V. Sugunamma

Aligned magnetic field and cross-diffusion effects of a nanofluid over an exponentially stretching surface in porous medium

In this paper, we investigated the effects of aligned magnetic field, thermal radiation, heat generation/absorption, cross-diffusion, viscous dissipation, heat source and chemical reaction on the flow of a nanofluid past an exponentially stretching sheet in porous medium. The governing partial differential equations are transformed to set of ordinary differential equations using self-similarity transformation, which are then solved numerically using bvp4c Matlab package. Finally the effects of various non-dimensional parameters on velocity, temperature, concentration, skin friction, local Nusselt and Sherwood numbers are thoroughly investigated and presented through graphs and tables. We observed that an increase in the aligned angle strengthens the applied magnetic field and decreases the velocity profiles of the flow. Soret and Dufour numbers are helpful to enhance the heat transfer rate. An increase in the heat source parameter, radiation parameter and Eckert number increases the mass transfer rate. Mixed convection parameter has tendency to enhance the friction factor along with the heat and mass transfer rate.

Thermo Diffusion and Hall Current Effects on an Unsteady Flow of a Nanofluid under the Influence of Inclined Magnetic Field

In this paper, we investigated the effects of hall current and thermal diffusion on an unsteady flow of a nanofluid in the presence of inclined magnetic field and volume fraction of nanoparticles. We considered copper nanoparticles with base fluid as water and presented dual solutions for water and Cu-water cases. An analytical solution of the problem was performed using perturbation technique. The effects of various non-dimensional governing parameters on velocity, temperature and concentration fields along with the friction factor, local Nusselt and Sherwood numbers are discussed and presented through graphs and tables. To validate the results of the present study we compared the present results with the existed results and found an excellent agreement. Moreover, through this study we observed that an increase in the Hall current parameter increases the velocity profiles and depreciates the friction factor. It is also observed that an increase in Soret number causes to enhance the velocity and concentration boundary layer thicknesses.

Numerical study of chemically reacting unsteady Casson fluid flow past a stretching surface with cross diffusion and thermal radiation

Abstract The problem of an unsteady MHD Casson fluid flow towards a stretching surface with cross diffusion effects is considered. The governing partial differential equations are converted into a set of nonlinear coupled ordinary differential equations with the help of suitable similarity transformations. Further, these equations have been solved numerically by using Runge-Kutta fourth order method along with shooting technique. Finally, we studied the influence of various non-dimensional governing parameters on the flow field through graphs and tables. Results indicate that Dufour and Soret numbers have tendency to enhance the fluid velocity. It is also found that Soret number enhances the heat transfer rate where as an opposite result is observed with Casson parameter. A comparison of the present results with the previous literature is also tabulated to show the accuracy of the results.

Dual Solutions for Thermo Diffusion and Diffusion Thermo Effects on 3D MHD Casson Fluid Flow over a Stretching Surface

In this paper, we analyse the thermo diffusion and diffusion thermo effects on MHD Casson fluid flow over a linear/nonlinear stretching sheet. By making use of appropriate similarity transformations, the governing equations of the flow are reduced into a set of nonlinear coupled ordinary differential equations. Further, these equations are solved numerically using Runge-Kutta based shooting technique. The effect of pertinent parameters on velocity, temperature and concentration profiles along with friction factors, local Nusselt and Sherwood numbers are discussed and presented with the help of graphs and tables. From the results, we found that heat transfer performance on the flow over a nonlinear stretching surface is higher than that of the flow over a linear stretching surface.

Simultaneous impacts of Joule heating and variable heat source/sink on MHD 3D flow of Carreau-nanoliquids with temperature dependent viscosity

Abstract The 3D flow of non-Newtonian nanoliquid flows past a bidirectional stretching sheet with heat transfer is investigated in the present study. It is assumed that viscosity of the liquid varies with temperature. Carreau non-Newtonain model, Tiwari and Das nanofluid model are used to formulate the problem. The impacts of Joule heating, nonlinear radiation and non-uniform (space and temperature dependent) heat source/sink are accounted. Al-Cu-CH3OH and Cu-CH3OH are considered as nanoliquids for the present study. The solution of the problem is attained by the application of shooting and R.K. numerical procedures. Graphical and tabular illustrations are incorporated with a view of understanding the influence of various physical parameters on the flow field. We eyed that using of Al-Cu alloy nanoparticles in the carrier liquid leads to superior heat transfer ability instead of using only Aluminum nanoparticles. Weissenberg number and viscosity parameter have inclination to exalt the thermal field.

