Thermal dispersion effects on forced convection in a parallel plate porous channel

Thermal dispersion effects on fully developed forced convection inside a porous-saturated parallel plates duct with uniform heat flux at the wall are investigated on the basis of the Brinkman model. Having known the velocity distribution, the energy equation is solved using asymptotic techniques for the limiting case when thermal conductivity, as a result of thermal dispersion, weakly changes with the Péclet number. A numerical solution, valid for the entire range of thermal dispersion conductivity, is also presented. This latter solution is performed to check the accuracy of the former one. It was seen that in the limiting regions the results of both methods are in close agreement with each other and also with those previously reported in the literature. Validity range for the presented closed form solution is also discussed as a function of the Péclet number.