<DOC>
<DOCNO>
1275
</DOCNO>
<TITLE>
flow about an unsteadily rotating disc .
</TITLE>
<AUTHOR>
sparrow,e.m. and gregg,j.l.
</AUTHOR>
<BIBLIO>
j. ae. scs.1960,252.
</BIBLIO>
<TEXT>
  an analysis is made of the unsteady laminar flow about a
rotating disc whose angular velocity may vary with time .
the deviation of the actual instantaneous state of the flow from
the quasi-steady state (instantaneous steady state) is determined
.  from this, a simplified criterion, is derived
to define the conditions under which the flow can be considered
as quasi-steady for the purposes of shear stress and
torque computations .  since a turbulent flow responds more
rapidly than a laminar flow, the quasi-steady criterion found here
should also serve for the turbulent situation .
</TEXT>
</DOC>
