scholarly journals Effects of Nanolayer and Second Order Slip on Unsteady Nanofluid Flow Past a Wedge

Mathematics ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 1043 ◽  
Author(s):  
Zhu ◽  
Cao
Keyword(s):  
Friction Coefficient ◽  
Skin Friction ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
Second Order ◽  
Analysis Method ◽  
Similarity Transformations ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis ◽  
Fundamental Equations

This paper presents the study of unsteady nanofluids flow and heat transfer past a wedge with second order velocity slip and temperature jump. The model is modified by considering the existence of a nanolayer together with the effects of thermophoresis and Brownian motion. The fundamental equations were transformed into ordinary differential equations by a new set of similarity transformations and solved by using the homotopy analysis method (HAM). We determined that the error reached 10-6 and the effectiveness of HAM was attained. The influence of second-order slip on the fluid skin-friction coefficient was analyzed and we determined that the Nusselt number decreases and skin friction coefficient rises with an increase in the thickness of the nanolayer.

Effect of Velocity-Slip Boundary Conditions on Jeffery–Hamel Flow Solutions

2010 ◽  
Vol 77 (4) ◽  
Author(s):  
M. A. Al-Nimr ◽  
Vladimir A. Hammoudeh ◽  
M. A. Hamdan
Keyword(s):  
Friction Coefficient ◽  
Skin Friction ◽  
Flow Direction ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
Second Order ◽  
Slip Model ◽  
Wall Angle ◽  
First Order ◽  
Slip Boundary

In the present work, the Jeffery–Hamel flow problem has been studied using both first- and second-order velocity-slip models, and then compared with the no-slip model. The objectives are to observe the behavior of the flow predicted by the two slip models and to establish criteria for using the two velocity-slip models. The study concentrates on examining the effect of the change in the Knudsen number (Kn) on the velocity profiles, magnitude of slip at the wall, and skin friction coefficient. Assuming that a difference between the two slip models of the order of 10% or less justifies the use of the simple first-order model, the transitional Kn numbers have been found. These Kn numbers depend on the flow direction, being either inflow or outflow. Also, there are three distinct regions that specify where to use each of the no-slip, first-order, and second-order slip models. Further, the reversal of the flow has been investigated as a function of the Kn number and for different Re⋅α, where Re is Reynolds number and α is the wall angle. Using the second-order slip models, it is found that as the Kn number increases, reversal occurs at Re⋅α smaller than the 10.31 value at which flow reversal happens in the no-slip model, and increasing the Kn number leads to a reduction in the skin friction coefficient in all cases except when reversal occurs.

Hydromagnetic flow and heat transfer with various nanoparticle additives past a wedge with high order velocity slip and temperature jump

2017 ◽  
Vol 95 (5) ◽  
pp. 440-449 ◽  
Author(s):  
Qianfang Liu ◽  
Jing Zhu ◽  
Bandar Bin-Mohsin ◽  
Liancun Zheng
Keyword(s):  
Heat Transfer ◽  
Temperature Jump ◽  
Slip Flow ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
High Order ◽  
Solid Particles ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis ◽  
Fundamental Equations

Nanofluid slip flow with distinct solid particles past a wedge with convective surface and high order slip is discussed in this paper. The wedge model is modified by considering the effects of Brownian motion and thermophphoresis together with the high order velocity slip and temperature jump. In this study, the governing fundamental equations are first transformed into third-order ordinary differential equations and solved by using the homotopy analysis method (HAM). Through error analysis and comparison with previous research, the effectiveness of HAM is ascertained, and the crucial influence of nanoparticles and high-order slip on the fluid skin-friction coefficient and heat transfer coefficient is analyed. Thermophphoresis parameter and suction/injection parameter are found to cause an increase in velocity and temperature. The rate of heat transfer in the Cu–water nanofluid is found to be higher than the others.

Investigation Into the Similarity Solution for Boundary Layer Flows in Microsystems

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
Suhil Kiwan ◽  
M. A. Al-Nimr
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
Heat Transfer Characteristics ◽  
Boundary Layer Flows ◽  
Flow And Heat Transfer

