Synergistic Enhancement of Automotive Radiator Performance Using Coated Surfaces and Hybrid Nanofluids: Experimental Evaluation of Heat Transfer and Hydraulic Characteristics
J. Environ. Nanotechnol., Volume 14, No 4 (December 2025) pp. 54-71
Abstract
Nanofluids have emerged as promising alternatives to conventional coolants in automotive and industrial heat transfer applications due to their superior thermal conductivity and enhanced convective performance. However, ensuring long-term stability while achieving significant thermal gains without increasing pumping losses remains a critical challenge. This study addresses this gap by evaluating the effects of nanoparticle concentration and boron nitride (BN) surface coating on the thermophysical behavior of AlCeO₃ and CuFe₂O₄ nanofluids in radiator systems. The objective is to investigate how BN coating influences heat-transfer efficiency, stability, and pressure drop characteristics across different nanofluid loadings. AlCeO₃ and CuFe₂O₄ nanoparticles were synthesized, dispersed at 2% and 4% volume fractions, and tested in coated and uncoated radiators. Key metrics, including thermal conductivity, viscosity, zeta potential, heat-transfer coefficient (HTC), and pressure drop, were experimentally analyzed. Results show that thermal conductivity increased from 0.61 W/m·K (base fluid) to 0.86 W/m·K (4% AlCeO₃) and 0.83 W/m·K (4% CuFe₂O₄). The zeta potential values greater than 35 mV confirmed strong colloidal stability. BN-coated radiators achieved HTC values of up to 6200 W/m²·K, compared to 4600 W/m²·K in uncoated systems, and reduced pressure drops by 15–20% at higher Reynolds numbers. Additionally, coated systems exhibited stability over 30 days, outperforming uncoated counterparts that destabilized after 10–15 days. The study concludes that combining optimized nanofluid concentration with BN-coated radiators significantly boosts thermal performance while mitigating pressure losses. Future research could explore higher flow rates, scaling effects, and hybrid coatings for commercial adoption.
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Reference
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