Abstract
A novel jet nozzle equipped with a row of miniature electromagnetic flap actuators was developed for active control of mixing and combustion. The spatio-temporal flow structures of the axsymmetric and coaxial jets were studied through flow visualization and quantitative measurements by PTV, PLIF and LDV. It is demonstrated that various disturbances introduced in the initial shear layer by the flap actuators can significantly modify the process of formation and evolution of large-scale vortical structures. In particular, when each half cluster of the flap actuators are driven 180 degree out of phase, the jet bifurcates clearly into two branches. For coaxial jet, mixing between the inner and outer fluids was markedly enhanced by the axisymmetric motion. A preliminary attempt for active combustion control shows that the present control scheme is also effective in stabilizing lifted flame.
