Combined Influence of Thermal Radiation and Radiation Absorption on MHD Mixed Convective Heat and Mass Transfer Flow in Circular Annulus

The aim of the problem is to analyze theoretically the combined effects of thermal radiation and radiation absorption on hydromagnetic Brinkman-Forchhimer mixed convection flow of optically dense fluid flow under the influence of magnetic field and chemical reaction on through a vertical circular annulus filled with a saturated porous medium. The outer cylinder is maintained at constant heat flux while the inner cylinder is at a constant temperature. Based on the assumptions, the nonlinear model equations of momentum, energy and species concentration balance are obtained and tacked numerically using an efficient implicit Galerkin finite element method with quadratic polynomial approximation technique. The behavior of velocity, temperature and concentration is analyzed for different parametric values at different axial positions numerically. The local skin friction, local Nusselt number and local Sherwood number are illustrated to show interesting features of the solution. Keywords: Heat & Mass Transfer; Thermal Radiation; Radiation absorption; Soret and Dufour effects; Concentric Annulus; Chemical reaction

Effect of Hall Current, Thermal Radiation, Dissipation and Chemical Reaction on Hydromagnetic Non-Darcy Mixed Convective Heat and Mass Transfer Flow Past a Stretching Sheet in the Presence of Heat Sources

We study the combined influence of Hall current, radiation  and dissipation on convective heat and mass transfer flow of a viscous electrically conducting g fluid past a stretching sheet. The equations governing the flow , heat and mass transfer have been solved by Galerkin finite element analysis with three nodded line segments. The velocity, temperature and concentration have been analysed for different values of m, N, F, g, Ec  and Q. The rate of heat and mass transfer on the plate has been evaluated numerically for different variations

Rotating unsteady multi-physico-chemical magneto-micropolar transport in porous media : Galerkin finite element study

In this paper, a mathematical model is developed for magnetohydrodynamic (MHD), incompressible, dissipative and chemically reacting micropolar fluid flow, heat and mass transfer through a porous medium from a vertical plate with Hall current, Soret and Dufour effects. The entire system rotates with uniform angular velocity about an axis normal to the plate. Rosseland’s diffusion approximation is used to describe the radiative heat flux in the energy equation. The governing partial differential equations for momentum, heat, angular momentum and species conservation are transformed into dimensionless form under the assumption of low Reynolds number with appropriate dimensionless quantities. The emerging boundary value problem is then solved numerically with a Galerkin finite element method employing the weighted residual approach. The evolution of translational velocity, micro-rotation (angular velocity), temperature and concentration are studied in detail. The influence of many multi-physical parameters in these variables is illustrated graphically. Finally, the friction factor, surface heat transfer and mass transfer rate dependency on the emerging thermo-physical parameters are also tabulated. The finite element code is benchmarked with the results reported in the literature to check the validity and accuracy under some limiting cases and an excellent agreement with published solutions is achieved. The study is relevant to rotating MHD energy generators utilizing non-Newtonian working fluids and also magnetic rheo-dynamic materials processing systems

A Numerical Model for Analysis of Heat Transfer in MHD Casson Fluid with Radiation and Viscous Dissipation

This article is, concerned a numerical model for analysis of heat transfer (HT) in MHD Casson fluid (CF) with radiation and viscous dissipation. The governing PDE's are developed for the physical model and converted into non-dimensional form and then with the help of Galerkin finite element method (GFEM) solution is obtained. The impact of dimensionless parameters which are supervising the flow such as Magnetic parameter  , Casson parameter ( )  thermal Grashof number Permeability of porous medium    Prandtl number Heat absorption parameter  Viscous dissipation   and Radiation parameter  are analyzed through graphs for fluid properties. The  results obtained were compared with earlier reported results for correctnes

A Numerical Model for Analysis of Heat Transfer in MHD Casson Fluid with Radiation and Viscous Dissipation

This article is, concerned a numerical model for analysis of heat transfer (HT) in MHD Casson fluid (CF) with radiation and viscous dissipation. The governing PDE's are developed for the physical model and converted into non-dimensional form and then with the help of Galerkin finite element method (GFEM) solution is obtained. The impact of dimensionless parameters which are supervising the flow such as Magnetic parameter  , Casson parameter ( )  thermal Grashof number Permeability of porous medium    Prandtl number Heat absorption parameter  Viscous dissipation   and Radiation parameter  are analyzed through graphs for fluid properties. The  results obtained were compared with earlier reported results for correctnes

Unsteady nonlinear magnetohydrodynamic micropolar transport phenomena with hall and ion-slip current effects : numerical study

Unsteady viscous two-dimensional magnetohydrodynamic micropolar flow, heat and mass transfer from an infinite vertical surface with Hall and Ion-slip currents is investigated theoretically and numerically. The simulation presented is motivated by electro-conductive polymer (ECP) materials processing in which multiple electromagnetic effects arise. The primitive boundary layer conservation equations are transformed into a non-similar system of coupled non-dimensional momentum, angular momentum, energy and concentration equations, with appropriate boundary conditions. The resulting two-point boundary value problem is solved numerically by an exceptionally stable and welltested implicit finite difference technique. A stability analysis is included for restrictions of the implicit finite difference method (FDM) employed. Validation with a Galerkin finite element method (FEM) technique is included. The influence of various parameters is presented graphically on primary and secondary shear stress, Nusselt number, Sherwood number and wall couple stress. Secondary (cross flow) shear stress is strongly enhanced with greater magnetic parameter (Hartmann number) and micropolar wall couple stress is also weakl y enhanced for small time values with Hartmann number. Increasing thermo-diffusive Soret number suppresses both Nusselt and Sherwood numbers whereas it elevates both primary and secondary shear stress and at larger time values also increases the couple stress. Secondary shear stress is strongly boosted with Hall parameter. Ion slip effect induces a weak modification in primary and secondary shear stress distributions. The present study is relevant to electroconductive non-Newtonian (magnetic polymer) materials processing systems

