<DOC>
<DOCNO>
573
</DOCNO>
<TITLE>
viscous hypersonic similitude .
</TITLE>
<AUTHOR>
hayer,w.d. and probstein,r.f.
</AUTHOR>
<BIBLIO>
j. ae. scs. 26, 1959, 815.
</BIBLIO>
<TEXT>
  an extension of classical hypersonic similitude is developed
which takes into account the interaction effect of the displacement
thickness of the boundary layer .  a basic result of this
viscous similitude is that the total drag including frictional drag
obeys the classical similarity law for the pressure drag .  additional
similarity conditions governing viscous effects must be
imposed in this similitude .
  underlying the similitude is a new hypersonic boundary-layer
independence principle .  according to this principle, the principal
part of a hypersonic boundary layer with given pressure
and wall temperature distributions and free-stream total enthalpy
is independent of the (high) external mach number distribution
outside the boundary layer .
  various features of viscous hypersonic similitudes are discussed
.  it is found, for example, that it applies to three-dimensional
boundary-layer interaction effects on flat bodies, provided
the concepts of strip theory may be applied, and provided the
aspect ratio is an invariant .
</TEXT>
</DOC>
