Upload
others
View
11
Download
0
Embed Size (px)
Citation preview
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 145
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
MHD Stagnation Point Flow of Viscoelastic
Nanofluid Past a Circular Cylinder with non-Fourier
heat Flux and Variable Fluid Properties Adigun, J. A1*., 2Adeniyan, A., 3Sobamowo, M. G.
1Bells University of Technology, Ota 2University of Lagos, Akoka 3University of Lagos, Akoka
https://orcid.org/0000-0003-3834-1225
Abstract-- Stagnation point MHD flow of a viscoelastic
nanofluid over a stretching cylinder with temperature-
dependent dynamic viscosity is studied. Heat transfer is
characterized by Cattaneo-Christov heat flux and temperature
dependent thermal conductivity. The nonlinear governing
equations with velocity slip and thermal slip boundary
conditions are redacted and transmuted into dimensionless
forms by similarity transformations to obtain a set of coupled
non-linear ordinary differential equations which are
accordingly solved via the Spectral Quasi-linearization method
(SQLM). The usual heat source parameter is used and a new one
emerges from the heat generation/absorption body force
through mathematical derivation from first principle. The
upshots of the engrafted flow parameters on the dimensionless
velocity and temperature profiles, as well as on the skin friction
coefficient are analysed. Obtained outcome shows that
increasing values of the curvature parameter and viscoelastic
parameter enhances fluid velocity but nanoparticle volume
fraction slows it down. Temperature quashes for larger values
of thermal relaxation parameter, indicating that the non-
Fourier heat flux model produces lower temperature within the
flow system than that of the Fourier law. However, the nanofluid
temperature is raised by increasingly varying values of heat
generation parameter. The skin-friction coefficient exhibits an
increasing behaviour against both curvature and viscoelastic
parameters.
Index Term-- Catteneo-Christov heat flux; Cylinder;
Nanofluid; Quasi-linearization Method; Second grade fluid
1. INTRODUCTION
Applications of nanotechnology has been all-encompassing. Due to its higher thermal conductivity and
convective heat transfer rates, nanofluids are used in a wide
range of areas. Its applications to biotechnology include like
delivering drugs, heat, light or other substances to specific
types of cells in cancer therapy while in engineering and
industry at large, it's used in microelectronics and thermal
generation and as cooling agents in nuclear reactors and heat-
transfer devices in air planes, cars and microreactors among
others. However, the traditional fluids which would be
referred to as base fluids in this context, such as water,
mineral oils, ethylene glycol have very minimal appreciable
level of thermal conductivity. Since the main property of an ideal cooling fluid is its heat absorption (due to its high
thermal conductivity), nanofluids became most appropriate
for the aforementioned processes. Firstly, introduced by Choi
[1], a nanofluid is referred to as a two-phase mixture of a base
fluid with suspended particle solid phase which consists of
ultrafine particles. Nanoparticles could be metallic, non-
metallic or polymeric, could portray in rod-like, tabular and
spherical shapes and are less than 100nanometers in shape,
hence, behave more like fluids than a mixture. Usually, Al,
Cu, TiO2, Al2O3 and many others are used as nanoparticles.
Xuan and Roetzel [2], proposed a homogeneous flow model where the convective transport equations of pure fluids are
directly extended to nanofluids. This implied that all the
conventional heat transfer correlations could be used for
nanofluids provided the properties of pure fluids are replaced
by those of nanofluids involving the volume fraction of the
nanoparticles. A conflicting report to this homogeneous flow
model ensued from the experimental observations of Maliga
et al. [3] who considered the case of forced convection, as
they underpredict the heat transfer coefficients of nanofluids.
The basic flow in a nanofluid involves the effects of gravity,
Brownian force and the friction force between the fluid and
the ultrafine particles, the phenomena of Brownian diffusion, sedimentation and dispersion. Thus, although the
nanoparticles are ultrafine, the slip between the fluid and the
particles may not be zero. Later, Buongiorno [4] developed a
mathematical model which exhibits the thermophoretic
properties and Brownian motion of nanoparticles. Eastman et
al. [5] investigated the enhanced thermal conductivity
through the development of nanofluids and ascertained that
with 5% volume of CuO nanoparticles in water, there would
be an increase in thermal conductivity of the resulting
nanofluid by approximately 60%. This is ascribed to the
increase in surface area due to the suspension of nanoparticles. For example, copper (Cu) has a thermal
conductivity 700 times greater than water and 3000 times
greater than engine oil. Masuda [6] also had a similar
conclusion. Tiwari and Das [7] brought a new dimension to
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 146
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
the study of nanofluids by studying the numerical modelling
of mixed convection in two-sided lid-driven differentially
heated square cavity filled with nanofluid. They developed
the model to analyse the behaviour of nanofluids by
considering the solid volume fraction and found out that
nanoparticles were able to change the flow pattern of a fluid from natural convection to forced convection regime. Das
and Jana [8] took an investigation of the hydromagnetic
boundary layer flow past a moving vertical plate in nanofluids
in the presence of a uniform transverse magnetic field and
thermal radiation. They established that fluid temperature
increases as volume fraction parameter enlarged. Also, the
thermal boundary layer for Cu–water was greater than pure
water.
Stagnation point flow has gained much attention
lately as a result of its diverse applications in industrial
processes and engineering procedures. These include
polymer extrusion, transpiration, oil recovery, nuclear reactors and production. The works of Massoudi and Rameza
[9] introduced a new dimension to its study when they
analysed the heat transfer characteristics of a boundary layer
flow of viscoelastic fluid towards a stagnation point.
Adeniyan and Adigun [10] analysed the convective plane
stagnation point chemically reactive MHD flow past a
vertical porous plate with a convective boundary condition in
the presence of a uniform magnetic field. Bachok et al. [11]
studied the stagnation point flow of a nanofluid over a
stretching or shrinking plate and observed in their research
that the skin friction and heat transfer coefficients are enhanced with nanofluid. Hayat et al. [12] discussed the
MHD stagnation point flow of Jeffrey nanofluid by a
stretching cylinder using the Buongiorno model. By applying
the Homotopy Analysis Method, they discovered that the
temperature and concentration profiles were reduced by the
Brownian movement but the thermophoretic parameter
enhanced the Nusselt number. Ogunseye et al. [13] studied
the mixed convection flow of a radiative
magnetohydrodynamic Eyring-Powell copper-water
nanofluid over a stretching cylinder. Aman et al. [14] studied
the steady two-dimensional stagnation-point flow over a
linearly stretching/shrinking sheet in a viscous and incompressible fluid in the presence of a magnetic field is
studied. Their results showed that the skin friction coefficient
decreases, but the heat transfer rate at the surface increases
when the effect of slip at the boundary is taken into
consideration. Also, dual solutions were found to exist for the
shrinking sheet, the solution was unique for the stretching
sheet.
