Investigation of Hydrothermal Characteristics of Nanofluids and Turbulators in Double Tube Heat Exchangers

Tavousi, Ebrahim (2024) Investigation of Hydrothermal Characteristics of Nanofluids and Turbulators in Double Tube Heat Exchangers. Doctoral thesis, Birmingham City University.

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Text Ebrahim Tavousi PhD _Thesis_Final Version_Final Award Oct 2024.pdf - Accepted Version Download (7MB)

Abstract

The growing demand for energy efficiency underscores the vital importance of heat exchangers in a wide range of industries, from power generation to HVAC systems. With growing demands for improved efficiency and reduced operational costs, there has been significant research into thermal management technologies. Double tube heat exchangers (DTHEs), due to their simplicity and effectiveness, are widely used in industrial applications. This research aims to enhance the performance of DTHEs by integrating innovative turbulator designs and advanced nanofluids, contributing to the development of more energy-efficient thermal systems.

Turbulators disrupt fluid flow, enhancing heat transfer by breaking up the boundary layer on heat transfer surfaces. This study examines various turbulator shapes—rectangular, triangular, oval, and trapezoidal—in both transverse and helical configurations. Additionally, it explores the effects of different nanofluids, such as CuO, ZnO, Fe3O4, Diamond, Ag, TiO2, Al2O3, SiC, and SiO2, on heat transfer. Using volume fractions from 0 to 0.1, the nanofluids are selected for their ability to enhance thermal conductivity and convective heat transfer. The research employs the finite volume method and advanced computational tools, including ANSYS Fluent, to model and analyze these effects.

The results indicate that SiO2 nanofluids provide the highest improvement in heat transfer efficiency, with an 18.4% enhancement compared to the base fluid. Among turbulator configurations, helical designs, particularly triangular ones, offer the best performance in terms of Nusselt number, pressure drop, and overall heat transfer efficiency. The study also highlights that adjusting the geometrical parameters of turbulators, such as rib height, can significantly impact heat transfer, with transverse turbulators showing up to a 471% increase. The substantial improvements observed in this study affirm the potential of these technologies to improve thermal systems design, offering significant advantages over traditional methods and contributing to sustainability and cost-effectiveness in thermal management.

Item Type:	Thesis (Doctoral)
Dates:	Date Event 9 October 2024 Accepted
Uncontrolled Keywords:	Double tube heat exchanger, Passive method, Heat transfer, Fluid flow, Turbulator, Nanofluid
Subjects:	CAH10 - engineering and technology > CAH10-01 - engineering > CAH10-01-09 - chemical, process and energy engineering
Divisions:	Doctoral Research College > Doctoral Theses Collection Faculty of Computing, Engineering and the Built Environment > College of Engineering
Depositing User:	Louise Muldowney
Date Deposited:	27 May 2025 10:25
Last Modified:	27 May 2025 10:25
URI:	https://www.open-access.bcu.ac.uk/id/eprint/16397

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