scholarly journals Heat transfer analysis of nanofluid flow through backward facing step

2020 ◽  
Vol 307 ◽  
pp. 01010 ◽  
Author(s):  
Ahlem Boudiaf ◽  
Fetta Danane ◽  
Youb Khaled Benkahla ◽  
Walid Berabou ◽  
Mahdi Benzema ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Thermal Characteristics ◽  
Heat Transfer Analysis ◽  
Backward Facing Step ◽  
Nanofluid Flow ◽  
Numerical Predictions ◽  
Flow Through ◽  
Volume Method

This paper presents the numerical predictions of hydrodynamic and thermal characteristics of nanofluid flow through backward facing step. The governing equations are solved through the finite volume method, as described by Patankar, by taking into account the associated boundary conditions. Empirical relations were used to give the effective dynamic viscosity and the thermal conductivity of the nanofluid. Effects of different key parameters such as Reynolds number, nanoparticle solid volume fraction and nanoparticle solid diameter on the heat transfer and fluid flow are investigated. The results are discussed in terms of the average Nusselt number and streamlines.

scholarly journals Numerical Analysis of The Thermo-Convective Behaviour of an Al2O3-H2O Nanofluid Flow Inside a Channel with Trapezoidal Corrugations

2021 ◽  
Vol 89 (2) ◽  
pp. 114-127
Author(s):  
Mostefaoui Amina ◽  
Saim Rachid ◽  
Abboudi Saïd
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Volume Fraction ◽  
High Volume ◽  
Reynolds Numbers ◽  
Constant Heat Flux ◽  
Nanofluid Flow ◽  
Nanoparticle Diameter ◽  
Flow Through ◽  
Volume Method

In this present article, a study of the dynamic and thermal behavior of the Al2O3-water nanofluid flow through a channel provided with trapezoidal undulations, under the action of a constant heat flux. To do this, the effect of various volume fractions (0-4%) and that of the nanoparticle diameter (30, 40, 60 nm) on the heat transfer and pressure drop within the channel was analyzed, for a range of Reynolds numbers between 100 to 1000. The equations governing the fluid flow, namely the equations of continuity, momentum and energy were integrated and discretized based on the finite volume method (FVM). The obtained results indicated that using nanofluids with a high-volume fraction and a small nanoparticle diameter makes it possible to improve the performance of the system in terms of heat transfer, pressure drop and friction factor.

Turbulent Nanofluid Flow Analysis Passing a Shell and Tube Thermal Exchanger with Kays-Crawford Model

2021 ◽  
Vol 10 (4) ◽  
pp. 518-537
Author(s):  
R. Nasrin ◽  
S. A. Sweety ◽  
I. Zahan
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Pure Water ◽  
Fluid Velocity ◽  
Solid Volume Fraction ◽  
Heat Transfer Analysis ◽  
Inlet Temperature ◽  
Industrial Sectors ◽  
Shell And Tube ◽  
Thermal Exchanger

Temperature dissipation in a proficient mode has turned into a crucial challenge in industrial sectors because of worldwide energy crisis. In heat transfer analysis, shell and tube thermal exchangers is one of the mostly used strategies to control competent heat transfer in industrial progression applications. In this research, a numerical analysis of turbulent flow has been conceded in a shell and tube thermal exchanger using Kays-Crawford model to investigate the thermal performance of pure water and different concentrated water-MWCNT nanofluid. By means of finite element method the Reynold-Averaged Navier-Stokes (RANS) and heat transport equations along with suitable edge conditions have been worked out numerically. The implications of velocity, solid concentration, and temperature of water-MWCNT nanofluid on the fluid flow formation and heat transfer scheme have been inspected thoroughly. The numerical results indicate that the variation of nanoparticles solid volume fraction, inflow fluid velocity and inlet temperature mannerism considerably revolutionize in the flow and thermal completions. It is perceived that using 3% concentrated water-MWCNT nanofluid, higher rate of heat transfer 12.24% is achieved compared that of water and therefore to enhance the efficiency of this heat exchanger. Furthermore, a new correlation has been developed among obtained values of thermal diffusion rate, Reynolds number and volume concentration of nanoparticle and found very good correlation coefficient among the values.

scholarly journals Numerical Investigation of Heat Transfer Enhancement in a Rectangular Heated Pipe for Turbulent Nanofluid

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Hooman Yarmand ◽  
Samira Gharehkhani ◽  
Salim Newaz Kazi ◽  
Emad Sadeghinezhad ◽  
Mohammad Reza Safaei
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Volume Fraction ◽  
Rectangular Channel ◽  
Thermal Characteristics ◽  
Reynolds Numbers ◽  
Constant Heat Flux ◽  
Energy Equations ◽  
Volume Method ◽  
Good Agreement

