A spectral relaxation method for thermal dispersion and radiation effects in a nanofluid flow

PurposeThe purpose of this paper is to consider a two-dimensional unsteady Casson magneto-nanfluid flow over an inclined plate embedded in a porous medium. The novelty of the present study is to investigate the effects of Soret–Dufour on unsteady magneto-nanofluid flow.Design/methodology/approachAppropriate similarity transformations are used to convert the governing non-linear partial differential equations into coupled non-linear dimensionless partial differential equations. The transformed equations are then solved using spectral relaxation method.FindingsThe effects of controlling parameters on flow profiles is discussed and depicted with the aid of graphs. Results show that as the non-Newtonian Casson nanofluid parameter increases, the fluid velocity decreases. It is found that the Soret parameter enhance the temperature profile, while Dufour parameter decreases the concentration profile close to the wall.Originality/valueThe novelty of this paper is to consider the combined effects of both Soret and Dufour on unsteady Casson magneto-nanofluid flow. The present model is in an inclined plate embedded in a porous medium which to the best of our knowledge has not been considered in the past. The applied magnetic field gives rise to an opposing force which slows the motion of the fluid. A newly developed spectral method known as spectral relaxation method (SRM) is used in solving the modeled equations. SRM is an iterative method that employ the Gauss–Seidel approach in solving both linear and non-linear differential equations. SRM is found to be effective and accurate.

Download Full-text

Effects of Newtonian heating on the boundary layer flow of non-Newtonian magnetohydrodynamic nanofluid over a stretched plate using spectral relaxation method

International Journal of Ambient Energy ◽

10.1080/01430750.2019.1694585 ◽

2019 ◽

pp. 1-14

Author(s):

K. Gangadhar ◽

D. Vijaya Kumar ◽

M. Venkata Subba Rao ◽

T. Kannan ◽

G. Sakthivel

Keyword(s):

Boundary Layer ◽

Boundary Layer Flow ◽

Relaxation Method ◽

Newtonian Heating ◽

Spectral Relaxation Method ◽

Layer Flow ◽

Spectral Relaxation

Download Full-text

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

Open Physics ◽

10.1515/phys-2017-0036 ◽

2017 ◽

Vol 15 (1) ◽

pp. 323-334 ◽

Cited By ~ 3

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.

Download Full-text

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

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.387.461 ◽

2018 ◽

Vol 387 ◽

pp. 461-473 ◽

Cited By ~ 1

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.

Download Full-text