Superior Performance of Nanofluids in an Automotive Radiator

Abstract

This study compares the performance of three different nanofluids containing aluminum oxide, copper oxide, and silicon dioxide nanoparticles dispersed in the same base fluid, 60:40 ethylene glycol and water by mass, as coolant in automobile radiators. The computational scheme adopted here is the effectivenessnumber of transfer unit (خµâ€‰âˆ’ NTU) method encoded in matlab. Appropriate correlations of thermophysical properties for these nanofluids developed from measurements are summarized in this paper. The computational scheme has been validated by comparing the results of pumping power, convective heat transfer coefficients on the air and coolant side, overall heat transfer coefficient, effectiveness and NTU, reported by other researchers. Then the scheme was adopted to compute the performance of nanofluids. Results show that a dilute 1% volumetric concentration of nanoparticles performs better than higher concentration. It is proven that at optimal conditions of operation of the radiator, under the same heat transfer basis, a reduction of 35.3% in pumping power or 7.4% of the surface area can be achieved by using the Al2O3 nanofluid. The CuO nanofluid showed slightly lower magnitudes than the Al2O3 nanofluid, with 33.1% and 7.2% reduction for pumping power or surface area respectively. The SiO2 nanofluid showed the least performance gain of the three nanofluids, but still could reduce the pumping power or area by 26.2% or 5.2%. The analysis presented in this paper was used for an automotive radiator but can be extended to any liquid to gas heat exchanger.