Axisymmetric Stagnation-Point Flow of Nanofluid Over a Stretching Surface

2014 ◽  
Vol 6 (2) ◽  
pp. 220-232 ◽  
Author(s):  
M. Nawaz ◽  
T. Hayat
Keyword(s):  
Nusselt Number ◽  
Sherwood Number ◽  
Base Fluid ◽  
Convective Heat Transfer Coefficient ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Homotopy Analysis ◽  
Local Skin Friction ◽  
Layer Flow ◽  
Local Sherwood Number

AbstractThis paper investigates the laminar boundary layer flow of nanofluid induced by a radially stretching sheet. Nanofluid model exhibiting Brownian motion and thermophoresis is used. Series solutions for a reduced system of nonlinear ordinary differential equations are obtained by homotopy analysis method (HAM). Comparative study between the HAM solutions and previously published numerical results shows an excellent agreement. Velocity, temperature and mass fraction are displayed for various values of parameters. The local skin friction coefficient, the local Nusselt number and the local Sherwood number are computed. It is observed that the presence of nanoparticles enhances the thermal conductivity of base fluid. It is found that the convective heat transfer coefficient (Nusselt number) is decreased with an increase in concentration of nanoparticles whereas Sherwood number increases when concentration of nanoparticles in the base fluid is increased.

Viscous Dissipation and Joule Heating Effects on MHD Bioconvection Flow of a Nanofluid Containing Gyrotactic Microorganisms Over a Vertical Isothermal Cone

2020 ◽  
Vol 9 (3) ◽  
pp. 242-255
Author(s):  
Hossam A. Nabwey ◽  
S. M. M. El-Kabeir ◽  
A. M. Rashad ◽  
M. M. M. Abdou
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Sherwood Number ◽  
Local Density ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Gyrotactic Microorganisms ◽  
Local Skin Friction ◽  
Local Sherwood Number

The main objective of the present study is to explore the flow of a nanofluid containing gyrotactic microorganisms over a vertical isothermal cone surface in the presence of viscous dissipation and Joule heating. The combined effects of a transverse magnetic field and Navier slip in the flow are considered. Using appropriate transforms the set of partial differential equations governing the flow are converted to a set of ordinary differential equations. Influence of the parameters governing the flow is shown for velocity, temperature, concentration and motilemicroorganisms as well as local skin Friction coefficient, local Nusselt number, local Sherwood number and local density of the motile microorganisms number. An increasing in the value of Eckert number rises the velocity of the fluid and reduce the temperature, concentration and density of motile microorganisms profiles, while buoyancy ratio Nr and magnetic field parameters increase local skin friction coefficient, local Nusselt number, local Sherwood number and local density of the motile microorganisms number decrease as a result of the presence of Lorentz force which resist the motion of the flow. On the other hand, the motile microorganisms boundary layer thickness decreases with an increasing on the bioconvection Lewis number.

Non-similar characteristics of mixed convective slip flow over a wedge with temperature-dependent thermo-physical properties

2019 ◽  
Vol 33 (36) ◽  
pp. 1950455
Author(s):  
Nepal Chandra Roy ◽  
Sudharonjon Roy ◽  
Naved Azum ◽  
Anish Khan ◽  
Abdullah M. Asiri ◽  
...  
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Sherwood Number ◽  
Local Nusselt Number ◽  
Slip Flow ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Local Skin Friction ◽  
Local Sherwood Number

We examined heat and mass transfer characteristics of mixed convective slip flow over a wedge taking into account the effect of variable transport properties. Unlike other studies, we have utilized non-similar transformation to get the non-similar features of the mixed convective slip flow. For comparison, stream function formulation is used to reduce the governing equation into a convenient form for short- and long-time regimes. We have determined the series solutions by adopting the perturbation techniques. The agreement between the numerical and series solutions is found to be excellent. Numerical solutions reveal that the slip parameters augment the momentum, thermal and concentration boundary layers. The local skin friction coefficient, the local Nusselt number and the local Sherwood number are found to decrease for higher value of slip parameters. For the increasing value of the variable viscosity parameter, the velocity is stronger, but the temperature and concentration lessen. Contrary to this, this parameter diminishes the local skin friction coefficient, local Nusselt number and local Sherwood number. Due to the increase of mass diffusivity parameter, the velocity and concentration significantly increase whereas the temperature remains almost unaffected. Moreover, the mass diffusivity variation parameter leads to an increase in the local skin friction coefficient and local Nusselt number, but it reduces the local Sherwood number.

