Thermal Analysis of Laminar Heat Transfer in Double-Layer Micro-Channel Heat Sink with Different Cross-Section

In this study thermal characteristics of a double-layer microchannel heat sink with varying cross-sections through numerical simulations. The two different layers are hourglass and rectangular shape, the rectangular shape is at bottom and the upper layer is an hourglass cross-section. Also, by interchanging the rectangular cross-section to the upper and the hourglass-shaped cross-section to the bottom layer. The numerical results obtained for double-layer and single-layer heat sinks it has been found the double-layer has a low wall temperature, low-pressure drop, and constant temperature variation. The heat transfer rate for case-1 is larger than all other additional mentioned cases and lower for case-2. Half a portion of the heat is removed by the lower micro-channels, so the temperature rises in the upper micro-channels is minimum. For all the cases of double micro-channel heat sink, temperature rise is similar and the temperature is getting uniform after a 7 mm distance from the inlet. The convective heat transfer is increased with Reynolds number for lower as well as upper surfaces. It has been seen that Reynolds number up to 40 convective heat transfer is almost constant. Thereafter, heat transfer continuously increases with Reynolds number.