<DOC>
<DOCNO>
1225
</DOCNO>
<TITLE>
the effect of adverse pressure gradients on the characteristics of
turbulent boundary layers in supersonic streams .
</TITLE>
<AUTHOR>
george h. mclafferty and robert e. barber
</AUTHOR>
<BIBLIO>
united aircraft corporation research laboratories
</BIBLIO>
<TEXT>
tests were conducted at mach numbers from 2.0 to 3.5 to determine
the thickness and profile shape characteristics of turbulent boundary
layers on two-dimensional and axisymmetric curved-surface models
having adverse pressure gradients .  the magnitude of the gradients
relative to the boundary-layer thickness at the beginning of the
gradient was varied by employing models having different radii of
curvature and by changing the boundary-layer thickness at the beginning
of the gradient .  the overall pressure rise in most cases was
greater than the value which would cause a turbulent boundary layer
to separate if the pressure rise were created by an oblique shock wave .
an analytical investigation was also conducted so that the results of
the experimental investigation could be applied to the prediction of
cases outside the range of the experiments .
it is shown that boundary-layer momentum thickness can be predicted
from the von karman boundary-layer momentum equation, but that measured
values of boundary-layer profile shape are in poor agreement with
values computed from procedures derived by extending conventional
methods for predicting profile shape in subsonic flow .  a new procedure
for calculating boundary-layer profile shapes, developed in this
paper, is shown to provide a good correlation between experimental
and calculated values of boundary-layer profile shapes in adverse
pressure gradients created by curved surfaces .  this procedure is based
on the experimental observation that the station at which high-energy
free-stream flow actually mixes into a turbulent boundary layer in
an adverse pressure gradient is well downstream of the station at
which flow would have to mix in order to maintain a flat-plate profile .
</TEXT>
</DOC>
