scholarly journals The paradox of heat conduction, influence of variable viscosity, and thermal conductivity on magnetized dissipative Casson fluid with stratification models

2021 ◽  
Vol 40 (6) ◽  
pp. 1657-1682
Author(s):  
M. T. Akolade ◽  
A. S. Idowu ◽  
B. O. Falodun ◽  
J. U. Abubakar

The boundary layer flow of temperature-dependent variable thermal conductivity and dynamic viscosity on flow, heat, and mass transfer of magnetized and dissipative Casson fluid over a slenderized stretching sheet has been studied. The model explores the Cattaneo-Christov heat flux paradox instead of the Fourier’s law plus the stratifications impact. The variable temperature-dependent plastic dynamic viscosity and thermal conductivity were assumed to vary as a linear function of temperature. The governing systems of equations in PDEs were transformed into non-linear ordinary differential equations using the suitable similarity transformations, hence the approximate solutions were obtained using Chebyshev Spectral Collocation Method (CSCM). Effects of pertinent flow parameters on concentration, temperature, and velocity profiles are presented graphically and tabled, therein, thermal relaxation and wall thickness parameters slow down the distribution of the flowing fluid. A rise in Casson parameter, temperature-dependent thermal conductivity, and velocity power index parameter increases the skin friction thus leading to a decrease in energy and mass gradient at the wall, also, temperature gradient attain maximum within 0.2 - 1.0 variation of Casson parameter.

2019 ◽  
Vol 6 (4) ◽  
pp. 625-633
Author(s):  
Razon Kumar Mondal ◽  
Sheikh Reza-E-Rabbi ◽  
Partha Protim Gharami ◽  
Sarder Firoz Ahmmed ◽  
Shikdar Mohammad Arifuzzaman

Open Physics ◽  
2020 ◽  
Vol 18 (1) ◽  
pp. 1073-1083
Author(s):  
Muhammad Sohail ◽  
Umar Nazir ◽  
Yu-Ming Chu ◽  
Hussam Alrabaiah ◽  
Wael Al-Kouz ◽  
...  

Abstract This article addresses the effects of thermal radiation, stratification, and Joule heating for the flow of magnetohydrodynamics Sutterby nanofluid past over a stretching cylinder. The transport phenomenon of heat and mass are modeled under temperature-dependent thermal conductivity and diffusion coefficients, respectively. Moreover, traditional Fourier and Fick’s laws have been implemented in thermal and mass transport expressions. The governing model that consists of a set of coupled partial differential equations is converted into system of nonlinear coupled ordinary differential equations via suitable similarity transformations. The resulting set of expressions is analytically treated through an optimal homotopy scheme. The effects of different dimensionless flow parameters on the velocity, temperature, and concentration fields are illustrated through graphs. The patterns of skin friction coefficient, local Nusselt, and Sherwood numbers are examined via bar charts. The major outcome of the proposed study is that variable thermal conductivity decays the temperature and radiation raises the temperature of the system. Stratification parameters show the reverse behavior for temperature and concentration boundary layers. Shear rate-dependent rheology in view of Sutterby liquid has the ability to reduce the flow of fluid. Therefore, the ability of flow in rheology of Sutterby liquid becomes reduced. Consequently, layer of momentum boundary has increased with respect to parameter of Sutterby liquid.


2008 ◽  
Vol 86 (2) ◽  
pp. 383-389 ◽  
Author(s):  
O D Makinde

This study investigates the inherent irreversibility in the flow of a variable (temperature-dependent) viscosity fluid through a channel with parallel plates. The channel is narrow so that the lubrication approximation may be applied, and the temperature-dependent nature of viscosity is assumed to follow an exponential model. The system is assumed to exchange heat with the ambient surroundings following Newton’s cooling law. Using a perturbation method coupled with a special type of Hermite–Padé approximation technique, the simplified governing nonlinear equations are solved and the important properties of overall flow structure, including velocity field, temperature field, and thermal criticality conditions are derived, which essentially expedite obtaining expressions for volumetric entropy generation numbers, irreversibility distribution ratio, and the Bejan number in the flow field. PACS Nos.: 44.10.+a, 47.11.–j, 47.15.gm


2016 ◽  
Vol 09 (02) ◽  
pp. 1650029 ◽  
Author(s):  
Q. Hussain ◽  
S. Asghar ◽  
T. Hayat ◽  
A. Alsaedi

In this paper, we investigate the effects of variable viscosity and thermal conductivity on peristaltic flow of Jeffrey fluid in an asymmetric channel. The inclined magnetic field, viscous dissipation and Joule heating are also considered. Wave frame and long wavelength approximations are made to formulate the problem. Pressure gradient, pressure drop per wavelength, velocity and temperature profiles are calculated analytically and discussed graphically. Comparison is made with the previous work for reliability.


2010 ◽  
Vol 15 (3) ◽  
pp. 257-270 ◽  
Author(s):  
M. M. M. Abdou

A numerical model is developed to study the effect of thermal radiation on unsteady boundary layer flow with temperature dependent viscosity and thermal conductivity due to a stretching sheet in porous media. The Rosseland diffusion approximation is used to describe the radiative heat flux in the energy equation. The governing equations reduced to similarity boundary layer equations using suitable transformations and then solved using the Runge–Kutta numerical integration, procedure in conjunction with shooting technique. A parametric study illustrating the influence of the radiation R, variable viscosity ε, Darcy number Da, porous media inertia coefficient γ, thermal conductivity κ and unsteady A parameters on skin friction and Nusselt number.


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