An investigation toward the existence of a complete similarity solution for boundary layer flows under the velocity slip and temperature jump conditions is carried out. The study is limited to the boundary layer flows resulting from an arbitrary freestream velocity U(x)=Uoxm and wall temperature given by Tw−T∞=Cxn. It is found that a similar solution exists only for m=1 and n=0, which represents stagnation flow on isothermal surface. This case has been thoroughly investigated. The analysis showed that three parameters control the flow and heat transfer characteristics of the problem. These parameters are the velocity slip parameter K1, the temperature jump parameter K2, and Prandtl number. The effect of these parameters on the flow and heat transfer of the problem has been studied and presented. It is found that the slip velocity parameter affects both the flow and heat transfer characteristics of the problem. It is found that the skin friction coefficient decreases with increasing K1 and most of changes in the skin friction takes place in the range 0<K1<1. The skin friction coefficient is found to be related to K1 and Rex according to the relation: Cf=3.38Rex−0.5(K1+1.279)−0.8 for 0<K1<5 with an error of ±4%. On the other hand, the correlation between Nu, K1, K2, and Pr has been found by the equation Nu=[(0.449+1.142K11.06)∕(0.515+K11.06)](K2+1.489Pr−0.44)−1, for 0<K1, K2<5, 0.7≤Pr≤5 within a maximum error of ±3%.

scholarly journals MHD Flow of Nanofluid with Homogeneous-Heterogeneous Reactions in a Porous Medium under the Influence of Second-Order Velocity Slip

Mathematics ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 220 ◽  
Author(s):  
Fahd Almutairi ◽  
S.M. Khaled ◽  
Abdelhalim Ebaid
Keyword(s):  
Porous Medium ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Volume Fraction ◽  
Heterogeneous Reaction ◽  
Mhd Flow ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
Second Order ◽  
Heterogeneous Reactions

The influence of second-order velocity slip on the MHD flow of nanofluid in a porous medium under the effects of homogeneous-heterogeneous reactions has been analyzed. The governing flow equation is exactly solved and compared with those in the literature for the skin friction coefficient in the absence of the second slip, where great differences have been observed. In addition, the effects of the permanent parameters on the skin friction coefficient, the velocity, and the concentration have been discussed in the presence of the second slip. As an important result, the behavior of the skin friction coefficient at various values of the porosity and volume fraction is changed from increasing (in the absence of the second slip) to decreasing (in the presence of the second slip), which confirms the importance of the second slip in modeling the boundary layer flow of nanofluids. In addition, five kinds of nanofluids have been investigated for the velocity profiles and it is found that the Ag-water nanofluid is the lowest. For only the heterogeneous reaction, the concentration equation has been exactly solved, while the numerical solution is applied in the general case. Accordingly, a reduction in the concentration occurs with the strengthening of the heterogenous reaction and also with the increase in the Schmidt parameter. Moreover, the Ag-water nanofluid is of lower concentration than the Cu-water nanofluid. This is also true for the general case, when both of the homogenous and heterogenous reactions take place.

Hybrid nanofluid flow and heat transfer over a nonlinear permeable stretching/shrinking surface

2019 ◽  
Vol 29 (9) ◽  
pp. 3110-3127 ◽  
Author(s):  
Iskandar Waini ◽  
Anuar Ishak ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Local Nusselt Number ◽  
Skin Friction Coefficient ◽  
Hybrid Nanofluid ◽  
Content Type ◽  
Flow And Heat Transfer ◽  
Shrinking Surface

PurposeThis paper aims to investigate the steady flow and heat transfer of a Cu-Al2O3/water hybrid nanofluid over a nonlinear permeable stretching/shrinking surface with radiation effects. The surface velocity condition is assumed to be of the power-law form with an exponent of 1/3. The governing equations of the problem are converted into a system of similarity equations by using a similarity transformation.Design/methodology/approachThe problem is solved numerically using the boundary value problem solver (bvp4c) in Matlab software. The results of the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles are presented through graphs and tables for several values of the parameters. The effects of these parameters on the flow and heat transfer characteristics are examined and discussed.FindingsResults found that dual solutions exist for a certain range of the stretching/shrinking and suction parameters. The increment of the skin friction coefficient and reduction of the local Nusselt number on the shrinking sheet is observed with the increasing of copper (Cu) nanoparticle volume fractions for the upper branch. The skin friction coefficient and the local Nusselt number increase when suction parameter is increased for the upper branch. Meanwhile, the temperature increases in the presence of the radiation parameter for both branches.Originality/valueThe problem of Cu-Al2O3/water hybrid nanofluid flow and heat transfer over a nonlinear permeable stretching/shrinking surface with radiation effects is the important originality of the present study where the dual solutions for the flow reversals are obtained.

