scholarly journals Computational analysis of viscous dissipation and joule-heating effects on non-Darcy MHD natural convection flow from a horizontal cylinder in porous media with internal heat generation

2014 ◽  
Vol 41 (1) ◽  
pp. 37-70 ◽  
Author(s):  
Ramachandra Prasad ◽  
Subba Rao ◽  
Anwar Bég
Keyword(s):  
Natural Convection ◽  
Heat Source ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Local Skin ◽  
Grashof Number ◽  
Dissipation Parameter ◽  
Local Skin Friction ◽  
Source Sink

In the present paper we examine the effects of viscous dissipation, Joule heating and heat source/sink on non-Darcy MHD natural convection heat transfer flow over permeable horizontal circular cylinder in a porous medium. The boundary layer equations, which are parabolic in nature, are normalized into non-similar form and then solved numerically with the well-tested, efficient, implicit, stable Keller-box finite difference scheme. A parametric study illustrating the influence of Darcy parameter (Da), Forchheimer parameter (?), Grashof number(Gr), heat source/sink parameter (?) and viscous dissipation parameter (Ec) on the fluid velocity, temperature as well as local skin-friction and Nusselt numbers is conducted Increasing Forchheimer inertial drag parameter (?) retards the flow considerably but enhances temperatures. Increasing viscous dissipation parameter(Ec) is found to elevate velocities i.e. accelerate the flow and increase temperatures. Increasing heat source/sink parameter (?) is found to elevate velocities and increase temperatures. Increasing the Grashof number (Gr) is found to elevate the velocity and decrease the temperatures. Local skin friction number is found to be increases with increasing heat source/sink parameter (?) where as Local Nusselt number is found to decrease with increasing heat source/sink parameter (?).

Effects of Viscous Dissipation and Joule Heating on Natural Convection Flow of a Viscous Fluid from Heated Vertical Wavy Surface

2011 ◽  
Vol 66 (6-7) ◽  
pp. 427-440 ◽  
Author(s):  
Nasser S. Elgazery ◽  
Nader Y. Abd Elazem
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Wavy Surface ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Local Skin Friction

A mathematical model will be analyzed in order to study the effects of viscous dissipation and Ohmic heating (Joule heating) on magnetohydrodynamic (MHD) natural convection flow of a temperature dependent viscosity from heated vertical wavy surface. The present physical problem is studied numerically by using the appropriate variables, which reduce the complex wavy surface into a flat one. An implicit marching Chebyshev collocation scheme is employed for the analysis. Numerical solutions are obtained for velocity, temperature, local skin friction, and Nusselt number for a selection of parameter sets consisting of Eckert number, Prandtl number, MHD variation, and amplitude-wavelength ratio parameter. Numerical results show that these parameters have significant influences on the velocity and the temperature profiles as well as for the local skin friction and Nusselt number

scholarly journals Viscous Dissipation Effects on MHD Natural Convection Flow along a Sphere

1970 ◽  
Vol 36 ◽  
pp. 44-48 ◽  
Author(s):  
Md. M Alam ◽  
MA Alim ◽  
Md. MK Chowdhury
Keyword(s):  
Nusselt Number ◽  
Natural Convection ◽  
Viscous Dissipation ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Local Skin ◽  
Boundary Layer Equations ◽  
Box Scheme ◽  
Dissipation Parameter ◽  
Local Skin Friction

In this paper, we describe the viscous dissipation effects in magnetohydrodynamic (MHD) natural convection flow on a sphere. The natural convection laminar flow from a sphere immersed in a viscous incompressible optically thin fluid in the presence of magnetic field has been investigated. The governing boundary layer equations are first transformed into a non-dimensional form and the resulting nonlinear system of partial differential equations are then solved numerically using a very efficient finite-difference method with Keller-box scheme. Here we have focused our attention on the evolution of shear stress in terms of the local skin friction and the rate of heat transfer in terms of local Nusselt number, velocity profiles as well as temperature profiles for some selected parameters consisting of magnetic parameter M, viscous dissipation parameter N and the Prandlt number Pr.Keywords: Viscous dissipation, magnetohydrodynamics, natural convection, Nusselt number. Journal of Mechanical Engineering Vol.36 Dec. 2006 pp.44DOI = 10.3329/jme.v36i0.810

Natural convection of fluid with variable viscosity and viscous dissipation from a heated vertical wavy surface in presence of magnetic field

2020 ◽  
Vol 17 (2) ◽  
pp. 101-113
Author(s):  
Nazma Parveen ◽  
M. A. Alim
Keyword(s):  
Magnetic Field ◽  
Nusselt Number ◽  
Natural Convection ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Local Nusselt Number ◽  
Variable Viscosity ◽  
Wavy Surface ◽  
Numerical Work ◽  
Dissipation Parameter

ABSTRACT   The present numerical work describes the effect of the temperature dependent variable viscosity and viscous dissipation on natural convection heat transfer boundary layer flow of a viscous incompressible electrically conducting fluid along a vertical wavy surface in presence of a transverse magnetic field. The wavy surface is maintained at uniform wall temperature that is higher than that of the ambient. A simple coordinate transformation is employed to transform the wavy surface into a flat plate. A marching finite difference scheme is used for present analysis. The numerical results, including the developments of the skin friction coefficients, the local Nusselt number, the streamlines as well as the isotherms are presented and discussed in detail. The results of this investigation illustrated that the skin friction coefficient increase with an increase of the variable viscosity and viscous dissipation parameter, while the local Nusselt number at the heated surface decrease with increasing values of variable viscosity, intensity of magnetic field and viscous dissipation parameter.

