Design Development and Experimental Investigation of Nano Fluid Car Radiator

Abstract

Heat exchangers play an important part in the field of energy conservation, conversion and recovery. Numerous studies have focused on direct transfer type heat exchanger, where heat transfer between fluids occurs through a separating wall or into and out of a wall in a transient manner. There are two important phenomena happening in a heat exchanger: fluid flow in channels and heat transfer between fluids and channel walls. Thus, improvements to heat exchangers can be achieved by improving the processes occurring during those phenomena. Nanofluids, on the other hand, display much superior heat transfer characteristics compared to traditional heat transfer fluids. Nanofluids refer to engineered fluids that contain suspended nanoparticles with average size below 100nm in traditional heat transfer fluids such as water, oil and ethylene glycol. An experimental system will be designed and constructed to investigate heat transfer behavior of different type of nanofluid a car-radiator heat exchanger. Heat transfer characteristics will be measured under the turbulent flow condition. The experiments is planned to be conducted for wide ranges of Peclet numbers, and volume concentrations of suspended nanoparticles. The outcome expectation is to measure the significance of Peclet number on the heat transfer characteristics. The optimum volume concentrations in which the heat transfer characteristics become the maximum enhancement is also addressed. Finally, the structure of different nanofluid is compared.

Introduction

Heat transfer plays a vital role in many industrial systems such as power plants, refrigeration, air conditioning, automotive cooling, electronics, and renewable energy. Conventional heat transfer fluids (water, ethylene glycol, oils) are widely used but have low thermal conductivity, which limits their heat transfer efficiency. Metals, in comparison, have extremely high thermal conductivity, motivating the development of enhanced fluids.

Early attempts to improve fluid properties involved mixing micrometer-sized solid particles with fluids. Although this increased thermal conductivity, it resulted in sedimentation, clogging, erosion, and high pumping power. The breakthrough came in 1995, when Choi and Eastman introduced nanofluids—stable suspensions of nanoparticles (1–100 nm) in base fluids. These nanoparticles have high surface area, remain suspended longer, and significantly enhance heat conduction and convection, making them attractive for advanced thermal systems.

Literature Review

Research has focused on overcoming limitations of traditional fluids. Maxwell, Hamilton & Crosser established early theoretical models for thermal conductivity enhancement. With the rise of nanotechnology, nanoparticles such as metals (Cu, Ag), metal oxides (Al?O?, TiO?), carbon-based materials (CNTs, graphene), and hybrid particles have been widely investigated. Nanofluids show improved thermal conductivity, heat transfer coefficient, and performance in radiators, solar collectors, condensers, and desalination systems. However, large-scale industry adoption is still limited due to cost, stability, and environmental concerns.

System Design

The project aims to experimentally analyze how nanoparticles improve heat transfer in a car-radiator heat exchanger. The design considers proper flow control, stability of nanoparticles, accuracy in readings, and optimization between heat transfer enhancement and pressure drop. Major equipment used includes a car radiator, fan, electric water pump, heater, sensors, and connecting pipes. Standard engineering practices (SASO, KATS) and environmental considerations were followed. SolidWorks was used to model the system before assembling the prototype.

Experimentation

The objective is to compare the heat transfer performance of pure water vs nanofluids under turbulent flow conditions and to determine the optimum nanoparticle concentration.

The experimental setup is a closed-loop system with:

• Reservoir + heater

• Pump

• Radiator heat exchanger

• Cooling fan

• Thermocouples & flow meters

Working principle:
Nanofluid is heated → pumped through radiator → cooled by fan → temperatures and flow rates are measured → heat transfer rate and effectiveness are calculated.

Experiments were performed with:

• Pure water

• Water with aluminum nanoparticles at various concentrations (0.1%, 0.5%, 0.9%)

Observations for Pure Water

Four cases were tested with two water flow rates (0.667 kg/s, 0.333 kg/s) and two air flow rates (0.5 kg/s, 1.0 kg/s).
Results showed:

• Effectiveness ranged from 8.69% to 12.31%

• Higher air flow improves effectiveness

• Higher water flow also shows better performance

Results for Aluminum Nanofluids

Nanoparticles significantly improved heat exchanger effectiveness:

• At 0.1% Al nanofluid, effectiveness increased to 14–16%

• At 0.5% concentration, improvement varied but was lower at some flow rates

• At 0.9% concentration, effectiveness reached the highest values (15–19%)

Overall trend:

• Nanoparticles improve thermal performance

• Too high concentration increases viscosity → reduces performance

• 0.9% concentration gave the best enhancement

Conclusion

The experiments with copper nanofluids establish several key findings: 1) Significant Enhancement: Copper nanoparticles nearly double the effectiveness of the heat exchanger compared to pure water. 2) Concentration Dependence: Performance consistently increases with nanoparticle concentration, peaking at 0.9%. 3) Air Flow Sensitivity: Higher air flow rates yield substantial improvements since the air side is the limiting factor. 4) Water Flow Influence: Higher water flow aids convection but has less impact than air flow or nanoparticle concentration. 5) Superiority Over Aluminium: Copper nanofluids deliver higher effectiveness than aluminium nanofluids at similar concentrations. Overall, copper nanofluids show great promise as advanced heat transfer fluids for demanding thermal management applications.

References

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Copyright

Copyright © 2025 Kapil B. Parse, Prof. K. M. Mahajan, Dr. T. A. Koli. 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.