Session: K10-02: Heat transfer equipment

Paper Number: 184484

184484 - Heat Transfer Enhancement of Mineral Oil Based Functionalized Nanodiamond Fluid in a Twisted-Turbulator Pipe: A Numerical Investigation 

Abstract: 

Improving convective heat transfer in internal flow systems is essential for advancing the performance of modern cooling and thermal management technologies. The integration of nanofluids with high-conductivity nanoparticles and passive turbulence-promoting inserts has shown significant promise in elevating heat transfer coefficients while enabling more compact heat-exchange equipment. Functionalized nanodiamond (FND) particles, in particular, offer unique advantages due to their exceptional thermal conductivity, chemical robustness, and ability to form stable dispersions in base fluids such as mineral oil. Meanwhile, twisted-tape turbulators are widely recognized for their capability to induce swirl flow, promote fluid mixing, and enhance near-wall heat transport without requiring additional external power input.

The objective of this study is to numerically investigate the synergistic thermal performance of FND-enhanced mineral-oil nanofluid flowing through a circular pipe fitted with a twisted turbulator. All simulations will be performed using ANSYS Fluent. Prior to the numerical work, a detailed thermophysical characterization of the FND–mineral-oil nanofluid will be conducted to determine density, dynamic viscosity, thermal conductivity, specific heat capacity, Prandtl number, and thermal diffusivity. The experimentally obtained values will be directly implemented into the computational model to ensure accurate representation of the nanofluid behavior and to minimize uncertainties associated with empirical property correlations.

The numerical investigation will involve a systematic comparison of three flow configurations representing increasing levels of thermal enhancement. The first configuration considers water flow in a smooth circular pipe, serving as the baseline. The second configuration replaces water with the FND-enhanced mineral-oil nanofluid while maintaining a smooth pipe geometry. The third configuration introduces a twisted turbulator within the pipe carrying the same nanofluid. The simulations will be carried out under turbulent, steady-state internal flow conditions across a range of Reynolds numbers. Key performance parameters, including temperature distribution, local and average heat transfer coefficients, Nusselt number variation, pressure drop, friction factor, and overall thermal–hydraulic performance, will be evaluated.

Although the study is ongoing, it is expected that the FND nanofluid will exhibit superior heat transfer performance relative to water due to its enhanced thermophysical properties. Furthermore, the addition of the twisted turbulator is anticipated to generate stronger swirl intensity and improved cross-sectional mixing, leading to further augmentation of convective transport. The combination of nanofluid-assisted thermal enhancement and turbulator-induced flow modification is expected to deliver the highest overall performance, offering valuable insights for the development of high-efficiency, compact heat-exchange systems suitable for next-generation energy and thermal management applications.

The combination of nanofluid-assisted thermal enhancement and turbulator-induced flow modification is expected to deliver the highest overall performance, offering valuable insights for the development of high-efficiency, compact heat-exchange systems suitable for next-generation energy and thermal management applications.

Presenting Author: Md Akter Hossain Bablu TTU

Presenting Author Biography: Bablu is a Grad Student at Tennessee Tech University.

Authors:

Md Akter Hossain Bablu TTU
Neal Patel TTU
Ethan Languri Tennessee Technological University
Jim Davidson FemtoSci International
Lu Liu University of Tennessee Space Institute