<DOC>
<DOCNO>
240
</DOCNO>
<TITLE>
a theoretical analysis of heat transfer in regions of separated flow
</TITLE>
<AUTHOR>
dean r. chapman
</AUTHOR>
<BIBLIO>
naca technote 3792
</BIBLIO>
<TEXT>
    the flow field analyzed consists of a thin, constant pressure
viscous mixing layer separated from a solid surface by an enclosed
region of low-velocity air (/dead air/) . the law of conservation of
energy is employed to relate calculated conditions within the
separated mixing layer to the rate of heat transfer at the solid surface
. this physical speed is applied to laminar separations in
compressible flow for various prandtl numbers, including consideration
of the case where air is injected into the separated region  .
application to turbulent separations is made for a prandtl number of
unity in low-speed flow without injection .
all calculations are for the case of zero boundary-layer thickness at
the position of separation .
     for laminar separations the differential equations for viscous flow
at arbitrary mach number are solved for the enthalpy and velocity
profiles within the thin layer where mixing with dead air takes place .
results are presented in tabular form for prandtl numbers between 0.1
and 10  . the rate of heat transfer to a separated laminar region in air
laminar boundary layer having the same constant pressure . injection
of gas into the separated region is calculated to have a powerful effect
in reducing the rate of heat transfn  to the wall  . it is calculated
that a moderate quantity of gas injection reduces to zero the heat
transfer in a laminar separated flow .
</TEXT>
</DOC>
