scholarly journals Heat source and sink effects on periodic mixed convection flow along the electrically conducting cone inserted in porous medium

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260845
Author(s):  
Asifa Ilya ◽  
Muhammad Ashraf ◽  
Aamir Ali ◽  
Zahir Shah ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Porous Medium ◽  
Finite Difference ◽  
Heat Source ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Current Density ◽  
Electrically Conducting ◽  
Source And Sink

The system of partial differential equations governing the unsteady hydromagnetic boundary-layer flow along an electrically conducting cone embedded in porous medium in the presence of thermal buoyancy, magnetic field, heat source and sink effects are formulated. These equations are solved numerically by using an implicit Finite-Difference Method. The effects of the various parameters that are source/sink parameter, porous medium parameter, Prandtl number, mixed convection parameter and magnetic Prandtl number on the velocity, temperature profiles, transverse magnetic field are predicted. The effects of heat source and sink parameter on the time-mean value as well as on transient skin friction; heat transfer and current density rate are delineated especially in each plot. The extensive results reveal the existence of periodicity and show that periodicity becomes more distinctive for source and sink in the case of the electrically conducting cone. As the source and sink contrast increases, the periodic convective motion is invigorated to the amplitude and phase angle as reflect in the each plot. The dimensionless forms of the set of partial differential equations is transform into primitive form by using primitive variable formulation and then are solved numerically by using Finite Difference Scheme which has given in literature frequently. Physical interpretations of the overall flow and heat transfer along with current density are highlighted with detail in results and discussion section. The main novelty of the obtained numerical results is that first we retain numerical results for steady part and then used in unsteady part to obtain transient skin friction, rate of heat transfer and current density. The intensity of velocity profile is increased for increasing values of porosity parameter Ω, the temperature and mass concentration intensities are reduced due heat source effects.

scholarly journals Periodic mixed convection flow along the surface of a thermally and electrically conducting cone

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 225-235
Author(s):  
Asifa Ilyas ◽  
Muhammad Ashraf
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Current Density ◽  
Magnetic Force ◽  
Convection Flow ◽  
Force Parameter ◽  
Mixed Convection Flow ◽  
Hydromagnetic Waves ◽  
Periodic Components

The main aim of the present work is to highlight the significances of periodic mixed convection flow and heat transfer characteristics along the surface of magnetized cone by exerting magnetic field exact at the surface of the cone. The numerical simulations of coupled non-dimensional equations are computed in terms of velocity field, temperature and magnetic field concentration and then used to examine the periodic components of skin friction, ?w, heat transfer, qw, and current density, jw, for various governing parameters. A nice periodic behavior of heat transfer qw is concluded for each value of mixed convection parameter, ?, but maximum periodicity is sketched at ? = 50. It is also computed that the lower value of magnetic Prandtl number ? = 0.1 gets poor amplitude in current density but highest amplitude is sketched for higher ? = 0.5. The behavior of heat and fluid-flow in the pres?ence of aligned magnetic field is associated with the phase angle and amplitude of oscillation. It is also noted that due to the increase in magnetic force parameter, ?, there are wave like disturbances generate within the fluid layers. These disturbances are basically hydromagnetic waves which becomes more prominent as the strength of magnetic force parameter is increased.

scholarly journals Periodic mixed convection flow along the surface of a thermally and electrically conducting cone

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 225-235
Author(s):  
Asifa Ilyas ◽  
Muhammad Ashraf
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Mixed Convection ◽  
Current Density ◽  
Magnetic Force ◽  
Convection Flow ◽  
Force Parameter ◽  
Mixed Convection Flow ◽  
Hydromagnetic Waves ◽  
Periodic Components

The main aim of the present work is to highlight the significances of periodic mixed convection flow and heat transfer characteristics along the surface of magnetized cone by exerting magnetic field exact at the surface of the cone. The numerical simulations of coupled non-dimensional equations are computed in terms of velocity field, temperature and magnetic field concentration and then used to examine the periodic components of skin friction, ?w, heat transfer, qw, and current density, jw, for various governing parameters. A nice periodic behavior of heat transfer qw is concluded for each value of mixed convection parameter, ?, but maximum periodicity is sketched at ? = 50. It is also computed that the lower value of magnetic Prandtl number ? = 0.1 gets poor amplitude in current density but highest amplitude is sketched for higher ? = 0.5. The behavior of heat and fluid-flow in the pres?ence of aligned magnetic field is associated with the phase angle and amplitude of oscillation. It is also noted that due to the increase in magnetic force parameter, ?, there are wave like disturbances generate within the fluid layers. These disturbances are basically hydromagnetic waves which becomes more prominent as the strength of magnetic force parameter is increased.

