scholarly journals Entropy generation analysis of free convection from a constant temperature vertical plate using similarity solution

2016 ◽  
Vol 20 (6) ◽  
pp. 1855-1866 ◽  
Author(s):  
Mohammad Mohaghegh ◽  
Esfahani Abolfazli
Keyword(s):  
Boundary Layer ◽  
Exact Solution ◽  
Differential Equations ◽  
Free Convection ◽  
Constant Temperature ◽  
Entropy Generation ◽  
Similarity Solution ◽  
Integral Method ◽  
Vertical Plate ◽  
Thermal Entropy

This paper presents a similarity solution analysis of entropy generation due to heat transfer and fluid flow which has been carried out for laminar free convection from a constant temperature vertical plate in an infinite quiescent fluid. The governing partial differential equations are transformed into a set of ordinary differential equations using similarity variables. So an analytical expression, in terms of entropy generation, entropy generation number, Bejan number and irreversibility distribution ratio are derived using velocity and temperature similarity (exact) solution. The rate of entropy generation is investigated and discussed in details. The results presented by the similarity solution are compared with integral method results. The similarity solution presents more appropriate and correct distribution of entropy generation in boundary layer because more accuracy than integral method. It shows true position of maximum entropy generation and value of it. Also, the result shows that the exact solution minimizes the rate of total entropy generation in the boundary layer compared to integral solution. By introducing group parameter (GP number) which is the ratio of friction entropy to thermal entropy generation, one can recognize that one of the thermal entropy and friction entropy generation is dominated in the boundary layer.

Impact of Entropy Generation on Stagnation-Point Flow of Sutterby Nanofluid: A Numerical Analysis

2016 ◽  
Vol 71 (9) ◽  
pp. 837-848 ◽  
Author(s):  
Ehtsham Azhar ◽  
Z. Iqbal ◽  
E.N. Maraj
Keyword(s):  
Boundary Layer ◽  
Differential Equations ◽  
Stagnation Point ◽  
Entropy Generation ◽  
Computational Analysis ◽  
Similarity Transformation ◽  
Nonlinear Partial Differential Equations ◽  
Stagnation Point Flow ◽  
Physical Parameters ◽  
Stretching Plate

AbstractThe present article dicusses the computational analysis of entropy generation for the stagnation-point flow of Sutterby nanofluid over a linear stretching plate. The Sutterby fluid is chosen to study the effect for three major classes of non-Newtonian fluids, i.e. pseudoplastic, Newtonian, and dilatant. The effects of pertinent physical parameters are examined under the approximation of boundary layer. The system of coupled nonlinear partial differential equations is simplified by incorporating suitable similarity transformation into a system of non-linear-coupled ordinary differential equations. Entropy generation analysis is conducted numerically, and the results are displayed through graphs and tables. Significant findings are listed in the closing remarks.

scholarly journals Effects of Hall current on unsteady hydromagnetic free convection flow past an impulsively moving vertical plate with Newtonian heating

2016 ◽  
Vol 21 (1) ◽  
pp. 187-203 ◽  
Author(s):  
G.S. Seth ◽  
S. Sarkar ◽  
R. Sharma
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Free Convection ◽  
Vertical Plate ◽  
Numerical Solutions ◽  
Hall Current ◽  
Convection Flow ◽  
Free Convection Flow ◽  
Partial Differential ◽  
Present Solution

Abstract An investigation of unsteady hydromagnetic free convection flow of a viscous, incompressible and electrically conducting fluid past an impulsively moving vertical plate with Newtonian surface heating embedded in a porous medium taking into account the effects of Hall current is carried out. The governing partial differential equations are first subjected to the Laplace transformation and then inverted numerically using INVLAP routine of Matlab. The governing partial differential equations are also solved numerically by the Crank-Nicolson implicit finite difference scheme and a comparison has been provided between the two solutions. The numerical solutions for velocity and temperature are plotted graphically whereas the numerical results of skin friction and the Nusselt number are presented in tabular form for various parameters of interest. The present solution in special case is compared with a previously obtained solution and is found to be in excellent agreement.

