Heat transfer between a gas jet and a porous wall

The action of a jet on a porous wall is usually studied on the basis of filtration equations obtained by generalizing the Darcy law, and assuming that the pressure and heat flux at the porous surface are the same as at a nonporous wall. This approach does not take into consideration the influence of porosity on these parameters nor the inertial effects that may arise at high filtration rates. In the present paper, the equations which describe filtration are derived from the equations of motion of a two-phase medium, so that inertial effects may be accounted for in a natural way.