Experimental Investigation of the Enhancement of Heat Transfer Rate in Automobile Radiator Using Low Concentration Hybrid Nanofluids

Engine coolant, also called antifreeze, is essential to a vehicle's performance since it controls engine temperature, keeps the cooling system from freezing in cold weather and prevents corrosion. To increase engine cooling efficiency, this study looks into using low-concentration hybrid nanofluids to accelerate heat transfer rates in automobile radiators. To maximise heat dissipation within the radiator system, the project focuses on the synthesis, characterisation and practical applications of these nanofluids. Through an extensive literature review, various nanoparticles, including metallic and oxide-based particles, were evaluated for their compatibility and effectiveness in enhancing heat transfer. The chosen nanoparticles underwent thorough characterisation for size, shape and surface properties to determine their suitability for dispersion in a base coolant. Reduced Graphene is known for its good thermal conductivity, making it an ideal candidate for enhancing cooling rates in various applications hence keeping this in mind, this experiment compares and investigates the heat transfer rate in the radiator of an automobile with a hybrid combination of Reduced Graphene Oxide (RGO) + Copper Oxide (CuO) with ethylene glycol and distilled water, at volume fractions of 0.001%, 0.005% and 0.01%. The results show a notable increase in the efficiency of the radiator both in terms of pressure drop and effectiveness. A maximum of 9.2 and 1.5 times increase in temperature drop is recorded at 0.001%, a maximum of 12.3 and 2.08 times increase in temperature drop is noted at 0.005% and the highest of 17.9 and 3.03 times increase in temperature drop is tabulated at 0.01% volume fraction of copper oxide and 0.01% the volume fraction of RGO hybrid nanofluid. It can safely be concluded that compared to the sixty experiments conducted, the recommended nanofluid among them would be Ethylene Glycol and Distilled Water + 0.01% concentration of RGO and CuO hybrid as they have exhibited higher pressure drop, effectiveness and reduction in temperature.