Heat sinks with minichannels and flow distributors based on constructal law

Abstract

The power and speed of computers processors have grown significantly, implying that a big amount of heat must be removed for better performance. A computational thermo-hydrodynamic analysis for six different non-conventional heat sinks with mini flow channels for large electronic equipment is presented. Three flow distributors were built based on constructal law and compared, choosing the best. Heat fluxes ranging from 20,000 W/m2 to 140,000 W/m2 in a 1406.25 mm2 (37.5 × 37.5 mm) area were dissipated. Water was used as the cooling fluid at 25 °C with five different mass flow rates, ranging from 7.6 g/s to 28.8 g/s. Geometrical configuration functionality is presented, as well as the distributor with the best fluid flow uniformity. Out of all the proposed geometries, the best are selected because they are capable of keeping the maximum temperatures around 36 °C at the heat sink base while keeping the pressure drop under 45 kPa. A factorial design 2k was applied in the analysis. Three factors, each with two levels and a single replica was used, having a factorial design 23. The results for the factorial design 23 shows that the heat flux supplied to each heat sink is more relevant for the maximum temperature value in the heat flux zone, and the mass flow is the most relevant factor affecting the pressure drop, while the heat flux value is not affected at all. The X, T, N, C and E heat sink designs (defined in the manuscript) have a very similar performance, where the P heat sink design is the one with worst thermo-hydraulic performance.