Acoustics of Single Slot Style Fluidic Injections on Rectangular Nozzles at Overexpanded Flow Condition

Fluidic injection has been investigated and has shown great promise in previous studies in reducing jet noise; however, most of those studies have focused on external fluidic injection just downstream of the nozzle lip. Studies in which internal fluid injection was explored have focused on axisymmetric style nozzles with limited studies on non-axisymmetric nozzles. Modern supersonic jets have transitioned to asymmetric exhaust shapes, leading to an increase in emphasis on asymmetric nozzle research. To aid in the understanding of noise mechanisms associated with internal fluidic injection, research has taken place at the University of Cincinnati which seeks to understand the relationship between injection angle, and injection pressure ratio on the far-field noise and flow features. This study focuses on the use of single slot style fluidic injectors, varying injection pressure ratio and injection angle the effect on the flow field and acoustic spectra. Preliminary results have shown a reduction in noise of over 11 dB, 5 dB, and 2 dB in the upstream, sideline, and downstream directions respectively.