Numerical simulations of the Stokes boundary layer over a three-dimens
ional wavy wall are performed in order to investigate the role played
by infinitesimal wall imperfections in triggering transition to turbul
ence. Our results show flow patterns qualitatively similar to those ex
perimentally detected. In particular the laminar, disturbed-laminar an
d intermittent turbulent regimes are recovered. The characteristics of
the above flow regimes are analyzed. (C) 1996 American Institute of P
hysics.