Numerical Analysis of Single Phase Multi Layered Micro-Channel Heat Sink With Inter-Connects Between Vertical Channels

Micro-channels embedded in solid matrix have already proven to be a very efficient way of electronics cooling. Traditional micro-channel heat sinks consist of single layer of parallel channels. Although micro-channel heat sink can achieve very high heat flux, its pumping requirement for circulating liquid through the channel increases very sharply as the flow velocity increases. The pumping requirement can be reduced by stacking multi layers of micro-channels. By introducing multi layers of channels, the flow velocity through each channel is reduced for the same total mass flow rate of the coolant. A novel approach to take advantage of multi layered channel is proposed in this study where the vertical channels are interconnected to allow cross flow of the coolant. The cross-flow between the channels disrupts boundary layer enhancing heat removal capacity of the heat sink. A CFD model has been developed using commercially available software package FLUENT to evaluate overall thermal performance of multi layered micro-channel heat sink. A parametric study of the flow rates and the effect of the number of layers and interconnections have been performed. Significant reduction in thermal resistance has been observed for multiple layers, it is also observed that this reduction in thermal resistance is dependent on the thermal conductivity of the heat sink material.