Ch. RamReddy

Influence of Viscous Dissipation on Free Convection in a Non-Darcy Porous Medium Saturated with Nanofluid in the Presence of Magnetic Field

The effects of viscous dissipation and magnetic field on free convection heat and mass transfer along a vertical plate embedded in a nanofluid saturated non-Darcy porous medium have been studied. The model used for the nanofluid incorporates the effects of Brownian motion and thermophoresis. The nonlinear governing equations and their associated boundary conditions are initially cast into dimensionless form by non-similarity variables. The resulting system of equations is then solved numerically by an accurate implicit finite-difference method. The numerical results are compared and found to be in good agreement with previously published results for a special case of the present investigation. The effect of the physical parameters on the flow, heat transfer and nanoparticle concentration characteristics of the model is presented through graphs and the salient features are discussed.

Double-Diffusive Free Convection Flow Past an Inclined Plate Embedded in a Non-Darcy Porous Medium Saturated with a Nanofluid

In this investigation, we intend to present the influence of the prominent Soret effect on double-diffusive free convection heat and mass transfer in the boundary layer region of a semi-infinite inclined flat plate in a nanofluid saturated non-Darcy porous medium. The transformed boundary layer ordinary differential equations are solved numerically using the shooting and matching technique. Consideration of the nanofluid and the coupled convective process enhanced the number of non-dimensional parameters considerably thereby increasing the complexity of the present problem. A wide range of parameter values are chosen to bring out the effect of Soret parameter on the free convection process with varying angle of inclinations making the wall geometry from vertical to horizontal plate. The effects of angle of inclination and Soret parameter on the flow, heat and mass transfer coefficients are analyzed. The numerical results obtained for the velocity, temperature, volume fraction, and concentration profiles, local wall temperature, local nanoparticle concentration, and local wall concentration reveal interesting phenomenon, and some of these qualitative results are presented through the plots.

Effect of Double Stratification on Free Convection in a Micropolar Fluid

This paper analyzes the flow and heat and mass transfer characteristics of the free convection on a vertical plate with uniform and constant heat and mass fluxes in a doubly stratified micropolar fluid. The nonlinear governing equations and their associated boundary conditions are initially cast into dimensionless forms by pseudosimilarity variables. The resulting system of equations is then solved numerically using the Keller-box method. The numerical results are compared and found to be in good agreement with previously published results on special cases of the problem. The obtained results are displayed graphically to illustrate the effect of the micropolar and stratification parameters on the dimensionless velocity, microrotation, wall temperature, and wall concentration. The numerical values of the skin friction, wall couple stress, and heat and mass transfer rates for different values of governing parameters are also tabulated.

Similarity Solution for Free Convection Flow of a Micropolar Fluid under Convective Boundary Condition via Lie Scaling Group Transformations

The free convective flow of an incompressible micropolar fluid along permeable vertical plate under the convective boundary condition is investigated. The Lie scaling group of transformations is applied to get the similarity representation for the system of partial differential equations and then the resulting systems of equations are solved using spectral quasi-linearisation method. A quantitative comparison of the numerical results is made with previously published results for special cases and the results are found to be in good agreement. The results of the physical parameters on the developments of flow, temperature, concentration, skinfriction, wall couple stress, heat transfer, and mass transfer characteristics along vertical plate are given and the salient features are discussed.

Magnetic and Double Dispersion Effects on Free Convection in a Non-Darcy Porous Medium Saturated with Power-Law Fluid

In this paper, effects of magnetic field and double dispersion on free convection heat and mass transfer along a vertical plate embedded in a doubly stratified non-Darcy porous medium saturated with power-law fluid is considered. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. The effects of magnetic parameter, dispersion parameters, and power-law index on the velocity, temperature, and concentration are illustrated graphically.

Magnetic effect on free convection in a non-darcy porous medium saturated with doubly stratified power-law fluid

Natural convection heat and mass transfer along a vertical plate embedded in a doubly stratified power-law fluid saturated non-Darcy porous medium with uniform heat and mass flux is presented. The governing partial differential equations are transformed into ordinary differential equations using similarity transformations and then solved numerically. The effects of magnetic parameter, stratification parameter and power-law index on the velocity, temperature and concentration are illustrated graphically.

Natural Convection Heat and Mass Transfer in a Micropolar Fluid with Thermal and Mass Stratification

The effects of thermal and solutal stratification on natural convection along a vertical plate embedded in a micropolar fluid are analyzed in both cases of buoyancy-assisting and buoyancy-opposing flows. The nonlinear governing equations and their associated boundary conditions are initially cast into dimensionless forms by pseudo-similarity variables. The resulting system of equations is then solved numerically using the Keller-box method. The numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. The velocity, microrotation, temperature, and concentration profiles are shown for different values of the coupling number, thermal, and solutal stratification parameters. The numerical values of the skin friction, wall couple stress, heat and mass transfer rates for different values of governing parameters are also tabulated.

Spectral Quasi-linearisation Method for Nonlinear Thermal Convection Flow of a Micropolar Fluid under Convective Boundary Condition

Abstract The significance of nonlinear temperaturedependent density relation and convective boundary condition on natural convection flow of an incompressible micropolar fluid with homogeneous-heterogeneous reactions is analyzed. In spite of the complicated nonlinear structure of the present setup and to allow all the essential features, the representation of similarity transformations for the system of non-dimensional fluid flow equations is attained through Lie group transformations and hence the governing similarity equations are worked out by a numerical approach known as spectral quasi-linearization method. It is noticed that in the presence of the nonlinear convection parameter enhance the velocity, species concentration, heat transfer rate, skin friction, but decreases the temperature and wall couple stress.

A spectral relaxation method for linear and non-linear stratification effects on mixed convection in a porous medium

In this composition, we use a new spectral relaxation method (SRM) to investigate the effects of linear and non-linear stratification on mixed convective transport along a vertical surface embedded in a porous medium and it is viewed for the first time in both aiding and opposing buoyancy cases. The governing partial differential equations are transformed into ordinary differential equations using similarity transformation and then the resulting differential equations are solved numerically using SRM. A comparison is also made about the accuracy of SRM results in relation to the results obtained using the shooting method. We show that the proposed technique is an efficient numerical algorithm with assured convergence that serves as an alternative to common numerical methods for solving nonlinear boundary value problems. A parametric study of the physical parameters involved in the problem is conducted and a representative set of numerical results is illustrated, with accent on the comparison between linear and non-linear stratification. It is significant to notice that the separation of flow is found to be more in the absence of stratification whereas it is less in the presence of stratification. Finally, thermal and solutal stratifications significantly affect the heat and mass transfer rates, besides delay the boundary layer separation.

Influence of viscous dissipation and thermo-diffusion on double diffusive convection over a vertical cone in a non-Darcy porous medium saturated by a non-Newtonian fluid with variable heat and mass fluxes

Abstract This paper emphasizes the thermo-diffusion and viscous dissipation effects on double diffusive natural convection heat and mass transfer characteristics of non-Newtonian power-law fluid over a vertical cone embedded in a non-Darcy porous medium with variable heat and mass flux conditions. The Ostwald–de Waele power-law model is employed to describe the behavior of non-Newtonian fluid. Local non-similarity procedure is applied to transform the set of non-dimensional partial differential equations into set of ordinary differential equations and then the resulting system of equations are solved numerically by Runge-Kutta fourth order method together with a shooting technique. The influence of pertinent parameters on temperature and concentration, heat and mass transfer rates are analyzed in opposing and aiding buoyancy cases through graphical representation and explored in detail.