Akademik Veri Yönetim Sistemi
Propulsion and Power Research, cilt.14, sa.3, ss.484-526, 2025 (SCI-Expanded, Scopus)
Radiators are used as a kind of heat exchanger to advance the performance of internal combustion engines by cooling different engine parts. Traditionally, water, ethylene glycol, engine oil, and their blends have been extensively used in radiators for improvement in thermal and lubrication characteristics. However, with recent advancements in technology, nanofluids have emerged as promising coolant alternatives due to their enhanced thermophysical properties. This study provides a comprehensive review of current developments in mono, hybrid, and ternary nanofluids and their applications in automotive radiators. Further, the variation of the thermophysical properties of nanofluids, the preparation methods of nanofluids, the stability of nanofluids, strategies for improving the stability of the prepared fluids, and several empirical correlations for estimating thermophysical properties are discussed. Finally, the review study discusses the future direction of research in this field and shares insights into how to develop an efficient cooling system for engineering applications (especially automobile radiators). The key findings of the review study are as follows: (1) Hybrid nanofluids have generally shown superior performance in enhancing thermal conductivity and heat transfer coefficient due to their synergetic effects than mono nanofluids. For example, hybrid nanofluids, such as CuO-MgO-TiO2 in water blends, show an improvement in thermal conductivity up to 50.78% at a concentration of 0.5% and a temperature of 50 °C. (2) Nanofluids can show stable behavior with minimal sedimentation for up to 30 days after preparation, even without the use of surfactants at lower concentrations. However, noticeable particle settling can be noticed between 30 and 45 days. The addition of the surfactant sodium dodecylbenzene sulphonate ensures stability for over 3 months without visible sedimentation in the MWCNTs-based nanofluids. (3) Einstein's model does not generally provide reasonable predictions for the viscosity ratio of nanofluids, as it neglects the effect of particle shape and size.