scholarly journals Heat transfer studies of Al2O3/water-ethylene glycol nanofluid using factorial design analysis

2021 ◽  
pp. 21-21
Author(s):  
Srinivasan Manikandan ◽  
Nesakumar Dharmakkan ◽  
Nagamani Sumana
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Ethylene Glycol ◽  
Transfer Coefficient ◽  
Heat Input ◽  
Base Fluid ◽  
Volume Fraction ◽  
Nanoparticle Volume Fraction ◽  
Experimental Heat ◽  
Fluid Concentration

The experimental study of heat transfer coefficient of nanofluid plays a significant role in improving the heat transfer rate of the heat exchanger. The research was conducted in a natural convection heat transfer apparatus by suspending Al2O3 nanoparticle in a base fluid of Water-Ethylene glycol mixture. The effects of heat input (A), nanoparticle volume fraction (B), and base fluid concentration (C) on experimental heat transfer coefficient (hexpnf) were studied. By the results obtained by MINITDesign software 23 full factorial design matrix, 16 experimental runs were performed with the lower and higher level of input factors. The levels for heat input are 10 and 100 W; nanoparticle volume fraction is 0.1 and 1 volume% and for base fluid concentration is 30 and 50 volume% of Ethylene Glycol in water. From the obtained experimental results residual plots, Pareto chart, contour plot and 3D surface plots were drawn. It can be found from the study that the experimental heat transfer coefficient showed highest enhancement with high level of nanoparticle volume fraction and moderate enhancement with high level of heat input and slight enhancement with base fluid concentration.

scholarly journals Numerical analysis of heat transfer enhancement with the use of γ-Al2O3/water nanofluid and longitudinal ribs in a curved duct

2012 ◽  
Vol 16 (2) ◽  
pp. 469-480 ◽  
Author(s):  
Hosseinali Soltanipour ◽  
Parisa Choupani ◽  
Iraj Mirzaee
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Volume Fraction ◽  
Particle Volume Fraction ◽  
Transfer Enhancement ◽  
Dean Number ◽  
Particle Volume ◽  
The Heat Transfer Coefficient

This paper presents a numerical investigation of heat transfer augmentation using internal longitudinal ribs and ?-Al2O3/ water nanofluid in a stationary curved square duct. The flow is assumed 3D, steady, laminar, and incompressible with constant properties. Computations have been done by solving Navier-Stokes and energy equations utilizing finite volume method. Water has been selected as the base fluid and thermo- physical properties of ?- Al2o3/ water nanofluid have been calculated using available correlations in the literature. The effects of Dean number, rib size and particle volume fraction on the heat transfer coefficient and pressure drop have been examined. Results show that nanoparticles can increase the heat transfer coefficient considerably. For any fixed Dean number, relative heat transfer rate (The ratio of the heat transfer coefficient in case the of ?- Al2o3/ water nanofluid to the base fluid) increases as the particle volume fraction increases; however, the addition of nanoparticle to the base fluid is more useful for low Dean numbers. In the case of water flow, results indicate that the ratio of heat transfer rate of ribbed duct to smooth duct is nearly independent of Dean number. Noticeable heat transfer enhancement, compared to water flow in smooth duct, can be achieved when ?-Al2O3/ water nanofluid is used as the working fluid in ribbed duct.

Experimental investigation and comparison of subcooled flow boiling of TiO2 nanofluid in a vertical and horizontal tube

2012 ◽  
Vol 227 (8) ◽  
pp. 1742-1753 ◽  
Author(s):  
E Abedini ◽  
A Behzadmehr ◽  
H Rajabnia ◽  
SMH Sarvari ◽  
SH Mansouri
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Turbulent Flows ◽  
Base Fluid ◽  
Volume Fraction ◽  
Flow Boiling ◽  
Horizontal Tube ◽  
Subcooled Flow Boiling ◽  
Subcooled Flow

