Model-Based Prediction and Comparative Analysis of Density and Specific Heat Capacity of CuO and Graphene Oxide Nanofluids in Water–Ethylene Glycol

Density and specific heat capacity are two very important thermo-physical properties used in evaluating the suitability of nanofluids for heat transfer and thermal management applications. In the present study, a model-driven comparative evaluation of copper oxide (CuO) and graphene oxide (GO) nanofluids suspended in a 60:40 by-volume water–ethylene glycol (W–EG) base fluid is proposed. The calculations were performed for the nanoparticle volume concentrations 0.05, 0.10, 0.25 and 0.50 % in the temperature range 25–55 °C. The density of W–EG base fluid was calculated from the temperature-dependent densities of water and ethylene glycol and the nanofluid density was calculated by a volume-fraction mixture relation. The specific heat capacity was calculated by a thermal-equilibrium, density-weighted mixture equation using the specific heat capacities and densities of base fluid and nanoparticles. The results show that the density decreases with increasing temperature and increases with increasing nanoparticle concentration and that the specific heat capacity increases with increasing temperature and decreases with increasing nanoparticle concentration. The density penalty of CuO is higher than that of GO because of its better density. About 2.51% and 0.38% density augmentation over base fluid at 0.5 vol% and 55 °C are predicted for CuO/W-EG and GO/W-EG respectively. For the same conditions, the calculated specific heat reduction is about 2.55% for CuO/W–EG and 0.70% for GO/W–EG. The trends are in good agreement with the experimental research carried out for GO/W–EG and CuO nanofluids, and also with the recent researches that emphasize the need for models that consider the variation of temperature and concentration. The values for current density and specific heat are theoretical and not experimental, so comparisons to the literature are to validate trends/models rather than claim a direct numerical concordance. Results show that the density penalty is lower and the base-fluid specific heat capacity is less compromised for GO/W-EG than for CuO/W-EG under the studied conditions.

CuO nanofluid; graphene oxide; water–ethylene glycol; density; specific heat capacity

1. Choi S.U.S., Eastman J.A. (1995). Enhancing thermal conductivity of fluids with nanoparticles. ASME International Mechanical Engineering Congress and Exposition, 99–105. [Google Scholar] [Crossref]

2. Said, Z., L Syam Sundar, Arun Kumar Tiwari, Hafiz Muhammad Ali, Mohsen Sheikholeslami, Evagleos Bellos, Hamza Babar (2022). Recent advances on the fundamental physical phenomena behind stability, dynamic motion, thermophysical properties, heat transport, applications, and challenges of nanofluids. Physics Reports, 946, 1–94. https://doi.org/10.1016/j.physrep.2021.07.002 [Google Scholar] [Crossref]

3. Le Ba, T., Mahian, O., Wongwises, S. et al. (2020). Review on the recent progress in the preparation and stability of graphene-based nanofluids. Journal of Thermal Analysis and Calorimetry, 142, 1145–1172. https://doi.org/10.1007/s10973-020-09365-9 [Google Scholar] [Crossref]

4. Lin Qiu, Ning Zhu, Yanhui Feng, Xinxin Zhang et al. (2020). A review of recent advances in thermophysical properties at the nanoscale: From solid state to colloids. Physics Reports, 843, 1–81. https://doi.org/10.1016/j.physrep.2019.12.001 [Google Scholar] [Crossref]

5. Rashidi, O., Sajadi, S.M., Soufivand, M. et al. (2024). Experimental study to improve the hydrodynamic and thermal efficiencies of a cross-flow car radiator using a new prepared hybrid nanofluid composed of graphene oxide and silicon oxide nanoparticles dispersed in water–ethylene glycol fluid. International Journal of Thermophysics, 45, 23. https://doi.org/10.1007/s10765-023-03310-2 [Google Scholar] [Crossref]

6. Jin W, Jiang L, Lv Y, Li K, Liu H, Cao W, Chen C, Chen Z, Li W (2024). Experimental study on preparation and heat transfer efficiency of ethylene glycol/water-based hybrid nanofluids enhanced by graphene oxide/MXene nanoparticles. Journal of Molecular Liquids, 405, 125033. https://doi.org/10.1016/j.molliq.2024.125033 [Google Scholar] [Crossref]

7. Mlangeni P.H., Huan Z, Sithebe T, Veeredhi V.R. (2023). Correlations for specific heat and density of Titanium Oxide Nanofluid at low nanoparticle concentrations. Materials Today: Proceedings, 92 (2), 1175–1181. https://doi.org/10.1016/j.matpr.2023.05.238 [Google Scholar] [Crossref]

8. Deymi O, Hadavimoghaddam F, Atashrouz S, Kar S, Abedi A, Mohaddespour A, Ostadhassan M, Hemmati-Sarapardeh A (2025). Innovative mathematical correlations for estimating mono-nanofluids' density: Insights from white-box machine learning. Results in Physics, 73, 108248. https://doi.org/10.1016/j.rinp.2025.108248 [Google Scholar] [Crossref]

9. Deymi O, Hadavimoghaddam F, Atashrouz S, Nedeljkovic D, Abuswer M.A, Hemmati-Sarapardeh A, Mohaddespour A (2023). Toward empirical correlations for estimating the specific heat capacity of nanofluids utilizing GRG, GP, GEP, and GMDH. Scientific Reports, 13, 20763. https://doi.org/10.1038/s41598-023-47327-x [Google Scholar] [Crossref]

10. Ijam A, Saidur R, Ganesan P, Moradi Golsheikh A (2015). Stability, thermo-physical properties, and electrical conductivity of graphene oxide-deionized water/ethylene glycol based nanofluid. International Journal of Heat and Mass Transfer, 87, 92–103. https://doi.org/10.1016/j.ijheatmasstransfer.2015.02.060 [Google Scholar] [Crossref]

11. Khouri O, Goshayeshi H.R., Mousavi S.B., Hosseini Nami S, Zeinali Heris S (2024). Heat Transfer Enhancement in Industrial Heat Exchangers Using Graphene Oxide Nanofluids. ACS Omega, 9(22), 24025–24038. https://doi.org/10.1021/acsomega.4c02581 [Google Scholar] [Crossref]

12. Zhou L.-P., Wang B.-X., Peng X.-F., Du X.-Z., Yang Y.-P. (2010). On the Specific Heat Capacity of CuO Nanofluid. Advances in Mechanical Engineering, 2010, 172085. https://doi.org/10.1155/2010/172085 [Google Scholar] [Crossref]

13. Zhong H, Yang L, Song J, Wu X, Li X (2026). Recent Progress in Nanofluid Specific Heat Capacity: A Comprehensive Review. Journal of Thermal Science, 35, 256–283. https://doi.org/10.1007/s11630-025-2164-8 [Google Scholar] [Crossref]

14. Gałek R, Wilk J (2024). Investigations of the specific heat capacity of selected heterogeneous materials. Archives of Thermodynamics, 45(2), 91–98. https://doi.org/10.24425/ather.2024.150855. [Google Scholar] [Crossref]

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