Multiscale Design and Optimisation of a Radial Flow Heatsink

Demands for increased functionality from mobile electronic products have led to an increase in the amount of heat that needs to be dissipated. The authors propose a novel mini-heatsink to meet the growing power density needs of the miniature electronics market. This paper looks at the optimisation of a miniature radial flow heatsink with laminar forced convection flow originating from the center. Two single length scale fins positioned at different angles were used to simulate a segment of the heatsink. A Labview PID program was used to monitor and maintain the temperature of these fins. The optimum angle at which maximum heat transfer occurred was determined as a function of pressure drop. The design was varied using the multiscale approach by inserting fins of a smaller length scale into regions of underutilised flow at the exit to achieve the highest heat transfer rate while simultaneously minimising the viscous drag. This method is in contrast to previous work where investigators inserted smaller length scales into the inlet of the original architecture in the regions of unused (isothermal) flow. Non-dimensional results are presented which show increased heat transfer with the addition of smaller length scales. This paper concludes that the multiscale design feature increased the heat transfer rate.