Thermal characteristics of turbulent nanofluid flow in a rectangular pipe have been investigated numerically. The continuity, momentum, and energy equations were solved by means of a finite volume method (FVM). The symmetrical rectangular channel is heated at the top and bottom at a constant heat flux while the sides walls are insulated. Four different types of nanoparticles Al2O3, ZnO, CuO, and SiO2at different volume fractions of nanofluids in the range of 1% to 5% are considered in the present investigation. In this paper, effect of different Reynolds numbers in the range of 5000 < Re < 25000 on heat transfer characteristics of nanofluids flowing through the channel is investigated. The numerical results indicate that SiO2-water has the highest Nusselt number compared to other nanofluids while it has the lowest heat transfer coefficient due to low thermal conductivity. The Nusselt number increases with the increase of the Reynolds number and the volume fraction of nanoparticles. The results of simulation show a good agreement with the existing experimental correlations.

scholarly journals Hydrothermal and Entropy Investigation of Ag/MgO/H2O Hybrid Nanofluid Natural Convection in a Novel Shape of Porous Cavity

2021 ◽  
Vol 11 (4) ◽  
pp. 1722
Author(s):  
Nidal Abu-Libdeh ◽  
Fares Redouane ◽  
Abderrahmane Aissa ◽  
Fateh Mebarek-Oudina ◽  
Ahmad Almuhtady ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Natural Convection ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Hybrid Nanofluid ◽  
The Finite Element Method ◽  
Governing Equations ◽  
Nanofluid Flow ◽  
The Magnetic Field

In this study, a new cavity form filled under a constant magnetic field by Ag/MgO/H2O nanofluids and porous media consistent with natural convection and total entropy is examined. The nanofluid flow is considered to be laminar and incompressible, while the advection inertia effect in the porous layer is taken into account by adopting the Darcy–Forchheimer model. The problem is explained in the dimensionless form of the governing equations and solved by the finite element method. The results of the values of Darcy (Da), Hartmann (Ha) and Rayleigh (Ra) numbers, porosity (εp), and the properties of solid volume fraction (ϕ) and flow fields were studied. The findings show that with each improvement in the Ha number, the heat transfer rate becomes more limited, and thus the magnetic field can be used as an outstanding heat transfer controller.

scholarly journals Investigation of Forced Convection Enhancement and Entropy Generation of Nanofluid Flow through a Corrugated Minichannel Filled with a Porous Media

Entropy ◽  
2020 ◽  
Vol 22 (9) ◽  
pp. 1008
Author(s):  
Ehsan Aminian ◽  
Hesam Moghadasi ◽  
Hamid Saffari ◽  
Amir Mirza Gheitaghy
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Entropy Generation ◽  
Volume Fraction ◽  
Numerical Procedure ◽  
Numerical Data ◽  
Flow In Porous Media ◽  
Geometrical Parameters ◽  
Nanofluid Flow ◽  
Flow Through

Corrugating channel wall is considered to be an efficient procedure for achieving improved heat transfer. Further enhancement can be obtained through the utilization of nanofluids and porous media with high thermal conductivity. This paper presents the effect of geometrical parameters for the determination of an appropriate configuration. Furthermore, the optimization of forced convective heat transfer and fluid/nanofluid flow through a sinusoidal wavy-channel inside a porous medium is performed through the optimization of entropy generation. The fluid flow in porous media is considered to be laminar and Darcy–Brinkman–Forchheimer model has been utilized. The obtained results were compared with the corresponding numerical data in order to ensure the accuracy and reliability of the numerical procedure. As a result, increasing the Darcy number leads to the increased portion of thermal entropy generation as well as the decreased portion of frictional entropy generation in all configurations. Moreover, configuration with wavelength of 10 mm, amplitude of 0.5 mm and phase shift of 60° was selected as an optimum geometry for further investigations on the addition of nanoparticles. Additionally, increasing trend of average Nusselt number and friction factor, besides the decreasing trend of performance evaluation criteria (PEC) index, were inferred by increasing the volume fraction of the nanofluid (Al2O3 and CuO).

scholarly journals Forced Convection of Pulsating Nanofluid Flow over a Backward Facing Step with Various Particle Shapes

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3068 ◽  
Author(s):  
Ali Chamkha ◽  
Fatih Selimefendigil
Keyword(s):  
Nusselt Number ◽  
Strouhal Number ◽  
Average Nusselt Number ◽  
Volume Fraction ◽  
Spherical Particles ◽  
Backward Facing Step ◽  
Nanofluid Flow ◽  
Flow Configurations ◽  
Volume Method ◽  
Nanoparticle Shapes

