Motion of circular cylinders during natural convection flow in X-shaped cavity filled with a nanofluid using ISPH method

2021 ◽  
Vol 31 (5) ◽  
pp. 1449-1474 ◽  
Author(s):  
Abdelraheem M. Aly ◽  
Ehab Mahmoud Mohamed
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Natural Convection ◽  
Thermal Conditions ◽  
Circular Cylinders ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Content Type ◽  
Temperature Distributions ◽  
Cold Source

Purpose This study aims to illustrate the impacts of the motion of circular cylinders on the natural convection flow from variable heated partitions inside the X-shaped cavity filled with Al2O3-water nanofluid. A partial layer of a homogeneous/heterogeneous porous medium is located in the top area of the X-shaped cavity. Design/methodology/approach Three different cases of the porous media including homogeneous, horizontal heterogeneous and vertical heterogeneous porous media were considered. Three different thermal conditions of the embedded circular cylinders including hot, cold and adiabatic conditions are investigated. An incompressible scheme of smoothed particle hydrodynamics (ISPH) method is modified to compute the non-linear partial differential equations of the current problem. Two variable lengths of the left and right sides of the X-shaped cavity have a high-temperature Th and a low-temperature Tc, respectively. The other wall parts are adiabatic. The numerical simulations are elucidating the dependence of the heat transfer and fluid flow characteristics on lengths of hot/cold source Lh, porous cases, Darcy parameter, thermal conditions of the embedded circular cylinders and solid volume fraction. Findings Overall, an increment in length of hot/cold source leads to augmentation on the temperature distributions and flow intensity inside the X-shaped cavity. The hot thermal condition of the circular cylinder augments the temperature distributions. The homogeneous porous medium slows down the flow speed in the top porous layer of the X-shaped cavity. The average Nusselt number decreases as Lh increases. Originality/value ISPH method simulated the motion of circular cylinders in the X-shaped cavity. The X-shaped cavity is saturated with a partial layer porous medium. It is found that an increase in hot source length augments the temperature and fluid flow. ISPH method can easily handle the motion of cylinders in the X-shaped cavity. Different thermal conditions of cylinders can change the temperature distributions in X-cavity.

Heat and mass transfer by natural convection flow about a truncated cone in porous media with Soret and Dufour effects

2014 ◽  
Vol 24 (3) ◽  
pp. 595-612 ◽  
Author(s):  
A. Rashad ◽  
A. Chamkha
Keyword(s):  
Mass Transfer ◽  
Porous Media ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Heat And Mass Transfer ◽  
Chemical Reaction ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Soret And Dufour Effects ◽  
Content Type

Purpose – The purpose of this paper is to study the effects of chemical reaction, thermal radiation and Soret and Dufour effects of heat and mass transfer by natural convection flow about a truncated cone in porous media. Design/methodology/approach – The problem is formulated and solved numerically by an accurate implicit finite-difference method. Findings – It is found that the Soret and Dufour effects as well as the thermal radiation and chemical reaction cause significant effects on the heat and mass transfer charateristics. Originality/value – The problem is relatively original as it considers Soret and Dufour as well as chemical reaction and porous media effects on this type of problem.

Incompressible smoothed particle hydrodynamics simulations of natural convection flow resulting from embedded Y-fin inside Y-shaped enclosure filled with a nanofluid

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Zehba Raizah ◽  
Mitsuteru Asai ◽  
Abdelraheem M. Aly
Keyword(s):  
Fluid Flow ◽  
Natural Convection ◽  
Smoothed Particle Hydrodynamics ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Content Type ◽  
Temperature Distributions ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Incompressible Smoothed Particle Hydrodynamics

Purpose The purpose of this study is to apply the incompressible smoothed particle hydrodynamics (ISPH) method to simulate the natural convection flow from an inner heated Y-fin inside Y-shaped enclosure filled with nanofluid. Design/methodology/approach The dimensionless governing partial differential equations are described in the Lagrangian form and solved by an implicit scheme of the ISPH method. The embedded Y-fin is kept at a high temperature Th with variable heights during the simulations. The lower area of Y-shaped enclosure is squared with width L = 1 m and its side-walls are kept at a low temperature Tc. The upper area of the Y-shaped enclosure is V-shaped with width 0.5 L for each side and its walls are adiabatic. Findings The performed simulations revealed that the height of the inner heated Y-fin plays an important role in the heat transfer and fluid flow inside the Y-shaped enclosure, where it enhances the heat transfer. Rayleigh number augments the buoyancy force inside the Y-shaped enclosure and, consequently, it has a strong impact on temperature distributions and strength of the fluid flow inside Y-shaped enclosure. Adding more concentration of the nanofluid until 10% has a slight effect on the temperature distributions and it reduces the strength of the fluid flow inside Y-shaped enclosure. In addition, the average Nusselt number is measured along the inner heated Y-fin and it grows as the Rayleigh number increases. The average Nusselt number is decreasing by adding more concentrations of the nanofluid. Originality/value An improved ISPH method is used to simulate the natural convection flow of Y-fin embedded in the Y-shaped enclosure filled with a nanofluid.

