A Parametric Study of the Induced Recirculation Zone using Single/Double Planar Jet Injection

Planar jet injection into a cross flow induces a large-scale recirculation zone. The relative importance of momentum and mass flux ratios is experimentally studied using injection slots having different widths. To acquire additional secondary control of the recirculation zone, a second downstream slot is employed with the objective of tailoring the recirculation bubble characteristics. Blowing and suction were explored for the downstream slot location. The control of dominant frequencies is documented for different operating conditions and geometries. The ability to control the mean and turbulent characteristics and vortex shedding frequency through multiple injection jets will aid in improving flame holding, burring rates, and control of combustion instabilities for combustion devices.