scholarly journals Unsteady mixed convection flow through a permeable stretching flat surface with partial slip effects through MHD nanofluid using spectral relaxation method

Open Physics ◽  
2017 ◽  
Vol 15 (1) ◽  
pp. 323-334 ◽  
Author(s):  
Sami M. Ahamed ◽  
Sabyasachi Mondal ◽  
Precious Sibanda
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Flat Surface ◽  
Internal Heat ◽  
Relaxation Method ◽  
Skin Friction Coefficient ◽  
Partial Slip ◽  
Spectral Relaxation Method ◽  
Flow Through ◽  
Spectral Relaxation

AbstractAn unsteady, laminar, mixed convective stagnation point nanofluid flow through a permeable stretching flat surface using internal heat source or sink and partial slip is investigated. The effects of thermophoresis and Brownian motion parameters are revised on the traditional model of nanofluid for which nanofluid particle volume fraction is passively controlled on the boundary. Spectral relaxation method is applied here to solve the non-dimensional conservation equations. The results show the illustration of the impact of skin friction coefficient, different physical parameters, and the heat transfer rate. The nanofluid motion is enhanced with increase in the value of the internal heat sink or source. On the other hand, the rate of heat transfer on the stretching sheet and the skin friction coefficient are reduced by an increase in internal heat generation. This study further shows that the velocity slip increases with decrease in the rate of heat transfer. The outcome results are benchmarked with previously published results.

Thermal Slip Flow of a Three-Dimensional Casson Fluid Embedded in a Porous Medium with Internal Heat Generation

2021 ◽  
Vol 10 (1) ◽  
pp. 58-66
Author(s):  
K. Gangadhar ◽  
M. Venkata Subba Rao ◽  
K. Venkata Ramana ◽  
Ch. Suresh Kumar ◽  
Ali J. Chamkha
Keyword(s):  
Skin Friction ◽  
Slip Flow ◽  
Three Dimensional ◽  
Internal Heat ◽  
Relaxation Method ◽  
Casson Fluid ◽  
Skin Friction Coefficient ◽  
Newtonian Case ◽  
Spectral Relaxation Method ◽  
Spectral Relaxation

Present assessment is considered to analysis flow as well as heat characteristics of steady, thermal slip flow of three-dimensional Casson fluid embedded in a porous medium with internal heat generation. Geometry of the present analysis is linearly stretched surface. Later, all the PDEs corresponding to the study are altered to set of nonlinear equations ODEs by means of appropriate similarity transformations. An efficient numerical scheme of spectral relaxation method (SRM) is applied to solve the nonlinear ordinary system. Variations of Nusselt number, temperature, velocity, and local skin friction coefficient with fluid parameters exhibited by graphs and tables. Spectral relaxation method gives an exact convergence to the nonlinear boundary value problems compare with general methods. In this study, to improve the precision and accuracy of the SRM successive over-relaxation (SOR) strategy is utilized. Proposed method as well as outcomes is checked with the comparison. A sensible connection is acquired between the current outcomes and accessible outcomes in writing. Some of the observations are skin friction coefficient raises and velocities decreases by the magnetic field strength. Skin friction and Local Nusselt number at the surface is more pronounced for non-Newtonian case than that of Newtonian case.

Spectral Relaxation Method for Powell-Eyring Fluid Flow Past a Radially Stretching Heated Disk Surface in a Porous Medium

2018 ◽  
Vol 387 ◽  
pp. 575-586 ◽  
Author(s):  
K. Gangadhar ◽  
P.R. Sobhana Babu ◽  
Oluwole Daniel Makinde
Keyword(s):  
Porous Medium ◽  
Nonlinear Boundary ◽  
Nonlinear Differential Equations ◽  
Slip Flow ◽  
Relaxation Method ◽  
Disk Surface ◽  
Skin Friction Coefficient ◽  
Nonlinear Boundary Value Problems ◽  
Spectral Relaxation Method ◽  
Spectral Relaxation

In this study we use a spectral relaxation method to investigate heat transfer in axisymmetric slip flow of a MHD Powell-Eyring fluid over a radially stretching surface embedded in porous medium with viscous dissipation. The transformed governing system of nonlinear differential equations was solved numerically using the spectral relaxation method that has been proposed for the solution of nonlinear boundary layer equations. Results were obtained for the skin friction coefficient, the local Nusselt number as well as the velocity and temperature profiles for the same values of the governing physical and fluid parameters. Validation of the results was reached by the comparison with limiting cases from previous studies in the literature. 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. We show that the convergence rate of the spectral relaxation method is significant improved by using the method in conjunction with the successive over - relaxation method.

