On the Control of a Complex Multi-Stream Supersonic Nozzle*

The need to increase aircraft performance in terms of efficiency and maneuverability necessitates the design of increasingly complex nozzle configurations often yielding unwanted phenomena that clash with the benefits of the design. This study focuses on a multi aperture rectangular SERN , represented experimentally as a core (M = 1.6) and bypass (M = 1.0) flow that coalesce behind a splitter plate and exit onto an aft deck. Preliminary simulation and experiment have indicated that the instability associated with the splitter plate leads to unwanted tones in the flow field. To mitigate this, a spanwise wavenumber has been introduced to the splitter plate trailing edge as a form of passive control. This study extends this effort by laying the framework for active control of the flow via micro jets embedded within the splitter plate. Flow through the jet actuators is to be adjusted using the duty cycle of valves within the pressurized lines. Both open and closed loop techniques are proposed utilizing pressure sensors within the aft deck plate as well as acoustic microphones in the far field. PIV measurements quantify the effect of the control techniques and POD analysis provides insight into the optimal placement of sensors to feed back the most pertinent information of the flow.