Asymmetrical non-uniform heat flux distributions for laminar flow heat transfer with mixed convection in a horizontal circular tube

dc.contributor.authorOkafor, Izuchukwu F.
dc.contributor.authorDirker, Jaco
dc.contributor.authorMeyer, Josua P.
dc.contributor.emailjaco.dirker@up.ac.zaen_ZA
dc.date.accessioned2018-02-06T04:46:09Z
dc.date.issued2019
dc.description.abstractNon-symmetric heat flux distributions in terms of gravity in solar collector tubes influence buoyancy-driven secondary flow which has an impact on the associated heat transfer and pressure drop performance. In this study the influence of the asymmetry angle (0°, 20°, 30° and 40°) with regard to gravity for non-uniform heat flux boundaries in a horizontal circular tube was investigated numerically. A stainless steel tube with an inner diameter of 62.68 mm, a wall thickness of 5.16 mm, and a length of 10 m was considered for water inlet temperatures ranging from 290 K to 360 K and inlet Reynolds numbers ranging from 130 to 2000. Conjugate heat transfer was modelled for different sinusoidal type outer surface heat flux distributions with a base-level incident heat flux intensity of 7.1 kW/m2. It was found that average internal heat transfer coefficients increased with the circumferential span of the heat flux distribution. Average internal and axial local heat transfer coefficients and overall friction factors were at their highest for symmetrical heat flux cases (gravity at 0º) and lower for asymmetric cases. The internal heat transfer coefficients also increased with the inlet fluid temperature and decreased with an increase in the external heat loss transfer coefficient. Friction factors decreased with an increase in fluid inlet temperature or an increase in the external heat loss transfer coefficients of the tube model.en_ZA
dc.description.departmentMechanical and Aeronautical Engineeringen_ZA
dc.description.embargo2019-01-16
dc.description.librarianhj2018en_ZA
dc.description.urihttp://www.tandfonline.com/loi/uhte20en_ZA
dc.identifier.citationIzuchukwu F. Okafor, Jaco Dirker & Josua P. Meyer (2019) AsymmetricalNon-Uniform Heat Flux Distributions For Laminar Flow Heat Transfer With MixedConvection In a Horizontal Circular Tube, Heat Transfer Engineering, 40:1-2, 109-127, DOI:10.1080/01457632.2017.1421055.en_ZA
dc.identifier.issn0145-7632 (print)
dc.identifier.issn1521-0537 (online)
dc.identifier.other10.1080/01457632.2017.1421055
dc.identifier.urihttp://hdl.handle.net/2263/63857
dc.language.isoenen_ZA
dc.publisherTaylor and Francisen_ZA
dc.rights© 2018 Taylor & Francis Group, LLC. This is an electronic version of an article published in Heat Transfer Engineering, vol. 40, no. 1-2, pp. 109-127, 2019, doi : 10.1080/01457632.2017.1421055. Heat Transfer Engineering is available online at : http://www.tandfonline.comloi/uhte20.en_ZA
dc.subjectHeat fluxen_ZA
dc.subjectTransfer coefficienten_ZA
dc.subjectNon-uniform heat fluxesen_ZA
dc.subjectLocal heat transfer coefficienten_ZA
dc.subjectHeat flux distributionsen_ZA
dc.subjectFluid inlet temperatureen_ZA
dc.subjectConjugate heat transferen_ZA
dc.subjectTubular steel structuresen_ZA
dc.subjectTubes (components)en_ZA
dc.subjectStainless steelen_ZA
dc.subjectReynolds numberen_ZA
dc.subjectLaminar flowen_ZA
dc.subjectHeat transfer coefficientsen_ZA
dc.subjectHeat transferen_ZA
dc.subjectHeat lossesen_ZA
dc.subjectFrictionen_ZA
dc.subjectPressure dropen_ZA
dc.subjectInternal heat transferen_ZA
dc.subject.otherEngineering, built environment and information technology articles SDG-07
dc.subject.otherSDG-07: Affordable and clean energy
dc.subject.otherEngineering, built environment and information technology articles SDG-09
dc.subject.otherSDG-09: Industry, innovation and infrastructure
dc.titleAsymmetrical non-uniform heat flux distributions for laminar flow heat transfer with mixed convection in a horizontal circular tubeen_ZA
dc.typePostprint Articleen_ZA

Files

Original bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Okafor_Asymmetrical_2019.pdf
Size:
1.64 MB
Format:
Adobe Portable Document Format
Description:
Postprint Article

License bundle

Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
license.txt
Size:
1.75 KB
Format:
Item-specific license agreed upon to submission
Description: