The present work extends previous investigations on the
secondary flows around a steady base flow to detailed timeaveraged
and time-resolved flow field measurements up- and
downstream of a low pressure turbine (LPT) cascade. Unsteady
inflow was generated by a moving bar system.
The inlet conditions were determined using single hot wire
anemometry and a pitot probe. Further detailed measurements
of the three-dimensional flow field were carried out
downstream of the cascade with triple hot wire anemometry, a
conventional five hole pressure probe, and a dynamic pressure
probe equipped with a single Kulite sensor. All measurements
have been performed with and without moving bars. Cases with
different Strouhal numbers and flow coefficients have been
considered by varying the pitch of the moving bars between 40
mm and 80 mm and circumferential speed between 10m/s and
20m/s in order to investigate the influence of unsteady inflow
in particular on the secondary flow field near the endwalls.
It turned out that the effects of the incoming wakes are
evident in the time-accurate data in terms of their interaction
with secondary flow vortices. On a time-averaged basis,
however, the influence of the incoming wakes on the secondary
flow field turned out to be small for the small inlet boundary
layer.
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