Abstract
Experimental investigation on forced convection heat transfer is applied to vehicles’ radiator filled with AL2O3 water nanofluid with different concentrations: 0.1%, 0.5%, 1%, 1.5%, and 2% by volume. The experiments are done for three cases, each case corresponds to different heat load, coolant flow rate, and air flow rate to simulate the vehicle engine cooling system at various loads relevant to the cooling system of Toyota Yaris 2007. The coolant and air heat transfer coefficients, Nusselt numbers, heat rate lost by the coolant and absorbed by the air, heat exchanger effectiveness, overall heat transfer coefficients, Reynolds number, and the pumping power are calculated. Log mean temperature difference (LMTD) and effectiveness-number of transfer units (ε-NTU) are used to determine the outside air heat transfer coefficient. Results show gradual enhancement in the heat transfer with concentrations 0.1%, 0.5%, and 1% by volume (optimum at 1%); however deterioration occurs at concentrations 1.5% and 2%.