scholarly journals MHD natural convection flow of Casson fluid in an annular microchannel containing porous medium with heat generation/absorption

2020 ◽  
Vol 9 (1) ◽  
pp. 223-232 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Skin Friction ◽  
Interaction Parameter ◽  
Heat Generation ◽  
Velocity Slip ◽  
Casson Fluid ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Wall Interaction

AbstractThis study has been conducted to focus on natural convection flow of Casson fluid through an annular microchannel formed by two cylinders in the presence of magnetic field. The process of heat generation/absorption is taken into consideration. Combined effects of various parameters such as porous medium, velocity slip and temperature jump are considered. Solution of the present mathematical model is obtained numerically using fourth-fifth order Runge-Kutta-Fehlberg method. The flow velocity, thermal field, skin friction and Nusselt number are scrutinized with respect to the involved parameters of interest such as fluid wall interaction parameter, rarefaction parameter, Casson parameter and Darcy number with the aid of graphs. It is established that higher values of Casson parameter increases the skin friction coefficient. Further it is obtained that rate of heat transfer diminishes as fluid wall interaction parameter increases.

Natural convection flow in a vertical micro-annulus with time-periodic thermal boundary conditions

2018 ◽  
Vol 14 (5) ◽  
pp. 1064-1081
Author(s):  
Basant Kumar Jha ◽  
Michael O. Oni
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Boundary Conditions ◽  
Skin Friction ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Content Type ◽  
Thermal Boundary Conditions ◽  
The Impact ◽  
Time Periodic

PurposeThe purpose of this paper is to investigate the impact of time-periodic thermal boundary conditions on natural convection flow in a vertical micro-annulus.Design/methodology/approachAnalytical solution in terms of Bessel’s function and modified Bessel’s function of order 0 and 1 is obtained for velocity, temperature, Nusselt number, skin friction and mass flow rate.FindingsIt is established that the role of Knudsen number and fluid–wall interaction parameter is to decrease fluid temperature, velocity, Nusselt number and skin friction.Research limitations/implicationsNo laboratory practical or experiment was conducted.Practical implicationsCooling device in electronic panels, card and micro-chips is frequently cooled by natural convection.Originality/valueIn view of the amount of works done on natural convection in microchannel, it becomes interesting to investigate the effect that time-periodic heating has on natural convection flow in a vertical micro-annulus. The purpose of this paper is to examine the impact of time-periodic thermal boundary conditions on natural convection flow in a vertical micro-annulus.

Non-Darcy natural convection flow for non-Newtonian nanofluid over cone saturated in porous medium with uniform heat and volume fraction fluxes

2015 ◽  
Vol 25 (2) ◽  
pp. 422-437 ◽  
Author(s):  
A Chamkha ◽  
S Abbasbandy ◽  
A.M. Rashad
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Mass Flux ◽  
Volume Fraction ◽  
Viscosity Index ◽  
Convection Flow ◽  
Content Type ◽  
Surface Mass ◽  
Uniform Heat ◽  
Nanoparticles Volume Fraction

Purpose – The purpose of this paper is to investigate the effect of uniform lateral mass flux on non-Darcy natural convection of non-Newtonian fluid along a vertical cone embedded in a porous medium filled with a nanofluid. Design/methodology/approach – The resulting governing equations are non-dimensionalized and transformed into a non-similar form and then solved numerically by Keller box finite-difference method. Findings – A comparison with previously published works is performed and excellent agreement is obtained. Research limitations/implications – The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. It is assumed that the cone surface is preamble for possible nanofluid wall suction/injection, under the condition of uniform heat and nanoparticles volume fraction fluxes. Originality/value – The effects of nanofluid parameters, Ergun number, surface mass flux and viscosity index are investigated on the velocity, temperature, and volume fraction profiles as well as the local Nusselt and Sherwood numbers.

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