Paper presented to the 10th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Florida, 14-16 July 2014.
This work investigates the entropy generation in a steady
flow of two immiscible couple stress fluids in a horizontal
channel bounded by two porous beds at the bottom and top.
The flow is considered in FOUR zones: zone-IV contains the
flow of viscous fluid in the large porous bed with low
permeability at the bottom, zone-I and II contain free flow of
two immiscible couple stress fluids and zone-III contains the
flow of viscous fluid in the thin porous bed with high
permeability at the top. The flow is assumed to be governed by
Stokes’s couple stress fluid flow equations in the free channel.
In zone-IV, Darcy’s law together with the Beavers-Joseph (B-J)
slip condition at the interface is used whereas in zone-III
Brinkman’s model is used for flow. The plates of the channel
are maintained at constant temperatures higher than that of the
fluid. The closed form expressions for entropy generation
number and Bejan number are derived in dimensionless form
by using the expressions of velocity and temperature. The
effects of relevant parameters on velocity, temperature, entropy
generation number and Bejan number are analyzed and
presented through graphs.
