ANN modelling and experimental investigation on effective thermal conductivity of ethylene glycol:water nanofluids

2020 ◽  
Author(s):  
K. Marigowda Yashawantha ◽  
A. Venu Vinod
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Effective Thermal Conductivity

Experimental Investigation of Effective Thermal Conductivity for LHP Wicks

2010 ◽  
Author(s):  
Gongming Xin ◽  
Kehang Cui ◽  
Yan Chen ◽  
Wenjing Du ◽  
Yong Zou ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Effective Thermal Conductivity ◽  
Pure Copper ◽  
Pure Nickel ◽  
Loop Heat Pipe ◽  
Porosity Level ◽  
Nickel Powders ◽  
Copper Powders ◽  
Reasonable Prediction

In this study, the effective thermal conductivity (ETC) of sintered loop heat pipe wicks, with pure nickel powders, pure copper powders, Ni-10wt%Cu powders and Ni-20wt%Cu powders were experimentally investigated. The ETC of sintered Ni-Cu wicks is found less than those of sintered pure nickel wick and sintered pure copper wicks. In the same porosity level, addition of copper into nickel will reduce ETC of the sintered Ni-Cu wicks. The sintered Ni-20wt%Cu wick presents the lowest ETC among the tested wick samples. Compared to experimental results, Alexander model can provide a reasonable prediction in some wick samples.

Experimental Investigation of a Three-Layer Oscillating Heat Pipe

2014 ◽  
Vol 136 (5) ◽  
Author(s):  
C. D. Smoot ◽  
H. B. Ma
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Effective Thermal Conductivity ◽  
Heat Transport ◽  
Total Power ◽  
Oscillating Heat Pipe ◽  
Layer Effect ◽  
Layering Effect ◽  
Heat Transport Capability

An experimental investigation of a compact, triple-layer oscillating heat pipe (OHP) has been conducted to determine the channel layer effect on the heat transport capability in an OHP. The OHP has dimensions 13 mm thick, 229 mm long, and 76 mm wide embedded with two-independent closed loops forming three layers of channels. The unique design of the investigated OHP can be readily used to explore the channel layering effect on the heat transport capability in the OHP. The experimental results show that the addition of channel layers can increase the total power and at the same time, it can increase the effective thermal conductivity of the OHP. When the OHP switches from one layer of channels to two layers of channels, the highest effective thermal conductivity can be increased from 5760 W/mK to 26,560 W/mK. At the same time, the dryout limit can be increased. With three layers of channels, the OHP investigated herein can transport a power up to 8 kW with a heat flux level of 103 W/cm2 achieving an effective thermal conductivity of 33,170 W/mK.

Effective Thermal Conductivity and Viscosity of Nanofluids

2005 ◽  
Author(s):  
S. M. S. Murshed ◽  
K. C. Leong ◽  
C. Yang
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Aluminum Oxide ◽  
Effective Thermal Conductivity ◽  
Titanium Oxide ◽  
Present Model ◽  
Geometrical Structure ◽  
Dispersion Of Nanoparticles

This paper presents a model to determine the effective thermal conductivity (ETC) of nanofluids. The model was developed by considering the geometrical structure of dispersed nanoparticles in base fluids. For the experimental investigation, nanofluids were prepared by suspending aluminum oxide (Φ80 nm) and titanium oxide (Φ15 nm and Φ10×40 nm) nanoparticles in deionized (DI) water and taken through longtime (8–10 hours) sonication for proper mixture of nanoparticles. Cetyltrimethylammoniumbromide (CTAB) surfactant was used to ensure better stability and dispersion of nanoparticles in the base fluids. The thermal conductivity and viscosity of the nanofluids were measured and compared with the predictions by various models. The present model gives better prediction of the effective thermal conductivity of nanofluids compared to existing models.

EXPERIMENTAL INVESTIGATION OF PARAMETERS AFFECTING NANOFLUID EFFECTIVE THERMAL CONDUCTIVITY

2014 ◽  
Vol 201 (5) ◽  
pp. 593-611 ◽  
Author(s):  
A. Kazemi-Beydokhti ◽  
S. Zeinali Heris ◽  
N. Moghadam ◽  
M. Shariati-Niasar ◽  
A. A. Hamidi
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Effective Thermal Conductivity

Experimental Investigation of Micro Heat Pipes Fabricated in Silicon Wafers

1993 ◽  
Vol 115 (3) ◽  
pp. 751-756 ◽  
Author(s):  
G. P. Peterson ◽  
A. B. Duncan ◽  
M. H. Weichold
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Heat Pipe ◽  
Effective Thermal Conductivity ◽  
Heat Pipes ◽  
Silicon Wafers ◽  
Temperature Gradients ◽  
Cover Plate ◽  
Micro Heat Pipe ◽  
Micro Heat Pipes

An experimental investigation was conducted to determine the thermal behavior of arrays of micro heat pipes fabricated in silicon wafers. Two types of micro heat pipe arrays were evaluated, one that utilized machined rectangular channels 45 μm wide and 80 μm deep and the other that used an anisotropic etching process to produce triangular channels 120 μm wide and 80 μm deep. Once fabricated, a clear pyrex cover plate was bonded to the top surface of each wafer using an ultraviolet bonding technique to form the micro heat pipe array. These micro heat pipe arrays were then evacuated and charged with a predetermined amount of methanol. Using an infrared thermal imaging unit, the temperature gradients and maximum localized temperatures were measured and an effective thermal conductivity was computed. The experimental results were compared with those obtained for a plain silicon wafer and indicated that incorporating an array of micro heat pipes as an integral part of semiconductor devices could significantly increase the effective thermal conductivity; decrease the temperature gradients occurring across the wafer; decrease the maximum wafer temperatures; and reduce the number and intensity of localized hot spots. At an input power of 4 W, reductions in the maximum chip temperature of 14.1°C and 24.9°C and increases in the effective thermal conductivity of 31 and 81 percent were measured for the machined rectangular and etched triangular heat pipe arrays, respectively. In addition to reducing the maximum wafer temperature and increasing the effective thermal conductivity, the incorporation of the micro heat pipe arrays was found to improve the transient thermal response of the silicon test wafers significantly.

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