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

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.

Author(s):  
M. Umamaheswar ◽  
M.C. Raju ◽  
S.V.K. Varma

In this manuscript, we have investigated the influence of radiation absorption on an unsteady MHD convective heat and mass transfer flow of a Newtonian fluid past a vertical porous plate in the presence of thermal radiation and chemical reaction. The non dimensional governing equations have been solved by using a multiple perturbation method, subject to the corresponding boundary conditions. The effects of various physical parameters such as velocity, temperature and concentration are studied through graphs. The expressions for local skin friction, Nusselt number and Sherwood number are derived and discussed with the help of a table. It is noticed that velocity increases when an increase in modified Grashof number Gm, radiation absorption parameter χ, Sorret number S0, time t whereas it decreases when an increase in Schmidt number Sc, chemical reaction parameter Kr and radiation parameter F. Temperature increases with an increase in radiation parameter χ and Sorret number S0whereas it decreases with an increase in chemical reaction parameter Kr, F and ϕ. Concentration is observed to be decreased when chemical reaction parameter Kr and Schmidt number Sc increase whereas it increases with an increase in Sorret number S0. Skin friction increases with an increase modified Grashof number Gm, radiation parameter χ and Sorret number S0whereas it has reverse effect in the case of Schmidt number Sc, chemical reaction parameter Kr. Nusselt number increases with an increase in Sc, S0, χ whereas it has reverse effect in the case of Kr. Sherwood number gets decreased when Sc, χ and Kr both are increased whereas it has shown revere effect in the case of S0.


10.29007/g5p6 ◽  
2018 ◽  
Author(s):  
Harshad Patel ◽  
Hari Kataria

This article studies effect of thermal radiation, chemical reaction and parabolic motion on the unsteady MHD Casson fluid flow past an infinite vertical plate embedded with ramped wall temperature. The fluid is electrically conducting and passing through a porous medium. This phenomenon is modeled in the form of partial differential equations with initial and boundary conditions. Some suitable non-dimensional variables are introduced and corresponding dimensionless equations are solved using the Laplace transform technique. Analytical expressions for velocity, temperature and concentration profiles are obtained. The features of the velocity, temperature and concentration are analyzed by plotting graphs and the physical aspects are studied for different parameters like the magnetic field parameter M, thermal radiation parameter R, chemical reaction parameter〖 R〗^', thermal Grashof number Gr, mass Grashof number Gm, Schmidt number Sc, Prandtl number Pr and time variable t. It is seen that velocity profiles decrease with increase in thermal radiation R and chemical reaction parameter〖 R〗^'.


2020 ◽  
Vol 25 (3) ◽  
pp. 198-211
Author(s):  
B. Zigta

AbstractThis paper focuses on the theoretical analysis of blood flow in the presence of thermal radiation and chemical reaction under the influence of time dependent magnetic field intensity. Unsteady non linear partial differential equations of blood flow consider time dependent stretching velocity, the energy equation also accounts time dependent temperature of vessel wall and the concentration equation includes the time dependent blood concentration. The governing non linear partial differential equations of motion, energy and concentration are converted into ordinary differential equations using similarity transformations solved numerically by applying ode45. The effect of physical parameters, viz., the permeability parameter, unsteadiness parameter, Prandtl number, Hartmann number, thermal radiation parameter, chemical reaction parameter and Schmidt number on flow variables, viz., velocity of blood flow in vessel, temperature and concentration of blood, has been analyzed and discussed graphically. From the simulation study the following important results are obtained: velocity of blood flow increases with the increment of both permeability and unsteadiness parameter. The temperature of blood increases at the vessel wall as the Prandtl number and Hartmann number increase. Concentration of blood decreases as time dependent chemical reaction parameter and Schmidt number increases.


2013 ◽  
Vol 8 (1) ◽  
pp. 721-729
Author(s):  
Ruchi Chaturvedi ◽  
Dr.R.K. Shrivatav ◽  
Dr.Mohd Salim Ahemad

In this paper we have studied and discussed the problem of unsteady flow of a visco-elastic (walter’s liquid model B) fluid through porous medium in presence of a heat source and a uniform magnetic field with effect of chemical reaction parameter. The effect of chemical reaction parameter g, porous parameter K and magnetic parameter on fluid velocity, temperature and concentration with respect to vertical axis Y and time t are discussed graphically.


