Title: Bingham flow in porous media with obstacles of different size,
Abstract: By using the unfolding operators for periodic homogenization, we give a
general compactness result for a class of functions defined on bounded domains
presenting perforations of two different size. Then we apply this result to the
homogenization of the flow of a Bingham fluid in a porous medium with solid
obstacles of different size. Next we give the interpretation of the limit
problem in term of a non linear Darcy law.