In this study, numerical analysis of forced convective pulsating nanofluid flow over a backward-facing step with different nanoparticle shapes was performed by the finite volume method. The effects of the Strouhal number (between 0.1 and 2), solid nanoparticle volume fraction (between 0 and 0.04) and nanoparticle shapes (spherical, blade and cylindrical) on the heat transfer and fluid flow were examined with the aid of numerical simulation. It was observed that the average Nusselt number is a decreasing function of the Strouhal number for the considered range, and it enhances for higher solid particle fractions. Using nanofluids with spherical particles is advantageous in pulsating flow, whereas cylindrically-shaped particles are preferred in steady flow configurations. Average Nusselt number enhancements up to 30.24% and 27.95% are achieved with cylindrical- and spherical-shaped particles at the highest volume fraction.

scholarly journals The effect of volume fraction of SiO2 nanoparticle on flow and heat transfer characteristics in a duct with corrugated backward-facing step

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1435-1447 ◽  
Author(s):  
Recep Ekiciler ◽  
Emre Aydeniz ◽  
Kamil Arslan
Keyword(s):  
Heat Transfer ◽  
Volume Fraction ◽  
Numerical Study ◽  
Expansion Ratio ◽  
Uniform Heat Flux ◽  
Heat Transfer Characteristics ◽  
Backward Facing Step ◽  
Nanofluid Flow ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

In this paper, flow and heat transfer characteristics of SiO2-water nanofluid flow over a corrugated backward-facing step are numerically investigated. The numerical study is performed by solving governing equations (continuity, momentum, and energy) with finite volume method. The duct inlet and step heights are 4.8 mm. The expansion ratio is 2. The upstream wall, Lu, and downstream wall, Ld, lengths are 48 cm and 96 cm, respectively. The downstream wall of the duct is subjected to a constant and uniform heat flux of 2000 W/m2. The ranges of the volume fraction of nanoparticles and Reynolds number are 0%-3.0% and 135-240, respectively. The effects of the volume fraction of nanoparticles on the average Nusselt number, average Darcy friction factor, and velocity distribution are investigated under laminar forced convective nanofluid flow condition. It is revealed that the nanoparticle volume fraction substantially influences the heat transfer and flow characteristics. The volume fraction of 3.0% shows the highest heat transfer performance.

scholarly journals Three-dimensional and two-phase nanofluid flow and heat transfer analysis over a stretching infinite solar plate

2018 ◽  
Vol 22 (2) ◽  
pp. 871-884 ◽  
Author(s):  
Mohammad Hatami ◽  
Mehdi Khazayinejad ◽  
Jiandong Zhou ◽  
Dengwei Jing
Keyword(s):  
Heat Transfer ◽  
Collocation Method ◽  
Volume Fraction ◽  
Three Dimensional ◽  
Heat Transfer Analysis ◽  
Nanofluid Flow ◽  
Two Phase ◽  
Flow And Heat Transfer ◽  
Nanoparticles Concentration ◽  
Accuracy Of Results

In this work, 3-D and two-phase nanofluid flow and heat transfer is modeled over a stretching infinite solar plate. The governing equations are presented based on previous studies. The infinite boundary condition and shortcoming of traditional analytical collocation method have been overcome in our study by changing the problem into a finite boundary problem with a new analytical method called optimal collocation method. The accuracy of results is examined by fourth order Runge-Kutta numerical method. Effect of some parameters, Prandtl number, Schmidt number, Brownian motion parameter, thermophoresis parameter, ?=b/a (ratio of the stretching rate along y- to x-directions), and power-law index on the velocities, temperature, and nanoparticles concentration functions are discussed. As an important outcome of our 3-D model analysis, it is found that increase in thermophoretic forces can enhance the thickness of both thermal and nanoparticle volume fraction boundary-layers.

scholarly journals Entropy generation of zirconia-water nanofluid flow through rectangular micro-channel

2018 ◽  
Vol 22 (Suppl. 5) ◽  
pp. 1395-1405
Author(s):  
Cuneyt Uysal ◽  
Kamil Arslan ◽  
Huseyin Kurt
Keyword(s):  
Entropy Generation ◽  
Volume Fraction ◽  
Constant Heat Flux ◽  
Bottom Surface ◽  
Bejan Number ◽  
Micro Channel ◽  
Nanoparticle Volume Fraction ◽  
Nanofluid Flow ◽  
Flow Through ◽  
Volume Method

The fluid flow and heat transfer characteristics and entropy generation of zirconia, ZrO2-water, nanofluid flow through a rectangular micro-channel are numerically investigated. The flow is considered under single-phase 3-D steady-state incompressible laminar flow conditions. The constant heat flux is applied to the bottom surface of micro-channel. The finite volume method is used to discretize the governing equations. As a result, the average Nusselt number decreases with increasing nanoparticle volume fraction, while the average Darcy friction factor is not affected. Moreover, the total entropy generation decreases with increase in nanoparticle volume fraction, while the Bejan number is almost not affected.

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