Management of conjugate heat transfer using various arrangements of cylindrical vortex generators in micro-channels

Placing cylindrical vortex generators (VGs) at the base of a uniform micro-channel heat sink (MCHS) enhances the heat transfer, but incurs a substantial pressure drop. The effect of different VG parameters, including position (front, middle or back), radius (R) in the range of (100–300) μm and distance (D) between them (0–500) μm are considered to enhance the conjugate heat transfer. Laminar flow and heat flux conditions relevant to microelectronics water cooling systems (100 W/cm2) are used. The numerical approach, using COMSOL Multiphysics® software, is validated and found to be in good agreement against benchmark experimental and numerical studies. It is generally found that VGs enhance heat transfer but that the pressure drop increases. The lowest thermal resistance is achieved when placing VGs at the front of the MCHS with no distance between them and R = 300 μm, but this also results in the highest pressure penalty. Results also show that it is not necessarily the best heat transfer enhancement that leads to the highest thermal-hydraulic performance (PEC) index. The highest PEC index is achieved at the front position, with R = 100, D = 0 μm and Re > 250