An Analytical Study to Compare the Heat Transfer Performances of Water-Based TiO2, SiO2, TiC and SiC Nanofluids

2021 ◽  
Vol 408 ◽  
pp. 119-128
Author(s):  
Md Yeashir Arafat ◽  
Shashwata Chakraborty
Keyword(s):  
Heat Transfer ◽  
Thermophysical Properties ◽  
Figure Of Merit ◽  
Analytical Study ◽  
Convection Heat Transfer ◽  
Effective Density ◽  
Dispersion Effects ◽  
Water Based ◽  
Laminar And Turbulent Flow ◽  
Transfer Properties

The thermophysical properties as well as the thermal performance of a nanofluid can be altered upon varying the nanoparticle type and/or nanoparticle volume concentration. Herein, the effects of variable nanoparticle concentration on water-based TiO2, SiO2, TiC, and SiC nanofluids have been studied analytically. The dispersion effects of 1-4% nanoparticle on the single-phase forced convection heat transfer performance of the nanofluids have been investigated. The effective thermophysical properties of the nanofluids are determined adopting the general correlations. The flow velocities of the nanofluids relative to their base fluids are assumed to be constant. Mouromtseff number has been employed as a convenient figure of merit to compare the nanofluids under fully developed internal laminar and turbulent flow conditions. The results indicate an increase in effective density, thermal conductivity, and dynamic viscosity of the nanofluids. Nanofluids containing carbide suspensions exhibit superior heat transfer properties compared to those having oxide suspensions.

scholarly journals Experimental Research and Development on the Natural Convection of Suspensions of Nanoparticles—A Comprehensive Review

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1855 ◽  
Author(s):  
S. M. Sohel Murshed ◽  
Mohsen Sharifpur ◽  
Solomon Giwa ◽  
Josua P. Meyer
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Thermal Management ◽  
Experimental Research ◽  
Thermophysical Properties ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Stability Evaluation ◽  
Convection Heat ◽  
Systems Research

Suspensions of nanoparticles, widely known as nanofluids, are considered as advanced heat transfer media for thermal management and conversion systems. Research on their convective thermal transport is of paramount importance for their applications in such systems such as heat exchangers and solar collectors. This paper presents experimental research on the natural convection heat transfer performances of nanofluids in different geometries from thermal management and conversion perspectives. Experimental results and available experiment-derived correlations for the natural thermal convection of nanofluids are critically analyzed. Other features such as nanofluid preparation, stability evaluation and thermophysical properties of nanofluids that are important for this thermal transfer feature are also briefly reviewed and discussed. Additionally, techniques (active and passive) employed for enhancing the thermo-convection of nanofluids in different geometries are highlighted and discussed. Hybrid nanofluids are featured in this work as the newest class of nanofluids, with particular focuses on the thermophysical properties and natural convection heat transfer performance in enclosures. It is demonstrated that there has been a lack of accurate stability evaluation given the inconsistencies of available results on these properties and features of nanofluids. Although nanofluids exhibit enhanced thermophysical properties such as viscosity and thermal conductivity, convective heat transfer coefficients were observed to deteriorate in some cases when nanofluids were used, especially for nanoparticle concentrations of more than 0.1 vol.%. However, there are inconsistencies in the literature results, and the underlying mechanisms are also not yet well-understood despite their great importance for practical applications.

Experimental Study of Mixed Convection Shell-and-Coil Heat Exchanger

2008 ◽  
Author(s):  
Nasser Ghorbani Mianroudi ◽  
Mofid Gorji ◽  
Hessam Taherian
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Mixed Convection ◽  
Convection Heat Transfer ◽  
Reynolds Numbers ◽  
Equivalent Diameter ◽  
Coil Diameter ◽  
Laminar And Turbulent Flow ◽  
Helical Coils ◽  
Coil Heat Exchanger

In this study the mixed convection heat transfer in a coil-in-shell heat exchanger for various Reynolds numbers, various tube-to-coil diameter ratios and different dimensionless coil pitch was experimentally investigated. The experiments were conducted for both laminar and turbulent flow inside coil. Effects of coil pitch and tube diameters on shell-side heat transfer coefficient of the heat exchanger were studied. Different characteristic lengths were used in various Nusselt number calculations to determine which length best fits the data and several equations were proposed. The particular difference in this study in comparison with the other similar studies was the boundary conditions for the helical coils. The results indicate that the equivalent diameter of shell is the best characteristic length.

An Analytical Investigation of Free Convection Heat Transfer to Supercritical Water

1970 ◽  
Vol 92 (3) ◽  
pp. 345-350 ◽  
Author(s):  
E. S. Nowak ◽  
A. K. Konanur
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Free Convection ◽  
Supercritical Water ◽  
Thermophysical Properties ◽  
Convection Heat Transfer ◽  
Analytical Investigation ◽  
Convection Heat ◽  
Free Convection Heat ◽  
Vertical Flat Plate

Heat transfer to supercritical water (at 3400 psia in the pseudocritical region) by stable laminar free convection from an isothermal, vertical flat plate was analytically investigated. The actual variations with temperature of all or some of the thermophysical properties of supercritical water were taken into consideration. Fair agreement was found between the analytical values of this paper and existing experimental data.

Effect of Temperature on Rheology and Nanoparticle Movements of Water Based Nanofluids by Molecular Dynamics Simulation

2016 ◽  
Author(s):  
Wenzheng Cui ◽  
Zhaojie Shen ◽  
Jianguo Yang ◽  
Shaohua Wu
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Cooling System ◽  
Combustion Engine ◽  
Dynamics Simulation ◽  
Effect Of Temperature ◽  
Water Based ◽  
Apparent Reason ◽  
Transfer Properties ◽  
Dynamics Method

Employing nanofluids is an innovative way to enhance heat transfer in cooling system of internal combustion engine. the reasons for the significantly enhanced heat transfer properties of nanofluids are various. On one hand, the markedly increased thermal conductivity is the most apparent reason; on the other hand, the changed rheology properties of base fluid due to the disordered movements of countless nanoparticles is even more important. Because the size scale of nanoparticles is too small, in some cases of computational simulations nanofluids is simplified as single-phase fluids. However, the influence of nanoparticles for flow behaviors of base fluids distinctly should not be ignored. By means of molecular dynamics method, a nano-scale simulation on the rheology of nanofluids could be conducted, therefore the movements of nanoparticles could be directly observed, which is conducive to reveal the influence of movements of nanoparticles for rheology of nanofluids. The present work is intended to perform a molecular dynamic simulation on the rheology of water based nanofluids. By applying temperature difference, the velocity and temperature distribution of fluid zone are calculated to evaluate heat transfer through nanofluids. Moreover, the influence of temperature for the movements of nanoparticle is discussed.

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