Dual solutions for nanofluid flow past a curved surface with nonlinear radiation, Soret and Dufour effects

Present work explores the numerical study of heat and mass transfer in nanofluid flow past a curve shaped stretchable (linearly/nonlinearly) geometry. The impact of Lorentz force caused by magnetic field, nonlinear radiation due to high temperature near the surface, frictional heating by virtue of viscous dissipation and cross diffusion by virtue of concentration and temperature differences are pondered while formulating the problem. The thermo physical properties of water and silver nanoparticles are used for calculations. Hamilton-Crosser model is considered for effective thermal conductivity of nanofluid. Shooting method and R.K. fourth order algorithm are adopted to solve the nonlinear coupled differential equations of the problem. The concentration, temperature and velocity fields are studied graphically for distinct values of flow parameters. Numerical values also calculated to know the impact of same parameters on mass and heat transfer coefficients. Results depict that mass and heat transfer performance in the flow via nonlinear curved surface is better when compared with the flow over linearly curved surface. As usually Eckert number and temperature ratio parameter boosts the fluid temperature in the present flow situation also.

Impact of Non-linear Radiation on MHD Non-aligned Stagnation Point Flow of Micropolar Fluid Over a Convective Surface

We aimed at examining the magnetohydrodynamic (MHD) radiative non-aligned stagnation point motion of non-Newtonian liquid over a stretched surface. The heat transfer mechanism is investigated in the presence of variable heat sink/source, non-linear Rosseland approximation and Biot number. Appropriate transmutations are exploited to metamorphose the flow equations into ODEs. The acquired non-linear ODEs are highly coupled. These are tackled with the consecutive implication of fourth-order Runge–Kutta and shooting techniques. The variations of flow governing parameters on the dimensionless velocity, microrotation and temperature plus the measure of heat transport, couple stress coefficient and friction factor are thoroughly explained using plots and tables. Outcomes stipulate that increasing the values of the stretching ratio parameter causes the thermal field to decline and the velocity field to inflate. Also, an upsurge in the micropolar parameter produces an increase in the rate of heat transport but an opposite outcome is detected with the couple stress coefficient. To the best of our knowledge the non-orthogonal stagnated motion of micropolar liquid with radiation as non-linear and variable heat source/sink has never before been scrutinized.

Cross-Diffusion Effects on MHD Cattaneo-Christov Flow of Casson Fluid Past a Convective Linear/Non-Linear Stretching Sheet

Through this article, we presented a comparative study for the MHD non- Newtonian fluid flow past a stretching sheet using Cattaneo-Christov heat flux model. The flow equations and the related convective boundary conditions have been altered as dimensionless ODEs by suitable similarity transformations. Further, these are resolved by employing fourth order Runge-Kutta method along with shooting technique. The influence of all flow regulating parameters on velocity, thermal and mass diffusive boundary layers are perceived through graphs. Also the variation in skin friction, mass and heat transfer coefficients for the same parameters are perceived via numerical values. The velocity of the flow past a linear stretching sheet is higher than that of the flow past a non-linear stretching sheet. But heat transfer performance in the flow via non-linear surface is better than that of flow via linear surface.

Impact of Soret and Dufour Numbers on MHD Casson Fluid Flow Past an Exponentially Stretching Sheet with Non-Uniform Heat Source/Sink

Present study deals with the impact of cross diffusion on Casson fluid flow in the presence of Lorentz force. Flow is caused by the exponential stretching of surface in two lateral directions. The influence of space dependent varying heat sink/source is also contemplated. The basic governing equations are first converted into system of ODEs and then solved using an efficient numerical procedure namely R.K. based shooting technique. From the solution we found that flow is affected by some physical parameters like Casson parameter, non uniform heat parameters, Soret and Dufour numbers etc. Hence the impact of such parameters on velocity, temperature and concentration profiles is shown via plots. Further the friction factor, local Nusselt and Sherwood numbers are also calculated and given in tables. Results indicate that an increase in the Casson parameter enhances the temperature and concentration fields. Dufour and Soret numbers have tendency to enhance temperature and concentration fields respectively.

Impact of Lorentz Force on Unsteady Bio Convective Flow of Carreau Fluid across a Variable Thickness Sheet with Non-Fourier Heat Flux Model

In this article, we examined the magnetohydrodynamic Cattaneo-Christov bio convective flow of Carreau liquid over a variable thickness sheet with irregular heat sink/source. The fluid motion is supposed to be time dependent and not turbulent. Firstly, proper transmutations are pondered to metamorphose the basic flow equations as ODE. The solution of these ODEs is procured by the sequential execution of R.K. and Shooting numerical treatments. The density of motile organisms, concentration, temperature and velocity distributions for dissimilar values of non-dimensional parameters are perused via graphs. Further, we analyzed the impact of same parameters on friction factor, local Nusselt number and the rate of mass transfer coefficients and presented in table. Results indicate that the distribution of the density of motile organisms is an increasing function of Peclet and Lewis numbers. Fluid velocity is proportional to the Weissenberg number. Also the space dependent heat sink/source parameters perform obligatory role in the mass and heat transport performance.