scholarly journals Effect of Lewis Number on Double-diffusive Natural Convection in a Triangular Cavity

2013 ◽  
Vol 78 (2) ◽  
pp. 17-21
Author(s):  
Kazi AnowarHussain ◽  
Md. Arifur Rahman Mazumder ◽  
Rifat Jahan ◽  
Sharmin Akter
Keyword(s):  
Natural Convection ◽  
Lewis Number ◽  
Double Diffusive

scholarly journals Double-Diffusive of Natural Convection in an Inclined Porous Square Domain Generalized Model

2019 ◽  
Vol 12 (3) ◽  
pp. 151-160
Author(s):  
Khaled Al-Farhany ◽  
A. Turan
Keyword(s):  
Natural Convection ◽  
Lewis Number ◽  
Boussinesq Approximation ◽  
Darcy Number ◽  
Governing Equations ◽  
Simpler Algorithm ◽  
Wide Range ◽  
Finite Volume Approach ◽  
Buoyancy Ratio ◽  
Double Diffusive

Numerical investigate of double-diffusive natural convection in an inclined porous square. Two opposing walls of the square cavity are adiabatic; while the other walls are, kept at constant concentrations and temperatures. The Darcy–Forchheimer–Brinkman model is used to solve the governing equations with the Boussinesq approximation. A code written in FORTRAN language developed to solve the governing equations in dimensionless forms using a finite volume approach with a SIMPLER algorithm. The results presented in U-velocity and V-velocity, isotherms, iso-concentration, streamline, the average Nusselt number, and the average Sherwood number for different values of the dimensionless parameters. A wide range of these parameters have been used including; Darcy Number, modified Rayleigh number, Lewis number, buoyancy ratio, and inclination angle.  The results show that for opposite buoyancy ratio (N≤-1), the Nu decreases when the Le increases and the Sh increase when the Le increases. For an (N>0), the Nu increases when the Le increases until Le is equal to 1 and then it decreases, also Sh increases when the Le increases

scholarly journals Non-Darcian effect on double-diffusive natural convection inside aninclined square Dupuit-Darcy porous cavity under a magnetic field

2019 ◽  
pp. 271-271
Author(s):  
Redha Rebhi ◽  
Noureddine Hadidi ◽  
Rachid Bennacer
Keyword(s):  
Magnetic Field ◽  
Natural Convection ◽  
Numerical Study ◽  
Lewis Number ◽  
Boussinesq Approximation ◽  
Buoyant Force ◽  
Porous Cavity ◽  
Effect Parameter ◽  
The Magnetic Field ◽  
Double Diffusive

This paper presents a numerical study of a double diffusive convection in an inclined square porous cavity filled with an electrically conducting binary mixture. The upper and bottom walls are maintained at a constant temperatures and concentrations whereas the left and right walls are assumed to be adiabatic and impermeable. A uniform and tilted magnetic field is applied at an angle, ?, about the horizontal, it is obvious that this is related to the orientation of the magnetic force that can help or oppose the buoyant force. The Dupuit-Darcy flow model, which includes effects of the inertial parameter, with the Boussinesq approximation, energy and species transport equations are solved numerically using the classical finite difference method. Governing parameters of the problem under study are the thermal Rayleigh number, Rt, Hartmann number, Ha, Lewis number, Le, the buoyancy ratio, ?,inclination angle, ? and tilting angle of the magnetic field, ?,. The numerical results are reported on the contours of streamline, temperature, and concentration and for the average Nusselt and Sherwood numbers for various parametric conditions. It is demonstrated that both the inertial effect parameter and the magnetic field, have a strong influence on the strength of the natural convection heat and mass transfer within the porous layer.

Double Diffusive Natural Convection Heat Transfer Enhancement in a Square Enclosure Using Nanofluids

2011 ◽  
Vol 2 (2) ◽  
Author(s):  
Javad Abolfazli Esfahani ◽  
Vahid Bordbar
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Simple Algorithm ◽  
Lewis Number ◽  
Solute Concentration ◽  
Convection Flow ◽  
Steady State Condition ◽  
Square Enclosure ◽  
Double Diffusive

Double-diffusive natural convection flow in square enclosure filled with nanofluid is studied in this paper. Water based nanofluid containing various nanoparticles including Cu, Ag, Al2O3, and TiO2 is used in the numerical analysis. The upper and lower walls of the enclosure are well insulated and impermeable and the left and right walls are imposed to constant temperatures and concentration. Laminar regime under steady state condition is considered. The Maxwell–Garnett model is used to predict the ratio of thermal conductivity. The system of conservation equations consisting of continuity, momentum, energy, and solute concentration in dimensionless form are solved by using finite volume SIMPLE algorithm. Results are presented for different values of the governing parameters Rayleigh and Lewis number, in terms of streamlines, isotherms, isoconcentration, local Nusselt number, and local Sherwood number. The effect of nanoparticle volume fractions are also discussed on heat transfer characteristics in the cavity.

UNSTEADY DOUBLE-DIFFUSIVE NATURAL CONVECTION AND THERMAL RADIATION WITHIN A VERTICAL POROUS ENCLOSURE

2013 ◽  
Vol 16 (2) ◽  
pp. 167-182 ◽  
Author(s):  
Abdesslem Jbara ◽  
Hosni Souheil Harzallah ◽  
Khalifa Slimi ◽  
Abdallah Mhimid
Keyword(s):  
Natural Convection ◽  
Thermal Radiation ◽  
Double Diffusive ◽  
Porous Enclosure

Incompressible smoothed particle hydrodynamics for MHD double-diffusive natural convection of a nanofluid in a cavity containing an oscillating pipe

2019 ◽  
Vol 30 (2) ◽  
pp. 882-917 ◽  
Author(s):  
Abdelraheem M. Aly
Keyword(s):  
Natural Convection ◽  
Smoothed Particle Hydrodynamics ◽  
Cavity Wall ◽  
Lagrangian Description ◽  
Content Type ◽  
Wide Range ◽  
Particle Hydrodynamics ◽  
Smoothed Particle ◽  
Incompressible Smoothed Particle Hydrodynamics ◽  
Double Diffusive

Purpose This paper aims to adopt incompressible smoothed particle hydrodynamics (ISPH) method to simulate MHD double-diffusive natural convection in a cavity containing an oscillating pipe and filled with nanofluid. Design/methodology/approach The Lagrangian description of the governing partial differential equations are solved numerically using improved ISPH method. The inner oscillating pipe is divided into two different pipes as an open and a closed pipe. The sidewalls of the cavity are cooled with a lower concentration C_c and the horizontal walls are adiabatic. The inner pipe is heated with higher concentration C_h. The analysis has been conducted for the two different cases of inner oscillating pipes under the effects of wide range of governing parameters. Findings It is found that a suitable oscillating pipe makes a well convective transport inside a cavity. Presence of the oscillating pipe has effects on the heat and mass transfer and fluid intensity inside a cavity. Hartman parameter suppresses the velocity and weakens the maximum values of the stream function. An increase on Hartman, Lewis and solid volume fraction parameters leads to an increase on average Nusselt number on an oscillating pipe and left cavity wall. Average Sherwood number on an oscillating pipe and left cavity wall decreases as Hartman parameter increases. Originality/value The main objective of this work is to study the MHD double-diffusive natural convection of a nanofluid in a square cavity containing an oscillating pipe using improved ISPH method.

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