A new experimental methodology was developed to study the transient mixing
process of the high temperature how field behind the backstep with low temp
erature fluid injected from the lower surface. Temporal data show that the
Row temperature at locations between 0.2 and 0.4 reattachment lengths, Xr,
at 1-mm height dropped faster than other places. Temporal temperature diffe
rence across the wall plate performed quite different trends before and aft
er 0.6 time the reattachment length. The temporal Nusselt number distributi
on over the entire wall plate reached its peak value about 5-10 s after the
wall injection initiated and gradually converged to a steady-state value.
(C) 2001 Published by Elsevier Science Ltd.