<DOC>
<DOCNO>
328
</DOCNO>
<TITLE>
the boundary layer near the stagnation point in hypersonic
flow past a sphere .
</TITLE>
<AUTHOR>
herring,t.r.
</AUTHOR>
<BIBLIO>
j. fluid mech. 7, 1960, 257.
</BIBLIO>
<TEXT>
  flow properties behind shock waves caused by bluff bodies
traveling at supersonic speeds are of major importance in missile
and high-speed aircraft design .  paper presents a mathematical solution
for the laminar boundary layer near the stagnation point of a
sphere .  surface temperature is free-stream static and shock is
strong .  air is assumed calorically and thermally perfect with a
prandtl number of 0.72 and a dynamic viscosity directly proportional
to temperature .
  based on work of homann (zamm 16, p. 153, 1936) and lighthill
simultaneous differential equations for the velocity and temperature
profiles .  these are solved by numerical integration along a
normal to the surface using a digital computer .  results are presented
as functions of free-stream mach number, reynolds
number, and specific heat ratio .  as increases, boundarylayer
thickness is shown to decrease while shock stand-off distance
increases .  stand-off distance also decreases with increasing
and decreasing specific heat .  for constant and specific
heat ratio, the product of skin-friction coefficient and the square
root of decreases with increasing only approaching a constant
value at greater than 10,000 .
  reviewer's comment is concerned with the perfect gas assumption
for air .  author suggests that the effects of dissociation on
flow properties are accounted for by a proper choice of specific
heat ratio .  a consideration of the kinetics of chemical reaction in
the cooled boundary layer emphasizes the oversimplification of
this approach .  the effect on transport properties could have been
approximated in present analysis by changing the prandtl number
to one more representative of the existing pressures and temperatures
.
</TEXT>
</DOC>
