Solar Radiation Effect on a Magneto Nanofluid Flow in a Porous Medium with Chemically Reactive Species

2018 ◽  
Vol 16 (9) ◽  
Author(s):  
Mohamed R. Eid ◽  
O.D. Makinde
Keyword(s):  
Porous Medium ◽  
Solar Radiation ◽  
Saturated Porous Medium ◽  
Surface Concentration ◽  
Radiation Absorption ◽  
Physical Parameters ◽  
Radiation Chemical ◽  
Electrically Conducting ◽  
Special Cases ◽  
Chemically Reactive Species

Abstract The combined impact of solar radiation, chemical reaction, Joule heating, viscous dissipation and magnetic field on flow of an electrically conducting nanofluid over a convectively heated stretching sheet embedded in a saturated porous medium is simulated. By using appropriate similarity transformation, the governing nonlinear equations are converted into ODEs and numerical shooting technique with (RK45) method is employed to tackle the problem. The effects of various thermo-physical parameters on the entire flow structure with heat and mass transfer are presented graphically and discussed quantitatively. Special cases of our results are benchmarked with some of those obtained earlier in the literature and are found to be in excellent agreement. It is found that both the temperature and surface concentration gradients are increasing functions of the non-Darcy porous medium parameter. One describing result is the incident solar radiation absorption and its transmission into the working nanofluid by convection.

Convection in a saturated porous medium at large Rayleigh number or Peclet number

1963 ◽  
Vol 15 (4) ◽  
pp. 527-544 ◽  
Author(s):  
R. A. Wooding
Keyword(s):  
Porous Medium ◽  
Saturated Porous Medium ◽  
Vertical Plane ◽  
Homogeneous Solution ◽  
Physical Parameters ◽  
Convective System ◽  
Two Dimensional ◽  
Source Strength ◽  
Special Cases ◽  
Plane Jet

When the dimensions of a convective system in a saturated porous medium are sufficiently great, diffusion effects can be neglected except in regions where the gradients of fluid properties are very large. A boundary-layer theory is developed for vertical plane flows in such regions. In special cases, the theory is equivalent to that for laminar incompressible flow in a two-dimensional half-jet, or in a plane jet or round jet, for which similarity solutions are well known.A number of experiments have been performed using a Hele-Shaw cell immersed in water, with a source of potassium permanganate solution located between the plates. At very small values of the source strength, a flow analogous to that of a plane jet from a slit is obtained. The distance advanced by the jet front, or cap, is measured as a function of time, and the velocity is found to be nearly proportional to the velocity of the fluid on the axis of the steady jet behind the cap, as given by the similarity law of Schlichting and Bickley. At large values of the source strength, a two-dimensional ‘broad jet’ of homogeneous solution descending under gravity is produced; the shape of the flow region can be calculated with little error from potential theory, neglecting the effect of the mixing layers.A possible example of a mixing layer observed in a geothermal region is examined. The theoretical form of the temperature distribution is calculated numerically, taking into account the large viscosity variation with temperature and also the possibility of a large permeability variation. These effects are found to have less influence upon the solution than might have been expected. Quantitative values obtained for the physical parameters are consistent with other geophysical observations.

Natural convective heat transfer in a hemispherical cavity filled with ZnO–H2O nanofluid saturated porous medium

2018 ◽  
Vol 29 (10) ◽  
pp. 1850097 ◽  
Author(s):  
Abderrahmane Baïri ◽  
Najib Laraqi
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Nusselt Number ◽  
Rayleigh Number ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Volume Fraction ◽  
Saturated Porous Medium ◽  
Physical Parameters ◽  
Numerical Work

This three-dimensional (3D) numerical work based on the volume control method quantifies the convective heat transfer occurring in a hemispherical cavity filled with a ZnO–H2O nanofluid saturated porous medium. Its main objective is to improve the cooling of an electronic component contained in this enclosure. The volume fraction of the considered monophasic nanofluid varies between 0% (pure water) and 10%, while the cupola is maintained isothermal at cold temperature. During operation, the active device generates a heat flux leading to high Rayleigh number reaching [Formula: see text] and may be inclined with respect to the horizontal plane at an angle ranging from 0[Formula: see text] to 180[Formula: see text] (horizontal position with cupola facing upwards and downwards, respectively) by steps of 15[Formula: see text]. The natural convective heat transfer represented by the average Nusselt number has been quantified for many configurations obtained by combining the tilt angle, the Rayleigh number, the nanofluid volume fraction and the ratio between the thermal conductivity of the porous medium’s solid matrix and that of the base fluid. This ratio has a significant influence on the free convective heat transfer and ranges from 0 (without porous media) to 70 in this work. The influence of the four physical parameters is analyzed and commented. An empirical correlation between the Nusselt number and these parameters is proposed, allowing determination of the average natural convective heat transfer occurring in the hemispherical cavity.