Hydromagnetic Nanofluids Flow through a Porous Medium with Thermal Radiation, Chemical Reaction and Viscous Dissipation using the Spectral Relaxation Method

2019 ◽  
Vol 16 (06) ◽  
pp. 1840020
Author(s):  
Nageeb A. H. Haroun ◽  
Sabyasachi Mondal ◽  
Precious Sibanda
Keyword(s):  
Porous Medium ◽  
Thermal Radiation ◽  
Viscous Dissipation ◽  
Chemical Reaction ◽  
Heat Generation ◽  
Relaxation Method ◽  
Spectral Relaxation Method ◽  
Flow Through ◽  
Spectral Relaxation ◽  
The Impact

We investigate the convective heat and mass transfer in a magnetohydrodynamic nanofluid flow through a porous medium over a stretching sheet subject to heat generation, thermal radiation, viscous dissipation and chemical reaction effects. We have assumed that the nanoparticle volume fraction at the wall may be actively controlled. Two types of nanofluids, namely Cu-water and Al2O3-water are studied. The physical problem is modeled using systems of nonlinear differential equations which have been solved numerically using the spectral relaxation method. Comparing the results with those previously published results in the literature shows excellent agreement. The impact of porosity, heat generation, thermal radiation, magnetic field, viscous dissipation and chemical reaction on the flow field is evaluated and explained.

On Spectral Relaxation Approach to Radiating Powell-Eyring Fluid Flow over a Stretching Disk with Newtonian Heating

2018 ◽  
Vol 387 ◽  
pp. 461-473 ◽  
Author(s):  
K. Gangadhar ◽  
D. Vijaya Kumar ◽  
S. Mohammed Ibrahim ◽  
Oluwole Daniel Makinde
Keyword(s):  
Boundary Layer ◽  
Nonlinear Boundary ◽  
Numerical Solutions ◽  
Relaxation Method ◽  
Newtonian Heating ◽  
Nonlinear Boundary Value Problems ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Spectral Relaxation Method ◽  
Spectral Relaxation

In this study we use a new spectral relaxation method to investigate an axisymmetric law laminar boundary layer flow of a viscous incompressible non-Newtonian Eyring-Powell fluid and heat transfer over a heated disk with thermal radiation and Newtonian heating. The transformed boundary layer equations are solved numerically using the spectral relaxation method that has been proposed for the solution of nonlinear boundary layer equations. Numerical solutions are obtained for the local wall temperature, the local skin friction coefficient, as well as the velocity and temperature profiles. 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. We show that the convergence rate of the spectral relaxation method is significantly improved by using method in conjunction with the successive over-relaxation method. It is observed that CPU time is reduced in SOR method compare with SRM method.

Free-convection effects in the boundary layer along a vertically stretching flat surface

1992 ◽  
Vol 70 (12) ◽  
pp. 1253-1260 ◽  
Author(s):  
John E. Daskalakis
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Free Convection ◽  
Skin Friction ◽  
Flat Surface ◽  
Relaxation Method ◽  
Boussinesq Approximation ◽  
Axial Coordinate ◽  
Prandtl Numbers ◽  
Energy Equations

We assess the effects of free convection on the boundary layer formed along a flat surface stretching vertically in a quiescent fluid. The flow is laminar and incompressible, the buoyancy forces conform to the Boussinesq approximation and the surface temperature is variable. The two-point boundary value problem of the coupled momentum and energy equations is solved using a simple and accurate relaxation method that provides the general nonsimilar solution to the flow. The effect of free-convection currents on velocity and temperature profiles, skin friction, and heat transfer is studied by varying the flow Grashof and Prandtl numbers. Zero shear stress and heat-transfer rate are predicted at some axial coordinate on a surface with decreasing wall temperature. Also the skin friction is markedly modified by the buoyancy while the heat transfer at the surface is correspondingly only moderately influenced.

Hall Effects on Unsteady Magnetohydrodynamic Flow of a Nanofluid Past an Oscillatory Vertical Rotating Flat Plate Embedded in Porous Media

2021 ◽  
Vol 10 (2) ◽  
pp. 259-269
Author(s):  
M. Veera Krishna ◽  
N. Ameer Ahamad ◽  
Ali J. Chamkha
Keyword(s):  
Heat Transfer ◽  
Porous Media ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Local Nusselt Number ◽  
Hall Current ◽  
Skin Friction Coefficient ◽  
Engineering Industry ◽  
Hall Effects ◽  
The Impact

In the current investigative paper, the impact of Hall current on an unsteady magnetohydrodynamic liberated convection revolving flow of a nanofluid restricted with a uniform absorbent medium over an oscillatory moving vertical smooth plate with convective as well as diffusive frontier conditions has been reviewed. The non-dimensionalized governing differential equations by the appropriate frontier conditions are resolved by the perturbations technique. The impacts of the physical constants on the flow as well as the heat transfer features are displayed graphically and analyzed for Cu as well as Al2O3 nanoparticles. For the engineering industry, the skin friction coefficient, local Nusselt number, along with the Sherwood’s number are examined numerically in detail.

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