浓度分别为0.5%、1.0%和2.0%，管倾角分别为±90度、±600度、±45度、±300度和00度时，雷诺数在4000 ~ 20000之间变化。利用可实现的动能- epsilon湍流模型在ANSYS Fluent环境下进行了仿真。结果表明，当雷诺数为4,000和12,000时，当体积浓度为0.5%和1.0%时，+45°管取向的热偏差最大，分别为0.006%。在相同条件下，- 45°的最大压力偏差为- 0.06%。当雷诺数为20,000，雷诺数为±90时，体积浓度为2.0%时，传热系数和压降的最大偏差分别为- 0.35%和- 0.39%。当体积浓度为2.0%时，当管道方向由水平方向向上或向下变化时，换热率和总熵产率分别增加95% ~ 99.8%和95% ~ 98%。原创/价值研究倾角对纳米流体管内湍流热水力性能和熵产率影响的文献很少。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

World Journal of Engineering ENGINEERING, MULTIDISCIPLINARY-

CiteScore

4.20

自引率

10.50%

发文量

期刊介绍： The main focus of the World Journal of Engineering (WJE) is on, but not limited to; Civil Engineering, Material and Mechanical Engineering, Electrical and Electronic Engineering, Geotechnical and Mining Engineering, Nanoengineering and Nanoscience The journal bridges the gap between materials science and materials engineering, and between nano-engineering and nano-science. A distinguished editorial board assists the Editor-in-Chief, Professor Sun. All papers undergo a double-blind peer review process. For a full list of the journal''s esteemed review board, please see below.