ISSN Online: 2377-424X
ISBN Print: 0-89116-299-2
International Heat Transfer Conference 7
EFFECT OF A WALL JET ON THE DYNAMIC CONFIGURATION OF THE WAKE BEHIND A BACKWARD STEP IN A STEADY FLOW
Resumo
We study the influence of a wall jet on the
dynamic configuration of the wake of a backward
step making an abrupt elargment in a rectangular
channel. By measurements of wall shear stress in
the wake, we show how the structure of the recirculating
zone and the wall reattachment region can be
affected by using steady and pulsated wall jets of
different mean velocities. We demonstrate that with
a steady wall jet two behaviours can exist : one
which presents only few modifications with regard
to the configuration without wall jet and another
which shows the disparition of the main eddy near
the wall. On the other hand, we note that with a
pulsating wall jet it is possible to obtain an early
destabilization of the wake which could subsequently
lead to an important increase of heat transfer
in these zones.