  In this article we describe, a numerical simulation has been performed for a
channel flow with sudden expansion. Different geometric expansion ratios are
considered in the current study such as 1:2, 1:3, and 1:4. The bifurcation
phenomenon has been investigated for the baseline case and the critical
Reynolds number is controlled using a passive modification in the channel. The
geometry of sudden expansion channel is modified by introducing a
two-dimensional plate along the center line of the channel at the expansion
plane. This is one of the passive control techniques, which has been explored
in the present study. The computations indicate that the critical Reynolds
number of the symmetry-breaking bifurcation increases as the length of the
plate increases. An empirical relation has been developed amongst the critical
Reynolds number, length of control plates and expansion ratio (h/H). The
critical Reynolds number predicted by the empirical relation for different
plate lengths are in good agreement with computational results.