Combined Effect of Temperature Modulation and Magnetic Field on the Onset of Convection in an Electrically Conducting-Fluid-Saturated Porous Medium

2008 ◽  
Vol 130 (5) ◽  
Author(s):  
B. S. Bhadauria
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Saturated Porous Medium ◽  
Effect Of Temperature ◽  
Temperature Modulation ◽  
Vertical Magnetic Field ◽  
Onset Of Convection ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Fluid Saturated Porous Medium

The effect of temperature modulation on the onset of thermal convection in an electrically conducting fluid-saturated-porous medium, heated from below, has been studied using linear stability analysis. The amplitudes of temperature modulation at the lower and upper surfaces are considered to be very small. The porous medium is confined between two horizontal walls and subjected to a vertical magnetic field; flow in porous medium is characterized by Brinkman–Darcy model. Considering only infinitesimal disturbances, and using perturbation procedure, the combined effect of temperature modulation and vertical magnetic field on thermal instability has been studied. The correction in the critical Rayleigh number is calculated as a function of frequency of modulation, Darcy number, Darcy Chandrasekhar number, magnetic Prandtl number, and the nondimensional group number χ. The influence of the magnetic field is found to be stabilizing. Furthermore, it is also found that the onset of convection can be advanced or delayed by proper tuning of the frequency of modulation. The results of the present model have been compared with that of Darcy model.

scholarly journals Effects of Chemical Reaction on Dissipative Radiative MHD Flow through a Porous Medium over a Nonisothermal Stretching Sheet

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
S. Mohammed Ibrahim
Keyword(s):  
Porous Medium ◽  
Differential Equations ◽  
Chemical Reaction ◽  
Stretching Sheet ◽  
Saturated Porous Medium ◽  
Mhd Flow ◽  
Electrically Conducting ◽  
Similarity Transformations ◽  
Temperature Parameter ◽  
Layer Flow

The steady two-dimensional radiative MHD boundary layer flow of an incompressible, viscous, electrically conducting fluid caused by a nonisothermal linearly stretching sheet placed at the bottom of fluid saturated porous medium in the presence of viscous dissipation and chemical reaction is studied. The governing system of partial differential equations is converted to ordinary differential equations by using the similarity transformations, which are then solved by shooting method. The dimensionless velocity, temperature, and concentration are computed for different thermophysical parameters, namely, the magnetic parameter, permeability parameter, radiation parameter, wall temperature parameter, Prandtl number, Eckert number, Schmidt number, and chemical reaction.

scholarly journals Thermal radiation effect on unsteady mixed convection boundary layer flow and heat transfer of nanofluid over permeable stretching surface through porous medium in the presence of heat generation

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110422
Author(s):  
Ahmed M. Sedki ◽  
S. M. Abo-Dahab ◽  
J. Bouslimi ◽  
K. H. Mahmoud
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Porous Medium ◽  
Mixed Convection ◽  
Thermal Radiation ◽  
Heat Generation ◽  
Convection Boundary Layer ◽  
Physical Parameters ◽  
Unsteady Mixed Convection ◽  
Special Cases

Here, we study the effect of mixed convection and thermal radiation on unsteady boundary layer of heat transfer and nanofluid flow over permeable moving surface through a porous medium. The effect of heat generation is also discussed. The equations governing the system are the continuity equation, momentum equation and the heat transfer equation. These governing equations transformed into a system of nondimensional equations contain many physical parameters that describe the study. The transformed equations are solved numerically using an implicit finite difference technique with Newton's linearization method. The thermo-physical parameters describe the study are the mixed convection parameter α, [Formula: see text], the Radiation parameter Rd, [Formula: see text] , porous medium parameter k, [Formula: see text], the nanoparticles volume [Formula: see text],[Formula: see text], the suction or injection parameter fw, [Formula: see text], the unsteadiness parameter At, [Formula: see text] and the heat source parameter λ  =  0.5 .The influence of the thermo-physical parameters is obtained analytically and displayed graphically. Comparisons of some special cases of the present study are performed with previously published studies and a good agreement is obtained.

scholarly journals Effect of Hall Current on MHD Oscillatory Slip Flow with Varying Temperature and Concentration

2017 ◽  
Vol 5 (2) ◽  
Author(s):  
K. Sumathi ◽  
T. Arunachalam ◽  
N. Radha
Keyword(s):  
Oscillatory Flow ◽  
Hall Current ◽  
Saturated Porous Medium ◽  
Slip Flow ◽  
Lower Boundary ◽  
Cross Flow ◽  
Radiation Chemical ◽  
Electrically Conducting ◽  
Electrically Conducting Fluid ◽  
Cross Flow Velocity

