| Abstract: | This paper is concerned with a equation, which is a model of filtration in partially saturated porous media, with mixed boundary condition of Dirichlet-Neumann type {∂_tb(u) - ∇ • a [∇u + k(b(u))] = f qquad in quad (0, ∞) × Ω u = h(t, x) qquad on quad (0, ∞) × Γ_0 v • a [∇u + k(b(u))] = g(t, x) qquad on quad (0, ∞) × Γ_1 We have proved that there exists one and only one periodic solution of the problem under the data f, g and h with same period. Moreover, we have proved that the unique periodic solution ω is asymptotically statble in the sense that for any solution u of the problem b(u(t)) - b(ω(t)) → 0qquad in L²(Ω) as t → ∞. |
