R. ATMANI1, A. BRIMA1, R. ASKOVIC2
1Département de Mécanique, Université de Biskra , 07000 Biskra, Algérie.
2Laboratoire de mécanique des fluides, Université de Valenciennes,
59326 Aulnoy lez Valenciennes, France.
In the case of three-dimensional flows, the separation can be defined in more than one way. Discussions of
three-dimensional boundary layer separation in the literature have attempted to fined a rational extension
of the zero skin friction. Attempts have been made to establish the identity of “separation lines”.
Among the definitions of these may be found: (a) envelopes of limiting streamlines; (b) lines dividing
flow which has come from different regions; (c) lines of singularities (problems of topology); (d) lines on
which some component of the skin friction vanishes. Each of these is valid under certain conditions, but
none is universally valid.
In the present work, we use the definition (d), i.e. at low incidence of a blunt body the separation line is
identified as the zero of the meridian skin friction component (K.C. Wang,1975).
So the separation line on a flatten spheroid (6:3:1) at 6 degrees of incidence is calculated, as well as
experimentally determined by using the electrochemical method, which allows to follow the evolution of
the parietal velocity gradient.