Second Law Analysis of Boundary Layer Flow With Variable Fluid Properties

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
M. I. Afridi ◽  
M. Qasim ◽  
O. D. Makinde
Keyword(s):  
Boundary Layer ◽  
Differential Equations ◽  
Entropy Generation ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Nonlinear Partial Differential Equations ◽  
Entropy Generation Rate ◽  
Bejan Number ◽  
Entropy Generation Number ◽  
Layer Flow

An entropy generation analysis of steady boundary layer flow of viscous fluid with variable properties over an exponentially stretching sheet is presented. The basic nonlinear partial differential equations that govern the flow are reduced to ordinary differential equations by using appropriate transformations. Numerical solutions are obtained by using shooting technique along with Runge–Kutta method. Expressions for the dimensionless volumetric entropy generation rate (NG) and Bejan number are also obtained. The effects of different dimensionless emerging parameters on entropy generation number (NG) and Bejan number (Be) are investigated graphically in detail.

scholarly journals Slip Effects on Boundary Layer Flow and Heat Transfer Along a Stretching Cylinder

2013 ◽  
Vol 18 (2) ◽  
pp. 447-459 ◽  
Author(s):  
S. Mukhopadhyay ◽  
R.S.R Gorla
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Velocity Slip ◽  
Heat Equations ◽  
Stretching Cylinder ◽  
Linear Ordinary Differential Equations ◽  
Layer Flow

An axi-symmetric laminar boundary layer flow of a viscous incompressible fluid and heat transfer towards a stretching cylinder is presented. Velocity slip is considered instead of the no-slip condition at the boundary. Similarity transformations are used to convert the partial differential equations corresponding to the momentum and heat equations into non-linear ordinary differential equations. Numerical solutions of these equations are obtained by the shooting method. It is found that the velocity decreases with increasing the slip parameter. The skin friction as well as the heat transfer rate at the surface is larger for a cylinder compared to those for a flat plate.

scholarly journals Dual Solutions in the Boundary Layer Flow and Heat Transfer in the Presence of Thermal Radiation with Suction Effect

2018 ◽  
Vol 7 (4.33) ◽  
pp. 17
Author(s):  
Siti Nur Aisyah Azeman ◽  
. .
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Thermal Radiation ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Dual Solutions ◽  
Shooting Technique ◽  
Flow And Heat Transfer ◽  
Layer Flow

The dual solutions in the boundary layer flow and heat transfer in the presence of thermal radiation is quantitatively studied. The governing partial differential equations are derived into a system of ordinary differential equations using a similarity transformation, and afterward numerical solution obtained by a shooting technique. Dual solutions execute within a certain range of opposing and assisting flow which related to these numerical solutions. The similarity equations have two branches, upper or lower branch solutions, within a certain range of the mixed convection parameters. Further numerical results exist in our observations which enable to discuss the features of the respective solutions.  

scholarly journals Inherent irreversibility impacts on thermal boundary layer flow over a mobile plate with convective surface boundary conditions

2019 ◽  
Vol 5 (2) ◽  
pp. 45
Author(s):  
Sajjad Haider ◽  
Adnan Saeed Butt ◽  
Asif Ali ◽  
Yun-Zhang Li ◽  
Tufail Hussain
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Temperature Profile ◽  
Entropy Generation ◽  
Free Stream ◽  
Entropy Generation Rate ◽  
Surface Boundary ◽  
Entropy Generation Number ◽  
Surface Boundary Conditions ◽  
Layer Flow

<p class="abstract"><strong>Background:</strong> The irreversibility impacts on flow and heat transfer processes can be quantified through entropy analysis. It is a significant tool which can be utilized to deduce about the energy losses. The current study investigates the inherent irreversibility impacts during a flow of boundary layer and heat transfer on a mobile plate.</p><p class="abstract"><strong>Methods:</strong> The flow is examined under thermal radiation and convective heat conditions. The fundamental governing equations of flow and heat phenomenon are transmuted into ordinary differential equations by employing similarity transmutations and shooting technique is utilized in order to solve the resultant equations. The temperature and velocity profiles are acquired to reckon Bejan and entropy generation number. Pertinent results are elucidated graphically for the movement of plate and flow in same and opposite directions.  </p><p class="abstract"><strong>Results:</strong> A decline in temperature profile is noted with rise in values of <em>Pr</em> in both cases when the movement of surface and free stream is in similar and converse directions. A decrease in temperature is observed for both cases with increase in <em>N<sub>R</sub></em> while with the rise in Biot number <em>a</em>, the temperature profile also increases. Entropy generation rate near the surface is high in case when surface and free stream are moving in opposite directions as compared to case when they move in same directions.</p><p class="abstract"><strong>Conclusions:</strong> It is observed that irreversibility impacts are more remarkable when the movement of fluid and plate is in opposite direction. Moreover, irreversibility impacts of heat transfer are prominent in free stream region.</p><p class="abstract"> </p><br /><em></em>

