<DOC>
<DOCNO>
788
</DOCNO>
<TITLE>
an approximate boundary layer theory for semi-infinite cylinders of
arbitrary cross-section .
</TITLE>
<AUTHOR>
varley, e.
</AUTHOR>
<BIBLIO>
j. fluid mech. vol. 3. 1958, p. 601-614 .
</BIBLIO>
<TEXT>
an estimate is given of the distribution of skin frictional force per
unit length, and of displacement area, on the outside of a semi-infinite
 cylinder, of arbitrary cross-section, moving steadily in a direction
parallel to its generators . a pohlhausen method is employed with a
velocity distribution chosen to yield zero viscous retarding force on
the boundary layer approximations . /the smallness of the fluid
acceleration far from the leading edge has been pointed out by batchelor
reasonable results atlarge distances from the leading edge . however,
for a large class of cross-sections, which includes all convex crosssections
and locally concave cross-sections with re-entrant angles
greater than 1/2, the method yields the expected square root growth of
the boundary layer at the leading-edge, with a fairly close approximation
to the coefficient, and it is supposed that the skin-frictional
force and displacement area are given with reasonable accuracy along the
 whole length of the cylinder .
results for the elliptic cylinder and the finite flat plate are given in
 closed form, valid for the whole length of the cylinder, and are expected
to be in error by at most 20 per cent . in addition, some estimate
is given of the effect of corners on skin frictional force and
displacement area .
</TEXT>
</DOC>