Second law analysis of MHD natural convection slip flow of Casson fluid through an inclined microchannel

2020 ◽  
Vol 16 (6) ◽  
pp. 1435-1455 ◽  
Author(s):  
B.J. Gireesha ◽  
A. Roja
Keyword(s):  
Heat Source ◽  
Viscous Dissipation ◽  
Entropy Generation ◽  
Joule Heating ◽  
Internal Heat ◽  
Internal Heat Source ◽  
Casson Fluid ◽  
Content Type ◽  
Flow Through ◽  
Source Sink

PurposeMicrofluidics is one of the interesting areas of the research in thermal and engineering fields due to its wide range of applications in a variety of heat transport problems such as micromixers, micropumps, cooling systems for microelectromechanical systems (MEMS) micro heat exchangers, etc. Lower cost with better thermal performance is the main objective of these devices. Therefore, in this study, the entropy generation in an electrically conducting Casson fluid flow through an inclined microchannel with hydraulic slip and the convective condition hves been numerically investigated. Aspects of viscous dissipation, natural convection, joule heating, magnetic field and uniform heat source/sink are usedDesign/methodology/approachSuitable non-dimensional variables are used to reduce the non-linear system of ordinary differential equations, and then this system is solved numerically using Runge-Kutta-Fehlberg fourth fifth order method along with shooting technique. The obtained numerical solutions of the fluid velocity and temperature are used to characterize the entropy generation and Bejan number. Also, the Nusselt number and skin friction coefficient for various values of parameters are examined in detail through graphs. The obtained present results are compared with the existing one which is perfectly found to be in good agreement.FindingsIt is established that the production of the entropy can be improved with the aspects of joule heating, viscous dissipation and internal heat source/sink. The entropy generation enhances for increasing values of Casson Parameter (β) and Biot number (Bi). Furthermore, it is interestingly noticed that the enhancement of Reynolds number and uniform heat source/sink shows the dual behaviour of the entropy generation due to significant influence of the viscous forces in the region close to the channel walls. It was observed that increasing behaviour of the heat transfer rate for enhancement values of the Eckert number and heat source/sink ratio parameter and the drag force are retarded with higher estimations of Reynolds number.Originality/valueEntropy generation analysis on MHD Casson fluid flow through an inclined microchannel with the aspects of convective, Joule heating, viscous dissipation, magnetism, hydraulic slip and internal heat source/sink has been numerically investigated.

Second law analysis on Hall effect of natural convection flow through vertical channel in the presence of uniform heat source/sink

2020 ◽  
Vol 30 (10) ◽  
pp. 4403-4423
Author(s):  
A. Roja ◽  
B.J. Gireesha
Keyword(s):  
Heat Flux ◽  
Heat Source ◽  
Viscous Dissipation ◽  
Joule Heating ◽  
Radiative Heat ◽  
Vertical Channel ◽  
Radiative Heat Flux ◽  
Content Type ◽  
Uniform Heat ◽  
Source Sink

Purpose Microfluidics is one of the extensive elaborated technologies in thermal and engineering fields due to its wide range of applications, such as micro heat exchangers, micro mixture and microchannel heat sinks, which is used to develop a large number of microscopic devices and systems. Enhancement of thermal energy using verity of nanoliquids is one of the challenges in these applications of microfluidics. Therefore, using single wall carbon nanotubes for enhancement of thermal energy in microchannel is the main purpose of this study. Hall effect of natural convection flow in a vertical channel with slip and temperature jump condition is considered. The impacts of radiative heat flux, uniform heat source/sink, viscous dissipation and joule heating are also taken into account. Design/methodology/approach Suitable non-dimension variables are applied to the governing equations to reduce the system into ordinary differential equations. The reduced nonlinear system is then solved numerically using Runge–Kutta–Fehlberg fourth–fifth-order method along with shooting technique. The impact of different pertinent parameters on numerical solutions of primary velocity, secondary velocity, temperature, entropy generation and Bejan number is comprehensively discussed in detail. Also, the obtained numerical results are compared with existing one which perfectly found to be in good agreement. Findings It is established that, with the aspects of Joule heating, viscous dissipation, radiative heat flux and uniform heat source/sink, the production in the entropy can be improved. Further, it is found that the increasing ratio of wall ambient temperature difference and nanoparticle volume fraction leads to enhance the entropy generation. The same effect reverses with increasing values of fluid wall interaction parameter (FWIP) and rare faction. The irreversibility ratio enhances with larger values of nanoparticle volume fraction and decelerates with increment values of FWIP. Originality/value The impact of single wall carbon nanoliquid in a vertical channel flow by using radiative heat flux, heat source/sink, joule heating and viscous dissipation is first time investigated. Further, the influence of Hall current is explored in detail.

