Numerical investigation of bifurcation phenomena occurring in flows through planar sudden expansions

A new convection scheme along with a multigrid algorithm were used for an in-depth study of bifurcation phenomena which occur in flows through, planar sudden expansions. The predicted flow bifurcation parameters compare very well with experiments, especially for Reynolds numbers higher or lower than a critical Reynolds number Re-cr, the latter being the value beyond which flow asymmetry takes place. For Reynolds numbers below Re-cr the flow remains symmetric throughout all the period of its development, during which the recirculation lengths increase monotonically with time towards their final stationary values. For Reynolds numbers above Re-cr the flow changes from a symmetric structure at the beginning to an asymmetric one at the steady state where one of the main recirculation zones becomes longer than the other and a third zone appears on the same side as the short primary recirculation zone.