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Thermal conductivity modeling of dielectric oils-based nanofluids using the finite element method


Ahmed Yassine Boukounacha1


 Boubakeur Zegnini1


 Belkacem Yousfi2


Tahar Seghier1
1 Department of Electrical Engineering, Laboratoire d'Etudes et Développement des Matériaux Semi- Conducteurs et Diélectriques, Amar Telidji University of Laghouat, BP 37 G, Route de Ghardaïa, Laghouat 03000, Algeria

Received: 26 December 2023
Revised: 20 February 2024
Accepted: 6 March 2024
Published: 31 March 2024


The enhancement of the thermal conductivity of dielectric oils has a positive effect on the performance of electrical equipment that uses these oils as a cooling medium. Nanofluids (NFs) have inspired high-voltage engineers to use them as alternative fluids in power transformers due to their impressive heat transfer and insulation compared to traditional dielectric oils. The present study is a numerical simulation by COMSOL Multiphysics of the thermal conductivity of NFs based on dielectric oils used in power transformers, to identify the effect of temperature, the concentration of nanoparticles (NPs), type of insulating fluid and NPs on thermal conductivity. The NFs were modeled inside a cube using the finite element method (FEM) by applying a temperature gradient. Several types of NPs were used (SiC, ZnO, TiO2 , and Al2O3) in addition to several volume concentrations (0%, 0.001%, 0.002%, 0.01%, and 0.02%). The results showed a significant improvement in the thermal conductivity of the NFs with increasing concentration since the best results were recorded at an estimated volume concentration of 0.02%, while the lowest results were obtained for samples using a volume concentration estimated at 0.001%. The base fluid (BF) type and NPs play a dominant role in the thermal performance of the NFs, as the vegetable oil-based nanofluid provided the highest thermal conductivity values and silicon carbides (SiC) was the best NPs used in this study. However, a decrease in thermal transfer capacities was observed for all samples with increasing temperature.


Dielectric oils, Finite element method, Modeling, Nanofluids, Nanoparticles, Thermal conductivity, Transformer, Temperature, Volume concentration


