<DOC>
<DOCNO>
294
</DOCNO>
<TITLE>
an investigation of laminar transitional and turbulent
heat transfer on blunt-nosed bodies in hypersonic flow .
</TITLE>
<AUTHOR>
cresci,r.j. and mackenzie,d.a.
</AUTHOR>
<BIBLIO>
j. ae. scs. 27, 1960.
</BIBLIO>
<TEXT>
  laminar, transitional, and turbulent heating rates have been
measured by means of the shrouded model technique .  the
reynolds number was varied over a ninefold range,. the enthalpy
ratio (stagnation to wall) varied from 2.3 to approximately 1.5 .
two different pressure distributions were imposed on the model
which consisted of a spherically capped cone .
  the experimental data are compared to the laminar hypersonic
boundary-layer theory and shown to be in good agreement on the
conical portion of the model .  on the spherical portion the data
are approximately 20 per cent higher than the theoretical prediction
.  some of this discrepancy can be attributed to radiation to
the nose of the model .
  the fully developed turbulent heat-transfer data are compared
to two theories ..  (1) a relatively simple turbulent theory which is
based on recent theoretical work and which takes into account
the upstream history of the boundary layer, and (2) the flat-plate
reference-enthalpy theory, which depends on only /local/ conditions
.  although both theories are in reasonable agreement with
the data, the latter method is simpler and somewhat more accurate
.
  for transitional flow the theory mentioned first can be readily
modified in order to permit reasonable estimates of transitional
heat transfer to be obtained .  on this basis it is possible to estimate
laminar, transitional, and fully developed turbulent heat
transfer under hypersonic blunt-body conditions .
  the behavior of transition reynolds number based on momentum
thickness is also discussed and shown to be in quantitative
agreement with recent shock-tube measurements .
</TEXT>
</DOC>