Much attention in the past has been given to the law
of heat conduction suggested by Fourier [15]. The
presentation of its energy equation in parabolic form which
shows that the whole system is instantly influenced by the initial disturbance was its limitation. In a bid to undo this, in
1948, Cattaneo [16] modified the classical Fourier’s law
through thermal relaxation time. Subsequently, Christov [17]
proposed a material-invariant version of the Maxwell-
Catteneo law wherein the thermal relaxation time is given by
Oldroyd’s upper-convected derivative. He showed that the
new formulation allows for the elimination of heat flux, thus
yielding a single equation for the temperature field. This
expression is named as Cattaneo–Christov heat flux model.
This mechanism plays a critical role in several processes such as milk pasteurization and thermization, making of
microchips and some other electronic devices. Han et al. [18]
in his letter, presented a study on coupled flow and heat
transfer of an upper-convected viscoelastic fluid above a
stretching plate with velocity boundary slip. Contrary to most
classical works, he used the newly proposed Christov new
heat flux model. Also, Hayat et al. [19] employed the
Cattaneo-Christov flux model for heat transfer in the
stagnation point flow due to a stretching cylinder with
thermal stratification and found out that the temperature for
Cattaneo-Christov heat flux model is less than the Fourier's
expression. Dil and Khan [20] took a non-Fourier approach to model the heat transfer phenomenon in nanofluids having
application to the automotive industries.
Beg et al. [21] numerically studied the free
convection magnetohydrodynamic heat and mass transfer
from a stretching surface to a saturated porous medium with
Soret and Dufour effects and examined the combined effects
of Soret and Dufour diffusion and porous impedance on
laminar magnetohydrodynamic flow. Makinde [22] and
Mukhopadhay [23] also incorporated the influence of
saturated porous medium into the study of MHD flow and
heat transfer past a vertical plate and cylinder respectively. Abel-Waheed and El-Said [24] studied the MHD flow and
heat transfer over a moving cylinder in a nanofluid under
convective boundary conditions and heat generation.
Mabood and Das [25] wrote an article to discuss the analysis
of MHD flow and melting heat transfer of a nanofluid over a
stretching surface wherein they used a second-order slip
model and thermal radiation. Nandeppanavar et al. [26] also
analysed the MHD flow and heat transfer over a stretching
sheet with non-linear Navier boundary condition. They
investigated the effects of the first and second-order slip
parameters on the fluid flow using both the prescribed surface
temperature and prescribed heat flux boundary conditions. Goyal and Bhargava [27] examined the effect of viscoelastic
parameter velocity slip boundary on the flow and heat
transfer of non-Newtonian nanofluid over a stretching sheet
with heat source/sink, under the action of a uniform magnetic
field. They employed variational finite element method
(VFEM) to obtain numerical solutions to the problem and
discovered that the viscoelastic parameter increased the
velocity profiles. Hayat et al. [28] investigated the heat and
mass transfer analysis in mixed convective radiative flow of
Jeffrey fluid over a moving surface with the effects of thermal
and concentration stratification. Makinde et al. [29] investigated the combined
effects of thermal radiation, thermophoresis, Brownian
motion, magnetic field and variable viscosity on boundary
layer flow, heat and mass transfer of an electrically
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 147
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
conducting nanofluid over a radially stretching convectively
heated surface but did not consider the case for a cylinder
where the curvature parameter is not zero. Hayat et al. [30]
took a comparative study for the flow of viscoelastic fluids
with Cattaneo-Christov heat flux but did not consider the case
of variable viscosity and thermal conductivity. Khan et al. [31] explored the stagnation point flow of second-grade fluid
towards an impermeable stretched cylinder with Non-Fourier
heat flux and thermal stratification but neglected the influence
of magnetic field. Hayat et al. [32] addressed double stratified
mixed convection stagnation point flow induced by an
impermeable inclined stretching cylinder with both thermal
and solutal buoyancy forces. Mahat et al. [33] examined the
steady case of two-dimensional convection boundary layer
flow of a viscoelastic nanofluid over a circular cylinder but
both [32, 33] limited their research to the case of the Fourier
law. Hence, the main goal of this research is to do a numerical
investigation of the effects of Cattaneo-Christov non-Fourier heat flux, variable viscosity, variable thermal conductivity,
velocity and thermal partial slip boundary conditions on the
MHD flow of nanofluid past a vertically positioned stretching
cylinder, using the Spectral Quasi-Linearization Method
(SQLM). To the best of our knowledge, this problem is yet to
be considered, haven gone through existing literature.
2. MATHEMATICAL FORMULATION
Consider a steady two-dimensional, laminar and
incompressible hydromagnetic boundary layer flow of a
viscous, electrically conducting and chemically reactive
nanofluid past a vertical circular cylinder of infinite extent embedded in a uniform porous medium. A magnetic field is
of strength 𝐵𝑜 is applied normal to the surface and parallel to
the 𝑟-axis and the induced magnetic field due to the motion
of a conducting nanofluid is neglected. The flow is invoked
by the stretching of the free stream fluid along the axial
cylinder along the axial direction (𝑧) with velocity e zU
due to the application of two but opposite forces localized
along the axial direction of the cylinder and far from the
cylinder.
Fig. 1. Physical flow geometry
The following equations govern the present flow
consideration
2.1 Equation of conservation of mass
0 v . (1)
2.2 Equation of motion:
d
tb
d
vτ , (2)
where d
dt
v is the material derivative and the Cauchy stress
tensor τ for the second-grade fluid, given by Rivlin and
Ericksen [34] is
21 1 2 2 1p τ I + A A A
, (3)
where p I is the spherical stress due to incompressibility
constraint in which p is the fluid pressure and I is the unit
tensor of order two, 1 2, are material constants. 1A and
2A represent first and second Rivlin-Ericksen tensors of
order two which are defined as
1
T
v vA and 12 1 1
Td
dt
v vA
A A A (4)
*T represents transpose.
