The experimental study of the entropy generation and energy performance of nano-fluid flow for automotive radiators

The present study focuses on the energy performance, entropy generation, and irreversibility of the use of nanofluid in an industrial Peugeot automobile radiator (size: 250 × 301 × 60.4 mm, channel number: 34 and hydraulic diameter: 1.923 mm) with a louvered fin type. 50:50 EG – water which is widely used in existing automobile radiators and a new generation of EG – water – Al2O3 (0.5%) nanofluid have been compared. In order to examine the effect of variable operating conditions on thermal performance for both fluid mixtures, experiments have been performed at variable air velocity (4–5 m/s), variable coolant flow rate (10–15 – 20 lt/min), and an inlet temperature of 95 °C (real automobile conditions). Thermo-hydraulics calculations such as entropy generation, irreversibility, effectiveness, NTU, heat transfer rate, pumping power have been obtained from experimental data. Among conducted experiments, with increasing coolant flow rate, entropy generation increases on the airside, while decreasing on the coolant side. When the entropy generation due to temperature and pressure difference is compared, entropy production due to pressure difference can be neglected. It has been evaluated that the use of nanofluid increases the heat transfer rate by 9.52%, reducing the irreversibility by about 68% at the 4 m/s air velocity and 10 lt/min coolant flow.