Li, Wenguang, Kadam, Sambhaji 
ORCID: 0000-0001-7523-4555, Song, Jian, Narayan, Surya, Markides, Christos N and Yu, Zhibin ORCID: 0000-0003-0845-9951
(2026)
Nanoscale surface morphology modifications for next-generation supercritical CO2 heat exchangers: Review and perspective
International Journal of Thermal Sciences, 219.
p. 110235.
ISSN 1290-0729
Abstract
Carbon nanotube (CNT) pin fin arrays, CNT, or nanoparticle coating have emerged in recent decades as novel techniques for enhancing heat transfer and reducing drag. In this paper, the suitability of these techniques is reviewed specifically for heat transfer enhancement and drag reduction in the gas side of supercritical carbon dioxide (SCO2) counterflow tube-in-tube or plate type heat exchangers for applications in CO2 refrigeration systems. The methodology and the applicability of various approaches for predicting the heat transfer rates and the frictional pressure drop associated with flow over a nanocoated surface have been reviewed. Findings from both experimental and numerical studies highlight critical limitations, including a lack of fundamental knowledge about flow over superhydrophobic surfaces and the absence of experimental data for crucial parameters such as temperature jump at the wall, velocity and temperature shifts, and the Reynolds analogy factor for nanotube or nanoparticle coatings in turbulent flow regimes. These limitations significantly hamper the predictive capabilities of both single-scale and multi-scale models for frictional pressure drops and heat transfer coefficients. To enhance the accuracy of these models, it is essential to consider surface parameters such as arithmetic mean roughness (Ra), root-mean-square roughness (Rq), effective slope (Es), skewness (Sk), and kurtosis (ku).
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | 4012 Fluid Mechanics and Thermal Engineering, 40 Engineering, Bioengineering, Nanotechnology |
| Divisions: | Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering |
| Depositing User: | Symplectic Admin |
| Date Deposited: | 29 Aug 2025 08:44 |
| Last Modified: | 13 Jan 2026 18:57 |
| DOI: | 10.1016/j.ijthermalsci.2025.110235 |
| Open Access URL: | https://doi.org/10.1016/j.ijthermalsci.2025.110235 |
| Related Websites: | |
| URI: | https://livrepository.liverpool.ac.uk/id/eprint/3194202 |
| Disclaimer: | The University of Liverpool is not responsible for content contained on other websites from links within repository metadata. Please contact us if you notice anything that appears incorrect or inappropriate. |
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