The present study report direct numerical simulation (DNS) of a circular jet
and the effect of a large scale perturbation at the jet inlet. The perturbation
is used to control the jet for increased spreading. Dual-mode perturbation is
obtained by combining an axisymmetric excitation with the helical. In the fluid
dynamics videos, an active control of the circular jet at a Reynolds number of
2000 for various frequency ratios (both integer and non-integer) has been
demonstrated. When the frequency ratio is fixed to 2, bifurcation of the jet on
a plane is evident. However, for a non-integer frequency ratio, the
axisymmetric jet is seen to bloom in all directions.Comment: 2 page