THREE-DIMENSIONAL SEPARATION OF BOUNDARY LAYER OVER BLUNT BODIES

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.