scholarly journals Series Solutions of Boundary Layer Flow of a Micropolar Fluid Near the Stagnation Point Towards a Shrinking Sheet

2009 ◽  
Vol 64 (9-10) ◽  
pp. 575-582 ◽  
Author(s):  
Sohail Nadeem ◽  
Saeid Abbasbandy ◽  
Majid Hussain
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Micropolar Fluid ◽  
Skin Friction Coefficient ◽  
Shrinking Sheet ◽  
Local Skin ◽  
Similarity Transformations ◽  
Homotopy Analysis ◽  
Local Skin Friction ◽  
Layer Flow

An analysis has been carried out to obtain the series solution of boundary layer flow of a micropolar fluid towards a shrinking sheet. The governing equations of micropolar fluid are simplified using suitable similarity transformations and then solved by homotopy analysis method (HAM). The convergence of the HAM solutions has been obtained by using homotopy-pade approximation. The effects of various parameters such as porosity parameter R, the ratio λ and the microinertia K on the velocity and microinertia profiles as well as local skin friction coefficient are presented graphically and in tabulated form.

Natural Convective Boundary Layer Flow of Nanofluids Above an Isothermal Horizontal Plate

2014 ◽  
Vol 136 (10) ◽  
Author(s):  
Kaustav Pradhan ◽  
Subho Samanta ◽  
Abhijit Guha
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Volume Fraction ◽  
Skin Friction Coefficient ◽  
Nanoparticle Volume Fraction ◽  
Convective Boundary ◽  
Local Skin ◽  
Local Skin Friction ◽  
Layer Flow

The natural convective boundary layer flow of a nanofluid over an isothermal horizontal plate is studied analytically. The model used for the nanofluid accounts for the effects of Brownian motion and thermophoresis. The analysis shows that the velocity, temperature, and nanoparticle volume fraction profiles in the respective boundary layers depend not only on the Prandtl number (Pr) and Lewis number (Le) but also on three additional dimensionless parameters: the Brownian motion parameter Nb, the buoyancy ratio parameter Nr and the thermophoresis parameter Nt. The velocity, temperature, and nanoparticle volume fraction profiles for the nanofluid are found to have a weak dependence on the values of Nb, Nr, and Nt. The effect of the above-mentioned parameters on the local skin-friction coefficient and Nusselt number has been studied extensively. It has been observed that as Nr increases, the local skin-friction coefficient decreases whereas local Nusselt number remains almost constant. As Nb or Nt increases, the local skin-friction coefficient increases whereas the local Nusselt number decreases.

scholarly journals Effects of Slip and Heat Generation/Absorption on MHD Mixed Convection Flow of a Micropolar Fluid over a Heated Stretching Surface

2010 ◽  
Vol 2010 ◽  
pp. 1-20 ◽  
Author(s):  
Mostafa Mahmoud ◽  
Shimaa Waheed
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Mixed Convection ◽  
Skin Friction ◽  
Heat Generation ◽  
Local Nusselt Number ◽  
Skin Friction Coefficient ◽  
Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A theoretical analysis is performed to study the flow and heat transfer characteristics of magnetohydrodynamic mixed convection flow of a micropolar fluid past a stretching surface with slip velocity at the surface and heat generation (absorption). The transformed equations solved numerically using the Chebyshev spectral method. Numerical results for the velocity, the angular velocity, and the temperature for various values of different parameters are illustrated graphically. Also, the effects of various parameters on the local skin-friction coefficient and the local Nusselt number are given in tabular form and discussed. The results show that the mixed convection parameter has the effect of enhancing both the velocity and the local Nusselt number and suppressing both the local skin-friction coefficient and the temperature. It is found that local skin-friction coefficient increases while the local Nusselt number decreases as the magnetic parameter increases. The results show also that increasing the heat generation parameter leads to a rise in both the velocity and the temperature and a fall in the local skin-friction coefficient and the local Nusselt number. Furthermore, it is shown that the local skin-friction coefficient and the local Nusselt number decrease when the slip parameter increases.

