Heat transfer and fluid flow of a non-Newtonian nanofluid over an unsteady contracting cylinder employing Buongiorno’s model

Author(s):  
A. Mahdy ◽  
A Chamkha

Purpose – The purpose of this paper is to discuss a combined similarity-numerical approach that is used to study the unsteady two-dimensional flow of a non-Newtonian nanofluid over a contracting cylinder using Buongiorno’s model and the Casson fluid model that is used to characterize the non-Newtonian fluid behavior. Design/methodology/approach – Similarity transformations are employed to transform the unsteady Navier-Stokes partial differential equations into a system of ordinary differential equations. The transformed equations are then solved numerically by means of the very robust symbolic computer algebra software MATLAB employing the routine bvpc45. Findings – The effect of increasing values of the Casson parameter is to suppress the velocity field (in absolute sense), the temperature and concentration decrease as Casson parameter increase. The heat and mass transfer rates decrease with the increase of unsteadiness parameters and Brownian motion parameter. In addition, they increase as the Casson parameter and the thermophoresis parameter increase. Originality/value – The problem is relatively original and represents a very important contribution to the field of non-Newtonian nanofluids.

2018 ◽  
Vol 388 ◽  
pp. 420-432
Author(s):  
Vinay Kumar Poorigaly Nanjundaswamy ◽  
Ulavathi Shettar Mahabaleshwar ◽  
Patil Mallikarjun ◽  
Mohaddeseh Mousavi Nezhad ◽  
Giulio Lorenzini

The theoretical study of laminar boundary layer flows of a non-Newtonian fluid past a stretching sheet in an embedded porous medium in the presence of suction/injection is of significant importance in the crystal growing, geothermal, metallurgical, polymer extrusion and several other technological processes. Casson fluid model is one such fluid model used to characterize the behaviour of non-Newtonian fluids. The present article discusses the Casson fluid flow past a permeable stretching sheet in the presence of mass transpiration. The physical problem is modelled into a system of nonlinear partial differential equations which are analytically solved by transforming them into nonlinear ordinary differential equations with constant coefficient by means of similarity transformations. The analysis reveals the effect of Casson parameter on the velocity boundary. In fact, the increasing Casson parameter results in the suppression of velocity boundary. It is found that the skin friction coefficient decreases with the decreasing values of Casson parameter. The effects of Darcy drag force and the mass transpiration are also analyzed by means of various plots.


2019 ◽  
Vol 15 (3) ◽  
pp. 559-574 ◽  
Author(s):  
Sampath Kumar V.S. ◽  
N.P. Pai

Purpose The purpose of this paper is to study the effect of injection and suction on velocity profile, skin friction and pressure distribution of a Casson fluid flow between two parallel infinite rectangular plates approaching or receding from each other with suction or injection at the porous plates. Design/methodology/approach The governing Navier–Stokes equations are reduced to the fourth-order non-linear ordinary differential equation through the similarity transformations. The approximated analytic solution based on the Homotopy perturbation method is given and also compared with the classical finite difference method. Findings From this study, the authors observed that the skin friction is less in non-Newtonian fluids compared to Newtonian fluids. The use of non-Newtonian fluids reduces the pressure in all the cases compared to Newtonian and hence load-carrying capacity will be more. As γ value increases velocity, skin friction and pressure decreases. When γ is fixed, it is observed that skin friction and pressure is minimum for A=0.5 and maximum when A=−0.5. The result of this study also shows that the effect of suction on the velocity profiles, pressure and skin friction is opposite to the effect of injection. Originality/value The present work analyzes the characteristic of non-Newtonian fluid having practical and industrial applications.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Asma Khalid ◽  
Ilyas Khan ◽  
Sharidan Shafie

The unsteady free flow of a Casson fluid past an oscillating vertical plate with constant wall temperature has been studied. The Casson fluid model is used to distinguish the non-Newtonian fluid behaviour. The governing partial differential equations corresponding to the momentum and energy equations are transformed into linear ordinary differential equations by using nondimensional variables. Laplace transform method is used to find the exact solutions of these equations. Expressions for shear stress in terms of skin friction and the rate of heat transfer in terms of Nusselt number are also obtained. Numerical results of velocity and temperature profiles with various values of embedded flow parameters are shown graphically and their effects are discussed in detail.


2021 ◽  
Vol 5 (1) ◽  
pp. 16-26
Author(s):  
Winifred N. Mutuku ◽  
Anselm O. Oyem

This study presents a convectively heated hydromagnetic Stagnation-Point Flow (SPF) of an electrically conducting Casson fluid towards a vertically stretching/shrinking sheet. The Casson fluid model is used to characterize the non-Newtonian fluid behaviour and using similarity variables, the governing partial differential equations are transformed into coupled nonlinear ordinary differential equations. The dimensionless nonlinear equations are solved numerically by Runge-Kutta Fehlberg integration scheme with shooting technique. The effects of the thermophysical parameters on velocity and temperature profiles are presented graphically and discussed quantitatively. The result shows that the flow field velocity decreases with increase in magnetic field parameter and Casson fluid parameter .


