Numerical Study of Turbulent Heat Transfer and Pressure Drop Characteristics in a Water-Cooled Minichannel Heat Sink

Abstract

With the rapid development of the Information Technology (IT) industry, the heat flux in integrated circuit (IC) chips cooled by air has almost reached its limit at about 100W∕cm2. Some applications in high technology industries require heat fluxes well beyond such a limitation. Therefore, the search for a more efficient cooling technology becomes one of the bottleneck problems of the further development of the IT industry. The microchannel flow geometry offers a large surface area of heat transfer and a high convective heat transfer coefficient. However, it has been hard to implement because of its very high pressure head required to pump the coolant fluid through the channels. A normal channel size could not give high heat flux, although the pressure drop is very small. A minichannel can be used in a heat sink with quite a high heat flux and a mild pressure loss. A minichannel heat sink with bottom size of 20mm×20mm is analyzed numerically for the single-phase turbulent flow of water as a coolant through small hydraulic diameters. A constant heat flux boundary condition is assumed. The effect of channel dimensions, channel wall thickness, bottom thickness, and inlet velocity on the pressure drop, temperature difference, and maximum allowable heat flux are presented. The results indicate that a narrow and deep channel with thin bottom thickness and relatively thin channel wall thickness results in improved heat transfer performance with a relatively high but acceptable pressure drop. A nearly optimized structure of heat sink is found that can cool a chip with heat flux of 350W∕cm2 at a pumping power of 0.314W.

Parametric study on thermal performance of microchannel heat sinks with internal vertical Y-shaped bifurcations

“…Kandlikar and Upadhye [12] appreciably extended the heat flux limit by using the microchannel designs and had proposed an optimization procedure for selecting the geometries of the microchannel under the given pressure condition. Also, Xie et al [13,14] provided a series of numerical studies on the heat transfer and pressure drop characteristics in microchannel heat sinks for chip cooling and concluded that utilization of a thinner thickness of bottom and channel could improve heat transfer performance for both laminar and turbulent flows with acceptable pressure drop penalty.…”

Performance improvements of microchannel heat sink using wavy channel and nanofluids

“…Based on the results, the conventional Navier-Stokes equations could be used to predict flow and heat transfer in the microchannels. Xie et al [13,14] investigate numerical studies on the laminar and turbulent flow and heat transfer characteristics of water-cooled straight microchannel heat sink. It showed that the removed heat flux increased from 256 W/cm 2 to 350 W/cm 2 with a nearly-optimized microchannel.…”

Numerical study on temperature uniformity in a novel mini-channel heat sink with different flow field configurations

“…The governing equations are continuity, momentum, and energy equations together with the standard k-e model, which are well documented in literature [4] and omitted here for simplicity.…”

“…Mini-channel heat sink has been considered as an effective heat removal tool and has caught much attention during the past decades, due to its advantages including high heat transfer performance, mild pressure loss and easy fabrication [4,5]. Much research has been conducted on the heat transfer and fluid flow characteristics of mini-channels, and most of them suppose that the inlet velocities of all the channels are the same [3][4][5][6][7]. Garimella and Sobhan [8] presented their results of theoretical and experimental studies in mini-channels under different flow regimes, and pointed out that fluid flow and heat transfer characteristics in mini-channels with the hydraulic diameter within 0.2-3 mm are still in accordance with conventional ones.…”