Defect and Diffusion Forum Vol. 388

Abstract: Dual solutions for the time-dependent flow of a Prandtl fluid containing nanoparticles along a stretching/shrinking surface are presented. The nano Prandtl fluid fills the porous stretching/shrinking surface. The Buongiorno model is employed by accounting Brownian motion and thermophoresis slip mechanisms in the analysis. The relevant nonlinear problem is treated numerically via Runge-Kutta-Fehlberg scheme. The flow profiles are scrutinized with respect to the different governing parameters. Results of this study indicate that the temperature boundary layer thickness increased due to the influence of nanoparticles.

Abstract: In this work, the convective flow of heat generating hydromagnetic fluid through a leaky channel is investigated. Due to channel porosity, the asymmetrical slip conditions are imposed on both walls. The coupled dimensionless partial differential equations are reduced to a system of second-order boundary-value problems based on some flow assumptions and solved by Adomian decomposition method (ADM). Variations in velocity and temperature profiles are presented and discussed in detail. The result of the analysis revealed that increasing Hartmann number decreases the flow velocity while the slip parameters enhance the flow.

Abstract: The study observes the flow and heat transfer in upper-convected Maxwell fluid over a rapidly stretching surface with viscous dissipation. Cattaneo-Christov heat flux model has been used in the preparation of the energy equation. The model is used in guessing the impacts of thermal relaxation time over boundary layer. Similarity method has been used to keep normal the supervising boundary layer equations. Local similarity solutions have been obtained through spectral relaxation method. The fluid temperature has a relation with thermal relaxation time inversely and our calculations have shown the same.. In addition the fluid velocity is a receding activity of the fluid relaxation time. A comparative study of Fourier’s law and the Cattaneo-Christov’s law has been done and inserted in this.

Abstract: Three-dimensional mixed convection flow, heat and mass transfer of Eyring-powell fluid over a convectively heated stretched sheet is inspected in this paper. The encouragement of Brownian motion, Thermophoresis and thermal radiations are accounted. Appropriate transformations are used to reduce the principal PDE’s into set of coupled highly non-linear ODE’s which are then solved numerically using RKF fourth-fifth order method. The consequence of several parameters on flow, heat and mass transfer characteristics are deliberated with the help of graphs and tables. It is observed that, the temperature and concentration profiles diminish for higher values mixed convection parameter.

Abstract: This research work is focused on the effects of combined heat and mass transfer on MHD stagnation point flow of Carreau nanaofluid embedded in porous medium with heat source. Thermal radiation and chemical reaction are also taken into account. The governing non-linear PDEs are transformed into a set of non-linear coupled ODEs which are then solved numerically by using the Runge– Kutta–Fehlberg fourth–fifth order method along shooting technique. The graphical and tabular results elucidate the influence of different non-dimensional governing parameters on the velocity, temperature and concentration fields along with the wall friction, local Nusselt and Sherwood numbers. We found the dual nature of the solutions for suction and injection cases. A good agreement of the present results has been observed by comparing with the existing literature results.

Abstract: A numerical computation has been carried out to study, MHD flow of an electrically conducting viscous fluid from a semi-infinite vertical plate in a porous medium in the presence of heat source and homogeneous first order chemical reaction. The fluid and porous properties, thermal and solutal diffusivity, permeability and porosity are considered to be varied. The governing non-linear partial differential equations for the fluid flow are derived and transformed into a system of ordinary differential equations using a suitable similarity transformations. A numerical computation of shooting technique is employed along Runge Kutta method of fourth order with the help of Newton-Raphson algorithm to compute the solution and analyze the behavior of velocity, temperature, concentration, skin friction, heat and mass transfer rates graphically for various non-dimensional parameters which are controlling the flow of the physical system. The results of the numerical scheme are validated and a numerical comparison has been made with the available literature in the absence of some parameters and it is found to be in good agreement.

Abstract: The present investigation addresses the mixed convection two-phase flow of dusty Oldroyd-B fluid towards a vertical stretching surface in the presence of convective boundary condition and nonlinear thermal radiation. The fluid and dust particles motion is coupled only in the course of drag and heat transfer between them. The Stokes linear drag theory is employed to model the drag force. The numerical solutions based on the Runge-Kutta-Fehlberg 45 scheme with shooting method are presented for both fluid and particle phase velocity and temperature fields. Further, numerical results are obtained for skin friction factor and local Nusselt number of prescribed values of pertinent parameters. The results are presented graphically and the physical aspects of the problem are analyzed. The obtained results are validated with existing results and found to be in good agreement. It is found that the mass concentration of the dust particle parameter plays a key role in controlling flow and thermal behaviour of non-Newtonian fluids.

Abstract: An investigation has been performed to analyze the impacts of Soret and Dufour on natural convective and heat absorbing flow of viscoelastic radiative nanofluid driven by a linearly stretched sheet considering inclined magnetic field. By making use of suitable linear transformations, the mathematical equations of problem are changed into the extremely non-linear coupled system of ordinary differential equations. Further, solutions of these differential equations are obtained by implementing GFEM (Galerkin finite element method). The consequence of various controlling pertinent parameters on nanofluid velocity, solutal concentration, temperature and nanofluid concentration are illustrated by means of various graphs while from engineering aspect numerical values of the shear stress, wall temperature gradient, solutal and nanoparticles concentration rate at the stretched sheet are presented in different tables. The numerical results are compared for mono and double diffusive nanofluids which yield that the aligned magnetic field, viscoelasticity, solutal and Brownian diffusivity have significant impacts on the flow field. The reliability of implemented method is authenticated by comparing our results with the previously published results under certain conditions, which signifies the correctness of the implemented method. The present investigation is applicable in several industrial processes such as coolant application, nano-drug delivery, cooling of microchip, heat exchanger technology, biological fluid movement and oceanography etc.Keywords: Magnetic field; Viscoelastic nanofluid; Thermal radiation; Heat absorption

Abstract: In this paper, we theoretically analyzed the effects of non-uniform heat source/sink on the magnetohydrodynamic dissipative flow of a Carreau fluid towards a thermally stratified melting surface of the paraboloid of revolution. Exponential heat source along with the temperature dependent thermal conductivity and viscosity are taken into account. The representing differential conditions are changed into an arrangement of non-straight coupled ODE’s and solved by employing the R-K with shooting system. Numerical arrangements are obtained from the flow, temperature profiles of various parametric values and after that domino effect are exhibited graphically and also a friction factor and local Sherwood number of various physical parameters are demonstrated graphically and in tabular form. Boosting values of the Weissenberg number increase both the velocity and thermal profiles of Carreau fluid. Rising values of velocity power law index parameter depreciate both the flow and local Sherwood number.

Abstract: Through this study, we investigated the influence of nonlinear thermal radiation, Soret and Dufour effects on unsteady mixed convection boundary flow of micropolar fluid past a stretching sheet. The governing equations of the flow, heat and mass transfer are transformed into a system of nonlinear ordinary differential equations by using self-similarity transformation and solved numerically using bvp4c Matlab package. The influence of various non-dimensional governing parameters on velocity, microrotation, temperature and concentration profiles are discussed and presented with the help of the graphs. Also computed the friction factor, heat and mass transfer rates and presented through tables. Result indicates by increasing the radiation parameter, an improvement is observed in both friction factor and mass transfer rates. .