cranfield0072

<DOC>
<DOCNO>
72
</DOCNO>
<TITLE>
boundary layer behind shock or thin expansion wave
moving into stationary fluid .
</TITLE>
<AUTHOR>
mirels,h.
</AUTHOR>
<BIBLIO>
naca tn.3712, 1956.
</BIBLIO>
<TEXT>
  the boundary layer behind a shock or thin expansion wave advancing
into a stationary fluid has been determined .  laminar and turbulent
boundary layers were considered .  the wall surface temperature behind
the wave was also investigated .  the assumption of a thin expansion
wave is valid for weak expansions but becomes progressively less
accurate for strong expansion waves .
  the laminar-boundary-layer problem was solved by numerical integration
except for the weak wave case,
which can be solved analytically .
integral (karman-pohlhausen type)
solutions were also obtained to provide
a guide for determining expressions
which accurately represent the numerical
data .  analytical expressions
for various boundary-layer parameters
are presented which agree with the
numerical integrations within 1 percent .
  the turbulent-boundary-layer problem was solved using integral methods
similar to those employed for the
solution of turbulent compressible
flow over a semi-infinite flat plate .
the fluid velocity, relative to
the wall, was assumed to have a seventhpower
profile .  the blasius equation,
relating turbulent skin friction
and boundary-layer thickness, was
utilized in a form which accounted for compressibility .
  consideration of the heat transfer to the wall permitted the wall
surface temperature, behind the wave,
to be determined .  the wall thickness
was assumed to be greater than the
wall thermal-boundary-layer
thickness .  it was found that the wall
temperature was uniform (as a
function of distance behind the wave)
for the laminar-boundary-layer case
but varied with distance for the turbulent-boundary-layer case .
</TEXT>
</DOC>