scholarly journals Thermal Radiation Effects on Hydromagnetic Mixed Convection Flow along a Magnetized Vertical Porous Plate

2010 ◽  
Vol 2010 ◽  
pp. 1-30 ◽  
Author(s):  
Muhammad Ashraf ◽  
S. Asghar ◽  
Md. Anwar Hossain
Keyword(s):  
Magnetic Field ◽  
Finite Difference ◽  
Finite Difference Method ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Difference Method ◽  
Porous Plate ◽  
Physical Parameters ◽  
Local Skin ◽  
Vertical Porous Plate

Aim of the present work is to investigate the effect of radiation on steady mixed convection boundary layer flow of viscous, incompressible, electrically conducting fluid past a semi-infinite magnetized vertical porous plate with uniform transpiration and variable transverse magnetic field along the surface. The equations governing the flow magnetic and temperature field are reduced to dimensionless convenient form using the free variable transformations and solved numerically by using finite difference method. Effects of physical parameters like Prandtl number, Pr, the conduction-radiation parameterRd, magnetic field parameterS, magnetic Prandtl numberPm, mixed convection parameterλ, and the surface temperature,θwon the local skin friction coefficientCfx, local Nusselt number,Nux, and coefficient of magnetic intensity,Mgxagainst the local transpiration parameterξare shown graphically. Later, the problem is analysed by using series solution for small and large values ofξ, and the results near and away from the leading edge are compared with numerical results obtained by finite difference method and found to be in good agreement.

scholarly journals Analysis of the Physical Behavior of the Periodic Mixed-Convection Flow around a Nonconducting Horizontal Circular Cylinder Embedded in a Porous Medium

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Muhammad Ashraf ◽  
Zia Ullah ◽  
Saqib Zia ◽  
Sayer O. Alharbi ◽  
Dumitru Baleanu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Fluid Flow ◽  
Partial Differential Equations ◽  
Circular Cylinder ◽  
Differential Equations ◽  
Mixed Convection ◽  
Skin Friction ◽  
Current Density ◽  
Horizontal Circular Cylinder

An oscillatory mixed-convection fluid flow mechanism across a nonconducting horizontal circular cylinder embedded in a porous medium has been computed. For this purpose, a model in the form of partial differential equations is formulated, and then, the governing equations of the dimensionless model are transformed into the primitive form for integration by using primitive variable formulation. The impact of emerging parameters such as porous medium parameter Ω , Richardson number λ , magnetic force parameter ξ , and Prandtl number Pr on skin friction, heat transfer, and current density is interpreted graphically. It is demonstrated that accurate numerical results can be obtained by the present method by treating nonoscillating and oscillating parts of coupled partial differential equations simultaneously. In this study, it is well established that the transient convective heat transfer, skin friction, and current density depend on amplitude and phase angle. One of the objects of the present study is to predict the mechanism of heat and fluid flow around different angles of a nonconducting horizontal circular cylinder embedded in a porous medium.

Pore Scale Numerical Investigation of Mixed Convection From an Isolated Heat Source in a Channel With a Porous Insert

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Vijayalakshmi Yerramalle ◽  
B. Premachandran ◽  
Prabal Talukdar
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Porous Medium ◽  
Heat Source ◽  
Mixed Convection ◽  
Numerical Simulations ◽  
Circular Cylinders ◽  
Channel Height ◽  
Heater Surface ◽  
Pore Scale

Abstract Mixed convection heat transfer in a channel filled with porous medium and containing an isolated heat source at the bottom wall is studied in this work. The porous medium is assumed to be made of circular cylinders and is placed only on the heater surface. Three different configurations of porous medium are considered in this study. Pore-scale numerical simulations are carried out using the exact geometry of porous medium. The same configuration is also investigated using the volume-averaged approximation. The temperature distribution of the heater surface obtained from the pore-scale numerical simulation is compared with the results obtained from the volume-averaged numerical simulation. Parametric studies are carried out by varying the material of the cylinders, the porosity, and the height of the porous medium. The effects of Grashof number and Reynolds number of the flow are also studied as part of this investigation. The results obtained from the pore-scale numerical simulations show that the presence of the porous medium leads to reduction in heat transfer, while the results obtained from the volume-averaged numerical simulations show an enhancement of heat transfer due to the presence of the porous medium on the heater surface. However, the pore-scale numerical simulation results show that the heat transfer enhancement is only possible if the channel height is completely filled with the selected porous medium.

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