A Note on the Similar and Non-Similar Solutions of Powell-Eyring Fluid Flow Model and Heat Transfer over a Horizontal Stretchable Surface

2020 ◽  
Vol 401 ◽  
pp. 25-35
Author(s):  
Razi Khan ◽  
M. Zaydan ◽  
Abderrahim Wakif ◽  
B. Ahmed ◽  
R.L. Monaledi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Skin Friction ◽  
Power Law ◽  
Nonlinear Partial Differential Equations ◽  
Skin Friction Coefficient ◽  
Point Of View ◽  
Local Skin ◽  
Similarity Transformations ◽  
Similar Solutions

Deliberation on the dynamics of non-Newtonian fluids, most especially Powell-Eyring fluid flow can be described as an open question. In this investigation, the flow and heat transfer characteristics are examined numerically by means of similarity analysis for a Powell-Eyring fluid moving over an isothermal stretched surface along the horizontal direction, whose velocity varies nonlinearly as a function of and follows a specified power-law degree formula. In order to solve the problem under consideration, the resulting system of coupled nonlinear partial differential equations with their corresponding boundary conditions is transformed into a correct similar form by utilizing appropriate similarity transformations, which are exceptionally acceptable for a particular form of the power-law stretching velocity, whose exponent is equal to . From the mathematical point of view, the similar equations of the studied flow cannot be obtained for any form of the power-law surface stretching velocity. As a result, it was found that the use of a general power-law stretching velocity results in non-similar equations. Also, appropriate numerical methods for similar and non-similar equations are used to discuss the results of engineering significance. Furthermore, correlation expressions for the skin friction and Nusselt number have been derived by applying the linear regression on the data outputted from the used computational methods.On the contrary to the heat transfer rate, it was found that the local skin friction coefficient is a decreasing property of power-law stretching.

Coupling Effects of Viscous Sheet and Ambient Fluid on Boundary Layer Flow and Heat Transfer in Power-Law Fluids

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Xiaochuan Liu ◽  
Liancun Zheng ◽  
Goong Chen ◽  
Lianxi Ma
Keyword(s):  
Heat Transfer ◽  
Power Law ◽  
Numerical Solutions ◽  
Skin Friction Coefficient ◽  
Similarity Solutions ◽  
Temperature Fields ◽  
Ambient Fluid ◽  
Local Skin ◽  
Flow And Heat Transfer ◽  
Power Law Fluids

This paper investigates the flow and heat transfer of power-law fluids over a stretching sheet where the coupling dynamics influence of viscous sheet and ambient fluid is taken into account via the stress balance. A modified Fourier's law is introduced in which the effects of viscous dissipation are taken into account by assuming that the thermal conductivity is to be shear-dependent on the velocity gradient. The conditions for both velocity and thermal boundary layers admitting similarity solutions are found, and numerical solutions are computed by a Bvp4c program. The results show that the viscous sheet and rheological properties of ambient fluids have significantly influences on both velocity and temperature fields characteristics. The formation of sheet varies with the viscosity of fluid and draw ratio, which then strongly affects the relations of the local skin friction coefficient, the local Nusselt number, and the generalized Reynolds number. Moreover, for specified parameters, the flow and heat transfer behaviors are discussed in detail.

scholarly journals IMPACT OF SUCTION/INJECTION AND HEAT TRANSFER ON UNSTEADY MHD FLOW OVER A STRETCHABLE ROTATING DISK

2020 ◽  
Vol 50 (3) ◽  
pp. 159-165
Author(s):  
K. V. Prasad ◽  
Hanumesh Vaidya ◽  
O D Makinde ◽  
Kuppalapalle Vajravelu ◽  
V Ramajini
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Nonlinear Partial Differential Equations ◽  
Mhd Flow ◽  
Rotating Disk ◽  
Skin Friction Coefficient ◽  
Convective Boundary ◽  
Optimal Homotopy Analysis Method ◽  
Similarity Transformations

In this article, the unsteady magnetohydrodynamic two-dimensional boundary layer flow and heat transfer over a stretchable rotating disk with mass suction/injection is investigated. Temperature-dependent physical properties and convective boundary conditions are taken into account. The governing coupled nonlinear partial differential equations are transformed into a system of ordinary differential equations by adopting the well-known similarity transformations. Further, the solutions are obtained through the semi-analytical method called an Optimal Homotopy Analysis Method (OHAM). The obtained results are discussed graphically to predict the features of the involved key parameters which are monitoring the flow model. The skin friction coefficient and Nusselt number are also examined. The validation of the present work is verified with the earlier published results and is found to be in excellent agreement. It is noticed that an increase in the viscosity parameter leads to decay in momentum boundary layer thickness, and the inverse trend is observed in the case of the temperature profile.

