Among the important physical phenomena associated with the jet in crossflow is
the formation and evolution of vortical structures in the flow field, in particular
the counter-rotating vortex pair (CVP) associated with the jet cross-section. The
present computational study focuses on the mechanisms for the dynamical generation
and evolution of these vortical structures. Transient numerical simulations of the
flow field are performed using three-dimensional vortex elements. Vortex ring rollup,
interactions, tilting, and folding are observed in the near field, consistent with the
ideas described in the experimental work of Kelso, Lim & Perry (1996), for example.
The time-averaged effect of these jet shear layer vortices, even over a single period
of their evolution, is seen to result in initiation of the CVP. Further insight into
the topology of the flow field, the formation of wake vortices, the entrainment of
crossflow, and the effect of upstream boundary layer thickness is also provided in this
study.