Laminar heat transfer in porous ducts with variable suction

The steady, laminar heat transfer flow of a Newtonian, incompressible, constant property fluid along porous walled conduits is analysed for conditions of variable suction, or injection, through an open ended straight cylindrical tube and a flat duct formed by infinite parallel plates. The development of the velocity and temperature fields in the entrance region of the ducts are analysed for constant temperature and constant heat flux boundary conditions. The flowrate through the duct walls is assumed proportional to the difference of the internal and external pressures by using the law of Darcy for flow through porous media. The velocity, pressure, temperature and Nusselt number distributions are obtained for axial Reynolds number 1050 and 2100; radial Reynolds number in the range of -2 to 10; Prandtl number 0.7 and 7; and dimensionless permeability 4 x 10 to the -7 and 4 x 10 to the -9.