Multi‐Objective RSM Optimization of Coupled Momentum–Microrotation–Thermosolutal Transport in Double‐Stratified MHD Micropolar Fluid Flow With Suction and Injection

Free convection heat and mass transfer from a horizontal cylinder of elliptic cross section in micropolar fluids

An analysis is presented to investigate the effects of chemical reaction, thermal radiation and heat generation or absorption on unsteady free convective heat and mass transfer along an infinite vertical porous plate in the presence of a transverse magnetic field and Hall current. The governing partial differential equations are formulated and transformed by using a similarity transformation into a system of ordinary differential equations. The resulting equations are solved numerically using a fourth‐order Runge–Kutta scheme along with the shooting method. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. Numerical results for the velocity, temperature and concentration distributions are shown graphically for different parametric values. The effects of parameters on the local friction coefficients, the Nusselt number and Sherwood numbers are depicted in tabulated form. Copyright © 2009 John Wiley & Sons, Ltd.

Natural convection heat and mass transfer of non-Newtonian power law fluids with yield stress in porous media from a vertical plate with variable wall heat and mass fluxes

Heat and mass transfer in magnetohydrodynamic flow of micropolar fluid on a circular cylinder with uniform heat and mass flux

The present paper deals with the numerical investigation of Soret and Dufour effect on free convective heat and mass transfer characteristics of radiating water based nanofluid past a vertically moving porous plate in porous medium. The water based nanofluid with copper as a nanoparticle is considered in the present study. The dimensional governing equations relevant to the present model are transformed into non-dimensional form by using the appropriate parameters. The non-dimensional governing equations with the pertinent boundary conditions are solved numerically by using bvp4c function in Matlab software. The influence of suitable parameters on fluid velocity, temperature, concentration, Sherwood number (rate of mass transfer), Nusselt number (rate of heat transfer) and skin friction are exhibited graphically and discussed. Also, the effect of radiation parameter and Prandtl number in the absence of Dufour number has been compared with the help of contours. It is apparent from this study that fluid velocity increases with the increase in K, , & Du and decreases with increase in The fluid temperature increases with the increase in Du & R while it decreases with Pr. The fluid concentration increases with increase in whereas it decreases with . The rate of mass transfer (Sherwood number) increases with increase in Du and decreases with increase in & while the rate of heat transfer (Nusselt number) increases with increase in Du & Pr and decreases with increase in R. Shear stress (skin friction) decreases with the increase in , , K & Du.

Reduction of the Number of Variables in Systems of Partial Differential Equations, with Auxiliary Conditions

The paper investigates the numerical solution of problem of magnetohydrodynamic (MHD) micropolar fluid flow with heat and mass transfer towards a stagnation point on a vertical plate. In this study, we consider both strong concentrations (n = 0) and weak concentrations (n = 1/2). The governing equations have been transformed into nonlinear ordinary differential equations by applying the similarity transformation and have been solved numerically by using the finite difference method (FDM) and analytically by using (DTM). The effects of various governing parameters, namely, material parameter, radiation parameter, magnetic parameter, Prandtl number, Schmidt number, chemical reaction parameter and Soret number on the velocity, microrotation, temperature and concentration have been computed and discussed in detail through some figures and tables. In order to verify the accuracy of the present results, we have compared these results with the analytical solutions by using the differential transform method (DTM) and the multi-step differential transform method (MDTM). It is observed that this approximate numerical solution is in good agreement with the analytical solution.

This article investigates the Diffusion thermo and chemical reaction effects on the free convection heat and mass transfer flow of Jeffrey nanofluids (Cu and TiO2) over an inclined porous vertical plate embedded in a porous medium in the presence of radiation absorption and constant heat source under fluctuating boundary conditions. The plate is moved with a constant velocity U0, temperature and the concentration are assumed to be fluctuating with time harmonically from a constant mean at the plate. Perturbation technique is applied to solve the governing equations of the flow and pointed out the variations in velocity, temperature and concentration with the use of graphical presentations. The impact of several parameters on local skin friction, Nusselt number and Sherwood number is also noticed and discussed. It is concluded that the resultant velocity reduces with increasing Jeffrey parameter and Suction parameter, velocity and Temperature enhances with increasing Radiation absorption parameter. Also it is noticed that the solutal boundary layer thickness decreases with an increase in chemical reaction parameter. It is because chemical molecular diffusivity reduces for higher values of Kr.

Numerical modeling of thermophoresis and Brownian with heat transfer in shear-rate-dependent fluid: The finite element simulations

A two-dimensional steady MHD free convection and mass transfer flow past a semi-infinite vertical porous plate in a porous medium has been studied numerically including the Dufour and Soret effects. The resulting momentum, energy and concentration equations are then made similar by introducing the usual similarity transformations. These similar equations are then solved numerically by using the Nachtsheim-Swigert shooting method along with Runge-Kutta sixth order integration scheme. The numerical results are displayed graphically showing the effects of various parameters entering into the problem. Finally, the local values of the skin-friction coefficient (Cf), Nusselt number (Nu) and Sherwood number (Sh) are also shown in tabular form. Keywords: MHD, Free convection, Vertical plate, Steady flow, Porous medium, Dufour effect, Soret effect. doi: 10.3329/jname.v2i1.2030 Journal of Naval Architecture and Marine Engineering 2(1)(2005) 55-65

A theoretical study has been developed to investigate the influence of thermophoresis and couple stresses on the steady flow of non-Newtonian fluid with free convective heat and mass transfer over a channel bounded by two permeable plates. The considered non-Newtonian fluid follows a viscoelastic model. The problem is modulated mathematically by a system of non-linear differential equations pertaining to describe the continuity, momentum, energy, and concentration. These equations involve the effects of viscous dissipation and chemical reaction. The numerical solutions of the dimensionless equations are found as a function of the physical parameters of this problem. The numerical formulas of the velocity (u), temperature Φ and concentration Θ as well as skin friction coefficient T*, Nusselt number(Nu) and Sherwood number(Sh) are computed. The physical parameter's effects of the problem on these formulas are described and illustrated graphically through some figures and tables. It is observed that any increase in the thermophoretic parameter T leads to reduce in velocity profiles as well as concentration layers. In contrast, the velocity increases with increasing the couple stresses inverse parameter.

The flow, 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 saturated non-Darcy porous medium are studied. 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 effects of the micropolar, Darcy, non-Darcy and stratification parameters on the dimensionless velocity, microrotation, wall temperature, wall concentration, local skin-friction coefficient and wall couple stress coefficient are presented graphically.

Homogeneous-heterogeneous reactions in MHD flow of micropolar fluid by a curved stretching surface

The current reconnaissance emphasis on spanwise cosinusoidally fluctuating temperature along with time deepened as well as radiation absorption on unsteady magneto‐hydrodynamics free convective heat and mass transfer boundary layer flow with viscous dissipation, constant suction normal to an infinite hot vertical porous plate in the existence of chemical reaction by means of heat generation. The analytical solution of nonlinear PDE's governing the flow has been accomplished by employing a second‐order multiple regular perturbation method within the stipulated boundary conditions. Velocity, temperature, concentration as well as Sherwood have been exemplified graphically; along with Skin friction, and Nusselt numbers are ascertained in tabular form. Eventually, it was found that velocity, temperature, and Skin friction accelerated with the accumulative values of Eckert number and radiation absorption, but conflicting results emerged in the case of Prandtl number. Contemporaneously Sherwood's number depreciated with the magnification of the chemical reaction parameter as well as the Schmidt number.

Free convective heat transfer with hall effects, heat absorption and chemical reaction over an accelerated moving plate in a rotating system