Besides, for consistency of the model with thermodynamics,
it is assumed that when the fluid is locally at rest i.e. at
equilibrium, the specific Helmholtz free fluid energy is
minimal, and thus
1 2 10, 0, . (5)
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 148
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
In the cylindrical coordinates,
1
1
1
u u v u
r r r z
v v u v
r r r z
w w w
r r z
v = and
1
21
1
r rrrr zr
r z r
zrz zz rz
r r z r
r r z r
r r z r
τ = (6)
Utilizing the velocity field ( , z), 0, ( , z)u r w rV and the
Prandtl boundary-layer approximations for flow theory
within the boundary layer, 2
2, , ,
u u pu
z zz
are taken to be of
order 1 i.e. (1)O and ,r u to be of order , ( )V VO
respectively, where V is the thickness of boundary-layer
near the cylinder surface at 𝑟 = 𝑎. Thus, the governing equations of momentum and continuity reduce to
( ) ( ) 0ru rwr z
(7)
20
3 2 2
3 2 2
12 2
2
1( )
( )
1
nf nf
nf nf
nf
T nfP
ee
e
e
dw ww u
z r dz
wr T B w
r r r
Tw g T T
K
w w w uu w
z rr r r
w w w w w uu w
r z r z r r rr
UU
U
U (8)
and the applicable boundary conditions are
( , ) , 0, ats ww z a u U z u r a , (9)
,( s, a) ew z r z r U . (10)
In the aforementioned expressions, w and u are the
velocity components in the z and r directions respectively,
PK is the permeability of the porous medium, L is the
characteristic length, nf is the density of nanofluid, ( )nf T
is the temperature-dependent dynamic viscosity of the
nanofluid, nf is the kinematic viscosity of the nanofluid,
nf is the electrical conductivity of the nanofluid and a is
the radius of cylinder, 0w
U zU z
L and e
eL
zU z
U are
velocities with which the cylinder and free-stream stretch
linearly. Also, 2
2
w wu A B
s r r
is the nonlinear Navier
(second-order) slip velocity, where
23
4 2 *2
2
*3(12 3 1 21
3 2 4
), ,
n n
LLA B L L
K K
1min ,1
n
LK
, 0,1 is momentum accommodation
coefficient, * 0 is molecular mean free path,
*
nKL
is Knudsen number. It is known empirically that
for any value of nK , the characteristic length of the
geometry flow field 0,1 ,L and consequently constants
0A and 0B always. The thermophysical properties of
the nanofluid showing relationships between various
properties of the nanoparticles and base fluid are given below
[8], Sobamowo [35], Makinde et al. [36], Pandey and Kumar
[37]:
2.5
3 1
1 , 1 ,
2 1
1 ,
2 2, ,
21
( ), 1 (11)
s
nf f s nf f
s s
f f
nf f s
s f f sf nf nf
nf nfnf f s f f s
nf
nf P P Pnf f sP nf
k k k kk
k k k k k
k TC C C
C
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 149
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Table I
Thermophysical properties of water and nanoparticles Das and Jana [8].
Physical properties Water/base fluid Cu (copper) 𝐴𝑙2𝑂3 (Alumina) 𝑇𝑖𝑂2 (Titanium oxide)
𝜌 (𝑘𝑔/𝑚3) 997.1 8933 3970 4250
𝑐𝑝 (𝐽/𝑘𝑔𝐾) 4179 385 765 686.2
𝑘 (𝑊/𝑚𝐾) 0.613 401 40 8.9538
𝛽 × 105 (𝐾−1) 21 1.67 0.85 0.90
𝜑 0.0 0.05 0.15 0.2
𝜎 (𝑆/𝑚) 5.5 × 10−6 59.6 × 106 35 × 106 2.6 × 106
Here, P nfC is the heat capacitance of nanofluid, m is
shape factor, is nanoparticle volume fraction, subscript s
is nano solid particle, subscript f is base fluid, and subscript
nf is nanofluid. However, the dynamic viscosity of the of the
water base fluid which was proposed by Lings and Dybbs
[38] and seen in Animashaun and Aluko [39], Choudhury and
Hazarika [40], Prasad et al [41], Eldabe et al. [42] is
temperature-dependent and given as 11
( )f
T T
T
,
wherein
is a constant and is the freestream viscosity.
Considering the derivation of the dimensionless viscosity
variation parameter, let b T , and so nf could be
finally expressed as
2.5
1 1nf
b
. (12)
Implementing the similarity transformation, 2 2
2
Wr a
a z
U and the stream function ( )Wa z f U
, such that ur
and 1
vr z
, the continuity equation
is verified identically, and the momentum equation with its
boundary conditions transmutes as
2.5 2.5
32.5
2 21
2
22 2.5
1 11 2 2
(1 ) (1 )
11 2 (1 ) M
1 (1 )
(1 ) M 4 (1 )
(1 ) 1 2 2
1M (1 )
(1 )
iv
f f
bf b
b
f fb ff f b
ff
b f f f ff
b Ha Da
( ) 0 (13)f
**'(0) 1 ''(0) '''(0), (0) 0, '( )f f f f f (14)
where0P f
LDa
K U
is the Darcy parameter, 1 0
f
U
L
is
the viscoelastic parameter, 0UA
L
is the first order slip
parameter and ** 0U
BL
is the second order slip
parameter,
20
0
f
f
B LHa
U
is the Hartmann parameter,
Re
z
z
Gr is the mixed convection parameter,
3( )T f
z
g TzGr
is the local thermal Grashof number
and
20Rez
U z
L is the local Reynolds number,
0
e
U
Uis
the velocity ratio and
1 31( )
, 1( )
s
f
T s
T f
M M
2
3 1
1
2 1
s
f
s s
f f
M
are constants obtained from the thermophysical parameters in
Equation (11).
2.3 Energy equation
The energy balance equation, as dictated by the first law of
classical thermodynamics, takes the form Lukaszewicz,[43]:
: ,nf
TT
t
v q vτ (15)
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 150
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
where the second term on the right of (15) represents the
energy due to various sources such as body forces. It is taken
in this case as heat generation or absorption in the nanofluid
and modelled as 0Q Q T T . Additionally, ( )ijτ τ is
the Cauchy stress tensor, q is the thermal flux, : vτ is the
dyadic notation for ,v ,ij j iτ called the scalar product of τ
and v . Lastly,,
vv
j
j iix
v is a tensor of second rank.
Assuming the non-Fourier Cattaneo-Christov thermal flux,
Cattaneo [16], and Christov [17] instead of the conventional
Fourier’s type:
o nfk T Tt
qv q q v v q qτ ,
0nfk T , (16)
where oτ is the thermal flux relaxation time, ( , r)T z is
nanofluid temperature and nfk T is the temperature-
dependent thermal conductivity. The case of the Fourier's law
arises when 0o τ in equation (16). Considering the
steadiness of the flow and applying the criterion of
incompressibility i.e 0 v , equation (16) reduces to
o nfk T T v q q v qτ (17)
On further simplification, the energy equation yields
1 1nf r
P Pnf nf
Tk T r rq
r r rC r C r
0
P nf
Q T TT T w u
z rC
2 2 22 2
2 2
0
2
o
P nf
T T Tw u wu
z rz r
w w T u u Tw u w u
z r z z r r
Q T Tw u
z rC
(18)
with boundary conditions
1( ) , at , (19)w
TT T z e r T T asa r
r
where 0( ) Tw
zT z T
L
.
It is noteworthy to mention that most recent authors (see
Dogonchi and Ganji [44], Kahn et al. [45], Mahanthesh et al.
[46]) incorporated the heat generation/absorption and/or
thermal radiation into their studies without due consideration
for mathematical derivation from the first principle. In
consequence, their energy balance equations seemed a bit of
misnomer. They lost the last term on the RHS of equation
(18).
0T is a constant which is a measure of temperature. The
nanofluid temperature which was suggested by Ostrach [47]
and used by Sharma [48] is given as ( )
Nfk T T
k T
, while
the temperature difference ratio /T T . ( )fk T could
be recast as
( ) 1N
fk T k . (20)
Here, k is the freestream thermal conductivity. For 1N ,
the range of variation of value of takes the form Elbarbary
and Elgazery [49]: 0 6, for air; 0 0.12, for
water and 0.1 0, for lubrication oil.
