Evaluating the Impact of Nanofluids on Outlet Temperature of Coolants in Heat Exchangers

Abstract

The engine in a vehicle burns fuel and creates energy, which generates heat. Venting this heat away from engine parts is important to prevent damage. Radiators work to eliminate heat from the engine. The process begins when the thermostat in the front of the engine detects excess heat. Then coolant and water get released from the radiator and sent through the engine to absorb this heat. Once the liquid picks up excess heat, it is sent back to the radiator, which works to blow air across it and cool it down, exchanging the heat with the air outside the vehicle. In this project, aim is to get lowest possible temperature at the outlet of the radiator, which can be achieved by mixing non-fluids with water.

Introduction

The text explores advancements in automotive radiator technology, emphasizing the role of nanofluids and fin design in enhancing heat transfer performance. As modern engines demand higher efficiency, effective cooling becomes critical due to increased power, reduced engine size, and environmental concerns. Radiators, as heat exchangers, transfer thermal energy from engine coolant to the surrounding air, with cooling performance influenced by the coolant type, fin design, and material selection.

Nanofluids:
Nanofluids are suspensions of nanoscale metallic or non-metallic particles (e.g., Al?O?, TiO?, CuO) in base fluids like water or ethylene glycol. They offer superior thermal properties due to increased surface area, enhanced turbulence, and improved particle-fluid interactions. Studies have shown that Al?O? nanofluids can increase the heat transfer coefficient by up to 19% and may improve cooling efficiency by 20–45% compared to conventional fluids, albeit with a moderate increase in pressure drop (~13%).

Fin Design and Materials:
Fins increase the surface area for heat dissipation, with perforated and louvered designs shown to enhance heat transfer. Materials like aluminum are preferred for radiator fins due to high thermal conductivity, corrosion resistance, and cost-effectiveness.

Radiator Types:
Radiators are classified mainly into tubular and cellular (honeycomb) types, differing in coolant flow paths and air interaction. Efficient heat transfer is achieved by maximizing the contact area and airflow over the fins.

Design and Analysis Methodology:
The study focuses on modeling a radiator with nanofluids in ANSYS 2022. Key steps include modeling, meshing, applying boundary conditions, and iterative solution. The analysis calculates convective heat transfer coefficients using parameters like Reynolds number (Re = 20,905.43) and Prandtl number (Pr = 0.7092), indicating laminar external flow over the fins.

Key Findings:

• Nanofluids improve radiator efficiency, reduce outlet temperatures, and enable smaller, lighter radiator designs.

• Fin geometry and material choice significantly affect heat dissipation.

• Perforated or louvered fins combined with nanofluids provide the highest heat transfer enhancement.

Conclusion

It is observed that nano particle concentration plays an important role towards heat transfer enhancement. It is found that Effectiveness increases significantly with the increase of particle loading. But this is only true when velocity of the fluid is properly adjusted. If no changes done in velocity then there will not be significant drop in outlet temperature. By comparing both nano fluids with water, it is observed that effectiveness of Graphene Oxide nanofluids is higher than other nano-fluid mixture.

References

[1] Sandesh S. Chougule S. K. Sahu “Thermal Performance of Automobile Radiator Using Carbon Nanotube-Water Nanofluid—Experimental Study” \\ [2] K.Y. Leong, R. Saidur, S.N. Kazi, A.H. Mamun” Performance investigation of an automotive car radiator operated with nanofluid-based coolants (nanofluid as a coolant in a radiator)” [3] S.M. Peyghambarzadeh, S.H. Hashemabadi, M. Seifi Jamnani, S.M. Hoseini “Improving the cooling performance of automobile radiator with Al2O3/water nanofluid” [4] Muhammad Mahmood Aslam Bhutta, Nasir Hayat, Muhammad Hassan Bashir, Ahmer Rais Khan, Kanwar Naveed Ahmad, Sarfaraz Khan” CFD applications in various heat exchangers design: A review [5] Faheem Akthar , Abdul Razak Kaladgi, Asif Afzal, Abdulrajak Buradi, Abdul Aziz, Ahamed Saleel” Numerical analysis of rectangular fins with circular perforations” [6] C.Gopinath Dr.L.Poovazhagan” Design and Analysis of Fluid Flow and Heat Transfer in a Crossflow Radiator as Changing the Fin and Tube Material” [7] Vishwa Deepak Dwivedi, Ranjeet Rai “Design and Performance Analysis of Louvered Fin Automotive Radiator using CAE Tools” [8] K. Chinnarasu, M. Ranjithkumar, P. Lakshmanan, K. B. Hariharan, N. K. Vigneshwaran and S. Karan “Analysis of Varying Geometry Structures of Fins using Radiators” [9] Anzaman Hossen, Nazmus Sakib “Numerical Analysis on Heat Transfer with Nanofluid in an Automotive Radiator”-

Copyright

Copyright © 2025 Prof. Laxmikant Mangate, Mrunal Lenekar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.