scholarly journals Thermal Conductivity of Al2O3 and CeO2 Nanoparticles and Their Hybrid Based Water Nanofluids: An Experimental Study

2020 ◽  
Vol 65 (1) ◽  
pp. 50-60
Author(s):  
Mohammed Saad Kamel ◽  
Otabeh Al-Oran ◽  
Ferenc Lezsovits
Keyword(s):  
Experimental Data ◽  
Thermal Conductivity ◽  
Volume Concentration ◽  
Experimental Models ◽  
Deionized Water ◽  
Thermal Conductivity Enhancement ◽  
Hybrid Nanofluid ◽  
Step Method ◽  
Conductivity Enhancement ◽  
Good Agreement

In many heat exchange systems, there is a demand to improve the thermal conductivity of the working fluids to make those fluids more efficient, and this can be done by dispersing solid nanomaterials into conventional liquids. In the present work, the thermal conductivity of alumina, ceria, and their hybrid with ratio (50:50) by volume-based deionized water nanofluids was experimentally measured. The nanofluids were prepared by two-step method with a range of dilute volume concentration (0.01-0.5 % Vol.), and measured at various temperatures (35, 40, 45, and 50 ºC). The experimental data for basefluid and nanofluids were verified with theoretical and experimental models, and the results have shown good agreement within the accuracy of the thermal conductivity tester. The results demonstrated that the higher thermal conductivity enhancement percentages for Al2O3, CeO2, and their hybrid nanofluids were (5.3 %, 3.3 %, and 8.8 %) at volume concentration (0.5 % Vol.) and temperature (50 ºC) compared to deionized water, respectively. Moreover, a correlation was proposed for the thermal conductivity enhancement ratio of the hybrid nanofluid and showed good accuracy with measured experimental data.

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.

Thermal Conductivity Enhancement of Aluminium Oxide Nanofluid in Ethylene Glycol

2014 ◽  
Vol 660 ◽  
pp. 730-734 ◽  
Author(s):  
Khamisah Abdul Hamid ◽  
Wan Hamzah Azmi ◽  
Rizalman Mamat ◽  
Nur Ashikin Usri
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Properties ◽  
Ethylene Glycol ◽  
Volume Concentration ◽  
Conductivity Measurement ◽  
Thermal Conductivity Enhancement ◽  
Heat Transfer Fluid ◽  
Coolant Fluid ◽  
Conductivity Enhancement

Nanofluids are the new coolant fluid that has been widely investigates due to its ability to improved heat transfer better than conventional heat transfer fluid. The need to study the nanofluid properties has been increased to provide better understanding on nanofluid thermal properties and behavior. This study presents the measurement analysis on thermal conductivity enhancement of Al2O3 nanoparticles dispersed in ethylene glycol. The nanofluids are prepared using two step method for volume concentration range from 1.0 % to 4.0 %. The thermal conductivity measurement of the nanofluid is performed by KD2 Pro Thermal Properties Analyzer at working temperature range from 30 °C to 80 °C. The maximum enhancement in thermal conductivity is 21.1 % at volume concentration of 2.0 % and temperature of 70 °C. The results show that the thermal conductivity increases with the increase of nanofluid concentration and temperature. Also, the nanofluid shows enhancement in thermal conductivity compare to the base fluid.

Experimental Investigation on Thermophysical Performance of BN/EG Nanofluids Influenced by Dispersant

2015 ◽  
Vol 757 ◽  
pp. 7-12 ◽  
Author(s):  
Jian Feng Guo ◽  
Zhi Qing Guo ◽  
Xin Feng Wang ◽  
Yan Jiao Li ◽  
Qiu Juan Lv
Keyword(s):  
Thermal Conductivity ◽  
Experimental Investigation ◽  
Boron Nitride ◽  
Experimental Results ◽  
Thermal Conductivity Enhancement ◽  
Step Method ◽  
Conductivity Enhancement ◽  
The Stability ◽  
Severe Deterioration

Boron nitride/ethylene alcohol (BN/EG) nanofluid was synthesized by two-step method. The effect of dispersant on stability, viscosity and thermal conductivity enhancement was investigated. The experimental results indicated that the addition of anionic dispersant (SHMP) and catioic dispersant (CTAB) will induce the severe deterioration of stability of BN/EG nanofluids. PVP, which belonging to non-ionic dispersant, can improve the stability and fluidity obviously besides keeping the enhancement of thermal conductivity.

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

scholarly journals Anomalous thermal conductivity enhancement in low dimensional resonant nanostructures due to imperfections

Nanoscale ◽  
2021 ◽  
Author(s):  
Hongying Wang ◽  
Yajuan Cheng ◽  
Zheyong Fan ◽  
Yangyu Guo ◽  
Zhongwei Zhang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Energy Conversion ◽  
Thermal Conductivity Enhancement ◽  
Heat Management ◽  
Thermoelectric Energy Conversion ◽  
Conductivity Enhancement ◽  
Thermoelectric Energy ◽  
Low Dimensional

Nanophononic metamaterials have broad applications in fields such as heat management, thermoelectric energy conversion, and nanoelectronics. Phonon resonance in pillared low-dimensional structures has been suggested to be a feasible approach...

Sign in / Sign up

Export Citation Format

Share Document