Boundary value problem with unbounded, fast oscillatory random flows

We use Tartar's weak convergence method in conjunction with a variational principle to prove a sharp homogenization theorem for diffusion in steady random flows. The flow has a stationary and square integrable stream matrix. The key of our approach is introducing approximate correctors by means of a saddle point variational principle. We also obtain the two-term asymptotics. (C) 1998 Academic Press.