Flow and Heat Transfer of Nanofluids Over a Rotating Porous Disk with Velocity Slip and Temperature Jump

2015 ◽  
Vol 70 (5) ◽  
pp. 351-358 ◽  
Author(s):  
Chenguang Yin ◽  
Liancun Zheng ◽  
Chaoli Zhang ◽  
Xinxin Zhang
Keyword(s):  
Heat Transfer ◽  
Temperature Jump ◽  
Velocity Slip ◽  
Temperature Fields ◽  
Analysis Method ◽  
Governing Equations ◽  
Porous Disk ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis ◽  
Good Agreement

AbstractIn this article, we discuss the flow and heat transfer of nanofluids over a rotating porous disk with velocity slip and temperature jump. Three types of nanoparticles – Cu, Al2O3, and CuO – are considered with water as the base fluid. The nonlinear governing equations are reduced into ordinary differential equations by Von Karman transformations and solved using homotopy analysis method (HAM), which is verified in good agreement with numerical ones. The effects of involved parameters such as porous parameter, velocity slip, temperature jump, as well as the types of nanofluids on velocity and temperature fields are presented graphically and analysed.

scholarly journals MHD Flow and Heat Transfer in a Channel Bounded by a Shrinking Sheet and a Porous Medium Bed: Homotopy Analysis Method

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Dileep Singh Chauhan ◽  
Rashmi Agrawal
Keyword(s):  
Porous Medium ◽  
Mhd Flow ◽  
Temperature Fields ◽  
Shrinking Sheet ◽  
Analysis Method ◽  
Governing Equations ◽  
Similarity Transformations ◽  
Flow And Heat Transfer ◽  
Homotopy Analysis ◽  
Surface Similarity

MHD flow of viscous conducting fluid is considered between a shrinking sheet and a porous medium bed. Suction is applied at the upper shrinking sheet and its surface temperature is always maintained higher than the temperature of the lower porous bed surface. Similarity transformations and HAM are used to solve the governing equations for velocity and temperature fields. The effects of various pertinent parameters on the results are discussed graphically.

scholarly journals Magnetohydrodynamic Flow and Heat Transfer Over an Exponentially Stretching/Shrinking Sheet in Ferrofluids

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Nurfazila Rasli ◽  
Norshafira Ramli
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Differential Equations ◽  
Skin Friction ◽  
Skin Friction Coefficient ◽  
Magnetohydrodynamic Flow ◽  
Shrinking Sheet ◽  
Flow And Heat Transfer ◽  
Exponentially Stretching

In this research, the problem of magnetohydrodynamic flow and heat transfer over an exponentially stretching/shrinking sheet in ferrofluids is presented. The governing partial differential equations are transformed into nonlinear ordinary differential equations by applying suitable similarity transformations. These equations are then solved numerically using the shooting method for some pertinent parameters. For this research, the water-based ferrofluid is considered with three types of ferroparticles: magnetite, cobalt ferrite, and manganese-zinc ferrite. The numerical solutions on the skin friction coefficient, Nusselt number, velocity and temperature profiles influenced by the magnetic parameter, wall mass transfer parameter, stretching/shrinking parameter, and volume fraction of solid ferroparticle are graphically displayed and discussed in more details. The existences of dual solutions are noticeable for the stretching/shrinking case in a specific range of limit. For the first solution, an increasing number in magnetic and suction will also give an increment of skin friction coefficient and Nusselt number over stretching/shrinking sheet. For the skin friction coefficient only, it is showed a decreasing pattern after the intersection. Besides, the presence of ferroparticles in the fluids causes a high number of the fluid’s thermal conductivity and heat transfer rate.

Flow and Heat Transfer Over a Stretched Microsurface

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Suhil Kiwan ◽  
M. A. Al-Nimr
Keyword(s):  
Heat Transfer ◽  
Friction Coefficient ◽  
Flat Plate ◽  
Skin Friction ◽  
Convection Heat Transfer ◽  
Skin Friction Coefficient ◽  
Slip Parameter ◽  
Heat Transfer Characteristics ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

The convection heat transfer induced by a stretching flat plate has been studied. Similarity conditions are obtained for the boundary layer equations for a flat plate subjected to a power law temperature and velocity variations. It is found that a similarity solution exists only for a linearly stretching plate and only when the plate is isothermal. The analysis shows that three parameters control the flow and heat transfer characteristics of the problem. These parameters are the velocity slip parameter K1, the temperature slip parameter K2, and the Prandtl number. The effect of these parameters on the flow and heat transfer of the problem has been studied and presented. It is found that the slip velocity parameter affect both the flow and heat transfer characteristics of the problem. It is found that the skin friction coefficient decreases with increasing K1 and most of the changes in the skin friction takes place in the range 0<K1<1. A correlation between the skin friction coefficient and K1 and Rex has been found and presented. It is found that cf=23Rex−0.5(K1+0.64)−0.884 for 0<K1<10 with an error of ±0.8%. Other correlations between Nu and K1 and K2 has been found and presented in Eq. 28.

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