We investigated the role of nanofluid in a special car radiator and the effect of its different volume concentrations on pressure drop and friction factor of fluid flow. A mixture of 60/40 ratio of ethylene glycol (EG) and distilled water was used as the host fluid and CuO nanoparticles were dispersed well to make stable nanofluids. The influence of nanofluid concentrations on pressure drop was evaluated in the radiator at three different inlet fluid temperatures (35, 44, 54 oC). The results demonstrated that the presence of nanoparticles caused an increase in nanofluid pressure drop, which was intensified by increasing nanoparticle concentration as well as decreasing temperature of inlet fluid. A new empirical equation for prediction of nanofluid pressure drop through the radiator was developed as well. Also, with increasing the flow rate, the performance index increased and indicated that application of nanofluid in higher flow rate was affordable.

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