The heat radiation flux approximated by Rosseland is given
as
* * 44
* *
4 4
3 3r
Tq T
rk k
(21),
as the flux is radial from the surface of the cylinder, and
dependent on r only. Here * 2 4Wm K
is the Stefan-
Boltzmann constant and * 1k m
is the Rosseland mean
spectral absorption coefficient. It is further assumed that the
term 4T due to radiation within the flow can be expressed as
a linear function of temperature itself. Hence, 4T can be
expanded as Taylor series about T and can be approximated
after neglecting the higher order terms as,
4 3 4 3T T T T , (22)
so that
434
T TT
r r
.
It is gainful and instructive to follow Magyari &
Pantokratoras [50], wherein the effective heat flux
accounting for both thermal conduction and radiation heat
transfer is
( )eff nfeff
Tk T
r
q , (23)
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 151
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
where *
3
*
16( ) ( )
3nfeff nfk T k T T
k
(24)
is the nanofluid effective thermal conductivity. It is worthy to
mention that in this work, one drops the subscript of effq
2Wm
in equation (23) without dropping the meaning as
per effective conductivity.
In order to reflect the influence of radiation, equation (16)
now looks like
o effnfk T Tt
qv q q v v q qτ
In view of this modification of energy equation (18), the
first two terms on the left take the form
1 1
1( ) (25)
nf r
P Pnf nf
nfeff
P nf
Tk T r rq
r r rC r C r
Trk T
r rC r
where 1 1( )nfeffk T Wm K
is given by (24) and by virtue
of equation (25), equation (18) takes the form
2 2 22 2
2 2
0
0
2
1( ) (26)
o
P nf
nfeff
P Pnf nf
T T Tw u wu
z rz r
w w Tw u
z r z T Tw u
u u T z rw u
z r r
Q T Tw u
z rC
QTrk T T T
r rC r C
Employing (20) and w
T T
T T
, dimensionless forms of
equation (26) and (19) is given as
1 2
5
(1 2 ) 1 '' 1 '(27)
2 1 '
n n
n
nM
*
4
4 2 2
' ' ' '
Pr 0' '' ''
*' '
eff
Qf f f f
MQ M
f f ff
ff
1(0) 1 (0), ( ) 0 , (28)
where
4 51
2 2,
2
P s
P f
s f f s
s f f s
C
C
k k k kM M
k k k k
316
3
TR
k k
is the thermal radiation parameter,
Pr
pf
C
k
is the Prandtl number,
5
Pr 1Pr
1
n
eff nM R
is the effective Prandtl number,
0
0P f
Q LQ
C
U is the zeroth-order heat source/sink
parameter and * 0oU
L
is the thermal relaxation
parameter.
Also, originating from this study is
* 0 0
P f
C
, which is
the heat source/sink parameter of first order.
In addition, the skin friction coefficient is defined as
2,w
f
f w
CU
(29)
2
1 2
where
(30)w nf
r a
w w w w uu w
r z r r rr
3. METHOD OF SOLUTION
The general nonlinear, strongly coupled system of ordinary
differential equations defined by (13) and (27), with
conditions (14) and (28) are to be solved using the SQLM
technique, as described by Motsa [51] and Otegbeye [52].
The Taylor series for univariate function is applied to
linearize the nonlinear system, thereafter, integrated by the
Chebyshev Spectral Collocation method. An initial guess which satisfies the imposed boundary conditions is taken and
this ensures the nippy convergence and accuracy of the
obtained solutions.
Equations (13) and (27) can be expressed in their
decomposed form as a sum of both the linear and non-linear
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 152
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
constituents. Employing Taylor's series to linearize, the
iterative schemes (31) and (32) are obtained as
1, 1 2, 1 3, 1 4, 1 5, 1
6, 1 7, 1 (31)
'''' ''' '' '
'
n n n n n n n n n n
fn n n n n
f f f f f
R
8, 1 9, 1 10, 1 11, 1
12, 1 13, 1
'' ' ''
'
n n n n n n n n
n n n n n
f
f f R
(32)
with corresponding boundary conditions:
**1 1 1 1
1 1 1 1 1
(0) 0, (0) 1 (0),
( ) 0, (0) 1 (0), ( ) 0 (33)
' '' '''
' '
n n n n
n n n n
f f f f
f
where the coefficients , ( 1, ...,13)i n i , are known functions
from previous iterations and are given by,
1, ( 1)(2 1)'n n nf b ,
2, 2.5
1(2 1) 4( 1) 2 ( 1)(2 1)
1
'n n n n nb f b f
3, 2.5 2.5
1
(2 1)1 12
11 1
( 1) 4 2 (2 1)
'
' ''
n nn
n n n n
b
b
b M f f f
,
4, 1 2
2.5
( 1) 2 4 2 (2 1)
1
1
' '' '''n n n n nb M f f f M Ha
Da
5, 1 1( 1) 4 (2 1)'' ''' ''''n n n n nb M f f f
.
''b(2 1)16, 2.5 11
fn
n bn
22 '' ' ''' ' ''
7, 1
2'''' ' ''' ''
3 3
2'' ' '
22.5 2
4
(2 1) 2 ( 1)
(2 1)1,
1 1
n n n n n n n n
n n n n n n n
n n n
n
M b f f f b f f f f
b f f f f f M b M b
bf bM Ha f
b
2*
8, 5 4(2 1)( 1) Prn n eff nM b M f
19, 5 2(2 1) ( 1) 2 ( 1)'n n
n n n nM n
*
*4 4
4
Pr Pr Pr' neff n eff n n
Q fM f M f f
M
212 '''
10, 5
'
* '2
* ' ''4 4
4
1 ( 1)1(2 1)
1 1
2 1
1
PrPr Pr Pr'
nnn nn n
n n
n
n
n n
n
eff n
eff eff n eff n n n
n nn
M
n
Q fQ M f M f f f
M
*
11, 4 Prn eff n nM f
*
*12, 4 4
4
PrPr Pr 2 ' ' eff n
n eff n eff n n n n
QM M f f
M
*
*13, 4 4
4
PrPr Pr 2
'' '' '' ' ' eff n
n eff n eff n n n n n n
QM M f f f
M
'''' ''' '' '1, 2, 3, 4, 5,
'' ,6, 7,
'' ' ''8, 9, 10, 11,
' , (34)12, 13,
fR f f f f f
n n n n n n n n n n n
n n n n f
R fn n n n n n n n n
f fn n n n
1 '''1 22.5(1 )
1 ' ''1 22.51 (1 )
2 ''(1 ) (1 )3 1
' ''1 ''4 1 2
2.5''' (1 )
' ''' 2 '''1 1 2 2
(1 )2
ff n
bf
n nbn
b M b M f fn n n n n
f fn n
b fn n
f fn n
b f f f f fn n n n n
M bn
(35)
1 '
2.5(1 )
''1(1 2 )
1 ' 216
'2 1
Preff
Ha Da fn
n
n n
nM n
n n
n
n n
Qn
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 153
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Equations (31) – (33) form the SQLM iterative scheme,
which is a coupled linear system of equations, where
n terms are initial (previous) approximations and ( 1)n
terms are next (current) approximations. These would, in
turn, be solved by the Chebyshev pseudo-spectral technique
Canuto et al [53]. The results for 1nf and 1n , when
1, 2, 3, ..n are iteratively computed by initializing the
iterative algorithm with initial approximations. At this point,
the method of Chebyshev pseudo-spectral collocation is
applied and equations (31) and (32) are discretized using the
steps listed below:
truncate the semi-infinite domain 0, by replacing
it with 0, , where ¢ .
