Study of motor oil cooling at low Reynolds number in multi-port narrow channels

Mini and micro-scale channels have drawn researchers' attention in the past three decades. The use of these channels in a heat exchanger is due to the several advantages they provide. Motor oil was chosen as the working fluid since it is greatly utilized in automotive applications. In current investigations, experiments were performed to verify the aptness of cooling the oil through a cross-flow minichannel heat exchanger. The inlet temperature of the motor oil was kept constant at 75°C, while the air inlet temperatures were varied within the range of 20°C - 40°C. The range of oil Reynolds number was found to be between 0.85 to 3.5 whereas the air velocities were between 6 m/s and 18 m/s. Correlations were developed between the Nu oil and Reoil and Proil. The effect of Re oil on the heat transfer coefficient, NTU, and effectiveness were investigated. The results were compared with the findings of another viscous fluid where a similar test specimen was used and same trends were observed.