Unsteady thermal boundary layer flows of a Bingham fluid in a porous medium

Abstract

In this paper we consider some unsteady free convection flows of a Bingham fluid when it saturates a porous medium. These flows are induced by suddenly raising the constant temperature of a vertical bounding surface from that of the uniform ambient value to a new constant level. As time progresses heat conducts inwards and this induces flow. We consider both a semi-infinite domain and a vertical channel of finite width. Of interest here are (i) how the presence of yield surfaces alters the classical results for Newtonian flows and (ii) the manner in which the locations of the yield surfaces change as time progresses.

Unsteady thermal boundary layer flows of a Bingham fluid in a porous medium following a sudden change in surface heat flux

“…The present paper considers the unsteady unidirection convection which is set up by suddenly changing the boundary heat flux of a vertical surface. This is a natural extension to the work of Rees and Bassom [8] who studied an impulisive change in the boundary temperature. We will see that the final outcome here has many qualititative differences from those found in [8].…”

EMHD Laminar Flow of Bingham Fluid Between Two Parallel Riga Plates

“…The slow spreading of a sheet of Bingham fluid on an inclined plane, Hall impact and heat transfer about unsteady MHD Couette flow, numerical simulation of Taylor Couette flow, Couette-Poiseuille flow, explicit equations for laminar flow including or excluding suction, injection, slip condition through parallel plate or porous parallel plates or in a channel have been reviewed [11][12][13][14][15][16]. The MHD Couette flow including thermal radiation, laminar flow with suction and Hall current as well as Ion-slip, unsteady boundary layer flows in a porous medium, viscous incompressible flow including Hall current and MHD two-phase Couette flow for the Bingham fluid through parallel plates or moving plates with heat source and viscous dissipation have been numerically studied [17][18][19][20][21][22][23]. For Bingham Plastic, the circular heat and solute source within a viscoplastic porous enclosure: the critical source dimension for optimum transfers has been considered by [24].…”

The Effect of Internal and External Heating on the Free Convective Flow of a Bingham Fluid in a Vertical Porous Channel

“…Much depends on the competing effects of the internal and external heating mechanisms and how these interact with the yield threshold. This work is part of a study of different aspects of porous channel and boundary layer flows involving Bingham fluids; see Rees and Bassom [9][10][11]. These earlier works consider the unsteady evolution of yield surfaces in such flows.…”