Unsteady MHD natural convection flow of heat generating/absorbing fluid near a vertical plate with ramped temperature and motion

Abstract

This work investigates the unsteady natural convection flow of a viscous, incompressible and electrically conducting fluid near an infinite vertical plate with ramped temperature and ramped motion. A unified closed form solution is obtained for the velocity field and skin friction coefficient corresponding to the case when the magnetic field fixed relative to the fluid or the moving boundary. It is assumed that the boundary plate has a ramped temperature profile and ramped motion subject to a uniform transverse magnetic field under the supposition of negligible induced magnetic field. Exact solutions of energy and momentum equations are obtained using the Laplace transform techniques. Graphical representations are attained for different values of the Prandtl number, magnetic field and heat sink parameter. Results show that wall ramped temperature and ramped motion tend to decrease fluid temperature, velocity, Nusselt number and skin friction.

Influence of relative motion of magnetic field on time‐dependent MHD natural convection flow

“…Following the study by Lawal and Haruna, 11 the relevant dimensional boundary conditions governing the flow formation and heat transfer are presented as…”

“…Equations (15) and (16) are to be inverted to determine the temperature and velocity in time domain. Since these equations are difficult to invert in closed form, we use a numerical procedure used in Ellahi et al, 8 which is based on the Riemann-sum approximation.…”

“…Moreover, the various values of the nondimensional heat absorption parameter (A) and the corresponding values of annular gap are almost the same; other interesting investigations on MHD flow in an annulus under different physical and thermal conditions has been carried out by authors. [16][17][18][19][20][21][22][23][24][25][26] To the best of the authors' knowledge, no study has been reported concerning the combined effect of temperature-dependent heat generating/absorbing parameter, MHD, and ramped-like motion of the inner cylinder. The condition involving ramped-like cylindrical motion appears in aerodynamics and oil refinement industry.…”

Heat transfer in an unsteady vertical porous channel with injection/suction in the presence of heat generation

“…The evolution of entropy as a result of irreversibility can manifest in terms of entropy generation which is always against all thermal systems, for instance, energy storage, insulation, and geothermal energy system [8]. Since the temperature difference of entropy is dissipation, it can therefore be studied via thermodynamics second law [9]. The pioneering work of Bejan introduced the study of entropy within a vertical channel for different applications [10][11][12].…”

“…The possibility of a reduction of entropy generation in a viscous convection cooling system has been reported for a double face structure [9,14,16]. Several analyses have been conducted on the irreversibility of the entropy generation as a result of reactive flow in a channel [17][18][19][20][21][22][23][24][25][26][27].…”