  In this paper, we consider the homogenization problems for evolutionary
incompressible Navier-Stokes system in three dimensional domains perforated
with a large number of small holes which are periodically located. We first
establish certain uniform estimates for the weak solutions. To overcome the
extra difficulties coming from the time derivative, we use the idea of Temam
and consider the equations by integrating in time variable. After suitably
extending the weak solutions to the whole domain, we employ the generalized
cell problem to study the limit process.