In this study, variations of local heat transfer coefficient are obtained in subcooled flow boiling conditions for water/TiO2 nanofluid in a vertical and horizontal tube. The results for the base fluid are compared with the predictions of the well known Shah correlation and Gnielinski formula for laminar and turbulent flows for single-phase forced convection and also with Chen correlation for subcooled flow boiling. A good agreement between the results is realized. At the subcooled regime, heat transfer coefficient of nanofluid is less than that of the base fluid and it decreases by increasing nanoparticle concentration for both of the channels; however, addition of the nanopraticles into the fluid causes that the vapor volume fraction increases.

scholarly journals Numerical study of the effects of geometric parameters and nanofluid properties on heat transfer and pressure drop in helical tubes

2021 ◽  
Vol 3 (8) ◽  
Author(s):  
Reza Faridi-khouzestani ◽  
Ashkan Ghafouri ◽  
Mahmood Halalizade
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Base Fluid ◽  
Volume Fraction ◽  
Geometric Parameters ◽  
Nanoparticle Diameter ◽  
Helical Coils

AbstractIn this research the geometric parameters and nanofluid properties effects on heat transfer and pressure drop in helical tube, by using alumina-water nanofluid as cooling fluid, are numerically investigated. Friction factor and heat transfer coefficient are calculated by considering the effects of nanofluid properties, including nanoparticle diameter, nanofluid temperature, Reynolds number, and volume fraction, on the one hand, and the impact of geometric parameters, including tube diameter, coils diameter and coils pitch, on the other hand. Numerical analysis is performed in the Ansys Fluent 19.2 software using the SST k-ω turbulence model. By increasing the nanofluid volume fraction the heat transfer coefficient and pressure drop in helical coils increase, the same as the nanoparticle diameter reduction. The reduction of nanoparticle diameter causes an enhancement of heat transfer and friction factor, the best results happen in dp = 5 nm and φ = 4%, where the it was ~ 40.64% more efficient than base fluid. This amounts for φ = 3%, φ = 2% and φ = 1% are 31.80%, 18.02% and 8.83%, respectively. Finally, the performance evaluation criteria (PEC) is compared for different cases, the maximum value was happen on φ = 4% and dp = 5 nm, which it is 1.86 times higher than the base fluid. The results indicate that the thermal efficiency of the heat exchanger improve largely by using helical coils and nanofluids, rather than the base fluid, and direct tubes. In addition, increasing coil pitch and curvature ratio enhance heat transfer and reduce friction factor.

CFD study of slot jet impingement heat transfer with nanofluids

2015 ◽  
Vol 230 (2) ◽  
pp. 206-220 ◽  
Author(s):  
Rabijit Dutta ◽  
Anupam Dewan ◽  
Balaji Srinivasan
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Volume Fraction ◽  
Jet Impingement ◽  
Pumping Power ◽  
Inlet Velocity ◽  
Impingement Heat Transfer

We present a numerical investigation of hydrodynamic and heat transfer behaviors for Al2O3–water nanofluids for laminar and turbulent confined slot jets impingement heat transfer at nanoparticle volume fractions of 3% and 6%. A comparison of the nanofluid with the base fluid has been performed for the same Reynolds number and same jet inlet velocity. A single-phase fluid approach was used to model the nanofluid. Further, the thermo-physical properties of nanofluid were calculated using a recent approach. For the same value of Reynolds number, maximum increase in the average heat transfer coefficient at the impingement plate was found to be approximately 27% and 22% for laminar and turbulent slot impingements, respectively, for 6% volume fraction of nanofluid as compared to that of water. However, the pumping power curve showed a steep increase with the volume fraction with nearly five times increase in the pumping power observed for 6% volume fraction nanofluid. Further, the energy-based performance was assessed with the help of the performance evaluation criterion (PEC). PEC values indicate that nanofluids do not necessarily represent the most efficient coolants for this type of application. Moreover, at the same jet inlet velocity, a reduction in the heat transfer coefficient of 7% and 20% was observed for nanofluid as compared to base fluid for laminar and turbulent flows, respectively.

