scholarly journals Variable Viscosity Effects on Unsteady MHD an Axisymmetric Nanofluid Flow over a Stretching Surface with Thermo-Diffusion: FEM Approach

Symmetry ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 234 ◽  
Author(s):  
Bagh Ali ◽  
Rizwan Ali Naqvi ◽  
Yufeng Nie ◽  
Shahid Ali Khan ◽  
Muhammad Tariq Sadiq ◽  
...  

The present study investigated the unsteady magnetohydrodynamic (MHD) nanofluid flow over a radially nonlinear stretching sheet along with the viscosity dependent on temperature, convective boundary condition, thermo-diffusion, and the radiation effects. Moreover, the nanofluid’s viscous effects were considered dependent on temperature and the exponential Reynolds model was considered in this context. It was additionally assumed that a uniform suspension of nanoparticles is present in the base fluid. The Buongiorno model, which involves the thermophoresis and Brownian motion effects, was considered. For the sake of a solution, the variational finite element method was selected with coding in MATLAB and the numerical results were contrasted with the published articles. The influence of various physical parameters on the velocity, temperature, and concentration profiles are discussed by the aid of graphs and tables. It was detected that the nanofuid viscosity parameter declines the fluid flow velocity, while, for the temperature and the concentration profiles, it accomplished the reverse phenomenon.

2016 ◽  
Vol 13 (10) ◽  
pp. 7483-7492 ◽  
Author(s):  
Sicelo P Goqo ◽  
Sabyasachi Mondal ◽  
Precious Sibanda ◽  
Sandile S Motsa

We investigate the combined effects of a magnetic field and a convective boundary condition on unsteady Jeffrey nanofluid flow over a shrinking sheet with thermal radiation and heat generation. The effects of several important factors such as particle size and shape, the clustering of particles and the effective thermal conductivity of nanofluids has not been studied adequately. It is important for more research so as to ascertain the effects of these factors on the thermal conductivity of a wide range of nanofluids. The non-dimensional governing equations are derived and solved using a spectral quasilinearisation method. Among other findings, we show that thermal radiation enhances both the temperature and concentration profiles. Furthermore, the effects of different physical parameters on the flow velocity, temperature and concentration profiles are shown graphically and discussed in detail. Comparison with previously published work shows an excellent agreement.


2021 ◽  
Author(s):  
Gurrala Thirupathi ◽  
Kamatam Govardhan ◽  
Ganji Narender

The magnetohydrodynamics (MHD) stagnation point Casson nanofluid flow towards stretching surface with velocity slip and convective boundary condition has been investigated in this article. Effects of thermal radiation, viscous dissipation, heat source and chemical reaction have also been incorporated. Using appropriate similarity transformation Partial Differential Equations (PDEs) are converted into Ordinary Differential Equations (ODEs) and shooting technique along with Adams–Moulton method of order four has been used to obtain the numerical results. Different physical parameters effects on velocity, temperature and concentration of nanofluid flow have been presented graphically and discussed in detail. Numerical values of the skin friction coefficient, Nusselt number and Sherwood number are also and discussed.


Author(s):  
G. Manjunatha ◽  
C. Rajashekhar ◽  
K. V. Prasad ◽  
Hanumesh Vaidya ◽  
Saraswati

The present article addresses the peristaltic flow of a Jeffery fluid over an inclined axisymmetric porous tube with varying viscosity and thermal conductivity. Velocity slip and convective boundary conditions are considered. Resulting governing equations are solved using long wavelength and small Reynolds number approximations. The closed-form solutions are obtained for velocity, streamline, pressure gradient, temperature, pressure rise, and frictional force. The MATLAB numerical simulations are utilized to compute pressure rise and frictional force. The impacts of various physical parameters in the interims for time-averaged flow rate with pressure rise and is examined. The consequences of sinusoidal, multi-sinusoidal, triangular, trapezoidal, and square waveforms on physiological parameters are analyzed and discussed through graphs. The analysis reveals that the presence of variable viscosity helps in controlling the pumping performance of the fluid.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Qiu-Hong Shi ◽  
Aamir Hamid ◽  
M. Ijaz Khan ◽  
R. Naveen Kumar ◽  
R. J. Punith Gowda ◽  
...  

AbstractIn this study, a mathematical model is developed to scrutinize the transient magnetic flow of Cross nanoliquid past a stretching sheet with thermal radiation effects. Binary chemical reactions and heat source/sink effects along with convective boundary condition are also taken into the consideration. Appropriate similarity transformations are utilized to transform partial differential equations (PDE’s) into ordinary ones and then numerically tackled by shooting method. The impacts of different emerging parameters on the thermal, concentration, velocity, and micro-rotation profiles are incorporated and discussed in detail by means of graphs. Results reveal that, the escalation in magnetic parameter and Rayleigh number slowdowns the velocity and momentum of the fluid. The increase in Biot number, radiation and heat sink/source parameters upsurges the thermal boundary but, converse trend is seen for escalating Prandtl number. The density number of motile microorganisms acts as a growing function of bioconvection Lewis number and declining function of bioconvection Peclet number.


2020 ◽  
Vol 16 (5) ◽  
pp. 991-1018
Author(s):  
Mahantesh M. Nandeppanavar ◽  
M.C. Kemparaju ◽  
R. Madhusudhan ◽  
S. Vaishali

PurposeThe steady two-dimensional laminar boundary layer flow, heat and mass transfer over a flat plate with convective surface heat flux was considered. The governing nonlinear partial differential equations were transformed into a system of nonlinear ordinary differential equations and then solved numerically by Runge–Kutta method with the most efficient shooting technique. Then, the effect of variable viscosity and variable thermal conductivity on the fluid flow with thermal radiation effects and viscous dissipation was studied. Velocity, temperature and concentration profiles respectively were plotted for various values of pertinent parameters. It was found that the momentum slip acts as a boost for enhancement of the velocity profile in the boundary layer region, whereas temperature and concentration profiles decelerate with the momentum slip.Design/methodology/approachNumerical Solution is applied to find the solution of the boundary value problem.FindingsVelocity, heat transfer analysis is done with comparing earlier results for some standard cases.Originality/value100


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