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

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

Date of Award	9 Oct 2024
Original language	English
Awarding Institution	Birmingham City University
Supervisor	Noel Perera (Director of Studies), Mostafiz Rahman (Second Supervisor 1), Reaz Hasan (Second Supervisor 2) & Dominic Flynn (Second Supervisor 3)