Buoyancy Effects on Thermal Boundary Layer Over a Vertical Plate With a Convective Surface Boundary Condition

2010 ◽  
Vol 132 (4) ◽  
Author(s):  
O. D. Makinde ◽  
P. O. Olanrewaju
Keyword(s):  
Boundary Layer ◽  
Boundary Condition ◽  
Differential Equations ◽  
Vertical Plate ◽  
Nonlinear Partial Differential Equations ◽  
Integration Scheme ◽  
Surface Boundary ◽  
Thermal Buoyancy ◽  
Interface Characteristics ◽  
Surface Boundary Condition

This study aims to analyze the effects of thermal buoyancy on the laminar boundary layer about a vertical plate in a uniform stream of fluid under a convective surface boundary condition. Using a similarity variable, the governing nonlinear partial differential equations have been transformed into a set of coupled nonlinear ordinary differential equations, which are solved numerically by applying shooting iteration technique together with fourth-order Runge–Kutta integration scheme. The variations in dimensionless surface temperature and fluid-solid interface characteristics for different values of Prandtl number (Pr), local Grashof number Grx, and local convective heat transfer parameter Bix are graphed and tabulated. A comparison with previously published results on special case of the problem shows excellent agreement.

scholarly journals MHD Laminar Boundary Layer Flow of a Jeffrey Fluid Past a Vertical Plate Influenced by Viscous Dissipation and a Heat Source/Sink

Mathematics ◽  
2021 ◽  
Vol 9 (16) ◽  
pp. 1896
Author(s):  
Hillary Muzara ◽  
Stanford Shateyi
Keyword(s):  
Boundary Layer ◽  
Differential Equations ◽  
Heat Source ◽  
Viscous Dissipation ◽  
Laminar Boundary Layer ◽  
Boundary Layer Flow ◽  
Vertical Plate ◽  
Jeffrey Fluid ◽  
Physical Parameters ◽  
Layer Flow

This study investigates the effects of viscous dissipation and a heat source or sink on the magneto-hydrodynamic laminar boundary layer flow of a Jeffrey fluid past a vertical plate. The governing boundary layer non-linear partial differential equations are reduced to non-linear ordinary differential equations using suitable similarity transformations. The resulting system of dimensionless differential equations is then solved numerically using the bivariate spectral quasi-linearisation method. The effects of some physical parameters that include the Schmidt number, Eckert number, radiation parameter, magnetic field parameter, heat generation parameter, and the ratio of relaxation to retardation times on the velocity, temperature, and concentration profiles are presented graphically. Additionally, the influence of some physical parameters on the skin friction coefficient, local Nusselt number, and the local Sherwood number are displayed in tabular form.

scholarly journals A note on the non-inertial similarity solution for von Kármán swirling flow

2020 ◽  
pp. 2150030
Author(s):  
Madeleine L. Combrinck
Keyword(s):  
Boundary Layer ◽  
Partial Differential Equations ◽  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Similarity Solution ◽  
Shooting Method ◽  
Swirling Flow ◽  
Boundary Layer Equations ◽  
Von Karman ◽  
Von Kármán

This note proposes a non-inertial similarity solution for the classic von Kármán swirling flow as perceived from the rotational frame. The solution is obtained by implementing non-inertial similarity parameters in the non-inertial boundary layer equations. This reduces the partial differential equations to a set of ordinary differential equations that is solved through an integration routine and shooting method.

Investigation of Hot Film Calibration for Entropy Generation Rate Calculations

2002 ◽  
Author(s):  
R. Mahon ◽  
P. Frawley ◽  
M. R. D. Davies
Keyword(s):  
Boundary Layer ◽  
Numerical Methods ◽  
Circular Cylinder ◽  
Constant Temperature ◽  
Entropy Generation ◽  
Cross Flow ◽  
Entropy Generation Rate ◽  
Hot Wire ◽  
Hot Film ◽  
The Relationship

The objective of this paper is to investigate in detail the relationship between results obtained from flow over a circular cylinder in cross flow using Hot Film and Hot Wire Constant Temperature Anemometry (C.T.A.). The experimental results are compared with those obtained using numerical methods. The results obtained from Hot Wire Anemometry are used to attempt to calibrate the Hot Film Sensors for the purpose of evaluating entropy generation rates in the boundary layer of the cylinder.

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