Siva Reddy Sheri

MHD natural convective flow of nanofluids past stationary and moving inclined porous plate considering temperature and concentration gradients with suction

Purpose n n n n nThis paper aims to focus on the mathematical modeling of magnetohydrodynamic natural convective boundary layer flow of nanofluids past a stationary and moving inclined porous plate considering temperature and concentration gradients with suction effects. n n n n nDesign/methodology/approach n n n n nThe transformed non-dimensional and coupled governing partial differential equations are solved numerically using the finite element method. n n n n nFindings n n n n nThe obtained numerical results for physical governing parameters on the velocity, temperature and concentration distributions are exemplified graphically and presented quantitatively. The boundary layer thickness increased with the increasing values of Soret, Dufour and Grashof numbers, while the thickness of boundary layer decreased with increasing values of suction for both stationary and moving plate cases. The primary and secondary velocity profiles are decreasing with an angle of inclination for moving plate and inclination has no significant effect for the stationary plate. An increase of the Soret number and Dufour number tend to increase the heat and mass transfer, while an increase of suction reduces the heat and mass transfer. n n n n nOriginality/value n n n n nThe problem is an important contribution to the field of nanofluid science and technology and is relevant to high temperature rotating chemical engineering systems exploiting magnetized nanofluids. This study is relatively original in nanofluids.

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

This 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, copper and alumina, with spherical shaped metal nanoparticles 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 this investigation and are found to be in good agreement with published work. This investigation is relevant to electromagnetic nano-material manufacturing processes operating at high temperatures where radiation heat transfer is significant.

Oscillatory dissipative conjugate heat and mass transfer in chemically-reacting micropolar flow with wall couple stress : a finite element numerical study

High temperature non-Newtonian materials processing provides a stimulating area for process engineering simulation. Motivated by emerging applications in this area, the present article studies time-dependent free convective flow of a chemically reacting micropolar fluid from a vertical plate oscillating in its own plane adjacent to a porous medium. Thermal radiative, viscous dissipation and wall couple stress effects are included. The Rosseland diffusion approximation is used to model uni-directional radiative heat flux in energy equation. Darcy’s model is adopted to mimic porous medium drag force effect. The governing two-dimensional conservation equations are normalized with appropriate variables and transformed into a dimensionless, coupled, nonlinear system of partial differential equations under the assumption of low Reynolds number. The governing boundary value problem is then solved under physically viable boundary conditions numerically with a finite element method based on the weighted residual approach. Graphical illustrations for velocity, micro-rotation (angular velocity), temperature, and concentration are obtained as functions of the emerging physical parameters, i.e. thermal radiation, viscous dissipation, first-order chemical reaction parameter, etc. Furthermore, friction factor (skin friction), surface heat transfer and mass transfer rates have been tabulated quantitatively for selected thermo-physical parameters. A comparison with previously published article is made to check the validity and accuracy of the present finite element solutions under some limiting cases and excellent agreement is attained. Additionally, a mesh independence study is conducted. The model is relevant to reactive polymeric materials processing simulation.

Effect of Viscous Dissipation on MHD Free Convection Flow over an Inclined Plate Embedded In a Porous Medium with Heat Absorption

This work is devoted to investigate the influence of viscous dissipation on the magneto hydro dynamic (MHD) free convection flow of an electrically conducting incompressible viscous fluid over an inclined plate embedded in a porous medium with heat absorption. The dimensionless governing equations for this investigation are solved numerically by using Finite element method. With the help of graphs, the effects of the various important parameters entering into the problem on the velocity, temperature and concentration are discussed. The effects of the pertinent parameters on the skin friction, Nusselt number and Sherwood number at the wall are presented numerically in tabular form. In addition, the results obtained show that these parameters have significant influence on the flow. Finally present numerical results are compared with the existing literature and there is an excellent agreement between the results.