scholarly journals Investigation on Heat Transfer and Pressure Drop Performance Utilizing GNP-based Colloidal Suspension Flow in Finned Conduit

2021 ◽  
Vol 945 (1) ◽  
pp. 012056
Author(s):  
Yanru Wang ◽  
Cheen Sean Oon ◽  
Manh-Vu Tran ◽  
Joshua Yap Kee An
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Colloidal Suspension ◽  
Convective Heat Transfer Coefficient ◽  
Constant Heat Flux

Abstract Heat exchangers have been widely used in various engineering applications. It is important to develop a highly efficient heat transfer equipment to reduce carbon footprint. In the current research, the effect of 0.025wt% CGNP/water nanofluid on convective heat transfer and pressure drop performance is investigated numerically in finned conduits with circular and square geometry. ANSYS FLUENT is used to analyze the turbulent flow inside the conduits with Reynolds number ranging from 7360 to 28011 and constant heat flux 12254.90W/m2 and 9615.38W/m2 in circular and square geometry, respectively. Only 1/8 of the pipe was constructed in the simulation as the geometry is symmetrical. The numbers of mesh elements are 465488 and 469144 for circular and square conduits. SST k-omega viscous model, SIMPLEC scheme and second-order upwind solvers are used in this model, where SST k-omega viscous model is good at solving turbulence parameters in the near wall boundary regions. It is found that the use of CGNP/water nanofluid can increase convective heat transfer coefficient without increasing pressure drop compared with water. Besides, the circular pipe shows higher heat transfer enhancement compared with square pipe. Furthermore, the increase in Reynolds number enhances the Nusselt number and heat transfer coefficient in both circular and square geometries. It is recommended that circular finned pipe and CGNP/water colloidal suspension could be applied in low turbulence flow setting heat exchanger.

Convective Heat Transfer Coefficient and Pressure Drop of Al2O3-Water Nanofluid in a Single-Phase Microchannel for Cooling of High Heat Output Devices

2008 ◽  
Author(s):  
Guillermo E. Valencia ◽  
Miguel A. Ramos ◽  
Antono J. Bula
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Heat Output ◽  
Flux Boundary Condition

The paper describes an experimental procedure performed to obtain the convective heat transfer coefficient of Al2O3 nanofluid working as cooling fluid under turbulent regimen through arrays of aluminum microchannel heat sink having a diameter of 1.2 mm. Experimental Nusselt number correlation as a function of the volume fractions, Reynolds, Peclet and Prandtl numbers for a constant heat flux boundary condition is presented. The correlation for Nusselt number has a good agreement with experimental data and can be used to predict heat transfer coefficient for this specific nanofluid, water/Al2O3. Furthermore, the pressure drop is also analyzed considering the different nanoparticles concentration.

Convective Heat Transfer Characteristics of Silver-Water Nanofluid Under Laminar and Turbulent Flow Conditions

2012 ◽  
Vol 4 (3) ◽  
Author(s):  
Lazarus Godson ◽  
B. Raja ◽  
D. Mohan Lal ◽  
S. Wongwises
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Pure Water ◽  
Convective Heat Transfer Coefficient ◽  
Experimental Results

The convective heat transfer coefficient and pressure drop of silver-water nanofluids is measured in a counter flow heat exchanger from laminar to turbulent flow regime. The experimental results show that the convective heat transfer coefficient of the nanofluids increases by up to 69% at a concentration of 0.9 vol. % compared with that of pure water. Furthermore, the experimental results show that the convective heat transfer coefficient enhancement exceeds the thermal conductivity enhancement. It is observed that the measured heat transfer coefficient is higher than that of the predicted ones using Gnielinski equation by at least 40%. The use of the silver nanofluid has a little penalty in pressure drop up to 55% increase 0.9% volume concentration of silver nanoparticles.

Gas Solids Suspension Convective Heat Transfer at a Reynolds Number of 130,000

1968 ◽  
Vol 90 (4) ◽  
pp. 464-468 ◽  
Author(s):  
R. Briller ◽  
R. L. Peskin
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Particle Temperature ◽  
Convective Heat Transfer Coefficient ◽  
Loading Ratio ◽  
High Reynolds

An experiment was performed to determine the convective heat-transfer coefficient to heated and cooled gas solids suspensions at a Reynolds number of 130,000. Measurements of the heat transfer were performed by traversing the stream at various locations along the pipe with specially designed probes which measured air and particle temperature locally. The results showed that for a high Reynolds number, the heat-transfer coefficient for the suspension appears to be equal to that of the pure gas at the same Reynolds number, and independent of solids loading ratio, heating or cooling, and particle size (between 0.0011 and 0.0058 in. dia).

Heat Transfer Characteristics of an Array of Impinging Gaseous Slot Jets

2011 ◽  
Vol 396-398 ◽  
pp. 2234-2239
Author(s):  
Zu Ling Liu ◽  
Cheng Bo Wu ◽  
Xian Jun Wang ◽  
Zheng Rong Zhang
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Nozzle Exit ◽  
Convective Heat Transfer Coefficient ◽  
Heat Transfer Characteristics ◽  
Forced Convective Heat Transfer

A comprehensive experiment was conducted for heat transfer characteristics for an array of impinging gaseous slot jets to a flat plate with strong turbulence (nozzle exit Reynolds number Re=22500~64700).Find that turbulence intensity of flow has an important influence on local forced convective heat transfer coefficient. Meanwhile, the nozzle-to-plate spacing and nozzle exit Reynolds number Re would affect the mean forced convective heat transfer coefficient of the slot jets. And heat transfer efficiency of slot jets has been set to show the relation between ability of the jets and energy consumption of gas supply.

Influence of Various Nanofluid Types on Wavy Microchannels Heat Sink Cooling Performance

2013 ◽  
Vol 420 ◽  
pp. 118-122 ◽  
Author(s):  
Prem Gunnasegaran ◽  
Noel Narindra ◽  
Norshah Hafeez Shuaib
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Heat Sink ◽  
Convective Heat Transfer Coefficient ◽  
Volume Fractions ◽  
The Impact

This paper discusses the impact of using various types of nanofluids and nanoparticle volume fractions on heat transfer and fluid flow characteristics in a wavy microchannel heat sink (WMCHS) with rectangular cross-section. Numerical investigations using three different types of nanofluids including Al2O3-H2O, CuO-H2O, and diamond-H2O with a fixed nanoparticle volume fraction of 3% and using a diamond-H2O with nanoparticle volume fractions ranging from 0.5% to 5% are examined. This investigation covers Reynolds numbers in the range of 100 to 1000. The three-dimensional steady, laminar flow and heat transfer governing equations are solved using the finite-volume method (FVM). The computational model is used to study the variations of convective heat transfer coefficient, pressure drop and wall shear stress. It is inferred that the convective heat transfer coefficient of a WMCHS cooled with the nanofluid flow showed marked improvement over the pure water with a smaller pressure drop penalty.

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