[1] M. Rafiq, M. Shafique, A. Azam, M. Ateeq, I.A. Khan, A. Hussain, Sustainable, Renewable and Environmental-Friendly Insulation Systems for High Voltages Applications. Molecules, 25(17), 2020: 3901.
[2] M. Rafiq, M. Shafique, A. Azam, M. Ateeq, The impacts of nanotechnology on the improvement of liquid insulation of transformers: Emerging trends and challenges. Journal of Molecular Liquids, 302, 2020: 112482.
[3] N.S. Suhaimi, M.F.M. Din, M.T. Ishak, A.R.A. Rahman, J. Wang, M.Z. Hassan, Performance and limitation of mineral oil-based carbon nanotubes nanofluid in transformer application. Alexandria Engineering Journal, 61(12), 2022: 9623-9635.
[4] D. Amin, R. Walvekar, M. Khalid, M. Vaka, N. M. Mubarak, T.C.S.M. Gupta, Recent Progress and Challenges in Transformer Oil Nanofluid Development: A Review on Thermal and Electrical Properties. IEEE Access, 7, 2019: 151422-151438.
[5] K.S. Kassi, M.I. Farinas, I. Fofana, C. Volat, Analysis of Aged Oil on the Cooling of Power Transformers from Computational Fluid Dynamics and Experimental Measurements. Journal of Applied Fluid Mechanics, 9(Special Issue 2), 2016: 235-243.
[6] H. Jin, Dielectric Strength and Thermal Conductivity of Mineral Oil based Nanofluids (Ph.D. Thesis). Delft University of Technology, Delft, Netherlands, 2015.
[7] M. Rafiq, M. Shafique, A. Azam, M. Ateeq, Transformer oil-based nanofluid: The application of nanomaterials on thermal, electrical and physicochemical properties of liquid insulation-A review. Ain Shams Engineering Journal, 12(1), 2021: 555-576.
[8] D.A. Barkas, I. Chronis, C. Psomopoulos, Failure mapping and critical measurements for the operating condition assessment of power transformers. Energy Reports, 8, 2022: 527-547.
[9] J.L. Jiosseu, A. Jean‑Bernard, G.M. Mengounou, E.T. Nkouetcha, A.M. Imano, Statistical analysis of the impact of FeO3 and ZnO nanoparticles on the physicochemical and dielectric performance of monoester‑based nanofluids. Scientific Reports, 13, 2023: 12328.
[10] K.N. Koutras, G.D. Peppas, S.N. Tegopoulos, A. Kyritsis, A.G. Yiotis, T.E. Tsovilis, I.F. Gonos, E.C. Pyrgioti, Ageing Impact on Relative Permittivity, Thermal Properties and Lightning Impulse Voltage Performance of Natural Ester Oil Filled with Semi-conducting Nanoparticles. IEEE Transactions On Dielectrics And Electrical Insulation, 30(4), 2023: 1598-1607.
[11] N.A. Azizie, N. Hussin, Preparation of vegetable oil-based nanofluid and studies on its insulating property: A review. Journal of Physics: Conference Series, 1432(1), 2020: 012025.
[12] A.Y. Boukounacha, B. Zegnini, B. Yousfi, Effect of Temperature and Volume Concentration on the Thermal Conductivity of Mineral Oil-based Nanodielectrics, 3rd International Conference on Engineering and Applied Natural Sciences 2023 (ICEANS 2023), 14 January 2023, Konya, Turkey, pp.281-284
[13] S. Ab Ghani, N.A. Muhamad, Z.A. Noorden, H. Zainuddin, N. Abu Bakar, M.A. Talib, Methods for improving the workability of natural ester insulating oils in power transformer applications: A review. Electric Power Systems Research, 163, 2018: 655-667.
[14] M. Bhatt, P. Bhatt, Finite Element Based Comparative Analysis of Positive Streamers in Multi Dispersed Nanoparticle Based Transformer Oil. International Journal of Engineering & Technology Innovation, 12(1), 2021: 29-44.
[15] H. Lin, Q. Jian, X. Bai, D. Li, Z. Huang, W. Huang, S. Feng, Z. Cheng, Recent advances in thermal conductivity and thermal applications of graphene and its derivatives nanofluids. Applied Thermal Engineering, 218, 2023: 119176.
[16] T. Ambreen. M.-H. Kim, Influence of particle size on the effective thermal conductivity of nanofluids: A critical review. Applied Energy, 264, 2020: 114684.
[17] M.M. Ghislain, A. Jean-Bernard, M.I. Adolphe, Effect of FeO3 nanoparticles on the thermodynamic and physico-chemical properties of nanofluid based on kernel palm oil methyl ester (KPOME). Fuel Communications, 12, 2022: 100076.
[18] M.M. Bhunia, K.K. Chattopadhyay, P. Chattopadhyay, Transformer oil nanofluids by two-dimensional hexagonal boron nitride nanofillers. Electrical Engineering, 105, 2023:813-825.
[19] R.A. Farade, N.I.B.A. Wahab, D.E.A. Mansour, N.B. Azis, J. Jasni, N.R. Banapurmath, M.E.M. Soudagar, Investigation of the Dielectric and Thermal Properties of Non-Edible Cottonseed Oil by Infusing h-BN Nanoparticles. IEEE Access, 8, 2020: 76204-76217.
[20] H.Ş. Aybar, M. Sharifpur, M.R. Azizian, M. Mehrabi, J.P. Meyer, A Review of Thermal Conductivity Models for Nanofluids. Heat Transfer Engineering, 36(13), 2015:1085-1110.
[21] H. Yasmin, S.O. Giwa, S. Noor, M. Sharifpur, Thermal Conductivity Enhancement of Metal Oxide Nanofluids: A Critical Review. Nanomaterials, 13(3), 2023: 597.
[22] N. Ali, J.A. Teixeira, A. Addali, A Review on Nanofluids: Fabrication, Stability, and Thermophysical Properties. Journal of Nanomaterials, 2018, 2018: 6978130.
[23] P.K. Das, A review based on the effect and mechanism of thermal conductivity of normal nanofluids and hybrid nanofluids. Journal of Molecular Liquids, 240, 2017: 420-446.
[24] S.R. Babu, P.R. Babu, D.V. Rambabu, Effects of Some Parameters on Thermal Conductivity of Nanofluids and Mechanisms of Heat Transfer Improvement. International Journal of Engineering Research and Applications, 3(4), 2013: 2136-2140.
[25] A.Y. Boukounacha, B. Zegnini, B. Yousfi, T. Seghier, Thermal Conductivity in a Nanofluid Filled Transformer: Modeling by the Finite Element Method. 2nd International Conference on Electronics, Energy and Measurement 2023 (IC2EM 2023), 28 November 2023, Medea, Algeria.
[26] H.S. Karaman, A.Z. El Dein, D.-E.A. Mansour, M. Lehtonen, M.M.F. Darwish, Influence of Mineral Oil-Based Nanofluids on the Temperature Distribution and Generated Heat Energy Inside Minimum Oil Circuit Breaker in Making Process. Nanomaterials, 13(13), 2023:1951.
[27] A.H. Pordanjani, S. Aghakhani, M. Afrand, M. Sharifpur, J.P. Meyer, H. Xu, H.M. Ali, N. Karimi, G. Cheraghian, Nanofluids: Physical phenomena, applications in thermal systems and the environment effects- a critical review. Journal of Cleaner Production, 320, 2021: 128573.
[28] Z. Lafdaili, S. El-Hamdani, A. Bendou, K. Limam, B. El-Hafad, Numerical study of the turbulent natural convection of nanofluids in a partially heated cubic cavity. Thermal Science, 25(4A), 2021: 2741-2754.
[29] M. Liu, L. Cheng, S. Hu, Y. Jiang, J. Zhang, H. Xu, Study on the Temperature Rise Characteristic of Vegetable Insulated Oil Transformer under Different Loads Conditions. 2020 Asia Energy and Electrical Engineering Symposium (AEEES), 29 May 2020, Chengdu, China, pp.79-84.
[30] G. Liu, Z. Zheng, D. Yuan, L. Li, W. Wu, Simulation of Fluid-Thermal Field in Oil-Immersed Transformer Winding Based on Dimensionless Least-Squares and Upwind Finite Element Method. Energies, 11(9), 2018: 2357.
[31] M. Bukvić, S. Gajević, A. Skulić, S. Savić, A. Ašonja, B. Stojanović, Tribological Application of Nanocomposite Additives in Industrial Oils. Lubricants, 12(1), 2024: 6.

