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Research Papers: Heat Transfer Enhancement

# Constructal Vascular Structures With High-Conductivity Inserts for Self-Cooling

[+] Author and Article Information
Erdal Cetkin

Department of Mechanical Engineering,
Izmir Institute of Technology,
Urla, Izmir 35430, Turkey
e-mail: erdalcetkin@iyte.edu.tr

1Corresponding author.

Contributed by the Heat Transfer Division of ASME for publication in the JOURNAL OF HEAT TRANSFER. Manuscript received November 21, 2014; final manuscript received June 15, 2015; published online July 14, 2015. Assoc. Editor: Oronzio Manca.

J. Heat Transfer 137(11), 111901 (Jul 14, 2015) (6 pages) Paper No: HT-14-1758; doi: 10.1115/1.4030906 History: Received November 21, 2014

## Abstract

In this paper, we show how a heat-generating domain can be cooled with embedded cooling channels and high-conductivity inserts. The volume of cooling channels and high-conductivity inserts is fixed, so is the volume of the heat-generating domain. The maximum temperature in the domain decreases with high-conductivity inserts even though the coolant volume decreases. The locations and the shapes of high-conductivity inserts corresponding to the smallest peak temperatures for different number of inserts are documented, x = 0.6L and D/B = 0.11 with two rectangular inserts. We also document how the length scales of the inserts should be changed as the volume fraction of the coolant volume over the high-conductivity material volume varies. The high-conductivity inserts should be placed nonequidistantly in order to provide the smallest peak temperature in the heat-generating domain. In addition, increasing the number of the inserts after a limit increases the peak temperature, i.e., this limit is eight number of inserts for the given conditions and assumptions. This paper shows that the overall thermal conductance of a heat-generating domain can be increased by embedding high-conductivity material in the solid domain (inverted fins) when the domain is cooled with forced convection, and the summation of high-conductivity material volume and coolant volume is fixed.

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## Figures

Fig. 1

Heat-generating domain cooled by embedded channel in which coolant fluid flow without high-conductivity inserts (top) and with high-conductivity inserts (bottom)

Fig. 6

The effect of the location of the high-conductivity inserts on T˜max when B/H = 0.4 and φf = φs = 0.05, and the effect of B/H length scale on T˜#1max when the inserts are placed in the domain equidistantly with φf = φs = 0.05

Fig. 7

The effect of B/H length scale on maximum temperature with 6, 8, and 10 equidistant high-conductivity inserts

Fig. 2

(a) The effect of coolant volume fraction on maximum temperature without high-conductivity inserts. (b) The effect of the location of the high-conductivity inserts on maximum temperature. (c) The effect of the shape of the inserts on maximum temperature.

Fig. 3

(a) The effect of Re number on peak temperature with and without high-conductivity inserts. (b) The effect of the location of the high-conductivity inserts on peak temperature with Re = 200.

Fig. 4

The effect of the ratio of coolant volume to high-conductivity material volume on maximum temperature for D/B = 0.125, 0.15, 0.2, and 0.25

Fig. 5

The effect of the location of the second level of high-conductivity inserts on maximum temperature when the location of the first level of inserts is fixed

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