Control of a Circular Jet

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.