Numerical Analysis of Internal Flow Field of a Oil Cooler

The studied oil cooler consists of 14 wave-patterned oil channels, resulting in a complex internal geometry. It is necessary to examine the internal flow characteristics that could directly affect the performance of the oil cooler. In this study, the internal flow characteristics such as velocity, flow distribution, pressure drop, and recirculation zones within the oil cooler were analyzed using the ANSYS FLUENT solver. Mesh convergence study was successfully conducted by comparing the results of analyses with grid sizes 2.2 times, 1.42 times, and 1 times mesh. The analysis results of two turbulence models, Realizable k-𝜀 and SST k-ω, were compared, and the SST k-ω model was found to be more suitable. Recirculation phenomena near the walls, inlet, and outlet were observed. Initially, oil was slightly concentrated in the 4th channel of the 1^st pass, but it was evenly distributed into all channels from the 2^nd pass onward. At the oil path 1^st inlet, non-uniform velocity distribution due to impingement, recirculation, and transition was observed. The largest pressure drop occurred when passing through the 1^st pass and 2^nd pass, with each causing a pressure decrease of 0.85% relative to the oil inlet pressure. The oil outlet pressure was 2.3% lower than the oil inlet pressure.