Magnetohydrodynamic time-dependent computational natural convection flow, heat and mass transfer in inclined semi-circular enclosures

2016 ◽  
Vol 26 (8) ◽  
pp. 2310-2330 ◽  
Author(s):  
M.M. Rahman ◽  
Hakan F. Öztop ◽  
R. Saidur ◽  
A.G. Naim ◽  
Khaled S. Al-Salem ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Mass Transfer ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Inclination Angle ◽  
Time Dependent ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Content Type ◽  
Flow Heat

Purpose The purpose of this paper is to make a numerical analysis on unsteady analysis of natural convection heat and mass transfer to obtain flow field, temperature distribution, and concentration distribution. Design/methodology/approach A finite element method is applied to solve governing equations of natural convection in curvilinear-shaped system for different parameters as thermal Rayleigh numbers (103=RaT=106), inclination angle (0°=φ=60°) and Hartmann numbers (0=Ha=100). Findings Both magnetic field and inclination angle can be used as control parameter on heat and mass transfer. Flow strength decreases almost 100 percent between Ha=0 and Ha=100 on behalf of the higher values of thermal Rayleigh number. Originality/value The originality of this work is to application of magnetic field on time-dependent natural convection flow, heat and mass transfer for curvilinear geometry.

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.

MHD natural convection flow in cavities filled with square solid blocks

2014 ◽  
Vol 24 (8) ◽  
pp. 1813-1830 ◽  
Author(s):  
Majid Ashouri ◽  
Mohammad Behshad Shafii ◽  
Hossein Rajabi Kokande
Keyword(s):  
Magnetic Field ◽  
Thermal Conductivity ◽  
Nusselt Number ◽  
Natural Convection ◽  
Numerical Code ◽  
Thermal Conductivity Ratio ◽  
Convection Flow ◽  
Conductivity Ratio ◽  
Natural Convection Flow ◽  
Content Type

Purpose – The purpose of this paper is to study the influence of magnetic field on natural convection inside the enclosures partially filled with conducting square solid obstacles. Also, the effect of thermal conductivity ratio between the solid and fluid materials is investigated for different number of solid blocks. Design/methodology/approach – The dimensionless governing equations are transformed into sets of algebraic equations using finite volume method and momentum equations are solved by the SIMPLE algorithm with the hybrid scheme. The validation of the numerical code was conducted by comparing the results of average Nusselt number with previously published works. Findings – The results indicate that both the magnetic field and solid blocks can significantly affect the flow and temperature fields. It is shown that for a given Rayleigh number, variation of Nusselt number might be increasing or decreasing with change in solid-to-fluid thermal conductivity ratio depending on magnetic field strength and number of solid blocks. Originality/value – No work has been reported previously on the effect of magnetic field on natural convection flow in a cavity partially filled with square solid blocks. The numerical analysis of conductivity ratio between the solid and fluid materials under the effect of magnetic field have been carried out for the first time.

scholarly journals Corrigendum: https://doi.org/10.2298/TSCI150722093S by Simeon Oka, Editor-in-Chief of the journal Thermal Science request that it is necessary to correct affiliations of the authors

2017 ◽  
Vol 21 (3) ◽  
pp. 1561-1561
Author(s):  
E Editorial
Keyword(s):  
Mass Transfer ◽  
Information Technology ◽  
Natural Convection ◽  
Heat And Mass Transfer ◽  
Editorial Staff ◽  
Convection Flow ◽  
Technical Error ◽  
Transfer Effects ◽  
Natural Convection Flow ◽  
Font Color

Simeon Oka, Editor-in-Chief of the journal Thermal Science request that it is necessary to correct affiliations of the authors of the paper HEAT AND MASS TRANSFER EFFECTS ON NATURAL CONVECTION FLOW ALONG A HORIZONTAL TRIANGULAR WAVY SURFACE by Sadia SIDDIQAa*, M. Anwar HOSSAINb, and AQSAc published in the journal Thermal Science, Vol. 21, Year 2017, No. 2, pp. 977-987 since by technical error of the Editorial staff, affiliations of the authors are not correctly written. Sadia SIDDIQAa*, M. Anwar HOSSAINb, and AQSAa aDepartment of Mathematics, Quaid-e-Azam University, Islamabad, Pakistan bDepartment of Mathematics, University of Dhaka, Dhaka, Bangladesh has to be written: Sadia SIDDIQAa*, M. Anwar HOSSAINb, and AQSAc a Department of Mathematics, COMSATS Institute of Information Technology, Attock, Pakistan b Department of Mathematics, University of Dhaka, Dhaka, Bangladesh c Department of Mathematics, Quaid-e-Azam University, Islamabad, Pakistan. <br><br><font color="red"><b> Link to the corrected article <u><a href="http://dx.doi.org/10.2298/TSCI150722093S">10.2298/TSCI150722093S</a></b></u>