2020 ◽  
Vol 98 (1) ◽  
pp. 81-88
Author(s):  
Muhammad Nazim Tufail ◽  
Musharafa Saleem ◽  
Qasim Ali Chaudhry

The flow has been made by considering oscillation and radiation effects for the magnetohydrodynamic (MHD) Casson fluid model within an asymmetric wavy channel. Oscillation occurs during the flow by taking into account the pressure gradient across the ends of the channel. The governed mathematical statement is handled analytically by choosing the group theoretical method. The partial differential equations (PDEs) of the governed system are transformed into ordinary differential equations (ODEs) by calculating the symmetries. Further, the mathematical problem is concluded and the graphical results are shown for the following emerging parameters: Casson fluid parameter β, wavelength λ, oscillation parameter ω, Reynolds number Re, Hartmann number M, radiation parameter R, heat source–sink parameter Q, and Peclet number Pe. The magnitude of velocity profile f(η) increased with an increase in β, λ, Re, and K. With variations of H and ω, f(η) decreased. The temperature profile θ(η) increased when the values of Pe, Q, and R increased.


2020 ◽  
Vol 9 (1) ◽  
pp. 398-411 ◽  
Author(s):  
Abayomi S. Oke ◽  
Winifred N. Mutuku ◽  
Mark Kimathi ◽  
Isaac L. Animasaun

AbstractCasson fluid model is the most accurate mathematical expression for investigating the dynamics of fluids with non-zero plastic dynamic viscosity like that of blood. Despite huge number of published articles on the transport phenomenon, there is no report on the increasing effects of the Coriolis force. This report presents the significance of increasing not only the Coriolis force and reducing plastic dynamic viscosity, but also the Prandtl number and buoyancy forces on the motion of non-Newtonian Casson fluid over the rotating non-uniform surface. The relevant body forces are derived and incorporated into the Navier-Stokes equations to obtain appropriate equations for the flow of Newtonian Casson fluid under the action of Coriolis force. The governing equations are non-dimensionalized using Blasius similarity variables to reduce the nonlinear partial differential equations to nonlinear ordinary differential equations. The resulting system of nonlinear ordinary differential equations is solved using the Runge-Kutta-Gills method with the Shooting technique, and the results depicted graphically. An increase in Coriolis force and non-Newtonian parameter decreases the velocity profile in the x-direction, causes a dual effect on the shear stress, increases the temperature profiles, and increases the velocity profile in the z-direction.


2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110316
Author(s):  
Salman Akhtar ◽  
Luthais B McCash ◽  
Sohail Nadeem ◽  
Salman Saleem ◽  
Alibek Issakhov

The electro-osmotically modulated hemodynamic across an artery with multiple stenosis is mathematically evaluated. The non-Newtonian behaviour of blood flow is tackled by utilizing Casson fluid model for this flow problem. The blood flow is confined in such arteries due to the presence of stenosis and this theoretical analysis provides the electro-osmotic effects for blood flow through such arteries. The mathematical equations that govern this flow problem are converted into their dimensionless form by using appropriate transformations and then exact mathematical computations are performed by utilizing Mathematica software. The range of the considered parameters is given as [Formula: see text]. The graphical results involve combine study of symmetric and non-symmetric structure for multiple stenosis. Joule heating effects are also incorporated in energy equation together with viscous effects. Streamlines are plotted for electro-kinetic parameter [Formula: see text] and flow rate [Formula: see text]. The trapping declines in size with incrementing [Formula: see text], for symmetric shape of stenosis. But the size of trapping increases for the non-symmetric case.


2019 ◽  
Vol 33 (35) ◽  
pp. 1950448
Author(s):  
K. Ganesh Kumar ◽  
M. N. Khan ◽  
M. Osman ◽  
Abdulaziz R. Alharbi ◽  
Mohammad Rahimi-Gorji ◽  
...  

This work focused on slip flow over a non-Newtonian nanofluid fluid flow past a stretching sheet with particles–liquid suspension. The convective boundary condition is taken into account. Similarity transformations are utilized to reduce the nonlinear partial differential equations into a set of nonlinear ordinary differential equations. Runge–Kutta–Fehlberg scheme is used to get the numerical solution. Important parameters are analyzed through graphs and skin friction coefficient. Nusselt numbers are presented in tables. Investigation reveals that slip parameter decreases the velocity field and Biot number increases the temperature field.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdullah Dawar ◽  
Zahir Shah ◽  
Hashim M. Alshehri ◽  
Saeed Islam ◽  
Poom Kumam

AbstractThis study presents the magnetized and non-magnetized Casson fluid flow with gyrotactic microorganisms over a stratified stretching cylinder. The mathematical modeling is presented in the form of partial differential equations and then transformed into ordinary differential equations (ODEs) utilizing suitable similarity transformations. The analytical solution of the transformed ODEs is presented with the help of homotopy analysis method (HAM). The convergence analysis of HAM is also presented by mean of figure. The present analysis consists of five phases. In the first four phases, we have compared our work with previously published investigations while phase five is consists of our new results. The influences of dimensionless factors like a magnetic parameter, thermal radiation, curvature parameter, Prandtl number, Brownian motion parameter, Schmidt number, heat generation, chemical reaction parameter, thermophoresis parameter, Eckert number, and concentration difference parameter on physical quantities of interests and flow profiles are shown through tables and figures. It has been established that with the increasing Casson parameter (i.e. $$\beta \to \infty$$ β → ∞ ), the streamlines become denser which results the increasing behavior in the fluid velocity while on the other hand, the fluid velocity reduces for the existence of Casson parameter (i.e. $$\beta = 1.0$$ β = 1.0 ). Also, the streamlines of stagnation point Casson fluid flow are highly wider for the case of magnetized fluid as equated to non-magnetized fluid. The higher values of bioconvection Lewis number, Peclet number, and microorganisms’ concentration difference parameter reduces the motile density function of microorganisms while an opposite behavior is depicted against density number.


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