scholarly journals Magnetohydrodynamic(MHD) Boundary Layer Flow of Eyring-Powell Nanofluid Past Stretching Cylinder With Cattaneo-Christov Heat Flux Model

2019 ◽  
Vol 8 (1) ◽  
pp. 303-317 ◽  
Author(s):  
Wubshet Ibrahim ◽  
Bullo Hindebu
Keyword(s):  
Differential Equations ◽  
Magnetic Parameter ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Fluid Parameter ◽  
Non Linear ◽  
Local Skin Friction ◽  
Curvature Parameter ◽  
Layer Flow ◽  
Mhd Boundary Layer Flow

Abstract This study analyzed the MHD boundary layer flow of Eyring-Powell nanofluid past stretching cylinder with Cattaneo-Christov heat flux model. The governing non-linear partial differential equations corresponding to the momentum, energy and concentration have been formulated and transformed into a set of non-linear ordinary differential equations by using similarity transformations. Then the resulting non-linear high order ordinary differential equations of momentum, energy and concentration, subjected to boundary conditions were solved numerically by utilizing the second-order accurate implicit finite difference method known as Keller-Box which is programmed in the MATLABR2017b software. The results indicated that the velocity profile increases as the Eyring-Powell fluid parameter M and the curvature parameter γ increase but it decreases as the magnetic parameter Ha increases. Both the temperature and the concentration profiles have revealed an increment pattern for large values of the magnetic parameter Ha and the thermophoresis parameter Nt but a decrement manner with increasing values of the Eyring-Powell fluid parameter M. The Brownian motion parameter Nb has shown an opposite influence on the temperature and the concentration profiles. The results also depicted that the local skin friction coefficient increases with increasing in Eyring-Powell fluid parameter M, magnetic parameter Ha. Besides, it is found that both the local Nusselt number Nux and the local Sherwood number Shx are higher for large vales of Eyring-Powell fluid parameter M and curvature parameter γ. Furthermore, the present results for the local skin friction coefficient, the local Nusselt number and the local Sherwood number are validated with the data of previously published literature for various limiting conditions where a very sound agreement has been attained.

A numerical investigation of transient MHD free convective flow of a nanofluid over a moving semi-infinite vertical cylinder

2017 ◽  
Vol 34 (5) ◽  
pp. 1393-1412 ◽  
Author(s):  
V. Rajesh ◽  
A.J. Chamkha ◽  
Ch. Sridevi ◽  
A.F. Al-Mudhaf
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Volume Fraction ◽  
Vertical Cylinder ◽  
Skin Friction Coefficient ◽  
Free Convective Flow ◽  
Local Skin ◽  
Content Type ◽  
Local Skin Friction

Purpose The purpose of this paper is to study numerically the influence of a magnetic field on the transient free convective boundary layer flow of a nanofluid over a moving semi-infinite vertical cylinder with heat transfer Design/methodology/approach The problem is governed by the coupled non-linear partial differential equations with appropriate boundary conditions. The fluid is a water-based nanofluid containing nanoparticles of copper. The Brinkman model for dynamic viscosity and Maxwell–Garnett model for thermal conductivity are used. The governing boundary layer equations are written according to The Tiwari–Das nanofluid model. A robust, well-tested, implicit finite difference method of Crank–Nicolson type, which is unconditionally stable and convergent, is used to find the numerical solutions of the problem. The velocity and temperature profiles are studied for significant physical parameters such as the magnetic parameter, nanoparticles volume fraction and the thermal Grashof number Gr. The local skin-friction coefficient and the Nusselt number are also analysed and presented graphically. Findings The present computations have shown that an increase in the values of either magnetic parameter M or nanoparticle volume fraction decreases the local skin-friction coefficient, whereas the opposite effect is observed for thermal Grashof number Gr. The local Nusselt number increases with a rise in Gr and ϕ values. But an increase in M reduces the local Nusselt number. Originality/value This paper is relatively original and presents numerical investigation of transient two-dimensional laminar boundary layer free convective flow of a nanofluid over a moving semi-infinite vertical cylinder in the presence of an applied magnetic field. The present study is of immediate application to all those processes which are highly affected by heat enhancement concept and a magnetic field. Further the present study is relevant to nanofluid materials processing, chemical engineering coating operations exploiting nanomaterials and others.

