scholarly journals A numerical study on convection around a square cylinder using Al2O3-H2O nanofluid

2014 ◽  
Vol 18 (4) ◽  
pp. 1305-1314 ◽  
Author(s):  
Mohammad Valipour ◽  
Reza Masoodi ◽  
Saman Rashidi ◽  
Masoud Bovand ◽  
Mojtaba Mirhosseini

In this paper, a numerical simulation has been performed to study the fluid flow and heat transfer around a square cylinder utilizing Al2O3-H2O nanofluid over low Reynolds numbers. Here, both Reynolds and Peclet numbers are varied within the range of 1 to 40and the volume fraction of nanoparticles (?) is varied within the range of 0<?<0.05. Two-dimensional and steady mass continuity, momentum and energy equations have been discretized using Finite Volume Method (FVM). SIMPLE algorithm has been applied for solving the pressure linked equations. The effect of volume fraction of nanoparticles on fluid flow and heat transfer were investigated numerically. It was found that at a given Reynolds number, the Nusselt number, drag coefficient, recirculation length, and pressure coefficient increases by increasing the volume fraction of nanoparticles.

10.30544/450 ◽  
2020 ◽  
Vol 26 (1) ◽  
pp. 71-86
Author(s):  
Kamel Korib ◽  
Mohamed ROUDANE ◽  
Yacine Khelili

In this paper, a numerical simulation has been performed to study the fluid flow and heat transfer around a rotating circular cylinder over low Reynolds numbers. Here, the Reynolds number is 200, and the values of rotation rates (α) are varied within the range of 0 < α < 6. Two-dimensional and unsteady mass continuity, momentum, and energy equations have been discretized using the finite volume method. SIMPLE algorithm has been applied for solving the pressure linked equations. The effect of rotation rates (α) on fluid flow and heat transfer were investigated numerically. Also, time-averaged (lift and drag coefficients and Nusselt number) results were obtained and compared with the literature data. A good agreement was obtained for both the local and averaged values.


2019 ◽  
Vol 39 (3) ◽  
pp. 261-269
Author(s):  
Khelili Yacine ◽  
Abderrazak Allali ◽  
Rafik Bouakkaz

This paper presents a numerical solution for low Reynolds number, unsteady flow around, and heat transfer from a stationary circular cylinder placed in a uniform flow. The fluid is assumed to be incompressible and of constant property. Twodimensional and unsteady mass continuity, momentum, and energy equations have been discretized using finite volume method. A SIMPLE algorithm has been applied for solving the pressure linked equations. The range of Reynolds numbers was investigated which varied from 50 to 300 with volume fraction on Cu nanoparticles varying from 1 to 5 % at the constant wall temperature. The results of the heat transfer characteristics of nanofluid flow over a circular cylinder showed marked improvement comparing with the base fluid. It is found that the vorticity, pressure coefficient, and recirculation length are increased by the addition of nanoparticles into base fluid. Moreover, the local and mean Nusselt numbers are enhanced due to adding nanoparticles into base fluid.


2018 ◽  
Vol 16 ◽  
pp. 1-11
Author(s):  
Houssem Laidoudi

2D simulation is carried out to determine exactly the effect of blockage ratio on the flow and mixed convection heat transfer characteristics of Newtonian fluid across a square cylinder confined in horizontal channel, the numerical study is investigated in the range of these conditions:Re= 10 to 30,Ri= 0 to 1 and blockage ratioβ= 1/10 to 1/2. The flow structure and temperature field are visualized in terms of streamlines and isotherm contours. The total drag coefficient and average Nusselt number are also reported to show the combined effects of thermal buoyancy, Reynolds number and blockage ratio on the hydrodynamic flow forces and heat transfer rate. The obtained results showed that the effect of thermal buoyancy on fluid flow and heat transfer becomes more pronounced by decreasing the blockage ratio.


10.30544/242 ◽  
2017 ◽  
Vol 23 (1) ◽  
pp. 83-97
Author(s):  
Yacine Khelili ◽  
Abderrazak Allali ◽  
Rafik Bouakkaz

Numerical investigation of heat transfer phenomena of low Reynolds number nano-fluid flow over an isothermal cylinder is presented in this paper. Steady state governing equations (continuity, N–S and energy equations) have been solved using finite volume method. Stationary heat transfer, and flow characteristics over the cylinder have been studied for water based copper nanofluid with different solid fraction values. The effect of volume fraction of nano- particles on the fluid flow and heat transfer were investigated numerically. It was found that at a given Nusselt number, drag coefficient, re-circulation length, and pressure coefficient increase by increasing the volume fraction of nano-particles.


2011 ◽  
Vol 13 ◽  
pp. 75-80 ◽  
Author(s):  
Ghanbar Ali Sheikhzadeh ◽  
A. Arefmanesh ◽  
Mostafa Mahmoodi

In this study, the buoyancy-driven fluid flow and heat transfer in a differentially-heated rectangular cavity filled with the TiO2-water nanofluid is investigated numerically. The left and the top walls of the cavity are maintained at constant temperatures Thand Tc, respectively, with Th> Tc.The enclosure’s right and bottom walls are kept insulated. The governing equations are discretized using the finite volume method. A proper upwinding scheme is employed to obtain stabilized solutions for high Rayleigh numbers. Using the developed code, a parametric study is undertaken, and the effects of pertinent parameters, such as, the Rayleigh number, the aspect ratio of the cavity and the volume fraction of the nanoparticles on the fluid flow and heat transfer inside the cavity are investigated. It is observed from the results that by increasing the volume fraction of the nanoparticles, the mean Nusselt number of the hot wall increases for the shallow cavities; while, the reverse trend occurs for the tall cavities. Moreover, the heat transfer enhancement utilizing nanofluid is more effective at Ra = 103.


Symmetry ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 591 ◽  
Author(s):  
Zahra Abdelmalek ◽  
Annunziata D’Orazio ◽  
Arash Karimipour

Microchannels are widely used in electrical and medical industries to improve the heat transfer of the cooling devices. In this paper, the fluid flow and heat transfer of water–Al2O3 nanofluids (NF) were numerically investigated considering the nanoparticle shape and different cross-sections of a porous microchannel. Spherical, cubic, and cylindrical shapes of the nanoparticle as well as circular, square, and triangular cross-sections of the microchannel were considered in the simulation. The finite volume method and the SIMPLE algorithm have been employed to solve the conservation equations numerically, and the k-ε turbulence model has been used to simulate the turbulence fluid flow. The models were simulated at Reynolds number ranging from 3000 to 9000, the nanoparticle volume fraction ranging from 1 to 3, and a porosity coefficient of 0.7. The results indicate that the average Nusselt number (Nuave) increases and the friction coefficient decreases with an increment in the Re for all cases. In addition, the rate of heat transfer in microchannels with triangular and circular cross-sections is reduced with growing Re values and concentration. The spherical nanoparticle leads to maximum heat transfer in the circular and triangular cross-sections. The heat transfer growth for these two cases are about 102.5% and 162.7%, respectively, which were obtained at a Reynolds number and concentration of 9000 and 3%, respectively. However, in the square cross-section, the maximum heat transfer increment was obtained using cylindrical nanoparticles, and it is equal to 80.2%.


2015 ◽  
Vol 9 (3) ◽  
pp. 242 ◽  
Author(s):  
Efstathios Kaloudis ◽  
Dimitris Siachos ◽  
Konstantinos Stefanos Nikas

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