scholarly journals Unsteady Hydromagnetic Flow of Radiating Fluid Past a Convectively Heated Vertical Plate with the Navier Slip

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
O. D. Makinde ◽  
M. S. Tshehla
Keyword(s):  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Vertical Plate ◽  
Fluid Velocity ◽  
Nonlinear Partial Differential Equations ◽  
Skin Friction Coefficient ◽  
Newtonian Heating ◽  
Local Skin ◽  
Navier Slip

This paper investigates the unsteady hydromagnetic-free convection of an incompressible electrical conducting Boussinesq’s radiating fluid past a moving vertical plate in an optically thin environment with the Navier slip, viscous dissipation, and Ohmic and Newtonian heating. The nonlinear partial differential equations governing the transient problem are obtained and tackled numerically using a semidiscretization finite difference method coupled with Runge-Kutta Fehlberg integration technique. Numerical data for the local skin friction coefficient and the Nusselt number have been tabulated for various values of parametric conditions. Graphical results for the fluid velocity, temperature, skin friction, and the Nusselt number are presented and discussed. The results indicate that the skin friction coefficient decreases while the heat transfer rate at the plate surface increases as the slip parameter and Newtonian heating increase.

Flow and Heat Transfer in a Newtonian Nanoliquid due to a Curved Stretching Sheet

2017 ◽  
Vol 72 (9) ◽  
pp. 833-842 ◽  
Author(s):  
Pradeep Ganapathi Siddheshwar ◽  
Meenakshi Nerolu ◽  
Igor Pažanin
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Differential Equations ◽  
Skin Friction ◽  
Stretching Sheet ◽  
Volume Fraction ◽  
Nonlinear Partial Differential Equations ◽  
Skin Friction Coefficient ◽  
Variable Coefficients

AbstractFlow of a Newtonian nanoliquid due to a curved stretching sheet and heat transfer in it is studied. The governing nonlinear partial differential equations are reduced to nonlinear ordinary differential equations with variable coefficients by using a similarity transformation. The flow characteristics are studied using plots of flow velocity components and the skin-friction coefficient as a function of suction-injection parameter, curvature, and volume fraction. Prescribed surface temperature and prescribed surface heat flux are considered for studying the temperature distribution in the flow. The thermophysical properties of 20 nanoliquids are considered in the investigation by modeling them through the use of phenomenological laws and mixture theory. The results of the corresponding problem involving a plane stretching sheet is obtained as a particular case of those obtained in the present paper. Skin friction coefficient and Nusselt number are evaluated and it is observed that skin friction coefficient decreases with concentration of nanoparticles in the absence as well as presence of suction where as Nusselt number increases with increase in concentration of nanoparticles in a dilute range.

Mixed Thermal Convection of Power-Law Fluids Past Bodies With Uniform Fluid Injection or Suction

1990 ◽  
Vol 112 (1) ◽  
pp. 151-156 ◽  
Author(s):  
T.-Y. Wang ◽  
C. Kleinstreuer
Keyword(s):  
Heat Transfer ◽  
Skin Friction ◽  
Power Law ◽  
Viscosity Index ◽  
Fluid Injection ◽  
Local Skin ◽  
Power Law Fluids ◽  
Local Skin Friction ◽  
Transfer Group ◽  
Cylinders And Spheres

Steady laminar flow of power-law fluids past heated two-dimensional or axisym-metric bodies is strongly influenced by the rate of fluid mass transfer at the wall, the buoyancy force, and the characteristics of the power-law fluid. The effects of these parameters on the local skin friction group and heat transfer group are analyzed for wedges of different angles, horizontal cylinders, and spheres. The local heat transfer group, HTG~Nux, for wedge flows is greatly affected by the power-law viscosity index n, and by fluid withdrawal especially when the generalized Prandtl number is relatively high. Fluid suction at larger Prandtl numbers also generates high HTG values for cylinders and spheres. However, the local skin friction group, SFG~Cf, for cylinders or spheres increases with fluid injection and decreases with suction largely because of buoyancy effects.