An investigation of the effect of Hall current on an unsteady MHD mixed convective oscillatory flow of an electrically conducting fluid through a planar channel filled with saturated porous medium is carried out in this paper. The effect of buoyancy, heat source, thermal radiation, chemical reaction and Hall current are taken into account with slip velocity, varying temperature and concentration at the lower boundary. A series solution is found using perturbation techniques. The effects of various parameters on the main and cross flow velocity, temperature, Skin friction, rate of heat and mass transfer are discussed numerically. 

scholarly journals Radiation Absorption and Chemical Reaction Effects on Rivlin-Ericksen Flow Past a Vertical Moving Porous Plate

2019 ◽  
Vol 24 (3) ◽  
pp. 675-689 ◽  
Author(s):  
C.S. Sravanthi ◽  
R.S.R. Gorla
Keyword(s):  
Chemical Reaction ◽  
Fluid Velocity ◽  
Porous Plate ◽  
Radiation Absorption ◽  
Physical Parameters ◽  
Moving Plate ◽  
Suction Velocity ◽  
Electrically Conducting ◽  
Effects Of Radiation ◽  
Good Agreement

Abstract An analysis has been carried out to study the combined effects of radiation absorption and chemical reaction on an incompressible, electrically conducting and radiating flow of a Rivlin-Ericksen fluid along a semi-infinite vertical permeable moving plate in the presence of a transverse applied magnetic field. It is assumed that the suction velocity, the temperature and the concentration at the wall are exponentially varying with time. The dimensionless governing equations for this investigation are solved analytically using two-term harmonic and non-harmonic functions. A comparison is made with the available results in the literature for a special case and our results are in very good agreement with the known results. A parametric study of the physical parameters is made and results are presented through graphs and tables. The results indicate that the fluid velocity and temperature could be controlled by varying the radiation absorption.

scholarly journals MHD Free Convective Heat and Mass Transfer of a Chemically-Reacting Fluid from Radiate Stretching Surface Embedded in a Saturated Porous Medium

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
A.M. Rashad ◽  
M. Modather M. Abdou ◽  
Ali Chamkha
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Differential Equations ◽  
Heat And Mass Transfer ◽  
Convective Heat ◽  
Saturated Porous Medium ◽  
Skin Friction Coefficient ◽  
Electrically Conducting ◽  
Chemically Reacting ◽  
Thermal Radiation Effect

Magneto-hydrodynamic free convective heat and mass transfer of a viscous, incompressible, electrically conducting and chemically-reacting fluid adjacent to a vertical stretching sheet embedded in a saturated porous medium in the presence of a thermal radiation effect are investigated. The sheet is linearly stretched with uniform constant of temperature and concentration. The governing partial differential equations are transferred into a system of ordinary differential equations, which are solved numerically using a fourth order Runge-Kutta scheme with the shooting method. The effects of various parameters entering into the problem have been examined on the velocity and temperature profiles as well as the skin-friction coefficient, and Nusselt and Sherwood numbers are presented graphically and in tabular form.

scholarly journals Mixed Convection on MHD Flow with Thermal Radiation, Chemical Reaction and Viscous Dissipation Embedded in a Porous Medium

2020 ◽  
Vol 25 (1) ◽  
pp. 219-235
Author(s):  
B. Zigta
Keyword(s):  
Porous Medium ◽  
Velocity Profile ◽  
Chemical Reaction ◽  
Kinematic Viscosity ◽  
Schmidt Number ◽  
Radiation Absorption ◽  
Reaction Parameter ◽  
Radiation Chemical ◽  
Suction Velocity ◽  
Chemical Reaction Parameter

AbstractIn this paper, a theoretical analysis has been made to study the effect of mixed convection MHD oscillatory Couette flow in a vertical parallel channel walls embedded in a porous medium in the presence of thermal radiation, chemical reaction and viscous dissipation. The channel walls are subjected to a constant suction velocity and free stream velocity is oscillating with time. The channel walls are embedded vertically in a porous medium. A magnetic field of uniform strength is applied normal to the vertical channel walls. The nonlinear and coupled partial differential equations are solved using multi parameter perturbation techniques. The effects of physical parameters, viz., the radiation absorption parameter, Prandtl number, Eckert number, dynamic viscosity, kinematic viscosity, permeability of porous medium, suction velocity, Schmidt number and chemical reaction parameter on flow variables viz., temperature, concentration and velocity profile have been studied. MATLAB code is used to analyze theoretical facts. The important results show that an increment in the radiation absorption parameter and permeability of porous medium results in an increment of the temperature profile. Moreover, an increment in the Prandtl number, Eckert number and dynamic viscosity results in a decrement of the temperature profile. An increment in suction velocity results in a decrement of the velocity profile. An increment in the Schmidt number, chemical reaction parameter and kinematic viscosity results in a decrement of the concentration profile.

Sign in / Sign up

Export Citation Format

Share Document