A Comparative Study on Thermal-Hydraulic Performance of Different Non-Newtonian Nanofluids Through an Elliptical Annulus

2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Prabhakar Zainith ◽  
Niraj Kumar Mishra
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Volume Fraction ◽  
Flow Behavior ◽  
Pure Water ◽  
Reynolds Numbers ◽  
Power Law Model ◽  
Laminar Condition

Abstract This paper presents a numerical investigation on heat transfer and flow behavior for non-Newtonian nanofluids with different nanoparticles (Al2O3 and CuO) and carboxymethyl cellulose (CMC) with water as a base fluid. The analysis has been carried out in an elliptical tube. Power-law model is adopted to depict the non-Newtonian nature of nanofluid. The present study has been done with a range of nanosized particles 0–4% by volume, and the variation of Reynolds number is kept under the laminar condition. The physical model covers two concentric tubes used to create an annular space. The effects of volume fraction, particle type, and base fluid have been investigated at different Reynolds numbers numerically. Also, the effect of pressure and heat transfer coefficient on the flow behavior of non-Newtonian nanofluids is analyzed. The results concluded that Al2O3 particles showed 219% and CuO particles give 195% higher heat transfer coefficient as compared with pure water.

scholarly journals Experimental investigation of convective heat transfer enhancement using alumina/water and copper oxide/water nanofluids

2016 ◽  
Vol 20 (5) ◽  
pp. 1681-1692 ◽  
Author(s):  
Chidanand Mangrulkar ◽  
Vilayatrai Kriplani ◽  
Ashwinkumar Dhoble
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Fluid Flow ◽  
Transfer Coefficient ◽  
Base Fluid ◽  
Volume Fraction ◽  
Constant Heat Flux ◽  
Flow Through ◽  
The Heat Transfer Coefficient ◽  
Cuo Nanopowders

The nanofluids are widely used for heat transfer applications in the various engineering applications. The nanoparticles dispersed uniformly in the base fluid on proper mixing. In the present study, Al2O3 and CuO nanoparticles were selected and the changes in the heat transfer coefficient were investigated in the complete laminar and discrete points of transition fluid flow through a copper tube with constant heat flux. The heat transfer coefficient was investigated at different loading of Al2O3 and CuO nanopowders ranging from 0.1% to 0.5% of volume concentration in each case for the laminar and transition fluid flow zones, which is then compared with the distilled water as a plain base fluid. It is found that the optimum enhancement in heat transfer is observed at relatively lower volume fraction of nanoparticles ranging between 0.2 to 0.3%.

Investigation of Ethylene Glycol Heat Transfer Coefficient Trough Double Pipe and Coil Heat Exchanger

2021 ◽  
Vol 874 ◽  
pp. 165-170
Author(s):  
Sri Wuryanti ◽  
Tina Mulya Gantina ◽  
Indriyani
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Ethylene Glycol ◽  
Transfer Coefficient ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Test System ◽  
Double Pipe ◽  
The Heat Transfer Coefficient ◽  
Outer Pipe

The research objective is to assemble a convection test system which acts as a heat exchanger (HE) and test its applicability using ethylene glycol. A Double Pipe (DP)-type HE consists of an inner pipe surrounded by an outer pipe (annulus) whereas a Coil-type HE composed of a coil surrounded by an outer pipe. Water flows through the outer pipe in both types of HE, while ethylene glycol flows through the inner piper or coil. HE in combination with other components (such as) forms a convection test system. The applicability of the system was tested to determine the heat transfer coefficient of ethylene glycol in a DP-type and Coil-type HEs. After that, the heat transfer rate was calculated and compared. The results show that the heat transfer coefficient in the DP-type HE is the lowest at 12.2 W/m2 oC and the highest at 26.8 W/m2 oC; and the corresponding heat transfer rate is the lowest at 8.3 W and the highest is 56.3 W. In comparison, for Coil-type HE, the lowest heat transfer coefficient is 38.9 W/m2 oC and the highest is 66.2 W/m2 oC which correspond to the heat transfer rate 19.9 W at the lowest and 225 W at the highest.

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