<DOC>
<DOCNO>
342
</DOCNO>
<TITLE>
effect of diffusion fields on the laminar boundary
layer .
</TITLE>
<AUTHOR>
smith,j.w.
</AUTHOR>
<BIBLIO>
j.ze.scs. 21, 1954.
</BIBLIO>
<TEXT>
  a theory is developed which describes the effect of a general
diffusion field on the dynamic and thermal characteristics of a
laminar boundary layer on a flat plate in steady compressible
flow .  fluid properties are considered as functions of temperature
and local concentration of the foreign gas .  the diffusion
field is described by a differential equation that relates convective
and diffusion transfer and which considers diffusion currents
arising from gradients of concentration and temperature .  by
means of the usual transformations the system is reduced to a set
of ordinary differential equations, which in turn are transformed
into a set of integral equations .  the latter is amenable to solution
by the method of successive approximations .
  the theory and results have bearing on the problem of control
and reduction of aerodynamic heating at hypersonic speeds .
the special feature of this approach lies in the utilization of diffusion
fields for the purpose of reducing the detrimental effects
of viscous dissipation .  although the theory is adapted to a
fuller investigation of this problem, the numerical examples
considered involve mainly diffusion fields of helium, with which
good results have been achieved at mach numbers 8 and 12 .
whereas at the higher mach number the influx of heat was practically
eliminated, a reversal in the direction of heat flow has
been effected at the lower mach number .
</TEXT>
</DOC>