using the transformation 1
12
, transform the
interval 0, 1,1 a
compute the variables ( )f and ( ) using Chebyshev
differentiation matrix D , at the collocation point as a
matrix-vector product, that is:
0
( ) F, 0,1, 2, ..., ,
N
ij i
i
dfD f j N
d
D (36)
where 1N is the number of collocation points, 2D D
and 0 1( ), ( ), ..., ( )T
NF f f f is a vector function at the
collocation point. The Gauss-Lobatto points are selected to
define the nodes in 1, 1 as:
cos , 0,1, ..., ; 1 1k
kk N
N
(37)
In the same vein, we represent with alike vector function
. Higher-order derivatives of f and are evaluated as
powers of D , that is
( )s sf F D and ( )s s D , (38)
where s is the order of the derivative. Substituting equations
(35), (36) and (37) into (30) and (31), the following SQLM
scheme is obtained in a matrix form as:
1,1 1,2 1
2,1 2,2 1
fn n
n n
F R
R
(39)
where ( , 1, ..., 2)ij i j are 1 1N N matrices and
fnR and nR
are 1 1N vectors, defined by
4 3 21,1 1, 2, 3,
4, 5,
1,2 6, 7,
22,1 11, 12, 13,
22,2 8, 9,
n n n
n n
n n
n n n
n n
diag diag diag
diag diag
diag diag
diag diag diag
diag diag diag
= D D D
D
=
= D D
= D D
I,
D I
I,
10,
(40)
n
I,
subject to the boundary conditions
2 ** 31 1
0
0 1 0
0
1 1 1 0
0
( ) 0, ( ) 1,
( ) , (41)
( ) 1, ( ) 0
N
n nN Ni Ni Ni N
i
N
i n
i
N
n nNi Ni N
i
F F
F
D D D
D
I D
where I is the identity matrix and
1, 13,...n ndiag diag are diagonal matrices.
Below is an initial approximation for the SQLM scheme
which is found appropriate
0 **
01
1( ) 1 ,
1
1( )
1
f e
e
(42)
4. RESULTS AND DISCUSSIONS
With the aid of graphical illustrations and tables, the obtained
numerical results are crystallized for the parametric study of
the considered problem to have a good grasp of the physics
of the problem. For several values of the embedded
controlling parameters, the dimensionless fluid velocity
profiles and fluid temperature profiles have been presented in
Fig. (2) to (22), whereas table 3 shows their influence on the
skin friction coefficient. The accuracy of the numerical scheme is tested and shown in table 2, when compared with
the results of Ishak et al. [54].
4.1 Effects of variation of parameters on the velocity profiles
Fig. 2 depicts the effect of solid volumetric fraction of
nanoparticles on the fluid velocity. The fluid velocity together
with the momentum boundary layer thickness increased for
increasing values of . Fig. 3 shows the deportment of the
curvature parameter γ on the nanofluid velocity. Ordinarily,
any increase in curvature parameter would reduce the cylinder’s radius, which in turn reduces the cylinder’s surface
area which is in direct contact with the nanofluid particles.
Hence, the resistance offered to the fluid particles decreases
and velocity profiles increase accordingly. The effect of
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 154
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
viscosity variation parameter on the dimensionless velocity is
presented in Fig. 4. It is important to note that an increase in
viscosity parameter represents a decrease in the nanofluid
viscosity. The same escalating convention was observed as
regards the boundary layer thickness due to higher
temperature difference between the surface and the ambient fluid. The trend observed when the velocity ratio parameter
is being increased is of two-fold as pictured in Fig. 5. A
stratified pattern which showed increament in the velocity
profile of the nanofluid but thinning out of the momentum
boundary layer was ascertained. Fig. 6 is plotted to show the
influence of viscoelastic parameter β on the velocity profile.
Both velocity and associated momentum boundary layer
thickness increase when β increases. This is coherent with the
expression for β in its dimensionless expression, which
shows that β increases as the viscosity decreases. So, fluid
moves easily and as a result, velocity profile increases. From
Fig. 7, the velocity and momentum boundary layer thickness were observed to increase for large values of λ. The ratio of
buoyancy to inertial forces defines the Mixed Convection
parameter. It is, however, noteworthy that when λ = 0, the
mixed convection parameter is absent, implying a forced
convection flow and flow is opposed when 0. Also,
0 indicates that flow is aided when heat is convected
from the surface of the cylinder to the fluid flow i.e. cooling
of the cylinder surface or heating the fluid. With an increase
in , buoyancy forces increase. Therefore, the velocity of
the fluid increases. The effects of Magnetic field parameter,
Ha , on the velocity is limned in Fig. 8. It is right to
anticipate that increasing hydromagnetic drag bottles up the
flow (subjugates velocity values). The resistive Lorentz force
opposed the velocity at which fluid flowed and caused a
decrease in the boundary layer. Fig. 9 epitomizes the effects
of reducing how porous the medium is, by making some
increament in the porousity parameter. A directly
consequential resistance against the flow of the nanofluid was
observed in the flow system and the resultant effect is a
reduction in fluid velocity. As reported by Singh and
Makinde [55], the same trend is seen in Fig. 11 for the
variation of the First Order Slip parameter. It showed that both the fluid velocity and boundary layer thickness decrease
with an increase in , which happens because fluid
experiences less drag with increase in . However, the trend
was just the opposite for the Second Order Slip parameter in
Fig. 10.
4.2 Effects of variation of parameters on the temperature
profiles
All profiles decay smoothly from maximum values at the wall
to zero in the free stream (edge of the boundary layer). Like
the report of Makinde et al. [36], Fig. 12 expatiates the import
of heightening the volumetric fraction of the nanoparticle on the temperature. Fluid temperature and boundary layer
thickness rise with an increase in the values of . This is
imputable to the enhanced thermal conductivity of the base
fluid. Study proves that thermal conductivity of base fluid can
be substantially bettered by ducking of copper nanoparticles.