scholarly journals The Effect of Heat Transfer on MHD Marangoni Boundary Layer Flow Past a Flat Plate in Nanofluid

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
D. R. V. S. R. K. Sastry ◽  
A. S. N. Murti ◽  
T. Poorna Kantha
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Convection Boundary Layer ◽  
Similarity Transformations ◽  
Layer Flow

The problem of heat transfer on the Marangoni convection boundary layer flow in an electrically conducting nanofluid is studied. Similarity transformations are used to transform the set of governing partial differential equations of the flow into a set of nonlinear ordinary differential equations. Numerical solutions of the similarity equations are then solved through the MATLAB “bvp4c” function. Different nanoparticles like Cu, Al2O3, and TiO2 are taken into consideration with water as base fluid. The velocity and temperature profiles are shown in graphs. Also the effects of the Prandtl number and solid volume fraction on heat transfer are discussed.

scholarly journals Analysis of Boundary Layer Flow and Heat Transfer along a Stretching Cylinder in a Porous Medium

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Swati Mukhopadhyay
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Porous Medium ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Heat Equations ◽  
Stretching Cylinder ◽  
Highly Nonlinear ◽  
Layer Flow

This paper presents an axi-symmetric laminar boundary layer flow of a viscous incompressible fluid and heat transfer towards a stretching cylinder embedded in a porous medium. The partial differential equations corresponding to the momentum and heat equations are converted into highly nonlinear ordinary differential equations with the help of similarity transformations. Numerical solutions of these equations are obtained by shooting method. It is found that the velocity decreases with increasing permeability parameter. The skin friction as well as the heat transfer rate at the surface is larger for a cylinder compared to a flat plate.

scholarly journals Higher Order Compact Finite Difference Schemes for Unsteady Boundary Layer Flow Problems

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
P. G. Dlamini ◽  
S. S. Motsa ◽  
M. Khumalo
Keyword(s):  
Boundary Layer ◽  
Finite Difference ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Nonlinear Partial Differential Equations ◽  
Finite Difference Schemes ◽  
Unsteady Boundary Layer ◽  
Compact Finite Difference ◽  
Flow Problems ◽  
Layer Flow

We investigate the applicability of the compact finite difference relaxation method (CFDRM) in solving unsteady boundary layer flow problems modelled by nonlinear partial differential equations. The CFDRM utilizes the Gauss-Seidel approach of decoupling algebraic equations to linearize the governing equations and solve the resulting system of ordinary differential equations using compact finite difference schemes. The CFDRM has only been used to solve ordinary differential equations modelling boundary layer problems. This work extends its applications to nonlinear partial differential equations modelling unsteady boundary layer flows. The CFDRM is validated on two examples and the results are compared to results of the Keller-box method.

Entropy Analysis of MHD Variable Thermal Conductivity Fluid Flow Past a Convectively Heated Stretching Cylinder

2018 ◽  
Vol 387 ◽  
pp. 244-259 ◽  
Author(s):  
Sanatan Das ◽  
Subhajit Chakraborty ◽  
Oluwole Daniel Makinde ◽  
Rabindra Nath Jana
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Entropy Generation ◽  
Numerical Solutions ◽  
Fluid Velocity ◽  
Convective Heating ◽  
Bejan Number ◽  
Stretching Cylinder ◽  
Entropy Analysis ◽  
Entropy Generation Number

The present study is related to entropy analysis during magnetohydrodynamic (MHD) boundary layer flow of a viscous incompressible electrically conducting fluid past a stretching cylinder with convective heating in the presence of a transverse magnetic field. The governing boundary layer equations in cylindrical form are simplified by means of appropriate similarity transformations. Numerical solutions with high precision are obtained using Runge-Kutta fourth order scheme with eminent shooting technique. The effects of the pertinent parameters on the fluid velocity, temperature, entropy generation number, Bejan number as well as the shear stress at the surface of the cylinder are discussed graphically and quantitatively. It is examined that due to the presence of magnetic field, entropy generation can be controlled and reduced. Bejan number is plotted to present a comparative analysis of entropy generation due to heat transfer and fluid friction. It is found that Bejan number is an increasing function of Biot number.

