Numerical Study of Natural Convection in a Differentially-Heated Rectangular Cavity Filled with TiO2-Water Nanofluid

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.

2018 ◽  
Vol 7 (4.35) ◽  
pp. 148 ◽  
Author(s):  
Nur Irmawati Om ◽  
Rozli Zulkifli ◽  
P. Gunnasegaran

The influence of utilizing different nanofluids types on the liquid cold plate (LCP) is numerically investigated. The thermal and fluid flow performance of LCP is examined by using pure ethylene glycol (EG), Al2O3-EG and CuO-EG. The volume fraction of the nanoparticle for both nanofluid is 2%. The finite volume method (FVM) has been used to solved 3-D steady state, laminar flow and heat transfer governing equations. The presented results indicate that Al2O3-EG able to provide the lowest surface temperature of the heater block followed by CuO-EG and EG, respectively. It is also found that the pressure drop and friction factor are higher for Al2O3-EG and CuO-EG compared to the pure EG.


2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Abdelkader Boutra ◽  
Karim Ragui ◽  
Nabila Labsi ◽  
Youb Khaled Benkahla

AbstractThis paper reports a numerical study on mixed convection within a square enclosure, filled with a mixture of water and Cu (or Ag) nanoparticles. It is assumed that the temperature difference driving the convection comes from the side moving walls, when both horizontal walls are kept insulated. In order to solve the general coupled equations, a code based on the finite volume method is used and it has been validated after comparison between the present results and those of the literature. To make clear the effect of the main parameters on fluid flow and heat transfer inside the enclosure, a wide range of the Richardson number, taken from 0.01 to 100, the nanoparticles volume fraction (0% to 10%), and the cavity inclination angle (0º to 180º) are investigated. The phenomenon is analyzed through streamlines and isotherm plots, with special attention to the Nusselt number.


Author(s):  
Cornelia Revnic ◽  
Eiyad Abu-Nada ◽  
Teodor Grosan ◽  
Ioan Pop

Purpose This paper aims to develop a numerical study of the steady natural convection in a rectangular cavity filled with the CuO–water-based nanofluid. It is assumed that the viscosity of nanofluids depends on the temperature and on the nanofluids volume fraction. Design/methodology/approach The mathematical nanofluid model has been formulated on the basis of the model proposed by Buongiorno (2006). The system of partial differential equations is written in terms of a dimensionless stream function, vorticity, temperature and the volume fraction of the nanoparticles, and is solved numerically using the finite difference method for different values of the governing parameters. Findings It is found that both fluid flow and heat transfer coefficient are affected by the considered parameters. Thus, the Nusselt number is slowly increasing with increasing volume fraction from 2 per cent to 5 per cent and it is more pronounced increasing with increasing Rayleigh number from 103 to 105. Originality/value Buongiorno’s (2006) nanofluid model has been applied for the flow with the characteristics as mentioned in the paper. A comprehensive survey on the behavior of flow and heat transfer characteristics has been presented. All plots presented in the paper are new and are not reported in any other study.


2015 ◽  
Vol 19 (3) ◽  
pp. 1067-1076 ◽  
Author(s):  
Seyed Sebti ◽  
Mohammad Mastiani ◽  
Sina Kashani ◽  
Hooshyar Mirzaei ◽  
Ahmad Sohrabi

Heat transfer enhancement during melting in a two-dimensional cylindrical annulus through dispersion of nanoparticle is investigated numerically. Paraffin-based nanofluid containing various volume fractions of Cu is applied. The governing equations are solved on a non-uniform O type mesh using a pressure-based finite volume method with an enthalpy porosity technique to trace the solid and liquid interface. The effects of nanoparticle dispersion into pure fluid as well as the influences of some significant parameters, namely, nanoparticle volume fraction and natural convection on the fluid flow and heat transfer features are studied. The results are presented in terms of streamlines, isotherms, temperatures and velocity profiles and dimensionless heat flux. It is found that the suspended nanoparticles give rise to the higher thermal conductivity as compared to the pure fluid and consequently the heat transfer is enhanced. In addition, the heat transfer rate and the melting time increases and decreases, respectively, as the volume fraction of nanoparticle increases.


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.


2014 ◽  
Vol 18 (suppl.2) ◽  
pp. 283-300 ◽  
Author(s):  
Mostafa Mahmoodi ◽  
Arani Abbasian ◽  
Sebdani Mazrouei ◽  
Saeed Nazari ◽  
Mohammad Akbari

The problem of free convection fluid flow and heat transfer in a square cavity with a flush mounted heat source on its bottom wall and two heat sinks on its vertical side walls has been investigated numerically. Via changing the location of the heat sinks, six different arrangements have been generated. The cavity was filled with Cu-water nanofluid. The governing equations were discretized using the finite volume method and SIMPLER algorithm. Using the developed code, a parametric study was undertaken, and effects of Rayleigh number, arrangements of the heat sinks and volume fraction of the nanoparticles on fluid flow and heat transfer inside the cavity were investigated. Also for the middle-middle heat sinks arrangement, capability of five different water based nanofluids on enhancement of the rate of heat transfer was examined and compared. From the obtained results it was found that the average Nusselt number, for all six different arrangements of the heat sinks, was an increasing function of the Rayleigh number and the volume fraction of the nanoparticles. Also it was found that at high Rayleigh numbers, maximum and minimum average Nusselt number occurred for middle-middle and top-bottom arrangement, respectively. Moreover it was found that for the middle-middle arrangement, at high Rayleigh numbers, maximum and minimum rate of heat transfer was obtained by Cu-water and TiO2-water nanofluids respectively.


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.


2022 ◽  
Vol 17 ◽  
pp. 19-28
Author(s):  
Taloub Djedid ◽  
Bouras Abdelkrim ◽  
Zied Driss

In this document, a numerical study of the natural convection of steady-state laminar heat transfer in a horizontal ring between a heated hexagonal inner cylinder and a cold hexagonal outer cylinder. A Cu - water nanofluid traverses this annular space. The system of equations governing the problem was solved numerically by the fluent calculation code based on the finite volume method. Based on the Boussinesq approximation. The interior and exterior sides from the two cylinders are maintained at a fixed temperature. We investigated the impacts of various thermal Rayleigh numbers (103≤ Rat ≤2.5x105), and the volume fraction from the nanoparticles (0≤ Ø ≤0.12) on fluid flow and heat transfer performance. It is found that in high thermal Rayleigh numbers, a thin thermal boundary layer is illustrated at the flow that heavily strikes the ceiling and lower from the outer cylinder. In addition, the local and mean Nusselt number from a nanofluid are enhanced by enhancing the volume fraction of the nanoparticles.The results are shown within the figure of isocurrents, isotherms, and mean and local Nusselt numbers. Detailed results of the numerical has been compared with literature ones, and it gives a reliable agreement.


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

Sign in / Sign up

Export Citation Format

Share Document