Fluid Flow and Thermal Characteristics for a Microchannel Heat Sink Subject to an Impinging Jet

2003 ◽  
Author(s):  
Seok Pil Jang ◽  
Sung Jin Kim
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Sink ◽  
Sensor Array ◽  
Thermal Characteristics ◽  
Impinging Jet ◽  
Microchannel Heat Sink ◽  
Cooling Performance ◽  
Flow And Heat Transfer ◽  
Temperature Distributions

In the present study fluid flow and heat transfer characteristics of a microchannel heat sink subject to an impinging jet are experimentally investigated. In order to evaluate the cooling performance of a microchannel heat sink subject to an impinging jet under the fixed pumping power condition, the pressure drop across a microchannel heat sink and temperature distributions at the base of it are measured. Especially, a micro-thermal sensor array is manufactured with simple and convenient microfabrication processes to measure temperature distributions at the base of the heat sink accurately. Based on these experimental results, we suggest a correlation for the pressure drop across a microchannel heat sink subject to an impinging jet as well as a correlation for the thermal resistance of that. In addition, we show that the cooling performance of a microchannel heat sink subject to an impinging jet is superior to that of the microchannel heat sink subject to a parallel flow.

Fluid Flow and Thermal Characteristics of a Microchannel Heat Sink Subject to an Impinging Air Jet

2004 ◽  
Vol 127 (7) ◽  
pp. 770-779 ◽  
Author(s):  
Seok Pil Jang ◽  
Sung Jin Kim
Keyword(s):  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Sink ◽  
Thermal Characteristics ◽  
Impinging Jet ◽  
Microchannel Heat Sink ◽  
Pumping Power ◽  
Cooling Performance ◽  
Air Jet ◽  
Temperature Distributions

In the present study, fluid-flow and heat-transfer characteristics of a microchannel heat sink subject to an impinging jet are experimentally investigated. In order to evaluate the cooling performance of a microchannel heat sink subject to an impinging jet under the condition of fixed pumping power, the pressure drop across the heat sink and temperature distributions at its base are measured. Specifically, a microthermal sensor array is fabricated and used to accurately measure temperature distributions at the base of the heat sink. Based on these experimental results, a correlation for the pressure drop across a microchannel heat sink subject to an impinging jet and a correlation for its thermal resistance are suggested. In addition, it is shown that the cooling performance of an optimized microchannel heat sink subject to an impinging jet is enhanced by about 21% compared to that of the optimized microchannel heat sink with a parallel flow under the fixed-pumping-power condition.

Compact Modeling of Fluid Flow and Heat Transfer in Straight Fin Heat Sinks

2004 ◽  
Vol 126 (2) ◽  
pp. 247-255 ◽  
Author(s):  
Duckjong Kim ◽  
Sung Jin Kim
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Fluid Flow ◽  
Pressure Drop ◽  
Heat Sink ◽  
Volume Averaging ◽  
Thermal Design ◽  
Heat Sinks ◽  
Compact Modeling ◽  
Flow And Heat Transfer

In the present work, a compact modeling method based on a volume-averaging technique is presented. Its application to an analysis of fluid flow and heat transfer in straight fin heat sinks is then analyzed. In this study, the straight fin heat sink is modeled as a porous medium through which fluid flows. The volume-averaged momentum and energy equations for developing flow in these heat sinks are obtained using the local volume-averaging method. The permeability and the interstitial heat transfer coefficient required to solve these equations are determined analytically from forced convective flow between infinite parallel plates. To validate the compact model proposed in this paper, three aluminum straight fin heat sinks having a base size of 101.43mm×101.43mm are tested with an inlet velocity ranging from 0.5 m/s to 2 m/s. In the experimental investigation, the heat sink is heated uniformly at the bottom. The resulting pressure drop across the heat sink and the temperature distribution at its bottom are then measured and are compared with those obtained through the porous medium approach. Upon comparison, the porous medium approach is shown to accurately predict the pressure drop and heat transfer characteristics of straight fin heat sinks. In addition, evidence indicates that the entrance effect should be considered in the thermal design of heat sinks when Re Dh/L>∼O10.

A Three-Dimensional Simulation Analysis of Fluid Flow and Heat Transfer in Microchannel Heat Sinks with Different Structures

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jienan Shen ◽  
Xiuxiu Li ◽  
Yongsheng Zhu ◽  
Boya Zhang ◽  
Hang Guo ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Fluid Flow ◽  
Heat Sink ◽  
Simulation Analysis ◽  
Heat Sinks ◽  
Mixing Efficiency ◽  
Microchannel Heat Sink ◽  
Flow And Heat Transfer ◽  
Microchannel Heat Sinks

Abstract Numerical studies have been performed to analyze the fluid flow and heat transfer characteristics of nine microchannel heat sinks (MCHS) with different shapes and different arrangements of the ribs and cavities on the sidewalls, using three common shapes (square, triangle, and circular) of ribs or cavities as the basic structure in this work. The boundary conditions, governing equations, friction factor (f), Nusselt number (Nu), and performance evaluation criteria (ξ) were considered to determine which design was the best in terms of the heat transfer, the pressure drop, and the overall performance. It was observed that no matter how the circular ribs or cavities were arranged, its heat sink performance was better than the other two shapes for Reynolds number of 200–1000. Therefore, circular ribs or cavities can be considered as the best structure to improve the performance of MCHS. In addition, the heat sink performance of the microchannel heat sink with symmetrical circular ribs (MCHS-SCR) was improved by 31.2 % compared with the conventional microchannel heat sink at Re = 667. This was because in addition to the formation of transverse vortices in the channel, four symmetrical and reverse longitudinal vortices are formed to improve the mixing efficiency of the central fluid (low temperature) and the near-wall fluid (high temperature). Then, as the Reynolds number increases, the heat sink performance of MCHS-SCR dropped sharply. The heat sink performance of microchannel heat sinks with staggered ribs and cavities (MCHS-SCRC, MCHS-STRC, and MCHS-SSRC) exceeded that of MCHS-SCR. This indicated that the microchannel heat sink with staggered ribs and cavities was more suitable for high Reynolds number (Re > 800).

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