Natural MHD convection for an impulsively started infinite vertical plate with diffusion‐thermo effect, induced magnetic field, and ramped wall temperature and concentration

Heat Transfer ◽  
2021 ◽  
Author(s):  
Nazibuddin Ahmed ◽  
Dipunja Gohain
2014 ◽  
Vol 136 (4) ◽  
Author(s):  
N. Ahmed ◽  
M. Dutta

An exact solution to the problem of a magnetohydrodynamic viscous, incompressible free convective flow of an electrically conducting, Newtonian non-Gray fluid past a suddenly started infinite vertical plate with ramped wall temperature in presence of appreciable radiation heat transfer and uniform transverse magnetic field is presented. The fluid is assumed to be optically thin and the magnetic Reynolds number is considered small enough to neglect the induced hydromagnetic effects. The resulting system of the equations governing the flow is solved by adopting Laplace Transform technique in closed form. Detailed computations of the influence of Hartmann number, radiation conduction parameter Q, Reynolds number Re and time t on the variations in the fluid velocity, fluid temperature, and skin friction and Nusselt number at the plate are demonstrated graphically. The results show that the imposition of the transverse magnetic field retards the fluid motion and causes the viscous drag at the plate to fall. The investigation simulates that the fluid temperature drops and the rate of heat transfer from the plate to the fluid gets increased for increasing Reynolds number.


2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Naveed Khan ◽  
Farhad Ali ◽  
Muhammad Arif ◽  
Zubair Ahmad ◽  
Aamina Aamina ◽  
...  

The aim of this study is to investigate how heat and mass transfer impacts the unsteady incompressible flow of Maxwell fluid. An infinite vertical plate with ramped and isothermal wall temperature and concentration boundary conditions is considered with the Maxwell fluid. Furthermore, in this study, engine oil has been taken as a base fluid due to its enormous applications in modern science and technologies. To see the importance of nanofluids, we have suspended molybdenum disulfide in engine oil base fluid to enhance its heat transfer rate. To investigate the flow regime, the system of equations was derived in the form of partial differential equations. The exact solutions to the complex system are obtained using the Laplace transform technique. Graphically, the impact of different embedded parameters on velocity, temperature, and concentration distributions has been shown. Through using the graphical analysis, we were interested in comparing the velocity, temperature, and concentration profiles for ramped and isothermal wall temperature and concentration. The magnitude of velocity, temperature, and concentration distributions is greater for an isothermal wall and less for a ramped wall, according to our observations. We observed that adding molybdenum disulfide nanoparticles to the engine oil increased the heat transfer up to 12.899%. Finally, the corresponding skin friction, Nusselt number, and Sherwood number have been calculated and presented in a tabular form.


2013 ◽  
Vol 465-466 ◽  
pp. 149-154
Author(s):  
Marneni Narahari ◽  
Sowmya Tippa ◽  
Rajashekhar Pendyala

Theoretical analysis of unsteady magnetohydrodynamic free convection flow of a viscous incompressible radiative fluid past an infinite vertical plate with constant heat and mass flux is presented. The dimensionless governing linear partial differential equations have been solved using the Laplace transform technique. The exact solutions for the velocity, temperature and concentration fields are derived. The effects of radiation, magnetic field and buoyancy ratio parameters on the velocity and temperature fields are discussed through graphs. It is found that the velocity increases with increasing radiation parameter whereas it decreases with increasing magnetic field parameter for buoyancy assisted flows.


1991 ◽  
Vol 69 (12) ◽  
pp. 1451-1453 ◽  
Author(s):  
M. Y. Gokhale ◽  
V. M. Soundalgekar

A. magnetohydrodynamic transient-free convection flow of air past a semi-infinite vertical plate with a constant heat flux and a transversely applied uniform magnetic field is studied using the finite-difference method. The equations are solved by a computer using the Thomas algorithm. The transient temperature, transient velocity, average skin friction, and average Nusselt number are shown graphically. It is observed that the average skin friction and the average Nusselt number decrease owing to the application of the magnetic field. It also takes more time to reach a steady state when the magnetic field is present.


2016 ◽  
Vol 43 (1) ◽  
pp. 49-83 ◽  
Author(s):  
Raju Srinivasa ◽  
G. Aruna ◽  
Swamy Naidu ◽  
S.V.K. Varma ◽  
M.M. Rashidi

In this research paper, we found both numerical and analytical solutions for the effect of chemical reaction on unsteady, incompressible, viscous fluid flow past an exponentially accelerated vertical plate with heat absorption and variable temperature in a magnetic field. The flow problem is governed by a system of coupled non-linear partial differential equations with suitable boundary conditions. We have solved the governing equations by an efficient, accurate, powerful finite element method (FEM) as well as Laplace transform technique (LTT). The evaluation of the numerical results are performed and graphical results for the velocity, temperature and concentration profiles within the boundary layer are discussed. Also, the expressions for the skin-friction, Nusselt number and the Sherwood number coefficients have been derived and discussed through graphs and tabular forms for different values of the governing parameters.


2009 ◽  
Vol 14 (3) ◽  
pp. 345-356 ◽  
Author(s):  
G. Palani ◽  
U. Srikanth

An analysis is performed to study the MHD flow of an electrically conducting, incompressible, viscous fluid past a semi-infinite vertical plate with mass transfer, under the action of transversely applied magnetic field is carried out. The heat due to viscous dissipation and the induced magnetic field are assumed to be negligible. The dimensionless governing equations are unsteady, two-dimensional, coupled and non-linear partial differential equations. A most accurate, unconditionally stable and fast converging implicit finite difference scheme is used to solve the non-dimensional governing equations. The effects of external cooling (Gr > 0) of the plate by the free convection are studied.


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