Numerical simulation of single-phase flows in a multi-branch minichannel hot spot cooling system with segmented pin fins

Official URL: https://dx.doi.org/10.1615/TFEC2026.mpf.061078

This study presents a numerical investigation of single-phase water flow through a compact four-branch rectangular channel thermal management system equipped with segmented elliptical pin fins. The simulations were conducted under steady-state, incompressible, and laminar flow conditions, and the focus was on fluid dynamics—specifically pressure drop, velocity distribution, and pressure fields—without considering heat transfer. Each of the four parallel channel (3×14× 300 mm³) configurations contains eight uniformly spaced pin fin regions designed to represent hydrodynamically active hotspots. According to the results, although inlet geometries influence local velocity distributions, the overall pressure drop across all channels remains consistent due to pressure equalization through a downstream manifold. Detailed velocity field analysis exhibits flow confinement within sub-channels and acceleration between pin fins, without evidence of flow separation. Pressure contours confirm a smooth pressure decline along the channel length and localized gradients around the fins, reflecting their role in increasing flow resistance. The study further validates that a single-branch model accurately replicates the pressure drop behavior of the full system, allowing for computational simplification. Parametric simulations using the reduced geometry suggest that pressure drop increases nonlinearly with flow rate and significantly with the number of pin fin areas, indicating a trade-off between flow resistance and potential heat transfer enhancement. These findings offer valuable insights into the fluidic performance of pin-fin-enhanced microscale cooling systems and provide a foundation for optimizing such designs in practical applications under flow boiling configurations.