Heat transfer inside annular passages: A comparison of noncircular and fully circular passages using eco-friendly graphene nanofluid

AbdRabbuh, O. Almatar and Kazi, S.N. and Zubir, Mohd Nashrul Mohd and Chowdhury, Zaira Zaman and Abdelrazek, Ali H. (2024) Heat transfer inside annular passages: A comparison of noncircular and fully circular passages using eco-friendly graphene nanofluid. Case Studies in Thermal Engineering, 60. p. 104659. ISSN 2214-157X, DOI https://doi.org/10.1016/j.csite.2024.104659.

Full text not available from this repository.
Official URL: https://doi.org/10.1016/j.csite.2024.104659

Abstract

This research investigates the thermal performance of an annular passage using eco-friendly nanofluids as substitutes for conventional working fluids. Specifically, the study focuses on the utilization of covalently functionalized Graphene Nanoplatelets (GNPs) dispersed in an aqueous medium, with Gallic acid as the functionalizing agent. Nanofluids were synthesized at different weight concentrations (0.1 wt%, 0.05 wt%, and 0.025 wt%) and exhibited an excellent long-term colloidal stability for 39 days, with a relative concentration of 94.4% at 0.025 wt%. Thermophysical property evaluations revealed significant enhancements of 18.25% and 8.23% in thermal conductivity and viscosity, respectively at 0.1 wt%. The nanofluids exhibited average enhancements of convection heat transfer coefficient evaluations indicating improved thermal performance for GaGNPs/DW nanofluids, with the highest average enhancement of approximately 12.11% achieved at 0.1 wt%. To investigate the impact of different annular geometries, a numerical study (CFD) was conducted. Various inner rod shapes, including circular, rectangular, square, triangular, and pentagonal, were considered. The pentagonal cross-section exhibited the highest average increase in convection heat transfer coefficient at 13.9%, followed by rectangular and triangular shapes. In a numerical case study with different thermal boundary conditions, the circular inner rod shape demonstrated the highest thermal performance at 0.1 wt%.

Item Type: Article
Funders: Ministry of Education, Malaysia (FRGS/1/2019/TK03/UM/02/12 (FP143-2019A)) ; (ST077-2022), Universiti Teknologi Malaysia (UTM) (R.K130000.7113.06E34)
Uncontrolled Keywords: Eco-friendly nanofluid; Annular geometries; Concentric annular pipe; GNPs; CFD modelling
Subjects: Q Science > Q Science (General)
T Technology > TJ Mechanical engineering and machinery
Divisions: Faculty of Engineering > Department of Mechanical Engineering
Deputy Vice Chancellor (Research & Innovation) Office > Nanotechnology & Catalysis Research Centre
Depositing User: Ms. Juhaida Abd Rahim
Date Deposited: 17 Sep 2024 02:57
Last Modified: 17 Sep 2024 02:57
URI: http://eprints.um.edu.my/id/eprint/45105

Actions (login required)

View Item View Item