Simulation of Fractal Like Branching Microchannel Network on Rectangular Heat Sink for Single Phase Flow

Abstract

development of the very large-skill technology. However, with the increase of circuit

density and operating speed, more heat was generated by the microelectronics

devices. So, the objective of this project is to do a comparative study between two

different types of fractal microchannel at the same size and boundary condition by

using Computational Fluid Dynamics (CFD) Besides that, this study also will

investigate the hydrodynamic and thermal characteristics of T-shaped and Tree

shaped fractal microchannel network heat sinks by solving three-dimensional Navier–

Stokes equations and energy equation, taking into consideration the conjugate heat

transfers in microchannel walls. For the simulation, ANSYS software was used with

the inlet temperature set to be 300 K, inlet velocity will be in the range of 0.1 m/s to

0.5 m/s and uniform heat flux be set at 325 W/cm2 . From this study, it was found that

due to the structural limitation of right-angled fractal-shaped microchannel network,

hotspots may appear on the bottom wall of the heat sink where the microchannel are

sparsely distributed. With slight modifications in both fractal-shaped structure of

microchannel network, great improvements on the hydrodynamic and thermal

performance of heat sink can be achieved. A comparison of the performance of

modified fractal-shaped microchannel network heat sink with parallel microchannel

heat sink is also conducted numerically based on the same heat sink dimensions. It is

found that the modified fractal-shaped microchannel network is much better in

terms of thermal resistance and temperature uniformity under the conditions of the

same pressure drop or pumping power. Therefore, the modified fractal-shaped

microchannel network heat sink appears promising to be used for microelectronic

cooling in the future.