MHD mixed convection flow of radiating and chemically reactive Casson nanofluid over a nonlinear permeable stretching sheet with viscous dissipation and heat source

2018 ◽  
Vol 14 (3) ◽  
pp. 609-630 ◽  
Author(s):  
Jayarami Reddy Konda ◽  
Madhusudhana N.P. ◽  
Ramakrishna Konijeti
Keyword(s):  
Nusselt Number ◽  
Heat Source ◽  
Skin Friction ◽  
Viscous Dissipation ◽  
Sherwood Number ◽  
Stretching Sheet ◽  
Radiation Chemical ◽  
Local Skin ◽  
Content Type ◽  
Casson Nanofluid

PurposeThe purpose of this paper is to discuss the flow of Casson nanofluid past a nonlinear permeable stretching sheet in the presence of thermal radiation, chemical reaction, viscous dissipation, heat source, and magnetohydrodynamics.Design/methodology/approachAppropriate transformations are used to convert the boundary layer equations into nonlinear ODEs which are then solved numerically by using the Runge-Kutta-Fehlberg fourth-fifth order method along with shooting technique.FindingsSolution of this systems is obtained for velocity, temperature, and concentration profiles. Graphical illustrations are added to discuss the effect of evolving parameters against above-mentioned distributions. Tabular values of local skin friction factor, local Nusselt number, and local Sherwood number are also added and studied accordingly.Originality/valueA good agreement of the present results has been observed by comparing with the existing literature results. It is noted that skin friction coefficient, Nusselt number, and Sherwood number decrease with Casson parameter and increase with suction parameter.

scholarly journals Simultaneous impacts of Joule heating and variable heat source/sink on MHD 3D flow of Carreau-nanoliquids with temperature dependent viscosity

2019 ◽  
Vol 8 (1) ◽  
pp. 356-367 ◽  
Author(s):  
J. V. Ramana Reddy ◽  
V. Sugunamma ◽  
N. Sandeep
Keyword(s):  
Heat Transfer ◽  
Heat Source ◽  
Joule Heating ◽  
Uniform Space ◽  
Weissenberg Number ◽  
Physical Parameters ◽  
Temperature Dependent ◽  
3D Flow ◽  
Temperature Dependent Viscosity ◽  
Source Sink

Abstract The 3D flow of non-Newtonian nanoliquid flows past a bidirectional stretching sheet with heat transfer is investigated in the present study. It is assumed that viscosity of the liquid varies with temperature. Carreau non-Newtonain model, Tiwari and Das nanofluid model are used to formulate the problem. The impacts of Joule heating, nonlinear radiation and non-uniform (space and temperature dependent) heat source/sink are accounted. Al-Cu-CH3OH and Cu-CH3OH are considered as nanoliquids for the present study. The solution of the problem is attained by the application of shooting and R.K. numerical procedures. Graphical and tabular illustrations are incorporated with a view of understanding the influence of various physical parameters on the flow field. We eyed that using of Al-Cu alloy nanoparticles in the carrier liquid leads to superior heat transfer ability instead of using only Aluminum nanoparticles. Weissenberg number and viscosity parameter have inclination to exalt the thermal field.

MHD Stagnation Point Flow over Exponentially Stretching Sheet with Exponentially Moving Free-Stream, Viscous Dissipation, Thermal Radiation and Non-Uniform Heat Source/Sink

2017 ◽  
Vol 11 ◽  
pp. 182-190
Author(s):  
Gauri Shenkar Seth ◽  
Rohit Sharma ◽  
B. Kumbhakar ◽  
R. Tripathi
Keyword(s):  
Heat Source ◽  
Stagnation Point ◽  
Viscous Dissipation ◽  
Free Stream ◽  
Transverse Magnetic ◽  
Stagnation Point Flow ◽  
Uniform Heat ◽  
Highly Nonlinear ◽  
Exponentially Stretching ◽  
Source Sink

An investigation is carried out for the steady, two dimensional stagnation point flow of a viscous, incompressible, electrically conducting, optically thick heat radiating fluid taking viscous dissipation into account over an exponentially stretching non-isothermal sheet with exponentially moving free-stream in the presence of uniform transverse magnetic field and non-uniform heat source/sink. The governing boundary layer equations are transformed into highly nonlinear ordinary differential equations using suitable similarity transform. Resulting boundary value problem is solved numerically with the help of 4th-order Runge-Kutta Gill method along with shooting technique. Effects of various pertinent flow parameters on the velocity, temperature field, skin friction and Nusselt number are described through figures and tables. Also, the present numerical results are compared with the earlier published results for some reduced case and a good agreement has been found among those results.

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