<DOC>
<DOCNO>
1235
</DOCNO>
<TITLE>
a theory of the two dimensional laminar bounary layer
over a curved surface .
</TITLE>
<AUTHOR>
yen,k.t. and toba,k.
</AUTHOR>
<BIBLIO>
j. ae. scs. 1961, 877.
</BIBLIO>
<TEXT>
  the purpose of this paper is to present a theory to account for
surface curvature effects on the two-dimensional boundary-layer
flow which approaches a potential flow at free stream .
  the problem of two-dimensional viscous flow is first formulated
by using the streamlines and their orthogonal trajectories as the
generalized coordinates .  a boundary-layer approximation is
applied to the navier-stokes equations and the gauss equation
in the generalized coordinates to yield the boundary-layer equations
.  the conditions under which similar solutions of the
boundary-layer equations exist are determined .  by a simple
transformation, the governing differential equation can be expressed
in a form which reduces to the falkner-skan equation
for zero surface curvature .
  numerical results for a similar solution which corresponds to a
flow over a curved surface with zero surface pressure gradient
have been obtained .  the velocity profiles in the boundary layer
and the wall skin-friction distribution for concave and convex
surfaces are presented .  the wall skin friction for a convex wall
is found to be higher than the blasius value for a flat plate .  on
the other hand, for a concave wall, the skin friction will drop below
the blasius value as the curvature increases, but it appears to
reach a minimum, and beyond this minimum point it will increase
again .  the same flow problem was treated by murphy by a
different method of analysis .  comparison of murphy's results
with those obtained by the present method reveals some basic
differences in the boundary-layer characteristics .  in particular,
murphy's results indicate that the wall skin friction for a convex
surface is smaller than the blasius value, while for a concave wall
it is higher .
</TEXT>
</DOC>
