Improving Heat Transfer Properties of Corundum Alumina-Based Nanofluids: A Comprehensive Study on Thermal Conductivity and Characterization

Authors

• Amri Abdulah, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, Indonesia AND Department of Mechanical Engineering, Faculty of Engineering, Sekolah Tinggi Teknologi Wastukancana, Jl. Cikopak No.53 Purwakarta 41118, IndonesiaFollow
• Budi Kristiawan, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, Indonesia AND Research Group of Sustainable Thermofluids, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, IndonesiaFollow
• Wibawa Endra Juwana, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, Indonesia AND Research Group of Sustainable Thermofluids, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, IndonesiaFollow
• Sukarman Sukarman, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, Indonesia AND Department of Mechanical Engineering, Faculty of Engineering, Universitas Buana Perjuangan, Jl. HS Ronggo Waluyo, Karawang 41361, IndonesiaFollow
• Khoirudin Khoirudin, Department of Mechanical Engineering, Faculty of Engineering, Universitas Sebelas Maret, Jl. Ir. Sutami 36A Kentingan, Surakarta 57126, Indonesia AND Department of Mechanical Engineering, Faculty of Engineering, Universitas Buana Perjuangan, Jl. HS Ronggo Waluyo, Karawang 41361, IndonesiaFollow

Abstract

The thermal conductivity of nanofluids is affected by various factors. Consequently, a comprehensive investigation into nanofluid materials and their thermal conductivity is essential. This study examines Al₂O₃ samples with three different volume concentrations, 0.5, 0.75 and 1 vol.%, dispersed in a liquid water/ethylene glycol mixture with a volume ratio of EG–W (50:50). Multi-technique characterization was performed using XRD, SEM-EDS, TEM, UV-Visible, and Zeta Potential. Furthermore, thermal conductivity tests were performed on Al₂O₃ using TEMPOS TEM-1443. The XRD pattern revealed that the Al₂O₃ nanoparticles possess a trigonal crystal system with a rhombohedral lattice, corresponding to corundum α -Al₂O₃. The average crystallite size from the XRD data in the range of 36.18–50.92 nm, with results analyzed using the Scherrer method and William Hall (W–H) method. Stability analysis using UV-Vis spectroscopy and zeta potential measurements revealed moderate dispersion stability. The thermal conductivity enhancement ratio (k_nf/k_bf) of Al₂O₃/EG–W nanofluids increased with both temperature and concentration. For 1 vol.%, the ratio rose from 1.4 at 30 °C to 1.45 at 70 °C. These enhancements are attributed to intensified Brownian motion and higher nanoparticle loading, which promote efficient heat transfer. Linear fitting showed a strong temperature–conductivity correlation, with minimal deviation (1–1.2%) confirming measurement reliability. Monte Carlo analysis (10,000 iterations, ISO GUM) yielded a relative uncertainty of ± 1.05%, which is well within the instrument accuracy (± 5%), confirming the robustness and reliability of the measurements. Overall, the formulated Al₂O₃/EG–W nanofluids demonstrate stable and enhanced thermal performance suitable for heat transfer applications.

Keywords

Thermal conductivity, Corundum α -Al2O3 nanofluids, Monte carlo analysis, Crystallite size, Stability

Recommended Citation

Abdulah, Amri; Kristiawan, Budi; Juwana, Wibawa Endra; Sukarman, Sukarman; and Khoirudin, Khoirudin (2026) "Improving Heat Transfer Properties of Corundum Alumina-Based Nanofluids: A Comprehensive Study on Thermal Conductivity and Characterization," HBRC Journal: Vol. 22: Iss. 1, Article 54.
DOI: https://doi.org/10.65800/2090-9934.1053
Available at: https://journal.hbrc.edu.eg/journal/vol22/iss1/54