A semi-analytical solution for time-dependent natural convection flow with heat generation/absorption in an annulus partially filled with porous material

2018 ◽  
Vol 14 (5) ◽  
pp. 1042-1063 ◽  
Author(s):  
Taiwo S. Yusuf ◽  
Basant K. Jha
Keyword(s):  
Natural Convection ◽  
Porous Material ◽  
Heat Generation ◽  
Constant Heat Flux ◽  
Time Dependent ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Constant Heat ◽  
Content Type ◽  
Riemann Sum

Purpose The purpose of this paper is to present a semi-analytical solution for time-dependent natural convection flow with heat generation/absorption in an annulus partially filled with porous material. Design/methodology/approach The governing partial differential equations are transformed into the ordinary differential equations using the Laplace transform technique. The exact solution obtained is inverted from the Laplace domain to time domain using the Riemann-sum approximation approach. Justification of the Riemann-sum approximation approach is achieved by comparing the values obtained with those of the implicit finite difference method at both the transient state and the steady state at large time. Findings If is found that the peak axial velocity always occur in the clear fluid region. In addition, there is an indication that heat generating fluid is desirable for optimum mass flux in the annular gap most importantly when the convection current is enhanced by constant heat flux. Originality/value In view of the amount of works done on natural convection with internal heat generation/absorption, it becomes interesting to investigate the influence of this essential activity on natural convection flow in a vertical cylinder partially filled with porous material where the outer surface of the inner cylinder is either heated isothermally or with constant heat flux.

MHD natural convection flow past an impulsively started infinite vertical porous plate with Newtonian heating in the presence of radiation

2016 ◽  
Vol 26 (6) ◽  
pp. 1932-1953 ◽  
Author(s):  
Marneni Narahari ◽  
M Kamran
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Thermal Radiation ◽  
Transverse Magnetic Field ◽  
Porous Plate ◽  
Transverse Magnetic ◽  
Convection Flow ◽  
Newtonian Heating ◽  
Natural Convection Flow ◽  
Content Type

Purpose – The purpose of this paper is to investigate the effects of thermal radiation and viscous dissipation on steady natural convection flow of a viscous incompressible fluid along a uniformly moving infinite vertical porous plate with Newtonian heating in the presence of transverse magnetic field. The governing non-linear boundary layer equations are solved by using homotopy analysis method (HAM). The effects of various system parameters on velocity and temperature fields are discussed graphically, and the numerical values for skin friction and Nusselt number are presented in tabular form. Design/methodology/approach – The problem is formulated using the Boussinesq approximation under the effects of thermal radiation and transverse magnetic field. The resulting coupled system of non-linear differential equations is solved using HAM with appropriate boundary conditions for Newtonian heating of the plate. HAM is a powerful method which provides rapidly converging series solution for the velocity and temperature fields. The effects of Prandtl number, Grashof number, suction parameter, magnetic field parameter, radiation parameter and Eckert number on the fluid velocity, temperature, skin friction and Nusselt number have been investigated. Findings – The HAM solution has been successfully applied to find the converging series solution for velocity and temperature fields in terms of pertinent system parameters. Comparison of the exact solution results agree well with the HAM solution results in the absence of Eckert number and this indicates that the HAM solutions are accurate. It is found that the velocity and temperature profiles decreases with the increase of thermal radiation and suction parameters. An increase in the magnetic field parameter leads to a rise in the fluid temperature and fall in the fluid velocity. Research limitations/implications – The present analysis is limited to steady state laminar natural convection flow only. Unsteady natural- /mixed-convection laminar flow in the presence of thermal radiation, chemical reaction and transverse magnetic field will be investigated in a future work. Practical implications – The study provides very useful information for heat transfer engineers to understand the heat transfer rate when the moving vertical porous surface temperature is not known a prior. The present results have immediate relevance in the design of nuclear reactors where vertical moving porous plates are using as control rods. Originality/value – The present research work is relatively original and illustrates the effects of thermal radiation, viscous dissipation and transverse magnetic field on natural convection flow past a uniformly moving infinite vertical porous plate with Newtonian heating.

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