The transition of two dimensional flow within a crack
with oscillating wall is studied experimentally to establish
the role of the parameters involved. Multiple instabilities
in the fluid are produced by the motion of the oscillating
wall. For a better understanding of the flow structure and
displaying in the whole flow field at a time, flow
visualization was used. Frequency, amplitude, and crack
width were systematically varied. The present study shows
that, in general, the frequency and crack width play a role
in the transition process at low frequencies of
oscillations. However, amplitude becomes progressively
important at its higher range. Results also show that the
flow changes its character approximately after a Reynolds
number 11420. After that the transition process continues
until the Reynolds number 34322 which is the upper limit of
variation of frequency (Reynolds number) in the present
study.