Author(s):  
I. G. Baoku ◽  
K. I. Falade

This article is concerned with the study of heat and mass transfer of a MHD reactive flow of an upper-convected Maxwell fluid model over a stretching surface subjected to a prescribed heat flux with velocity slip effect in a Darcian porous medium in the presence of thermal radiation and internal heat generation/absorption. The basic boundary layer governing partial differential equations are transformed into a set of coupled ordinary differential equations, which are solved numerically using Runge-Kutta-Fehlberg integration scheme with shooting technique. The far field boundary conditions are asymptotically satisfied to support the accuracy of the numerical computations and the results obtained. The velocity, temperature and species concentration profiles are enhanced by increasing values of velocity slip parameter with Hartmann number, heat generation/absorption parameter and order of chemical reaction parameter respectively.  Increments in the values of velocity slip parameter, Hartmann number, rate of chemical reaction parameter and Prandtl number boost the wall shear stress, dimensionless surface temperature is increased by increasing values of Deborah number, heat generation/absorption and order of chemical reaction parameters while local rate of mass transfer is enhanced by increments in the values of Hartmann number, suction velocity, Darcian porous medium, rate of chemical reaction and velocity slip parameters. The presence of velocity slip on the flow distribution is found to be of great significance to the study.


2019 ◽  
Vol 16 (2) ◽  
pp. 99-108 ◽  
Author(s):  
U S Rajput ◽  
Gaurav Kumar

This research investigates the effects of radiation, chemical reaction and porosity of the medium on unsteady flow of a viscous, incompressible and electrically conducting fluid past an exponentially accelerated vertical plate with variable wall temperature and mass diffusion in the presence of transversely applied uniform magnetic field. The plate temperature and the concentration level near the plate increase linearly with time. The fluid model under consideration has been solved by Laplace transform technique. The model contains equations of motion, diffusion equation and equation of energy. To analyze the solution of the model, reasonable sets of the values of the parameters have been considered. The numerical data obtained is discussed with the help of graphs and tables. The numerical values obtained for skin-friction, Sherwood number and Nusselt number have been tabulated. It is found that the velocity of fluid increases when the values of permeability parameter, acceleration parameter and radiation parameter are increased. But trend is reversed with the chemical reaction parameter. It means that the velocity decreases when the chemical reaction parameter is increased.


2003 ◽  
pp. 209-220 ◽  
Author(s):  
R. Muthucumaraswamy

An exact solution to the problem of flow past an impulsively started infinite vertical isothermal plate with variable mass diffusion is presented here, taking into account of the homogeneous chemical reaction of first-order. The dimensionless governing equations are solved by using the Laplace - transform technique. The velocity and skin-friction are studied for different parameters like chemical reaction parameter, Schmidt number and buoyancy ratio parameter. It is observed that the veloc?ity increases with decreasing chemical reaction parameter and increases with increasing buoyancy ratio parameter.


2019 ◽  
Vol 24 (4) ◽  
pp. 169-182
Author(s):  
B. Prabhakar Reddy

Abstract The effects of chemical reaction on a transient MHD mixed convection flow with mass transfer past an impulsively fixed infinite vertical plate under the influence of a transverse magnetic field have been presented. The medium is considered to be non-scattering and the fluid to be non-gray having emitting-absorbing and optically thick radiation limit properties. The dimensionless governing equations of the flow and mass transfer with boundary conditions are solved numerically by using the Ritz finite element method. The numerical results for the velocity, temperature and the concentration profiles as well as the skin-friction coefficient for different values of physical parameters such as the radiation parameter, magnetic parameter, Schmidt number and chemical reaction parameter have been obtained and presented through graphs and tables. It has been found that there is a fall in the temperature and velocity for both air and water as the radiation parameter is increased. An increase in the Schmidt number and chemical reaction parameter results a decrease in the concentration and velocity profiles for both air and water. Furthermore, an increase in the radiation parameter, magnetic parameter, Schmidt number and chemical reaction parameter decreases the skin-friction.


Author(s):  
Pooja P Humane ◽  
Vishwambhar S Patil ◽  
Amar B Patil

The flow of Casson–Williamson fluid on a stretching surface is considered for the study. The movement of fluid is examined under the effect of external magnetic field, thermal radiation and chemical consequences. The model is formed by considering all the physical aspects responsible for the physical mechanism. The formed mathematical model (partial differential equation) is numerically solved after transforming it into an ordinary one (ordinary differential equation) via similarity invariants. The physical mechanism for velocity, temperature, and concentration is examined through the associated parameters like radiation index, Williamson and Casson parameter, suction/injection parameter, porosity index, and chemical reaction parameter.


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