Numerical and experimental analysis of the effect of nanofluid use in radiators on thermal performance

In this Master's thesis, the thermal performance of automobile radiator was investigated experimentally and numerically, using nanofluid instead of the conventional heat transfer fluid in automobile cooling systems. Water and ethylene glycol based nanofluids that contained Al2O3, CuO, MgO with %1volumetric concentration were used as the coolant in analyses. The analyses were carried out in three different volumetric flow rates (0.232, 0.260, 0.282 L/s) and three different air velocities (1.6, 2.3, 2.9 m/s). An automobile cooling system experimental setup was established for the experimental study and the analyses were conducted for four different coolants. For the numerical analysis, a radiator was designed using Ansys 14.5 program and its flow analysis was performed with Fluent software. The outlet temperatures of coolants were obtained as a result of the analyses carried out with different flow rates and air velocities for both experimental and numerical studies. Heat convection coefficient and Nusselt number were calculated based on these temperatures for each fluid. The thermal performance of nanofluids was observed to be better than that of base fluids based on the comparison between the heat convection coefficients and Nusselt numbers of coolants. The highest increase in Nusselt number was found fort he nanofluid containing Al2O3 and calculated to be 69.33% and 58.09%, respectively, for the experimental and numerical analysis. It was concluded that heat convection coefficient and Nusselt number increased with the rise of volumetric flow rate and air velocity for all coolants. The results of numerical and experimental analyses were compared and they were observed to be in agreement with the literature.