The upshot of variable thermal conductivity parameter 𝜖 is
evinced in Fig. 13. Fluid temperature is maximized with
larger values of 𝜖 in the case of injection. This is ascribable to the physical fact that thermal conductivity of the nanofluid
increases due to a large amount of heat which is transferred
from the cylinder surface to the nanofluid. In Fig. 15 and Fig.
16, the temperature field increases with the increment of heat
source parameter. Due to exothermic reaction, the heat
releases more rapidly which increases the temperature
profile. The effect of the effective Prandtl number on
is outlined in Fig. 17. A rise in the effective Prandtl number
from 0.02 (liquid metal) through and through to 0.7 (air) to
1.0 and lastly 7.0 (water). When effective Prandtl number is
increased, there is a thinner thermal boundary layer thickness
and more uniform temperature distributions across the
boundary layer is seen. Generally, fluids which have lower Prandtl number possess higher thermal conductivities and so
heat would diffuse away from the cylinder surface at a faster
rate. The thermal relaxation time is the delay(lag) required
for the beginning of heat flux at some point once a
temperature gradient is commenced. Thus, for larger values
of thermal relaxation, particles required more time to transfer
energy to adjacent fluid particles and therefore temperature
profiles decline. Fig. 18 expatiates this. Due to increased
tightness of the porous medium as the porousity parameter is
raised, there is more resistance to the fluid flow and thus the
heat is transferred from the hot surface of the cylinder and finally, the temperature gets higher, as shown in Fig. 19. In
Fig. 20, the thermal slip parameter is seen to increase the
temperature and the boundary layer.
The effects of the emergent parameters on the skin-friction
coefficient is shown in Table 3. The obtained values are
mostly negative, which measures the drag of the fluid on the
cylinder wall. It was ascertained that increase in 𝜑, 𝜆, 𝑏 and 휀
all increased the skin-friction coefficient but increasing
values of 𝐷𝑎 and 𝐻𝑎 reduced it.
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 155
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Table II
Comparison data of the Nusselt number reported by Ishak et al.[54] with SQLM for distinct values of 𝑃𝑟 when 𝛾 = 𝑏 = 𝛽 = 𝑁 = 𝐻𝑎 = 𝐷𝑎 = 𝛾∗∗ = 𝜖 =𝑛 = 𝛿 = 𝑅 = 𝑄 = 𝛾∗ = 𝑄∗ = 𝛬1 = 𝛬2 = 0, 𝜆 = 휀 = 𝑀1 = 𝑀2 = 𝑀3 = 𝑀4 = 𝑀5 = 𝑀6 = 1
𝑃𝑟 Ishak et al. [54]
𝑓′′(0)
Present (SQLM)
𝑓′′(0)
Absolute Difference Ishak et al. [54]
−𝜃′(0)
Present (SQLM)
−𝜃′(0)
Absolute Difference
0.72 0.3645 0.3645 0 1.0931 1.0931 0
6.8 0.1804 0.1804 0 3.2902 3.2895 7 × 10−4
40 0.0873 0.0872 1 × 10−4 7.9463 7.9383 8 × 10−3
60 0.0729 0.0727 2 × 10−4 9.7327 9.7180 1.47 × 10−2
100 0.0578 0.0587 9 × 10−4 12.5726 12.5411 3.15 × 10−2
Table III
Numerical values of Skin friction coefficient for distinct values of φ, b, γ∗∗, δ, Da, Ha, λ and ε when Λ1 = Q = Pr = R = Q∗ = γ∗ = n = ϵ = 0.1
𝜑 𝑏 𝛽 𝐷𝑎 𝐻𝑎 𝜆 휀 𝑓′′(0)
0.1 0.1 0.1 0.1 0.1 0.1 0.1 -1.52455507
0.5 -1.34270035
0.6 -1.11152139
0.7 -0.87146927
1.9 -2.67909042
2.0 -2.65337032
2.1 -2.63795113
0.1 -1.52455507
0.2 -1.70461236
0.35 -1.83520588
0.5 -1.73978129
1.0 -2.00118374
1.5 -2.26099116
0.2 -1.54293550
0.5 -1.66978531
1.0 -2.10963477
0.05 -1.56285503
0.09 -1.53214172
0.15 -1.48710704
0.20 -1.43767682
0.22 -1.42804568
0.25 -1.39736064
Fig. 2. Effect of Volumetric Fraction of Nanoparticle on the velocity
profile
Fig. 3. Effect of Curvature parameter on the velocity profile
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 156
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Fig. 4. Effect of Variable Viscosity parameter on the velocity profile
Fig. 5. Effect of Velocity Ratio parameter on the velocity profile
Fig. 6. Effect of Viscoelastic parameter on the velocity profile
Fig. 7. Effect of Mixed Convection parameter on the velocity profile
Fig. 8. Effect of Magnetic parameter on the velocity profile
Fig. 9. Effect of Porousity parameter on the velocity profile
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 157
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Fig. 10. Effect of Second-Order Velocity Slip parameter on the velocity
profile
Fig. 11. Effect of First Order Velocity Slip parameter on the velocity
profile
Fig. 12. Effect of Volumetric Fraction of Nanoparticle on the
temperature profile
Fig. 13. Effect of variable thermal conductivity parameter on the
temperature profile
Fig. 14. Effect of Index of temperature ratio on the temperature profile
Fig. 15. Effect of Heat Source/Sink parameter of zeroth-order on the
temperature profile
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 158
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Fig. 16. Effect of Heat Source/Sink parameter of first order on the
temperature profile
Fig. 17. Effect of the effective Prandtl number on the temperature profile
Fig. 18. Effect of Thermal Relaxation parameter on the temperature
profile
Fig. 19. Effect of Porousity parameter on the temperature profile
Fig. 20. Effect of Temperature Slip parameter on the temperature profile
5. CONCLUSION
The problem of stagnation point MHD flow of viscoelastic nanofluid past a circular cylinder with non-Fourier heat
flux and variable properties has been addressed
numerically with the aid of the iterative Spectral
Quasilinearization method. More importantly, the briny
upshots are summarized as follows:
This appears, as far as we know, that the “heat
source/sink parameter of first order” is new; and
perhaps it could be tested experimentally.
Velocity profiles were substantively enhanced
with increasing values of the volumetric fraction
of the nanoparticle and the curvature parameter
but was cut back by the variable viscosity parameter and porousity parameter.
The variable thermal conductivity parameter had
depreciating effects on the temperature profile,
but the temperature slip parameter supported it.
An increase in both the velocity ratio parameter
and first order velocity slip increased the skin-
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 159
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
friction coefficient but the variable viscosity
parameter and porousity parameter decreased it.
The case of Fourier law which arises when 𝛾∗ =0 has a higher temperature than that of non-
Fourier heat flux model
REFERENCES [1] Choi, S. (1995): Enhancing thermal conductivity of fluids with
nanoparticles. ASME Int Mech Eng, 66:99–105.