scholarly journals Similarity Solution of Marangoni Convection Boundary Layer Flow over a Flat Surface in a Nanofluid

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Norihan Md. Arifin ◽  
Roslinda Nazar ◽  
Ioan Pop
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Differential Equations ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Volume Fraction ◽  
Convection Boundary Layer ◽  
Flow And Heat Transfer ◽  
Different Types ◽  
Layer Flow

The problem of steady Marangoni boundary layer flow and heat transfer over a flat plate in a nanofluid is studied using different types of nanoparticles. The general governing partial differential equations are transformed into a set of two nonlinear ordinary differential equations using unique similarity transformation. Numerical solutions of the similarity equations are obtained using the Runge-Kutta-Fehlberg (RKF) method. Three different types of nanoparticles are considered, namely, Cu, Al2O3, and TiO2, by using water as a base fluid with Prandtl numberPr=6.2. The effects of the nanoparticle volume fractionϕand the constant exponentmon the flow and heat transfer characteristics are obtained and discussed.

Entropy Generation for Bypass Transitional Boundary Layers

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Richard S. Skifton ◽  
Ralph S. Budwig ◽  
John C. Crepeau ◽  
Tao Xing
Keyword(s):  
Boundary Layer ◽  
Pressure Gradient ◽  
Flat Plate ◽  
Entropy Generation ◽  
Boundary Layer Flow ◽  
Generation Rate ◽  
Entropy Generation Rate ◽  
Transitional Region ◽  
Bypass Transition ◽  
Layer Flow

The principal purpose of this study is to understand the entropy generation rate in bypass, transitional, boundary-layer flow better. The experimental work utilized particle image velocimetry (PIV) and particle tracking velocimetry (PTV) to measure flow along a flat plate. The flow past the flat plate was under the influence of a negligible “zero” pressure gradient, followed by the installation of an adverse pressure gradient. Further, the boundary layer flow was artificially tripped to turbulence (called “bypass” transition) by means of elevated freestream turbulence. The entropy generation rate was seen to behave similar to that of published computational fluid dynamics (CFD) and direct numerical simulation (DNS) results. The observations from this work show the relative decrease of viscous contributions to entropy generation rate through the transition process, while the turbulent contributions of entropy generation rate greatly increase through the same transitional flow. A basic understanding of entropy generation rate over a flat plate is that a large majority of the contributions come within a wall coordinate less than 30. However, within the transitional region of the boundary layer, a tradeoff between viscous and turbulent dissipation begins to take place where a significant amount of the entropy generation rate is seen out toward the boundary layer edge.

Compressibility Effects on the Extended Crocco Relation and the Thermal Recovery Factor in Laminar Boundary Layer Flow

2004 ◽  
Vol 126 (1) ◽  
pp. 32-41 ◽  
Author(s):  
B. W. van Oudheusden
Keyword(s):  
Boundary Layer ◽  
Prandtl Number ◽  
Pressure Gradient ◽  
Boundary Layer Flow ◽  
Numerical Solutions ◽  
Thermal Recovery ◽  
Recovery Factor ◽  
Perturbation Approach ◽  
Layer Flow ◽  
Compressibility Effects

The relation between velocity and enthalpy in steady boundary layer flow is known as the Crocco relation. It describes that for an adiabatic wall the total enthalpy remains constant throughout the boundary layer, when the Prandtl number (Pr) is one, irrespective of pressure gradient and compressibility. A generalization of the Crocco relation for Pr near one is obtained from a perturbation approach. In the case of constant-property flow an analytic expression is found, representing a first-order extension of the standard Crocco relation and confirming the asymptotic validity of the square-root dependence of the recovery factor on Prandtl number. The particular subject of the present study is the effect of compressibility on the extended Crocco relation and, hence, on the thermal recovery in laminar flows. A perturbation analysis for constant Pr reveals two additional mechanisms of compressibility effects in the extended Crocco relation, which are related to the viscosity law and to the pressure gradient. Numerical solutions for (quasi-)self-similar as well as non-similar boundary layers are presented to evaluate these effects quantitatively.

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