scholarly journals A Double Diffusive Unsteady MHD Convective Flow Past a Flat Porous Plate Moving through a Binary Mixture with Suction or Injection

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
D. R. V. S. R. K. Sastry ◽  
A. S. N. Murti
Keyword(s):  
Binary Mixture ◽  
Convective Flow ◽  
Porous Plate ◽  
Numerical Data ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Local Skin Friction ◽  
Suction Or Injection ◽  
Local Sherwood Number

The problem of unsteady magnetohydrodynamic convective flow with radiation and chemical reaction past a flat porous plate moving through a binary mixture in an optically thin environment is considered. The governing boundary layer equations are converted to nonlinear ordinary differential equations by similarity transformation and then solved numerically by MATLAB “bvp4c” routine. The velocity, temperature, and concentration profiles are presented graphically for various values of the material parameters. Also a numerical data for the local skin friction coefficient, the local Nusselt number, and local Sherwood number is presented in tabular forms.

scholarly journals Unsteady MHD chemically reacting fluid through a porous medium bounded by a non-isothermal impulsively-started vertical plate: a numerical technique

2014 ◽  
Vol 11 (1) ◽  
pp. 39-54
Author(s):  
Sahin Ahmed ◽  
Karabi Kalita
Keyword(s):  
Porous Medium ◽  
Nusselt Number ◽  
Skin Friction ◽  
Chemical Reaction ◽  
Sherwood Number ◽  
Vertical Plate ◽  
Convection Flow ◽  
Local Skin ◽  
Porosity Parameter ◽  
Local Skin Friction

A numerical modeling on MHD transient mass transfer by free convection flow of a viscous, incompressible, electrically-conducting, and Newtonian fluid through a porous medium bounded by an impulsively-started semi-infinite vertical plate in the presence of thermal radiation and chemical reaction of first order has been analyzed. The fluid is assumed optically thin gray gas, absorbing-emitting radiation, but a non-scattering medium. The dimensionless governing coupled, non-linear boundary layer partial differential equations are solved by an efficient, accurate, extensively validated and unconditionally stable finite difference scheme of the Crank-Nicolson type. The effects of the conduction-radiation parameter , chemical reaction and the porosity (K) on the velocity, temperature and concentration fields have been studied. The local skin friction, Nusselt number and the Sherwood number are also presented graphically and analyzed. Increasing magnetic parameter serves to decelerate the flow but increased temperatures and concentration values. It is found that the velocity is increased considerably with a rise in the porosity parameter (K) whereas the temperature and concentration are found to be reduced with increasing porosity (K). An increase in the porosity parameter (K) is found to escalate the local skin friction , Nusselt number and the Sherwood number . Possible applications of the present study include laminar aerodynamics, materials processing and thermo-fluid dynamics.DOI: http://dx.doi.org/10.3329/jname.v11i1.10269

scholarly journals Boundary-layer flow and heat transfer of cross fluid over a stretching sheet

2019 ◽  
Vol 23 (1) ◽  
pp. 307-318 ◽  
Author(s):  
Masood Khan ◽  
Mehwish Manzur ◽  
Masood Rahman
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Stretching Sheet ◽  
Skin Friction Coefficient ◽  
Weissenberg Number ◽  
Local Skin ◽  
Flow And Heat Transfer ◽  
Local Skin Friction

The current study is a pioneering work in presenting the boundary-layer equations for the 2-D flow and heat transfer of the Cross fluid over a linearly stretching sheet. The system of PDE is turned down into highly non-linear ODE by applying suitable similarity transformations. The stretching sheet solutions are presented via. a numerical technique namely the shooting method and graphs are constructed. The impact of the emerging parameters namely the power-law index, n, the local Weissenberg number, We, and the Prandtl number on the velocity and temperature fields are investigated through graphs. The numerical values of the local skin friction coefficient and the local Nusselt number are also presented in tabular form. Additionally, the graphs are sketched for the local skin friction coefficient and the local Nusselt number. It is observed that with growing values of the local Weissenberg number the velocity profiles exhibited a decreasing trend while opposite behavior is seen for the temperature field. Further, comparisons are made with previously available literature for some limiting cases and an excellent agreement is achieved.

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