[2] Xuan, Y., Roetzel, W. (2000): Conceptions for Heat Transfer
Correlation of Nanofluids. International Journal of Heat and
Mass Transfer, 43: 3701-3707.
http://dx.doi.org/10.1016/S0017-9310(99)00369-5.
[3] Buongiorno, J., Hu, L., (2009): A benchmark study on the
thermal conductivity of nanofluids. Journal of Applied
Physics, 106: 094312-1.
[4] Eastman, J. A., Choi, S. U. S., Li, S., Thompson, L. J., Lee, S.
(1997): Enhanced thermal conductivity through the
development of nanofluids, in: S. Komarneni, J.C. Parker, H.J.
Wollenberger (Eds.), Nanophase and Nanocomposite
Materials II, Materials Research Society, Pittsburgh.
[5] Masuda, H., Ebata, A., Teramae, K., Hishinuma, M. (1993):
Alteration of thermal conductivity and viscosity of liquids by
dispersing ultrafine particles. Netsu Busse, 7: 227–233.
[6] Tiwari, R. K., Das, M. K. (2007): Heat transfer augmentation
in a two-sided lid-driven differentially heated square cavity
utilizing nanofluids. International Journal of Heat and Mass
Transfer 50: 2002–2018.
[7] Das, S., Jana, R. N. (2015): Natural convective magneto-
nanofluid flow and radiative heat transfer past a moving
vertical plate. Alexandria Engineering Journal 54: 55 – 64.
[8] Massoudi, M., Rameza, M. (1990): Boundary layer heat
transfer analysis of a viscoelastic fluid at a stagnation point.
ASME J Heat Transfer, 130:81–86.
[9] Adeniyan, A., Adigun, J.A. (2013): Analysis of convective
plane stagnation point chemically reactive MHD flow past a
vertical porous plate with a convective boundary condition in
the presence of a uniform magnetic field. American Journal of
Engineering Research, 2(9): 234 – 243.
[10] Bachok, N., Ishak, A., Pop, I. (2011): Stagnation-point flow
over a stretching/shrinking in a nanofluid. Nano Scale Res
letter, 6:623–630.
[11] Hayat, T., Kiyani, M. Z., Ahmad, I., Khan, M. I., Alsaedi, A
(2018): Stagnation point flow of viscoelastic material over a
stretched surface. Results in Physics, 9: 518 – 526.
[12] Ogunseye, H. A., Sibanda, P., Mondao, H., (2019): MHD
mixed convective stagnation-point flow of Eyring-Powell
nanofluid over stretching cylinder with thermal slip
conditions. J. Cent. South Univ. 26: 1172−1183.
[13] Aman, A., Ishak, A., Pop, I. (2013): Magnetohydrodynamic
stagnation-point flow towards a stretching/shrinking sheet
with slip effects. International Communications in Heat and
Mass Transfer, 47: 68–72.
[14] Fourier, J. B. J. (1822): Théorie Analytique De La Chaleur,
Paris.
[15] Cattaneo, C. (1948): Sulla conduzione del calore, Atti Semin.
Mat Fis Univ Modena Reggio Emilia, 3: 83–101.
[16] Christov, C. I. (2009): On frame indifferent formulation of the
Maxwell-Cattaneo model of finite-speed heat conduction.
Mechanics Research Communications, 36: 481 – 486.
[17] Han. S., Zheng, L., Li, C., Zhang, X. (2014): Coupled flow and
heat transfer in viscoelastic fluid with Cattaneo–Christov heat
flux model. Applied Mathematics Letters. 38: 87–93,
http://dx.doi.org/10.1016/j.aml.2014.07.013
[18] Hayat, T., Khan, M. I., Waqas, M., Alsaedi, A. (2017): On
Cattaneo-Christov heat flux of variable thermal conductivity
Ering-Powell fluid. Results in Physics, 7: 446 – 450.
[19] Dil, T., Khan, M. S. (2018): A non-Fourier approach towards
the analysis of heat transfer enhancement with water-based
nanofluids through a channel. AIP Advances 8, 055311
(2018). https://doi.org/10.1063/1.5005870.
[20] Beg, O, A., Bakier, A. Y., Prasad, V. R. (2009): Numerical
study of free convection magnetohydrodynamic heat and mass
transfer from a stretching surface to a saturated porous
medium with Soret and Dufour effects. Computational
Material Science 46: 57 – 65.
[21] Makinde, O. D. (2009): On MHD boundary-layer flow and
mass transfer past a vertical plate in a porous medium with
constant heat flux. International Journal of Numerical Methods
for Heat and Fluid Flow, 19 (3 – 4): 546 – 564.
[22] Mukhopadhyay, S. (2012): Analysis of boundary-layer flow
and heat transfer along a stretching cylinder in a porous
medium. International Scholarly Research Network (ISRN),
Thermodynamics, 2012: 1 – 7.
[23] Abdel-Wahed, E. (2018): MHD flow and heat transfer over a
moving cylinder in a nanofluid under convective boundary
conditions and heat generation. Thermal Science International
Scientific Journal, pp 1 – 14,
doi.org/10.2298/TSCI170911279A.
[24] Mabood, F., Das, K. (2015): Melting heat transfer on
hydromagnetic flow of a nanofluid over a stretching sheet with
radiation and second-order slip. The European Physical
Journal, Eur. Phys. J. Plus (2016), 131: 3.
https://doi.org/10.1140/epjp/i2016-16003-1.
[25] Nandeppanavar, M. M., Vajravelu, K., Abel, M. S.,
Siddalingappa, M. N. (2012): Second order slip flow and heat
transfer over a stretching sheet with non-linear Navier
boundary condition. International Journal of Thermal
Sciences, 58: 143 - 150.
[26] Goyal, M., Bhargava, R. (2013): Numerical solution of
MHD Viscoelastic nanofluid flow over a stretching sheet
with partial slip and heat source/sink. Hindawi Publishing
Corporation, Volume (2013), Article ID 931021, 11 pages.
http://dx.doi.org/10.1155/2013/931021.
[27] Hayat, T., Hussain, T., Shehzad, S. A., Alsaedi, A. (2014):
Thermal and concentration stratifications effects in radiative
flow of Jeffrey fluid over a stretching sheet. PLoS ONE, 9
(10): 1 - 15.
[28] Makinde, O. D., Mabood, F., Khan, W. A., Tshehla, M. S.
(2016): MHD flow of a variable viscosity nanofluid over a
radially stretching convective surface with radiative heat.
Journal of Molecular Liquids 219 (2016) 624–630,
http://dx.doi.org/10.1016/j.molliq.2016.03.078.
[29] Hayat, T., Waqas, M., Shehzad, S. A., Alsaedi, A. (2016):
Mixed convection flow of viscoelastic nanofluid by a cylinder
with variable thermal conductivity and heat source/sink.
International Journal of Numerical Methods for Heat & Fluid
Flow, Vol. 26 Iss 1 pp. 214 – 234.
