Experimental study on the variation of car radiator frontal area using Al2O3/water-ethylene glycol nano coolant

In automobiles, the cooling system is essential in increasing engine performance. Conventional coolants like water and ethylene glycol have low thermal conductivity. Nanotechnology allows the development of a high thermal conductivity coolant named 'nanocoolant', a colloidal suspension. This study is focused on the effect of nanocoolant size on the radiator, which is also responsible for fuel consumption. To prepare nanocoolant two-step method was used, in which nanoparticles were prepared separately and dispersed in a base fluid under ultrasonic agitation. This research was carried out for the dispersion of Al2O3 in a water-ethylene glycol mixture with volume concentrations of 0%, 0.2%, 0.4% and 0.6%. The experimentation was carried out on 180, 216, 288 and 360 mm tube-length radiators. The experiments were conducted at a coolant inlet temperature 65 degrees C, air velocity of 1.05 m/s, and volume rate of 4 to 9 litres per minute. The result shows that using 0.2% Al2O3 nanoparticles, the overall heat transfer coefficient was augmented by 43% more than the base fluid. It is also seen that for 0.6% volume fraction nanocoolant, approximately 65% reduction in frontal radiator area is possible, which leads to decrement in the drag force and pumping power.