THE WALL AND FREE PLUMES ABOVE A HORIZONTAL LINE SOURCE IN NON-DARCIAN POROUS-MEDIA

The natural convection flows from the wall and free plumes above a hor izontal heat line source in a non-Darcian porous medium are investigat ed. The non-Darcian convective, boundary viscous and inertia effects a rc all considered. The results indicate that the non-Darcian effects d ecrease the peak velocities and increase the maximum temperatures, and thicken the temperature boundary layer. In addition, the wall plume h as a lower peak velocity and a higher maximum temperature than the cor responding free plume. Moreover, solutions by using local similarity a nd local non-similarity methods overestimate the maximum temperature a nd peak velocity for both wall and free plume cases.