scholarly journals Turbulent flow and heat transfer characteristics in U-tubes: A numerical study

2009 ◽  
Vol 13 (4) ◽  
pp. 175-181 ◽  
Author(s):  
Khalid Alammar
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Turbulent Flow ◽  
Skin Friction ◽  
Skin Friction Coefficient ◽  
Heat Transfer Characteristics ◽  
Local Skin ◽  
Transfer Characteristics ◽  
Flow And Heat Transfer

Using the standard k-e model, 3-dimensional turbulent flow and heat transfer characteristics in U-tubes are investigated. Uncertainty is approximated using experimental correlations and grid independence study. Increasing the Dean number is shown to intensify a secondary flow within the curved section. The overall Nusselt number for the tube is found to decrease substantially relative to straight tubes, while the overall skin friction coefficient remains practically unaffected. Local skin friction coefficient, Nusselt number, and wall temperature along the tube wall are presented.

The Effects of Thermocapillarity on the Thin Film Flow of MHD UCM Fluid over an Unsteady Elastic Surface with Convective Boundary Conditions

2019 ◽  
Vol 6 (3) ◽  
Author(s):  
Hanumesh Vaidya ◽  
K.V. Prasad ◽  
K. Vajravelu ◽  
Chiu-On Ng ◽  
S. Nadeem ◽  
...  
Keyword(s):  
Skin Friction ◽  
Velocity Slip ◽  
Convective Boundary Condition ◽  
Skin Friction Coefficient ◽  
Thin Film Flow ◽  
Convective Boundary ◽  
Local Skin ◽  
Similarity Transformations ◽  
Keller Box Method ◽  
Ucm Fluid

The study of two-dimensional flow and heat transfer in a liquid film of MHD Upper Convective Maxwell (UCM) fluid over an unsteady elastic stretching sheet subject to velocity slip and convective boundary condition is presented. Thermocapillarity effects are considered. Using suitable similarity transformations, the momentum and thermal energy equations are converted to a set of coupled nonlinear ordinary differential equations. These equations are solved numerically using the Keller-Box method. The velocity and the temperature distributions are presented graphically for different values of the pertinent parameters. The effects of the unsteady parameter on the skin friction, the wall temperature gradient, and the film thickness are tabulated and analyzed. The thermocapillarity parameter has a decreasing effect on the temperature field and the local skin-friction coefficient.

scholarly journals Heat Transfer Improvement in a Double Backward-Facing Expanding Channel Using Different Working Fluids

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1088 ◽  
Author(s):  
Tuqa Abuldrazzaq ◽  
Hussein Togun ◽  
Hamed Alsulami ◽  
Marjan Goodarzi ◽  
Mohammad Reza Safaei
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Nusselt Number ◽  
Friction Coefficient ◽  
Skin Friction ◽  
Thermal Performance ◽  
Skin Friction Coefficient ◽  
Local Skin ◽  
Heat Transfer Improvement ◽  
Expanding Channel

This paper reports a numerical study on heat transfer improvement in a double backward-facing expanding channel using different convectional fluids. A finite volume method with the k-ε standard model is used to investigate the effects of step, Reynolds number and type of liquid on heat transfer enhancement. Three types of conventional fluids (water, ammonia liquid and ethylene glycol) with Reynolds numbers varying from 98.5 to 512 and three cases for different step heights at a constant heat flux (q = 2000 W/m2) are examined. The top wall of the passage and the bottom wall of the upstream section are adiabatic, while the walls of both the first and second steps downstream are heated. The results show that the local Nusselt number rises with the augmentation of the Reynolds number, and the critical effects are seen in the entrance area of the first and second steps. The maximum average Nusselt number, which represents the thermal performance, can be seen clearly in case 1 for EG in comparison to water and ammonia. Due to the expanding of the passage, separation flow is generated, which causes a rapid increment in the local skin friction coefficient, especially at the first and second steps of the downstream section for water, ammonia liquid and EG. The maximum skin friction coefficient is detected in case 1 for water with Re = 512. Trends of velocities for positions (X/H1 = 2.01, X/H2 = 2.51) at the first and second steps for all the studied cases with different types of convectional fluids are indicated in this paper. The presented findings also include the contour of velocity, which shows the recirculation zones at the first and second steps to demonstrate the improvement in the thermal performance.

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