[30] Khan, M. I., Zia, Q. M. Z., Alasedi, A., Hayat, T. (2018):
Thermally stratified flow of second-grade fluid with non-
Fourier heat flux and temperature-dependent thermal
conductivity. Results in Physics 8 (2018), 799–804.
Doi.org/10.1016/j.rinp.2018.01.015.
[31] Hayat, T., Anwar, M. S., Farooq, M., Alsaedi, A. (2015):
Mixed convection flow of viscoelastic fluid by a stretching
cylinder with heat transfer, PLoS ONE 10 (3): 1 – 20.
[32] Mahat, R., Rawl, N. A., Kasim, A. R.M., Shafie, S. (2017):
Mixed convection boundary layer flow of viscoelastic
nanofluid past a horizontal circular cylinder: Case of
constant heat flux, IOP Conf. series: Journal of Physics
Conf. Series 890 (2019) 012052.
[33] Rivlin, R. S., Ericksen, J. L. (1955): Stress-deformation
relations for isotropic materials.
[34] Journal of Rational Mechanics and Analysis, 4 (2): 1-103.
[35] Sobamowo, M. G. (2018): Combined effects of thermal
radiation and nanoparticles on free convection flow and heat
transfer of Casson fluid over a vertical plate. International
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:06 160
192506-7373-IJMME-IJENS © December 2019 IJENS I J E N S
Journal of Chemical Engineering, Volume 2018, Article ID
7305973, 25 pages. https://doi.org/10.1155/2018/7305973.
[36] Makinde, O. D., Mahanthesh, B., Gireesha, B. J.,
Shashikumar, N. S., Monaledi, R. L., Tshehla, M. S. (2018):
MHD nanofluid flow past a rotating disk with thermal
radiation in the presence of Aluminium and Titanium alloy
nanoparticles, defect and diffusion Forum, Vol. 384: 60 – 79,
doi:10.4028/www.scientific.net/DDF.384.69.
[37] Pandey, K. A., Kumar, M., (2017): Natural convection and
thermal radiation influence on nanofluid flow over a stretching
cylinder in a porous medium with viscous dissipation.
Alendria Enginering Journal., 56: 55 – 62.
[38] Lings, J. X., Dybbs, A. (1987): Forced convection over a flat
plate submersed in a porous medium: variable viscosity case.
Paper 87-WA/HT-23. ASME, New York.
[39] Animasaun, I. L. (2015): Dynamics of unsteady MHD
convective flow with thermophoresis of particles and variable
thermo-physical properties past a vertical surface moving
through binary mixture. Open Journal of Fluid dynamics, 5,
106 – 120. http://dx.doi.org/10.4236/ojfd.2015.52013.
[40] Choudhury, M., Hazarika, G. C. (2006): The effects of
variable viscosity and thermal conductivity on MHD flow
due to a point sink. Matematicas: Ensenanza Universitaria,
vol. XVI, num 2, diciembre, 2008, pp. 21 – 28.
[41] Prasad, K.V., Vajravelu, K., Vaidya, H., Van Gorder, R. A
(2017): MHD flow and heat transfer in a nanofluid over a
slender elastic sheet with variable thickness. Results in
Physics, 7 (2017) 1462–1474.
[42] Eldabe, N. T. M., Elbashbeshy, E. M. A., Youssef, I. K.
(2014): The effects of temperature-dependent viscosity and
viscous dissipation on MHD convection flow from an
isothermal horizontal circular cylinder in the presence of
stress work and heat generation. European scientific Journal,
10(36): 1857 – 7881.
[43] Elbarbary, E. M. E., Elgazery, N. S. (2005): Flow and heat
transfer of a micropolar fluid in an axisymmetric stagnation
flow on a cylinder with variable properties and suction
(numerical study). Acta Mechanica 176, 213–229 (2005) DOI
10.1007/s00707-004-0205-z.
[44] Dogonchi, A. S. and Ganji, D. D. (2017): Effect of Cattaneo–
Christov heat flux on buoyancy MHD nanofluid flow and heat
transfer over a stretching sheet in the presence of Joule heating
and thermal radiation impacts. Indian J of Phys.
https://doi.org/10.1007/s12648-017-1156-2
[45] Khan, M. S., Rahman, M. M., Arifuzzaman, S. M., Biswas, P.
and Karim, I (2017): Williamson fluid flow behaviour of MHD
convective radiative Cattaneo–christov heat flux type over a
linearly stretched-surface with heat generation and Thermal-
diffusion. Frontiers in Heat and Mass Transfer (FHMT), 9, 15
(2017). DOI: 10.5098/hmt.9.15
[46] Mahanthesh, B., Gireesha, B. J. and Raju, C. S. K. (2017):
Cattaneo-Christov heat flux on UCM nanofluid flow across a
melting surface with double stratification and exponential
space dependent internal heat source. Informatics in Medicine
Unlocked. Informatics in Medicine Unlocked, 9: 26–34.
[47] Ostrach, S. (1952): An analysis of laminar free-convection
flow and heat transfer about a flat plate parallel to the direction
of the generating body force. NACA-TN 2635: 1-40.
[48] Sharma, P. R., Singh, G. (2010): Effects of variable thermal
conductivity, viscous dissipation on steady MHD natural
convection flow of low Prandtl fluid on an inclined porous
plate with Ohmic heating. Meccanica 45: 237–247,
DOI 10.1007/s11012-009-9240-0
[49] Elbarbary, E. M. E., Elgazery, N. S. (2005): Flow and heat
transfer of a micropolar fluid in an axisymmetric stagnation
flow on a cylinder with variable properties and suction
(numerical study). Acta Mechanica 176, 213–229 (2005).
DOI 10.1007/s00707-004-0205-z
[50] Magyari, E. and Pantokratoras, A. (2011): Note on the effect
of thermal radiation in the linearized Rosseland approximation
on the heat transfer characteristics of various boundary layer
flows. International Communications in Heat and Mass
Transfer 38: 554–556.
[51] Motsa, S. S. (2013): A new spectral local linearization method
for non-linear boundary layer flow problems. Hinduwai
Publishing Group: Journal of Applied Mathematics, Vol.
2013, 15 pages, http://dx.doi.org/10.1155/2013/423628.
[52] Otegbeye. O. (2014): On decoupled quasi-linearization
methods for solving systems of nonlinear boundary value
problems. M.Sc. Thesis, University of Kwazulu-Natal.
[53] Canuto, C., Hussaini, M. Y., Quarteroni, A., Thomas Jr, A.
(2012): Spectral methods in fluid dynamics. Springer Science
& Business Media, Berlin.
[54] Ishak, A. Nazar, R. and Pop. I. (2006). Mixed convection
boundary layers in the stagnation-point flow toward a
stretching vertical sheet. Meccanica 41:509–518.
DOI10.1007/s11012-006-0009-4.
[55] Singh, G., Makinde, O. D. (2013): MHD slip flow of viscous
fluid over an isothermal reactive stretching sheet. Annals of
Faculty of Engineering Hunedoara, Intl J of Eng, Vol 11(2):
41- 46.