Microchannel Heat Sink for Heat Transfer Enhancement

Description

Microchannel heat sinks address a core challenge in electrical and power engineering: dissipating high heat fluxes from compact electronic components and power devices where conventional air cooling falls short. This CFD study uses ANSYS Fluent to analyze a cylindrical microchannel heat sink built around 86 rectangular microchannels arranged circumferentially about a cylindrical core, with a hydraulic diameter of 560 micrometers, a 5 mm internal radius, and 10 mm wall thickness. The work examines how this microfluidic cooling geometry manages heat extraction under realistic operating conditions relevant to power electronics and high-density circuit packaging.

Methodology

Given the circumferential symmetry of the channel arrangement, the simulation models a single representative segment using periodic boundary conditions, reducing computational cost while preserving solution accuracy across the full structure. The domain is discretized with a structured mesh of 1.5 million elements to resolve thermal gradients and flow features within the narrow channels. The cylindrical core is treated as the heat-generating electronic component, assigned a constant heat flux boundary condition of 243,507 W/m², while water coolant enters the microchannels at 0.59 m/s and 297 K.

Results Analysis

The simulation produces three-dimensional pressure, temperature, and velocity fields throughout the microchannel passages, along with two-dimensional temperature contours at multiple cross-sections to illustrate the thermal coupling between the solid core and the coolant. Results show effective heat extraction from the core, confirming the design's cooling capability under the specified load. Rotational reconstruction of the segment results yields the complete thermal profile of the full heat sink, offering a comprehensive performance picture that supports design optimization for thermal management in power-dense electronic and electrical systems.