Thermal performance assessment of alumina/graphene oxide hybrid nanofluid in annular passage of multiple configurations

• Main Authors: Abdelrazek, Ali H., Alawi, Omer A., Mat Ali, Mohamed Sukri, Zaki, Sheikh Ahmad, Ahmed, Khaled I., Kazi, S. N.
• Format: Article
• Published: Springer 2024
• Subjects: TJ Mechanical engineering and machinery
• Online Access: http://eprints.um.edu.my/45659/; https://doi.org/10.1007/s10973-023-12821-x

The current study investigated the effect of both the intrinsic and extrinsic parameters of annular flow on the thermal performance of alumina/graphene oxide (Al2O3/GO) for fully developed turbulent flow by A 3-D CFD model. A fully circular annular pipe (the cross-section is a full circle for both the outer pipe and inner rod) and an annular pipe with a diamond-shaped inner rod were considered in the study. An aqua-based hybrid nanofluid containing Al2O3: GO nanocomposite of 80%: 20% mass mixing ratio, respectively, was tested in comparison with the distilled water (DW) as a heat transfer fluid in both annular passages. The hybrid nanofluid of volumetric concentrations 0.1%, 0.3%, 0.5%, and 0.75% was selected from a published work, and its density and specific heat were calculated theoretically by the current research. The effect of heating location on thermal performance was investigated by alternating a uniform heat flux boundary at the inner rod and outer pipe. The CFD model was verified experimentally using a DW run experiment with a fully circular annular pipe with inner heating under a Reynolds number range between 3000 and 8500. The results generally concluded that the annular pipe with a diamond-shaped inner rod has a higher shape performance index than the fully circular annular pipe, and the inner heating has a higher heat transfer coefficient than that of the outer heating for all nanofluid concentrations in both pipe configurations.