EFFECTS OF RADIATION AND VISCOUS DISSIPATION ON MHD BOUNDARY LAYER FLOW DUE TO AN EXPONENTIALLY MOVING STRETCHING SHEET IN POROUS MEDIUM

Aim of the paper is to investigate radiation effects on the MHD flow over an exponentially moving stretching sheet placed in a porous medium. A variable magnetic field is applied normal to the sheet. Similarity transformation is used to convert the governing nonlinear partial differential equations into a system of ordinary differential equations which are solved numerically using forth order Runge- Kutta integration scheme with shooting iteration technique. The effects of physical parameters on the dimensionless velocity and temperature profiles are depicted graphically and analyzed in details. Finally numerical values of physical quantities, such as the local skin friction coefficient and the local Nusselt number are presented in the tabular form

Influence of Radiation Absorption, Chemical Reaction on MHD Mixed Convective Heat and Mass Transfer Flow Past a Stretching Sheet in Slip Flow Regime

The aim of the problem is to analyze the combined influence of Radiation absorption and thermal radiation under the influence of chemical reaction on MHD mixed convective heat and mass transfer flow of a viscous electrically conducting fluid past a stretching sheet in the presence of non-uniform heat source with Hall currents in slip-flow regime. The governing equations of the heat and mass transfer flow have been solved by Galerkin finite element analysis with three nodded line segments. The velocity, temperature and concentration have been analyzed. The rate of heat and mass transfer on the plate has been discussed numerically for different parametric values. Keywords: Radiation absorption; Thermal Radiation; Non-Uniform Heat Source; Slip Regime; Hall Currents; Heat & Mass Transfer; Soret and Dufour effects; Stretching sheet; Chemical reaction

Numerical investigation of radiative optically-dense transient magnetized reactive transport phenomena with cross diffusion, dissipation and wall mass flux effects

High temperature electromagnetic materials fabrication systems in chemical engineering require ever more sophisticated theoretical and computational models for describing multiple, simultaneous thermophysical effects. Motivated by this application, the present article addresses transient magnetohydrodynamic heat and mass transfer in chemically-reacting fluid flow from an impulsively-started vertical perforated sheet. Thermal radiation flux, internal heat generation (heat source), Joule magnetic heating (Ohmic dissipation), thermo-diffusive and diffuso-thermal (i.e. cross-diffusion) effects and also viscous dissipation are incorporated in the mathematical model. To facilitate numerical solutions of the coupled, nonlinear boundary value problem, non-similar transformations are employed and the partial differential conservation equations are normalized into a dimensionless system of momentum, energy and concentration equations with associated boundary thermal conditions. An implicit finite difference method (FDM) is utilized to solve the unsteady equations. Verification of the FDM solutions for dimensionless velocity, temperature and concentration functions is achieved with a variational finite element method code (MAGNETO-FEM) and also a network simulation method code (MAG-PSPICE). The influence of the emerging thermo-physical parameters on transient velocity, temperature, concentration, wall shear stress, Nusselt number and Sherwood number is elaborated. The flow is accelerated with increasing thermal radiative flux, Eckert number, heat generation and Soret number whereas the flow is decelerated with greater wall suction, heat absorption, magnetic field and Prandtl number. Temperatures are also observed to be elevated with magnetic parameter, radiation heat transfer, Dufour number, heat generation (source) and Eckert number with the contrary effects computed for increasing suction parameter or Prandtl number. The species concentration is enhanced with Soret number and generative chemical reaction whereas it is depressed with greater wall suction, Schimidt number and destructive chemical reaction paramete

Finite element computation of magnetohydrodynamic nanofluid convection from an oscillating inclined plate with radiative flux, heat source and variable temperature effects

The present work describes finite element computations for radiative magnetohydrodynamic convective Newtonian nanofluid flow from an oscillating inclined porous plate with variable temperature. Heat source/sink and buoyancy effects are included in the mathematical model. The problem is formulated by employing Tiwari-Das nanofluid model and two water - based nanofluids with spherical shaped metal nano particles as copper and alumina are considered. The Brinkman and Maxwell-Garnetts models are used for the dynamic viscosity and effective thermal conductivity of the nanofluids respectively. An algebraic flux model, the Rosseland diffusion approximation is adopted to simulate thermal radiative flux effects. The dimensionless, coupled governing partial differential equations are numerically solved via the finite element method with weak variational formulation by imposing initial and boundary conditions with a weighted residual scheme. A grid independence study is also conducted. The finite element solutions are reduced to known previous solutions in some limiting cases of the present investigation and are found to be in good agreement with published work. This investigation is relevant to electromagnetic nanomaterial manufacturing processes operating at high temperatures where radiation heat transfer is significant