Dual Role of Nanoparticles in the Thermal Conductivity Enhancement of Nanoparticle Suspensions

2013 ◽  
Vol 2 (1) ◽  
pp. 20-24 ◽  
Author(s):  
Calvin H. Li ◽  
Peixue Jiang ◽  
G. P. Peterson
Keyword(s):  
Thermal Conductivity ◽  
Dual Role ◽  
Thermal Conductivity Enhancement ◽  
Conductivity Enhancement ◽  
Nanoparticle Suspensions

Dual Role of Nanoparticles in the Thermal Conductivity Enhancement of Nanoparticle Suspensions

2005 ◽  
Author(s):  
Calvin H. Li ◽  
G. P. Peterson
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Brownian Motion ◽  
Theoretical Models ◽  
Conductivity Enhancement ◽  
Nanoparticle Suspensions ◽  
The Difference ◽  
Physical Phenomena ◽  
Good Agreement

Experimental evidence exists that the addition of a small quantity of nanoparticles to a base fluid, can have a significant impact on the effective thermal conductivity of the resulting suspension. The causes for this are currently thought to be due to a combination of two distinct mechanisms. The first is due to the change in the thermophysical properties of the suspension, resulting from the difference in the thermal conductivity of the fluid and the particles, and the second is thought to be due to the transport of thermal energy by the particles, due to the Brownian motion of the particles. In order to better understand these phenomena, a theoretical model has been developed that examines the effect of the Brownian motion. In this model, the well-known approach first presented by Maxwell, is combined with a new expression that incorporates the effect of the Brownian motion and describes the physical phenomena that occurs because of it. The results indicate that the enhanced thermal conductivity may not in fact be due to the transport of energy by the particles, but rather, due to the stirring motion caused by the movement of the nanoparticles which enhances the heat transfer within the fluid. The resulting model shows good agreement when compared with the existing experimental data and perhaps more importantly helps to explain the trends observed from a fundamental physical perspective. In addition, it provides a possible explanation for the differences that have been observed between the previously obtained experimental data, the predictions obtained from Maxwell’s equation and the theoretical models developed by other investigators.

scholarly journals Thermal Conductivity Enhancement by Al2O3@Cu, core@shell Nanoparticle Suspensions in Nanofluid Coolant

2019 ◽  
Vol 43 (1) ◽  
pp. 23-28 ◽  
Author(s):  
Harshit Kulkarni ◽  
Raviraj Kulkarni ◽  
Mahantesh Nadakatti ◽  
Gururaj Gokak ◽  
Anand Deshpande
Keyword(s):  
Thermal Conductivity ◽  
Thermal Conductivity Enhancement ◽  
Core Shell ◽  
Conductivity Enhancement ◽  
Nanoparticle Suspensions

Contradictory Evidence for the Role of Temperature and Particle Size in Nanofluid Thermal Conductivity

2011 ◽  
Vol 1347 ◽  
Author(s):  
Rebecca J. Christianson ◽  
Jessica Townsend
Keyword(s):  
Thermal Conductivity ◽  
Particle Size ◽  
Cooling Capacity ◽  
Conductivity Enhancement ◽  
The Past ◽  
Nanoparticle Suspensions ◽  
Significant Step ◽  
Tremendous Amount ◽  
Contradictory Evidence

ABSTRACTThe prospects for increased cooling capacity from the use of nanofluid coolants has created a tremendous amount of interest. However, in the years since the initial thermal conductivity measurements of nanoparticle suspensions were reported, there has been much inconsistency in data published in the literature. The International Nanofluids Benchmarking Exercise was a significant step towards creating a reliable set of data on the thermal conductivity enhancement of stable nanofluids, however there remain many unanswered questions. Most significant, perhaps, is the contradictory results on the effects of particle size and temperature. In the past year alone it is possible to find published reports on nominally identical samples claiming precisely opposing trends in thermal conductivity with decreasing particle size at room temperature. Some studies also claim an increasing enhancement at higher temperatures, sometimes linking this to small particle sizes. In this work we review the literature claims for particle size and temperature results, the theories used to support those claims, as well as presenting new data with the aim of resolving the dispute and identifying the origins of the evidence for contradictory claims.

THERMAL CONDUCTIVITY ENHANCEMENT OF MATERIAL FOR CALCIUM CHLORIDE/WATER THERMOCHEMICAL ENERGY STORAGE

2018 ◽  
Author(s):  
Takuma Ohtaki ◽  
Maho Mitsuo ◽  
Takayuki Terauchi ◽  
Hiroshi Iguchi ◽  
Keiko Fujioka ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Calcium Chloride ◽  
Thermal Conductivity Enhancement ◽  
Conductivity Enhancement ◽  
Chloride Water
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