© 2024 by the authors. This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0)

Volume 9
Number 1
March 2024

Last Edition

Volume 9
Number 1
March 2024

How to Cite

A.Y. Boukounacha, B. Zegnini, B. Yousfi, T. Seghier, Thermal Conductivity Modeling of Dielectric Oils-Based Nanofluids Using the Finite Element Method. Applied Engineering Letters, 9(1), 2024: 1-11.

More Citation Formats

Boukounacha, A.Y., Zegnini, B., Yousfi, B., & Seghier, T. (2024). Thermal Conductivity Modeling of Dielectric Oils-Based Nanofluids Using the Finite Element Method. Applied Engineering Letters, 9(1), 1-11.

Boukounacha, Ahmed Yassine, et al. “Thermal Conductivity Modeling of Dielectric Oils-Based Nanofluids Using the Finite Element Method.“ Applied Engineering Letters, vol. 9, no. 1, 2024, pp. 1-11.

Boukounacha, Ahmed Yassine, Boubakeur Zegnini, Belkacem Yousfi, Tahar Seghier. 2024. “Thermal Conductivity Modeling of Dielectric Oils-Based Nanofluids Using the Finite Element Method.“ Applied Engineering Letters, 9 (1): 1-11.

Boukounacha, A.Y., Zegnini, B., Yousfi, B. and Seghier, T. (2024). Thermal Conductivity Modeling of Dielectric Oils-Based Nanofluids Using the Finite Element Method. Applied Engineering Letters, 9(1), pp. 1-11. doi: 10.46793/aeletters.2024.9.1.1.