<DOC>
<DOCNO>
623
</DOCNO>
<TITLE>
on the coupling between heat and mass transfer .
</TITLE>
<AUTHOR>
tewfik,o.e.
</AUTHOR>
<BIBLIO>
j. ae. scs. 28, 1962, 1009.
</BIBLIO>
<TEXT>
in mixtures of two different gases or liquids, one constituent
will migrate spontaneously toward the warmer parts, and
the other toward the colder parts .  this phenomenon, known
as the soret effect, and its converse the dufour effect, were
discovered as early as 1856 and 1873 respectively .  the two
effects can also be considered as a simultaneous transport of
mass and heat, or as a coupling between heat and mass transfer .
the effects of this coupling have been neglected in all investigations
of heat transfer in multicomponent flow systems so far,
on the a priori assumption that they are small .  in a recent
publication however, it was shown that they can be large in
laminar-boundary-layer-type flows with helium injection .  turbulent-boundary-layer
measurements and an analysis conducted
at the heat transfer laboratory clearly showed significant
effects of the coupling on heat transfer and adiabatic wall temperature
.  from additional measurements, the results of which
are presented below, it is possible to separate the heat flux at the
model wall into one part depending on the temperature gradient
and a second part caused by the coupling .  it is shown that
the latter exceeds the former, and hence the coupling may not
be neglected a priori without careful consideration .
</TEXT>
</DOC>
