Gas Turbine Engine Jet Noise & Plume IR Signature Attenuation

Novel techniques for jet noise mitigation and plume IR attenuation techniques will be evaluated by CRAFT Tech and NCPA for application to the F/A-18 E/F and the Joint Strike Fighter (JSF) aircrafts. Two concepts, featuring corrugated nozzle seals and lobed ejector seals, will be analyzed at 1/10th scale at NCPA, including characterization of jet noise and plume IR suppression. The experimental activities will be complemented by high-fidelity CFD simulations, including predictions of jet noise emissions and plume infra-red (IR) signature. Design optimization procedures will be utilized to identify optimal designs for the suppression concepts at varied power settings, e.g. FCLP (Field Carrier Landing Practice), mil-power, cruise, take-off and landing, including off-design performance. CFD studies will also support the scale-up and extrapolation of laboratory scale, static firing noise & plume IR measurements to include forward flight effects, as well as inclusion of “real world” engine effects, e.g. coupling with manufacturer’s cycle deck for the engine, partially mixed bypass flow, complex wall cooling, etc. and the influence of vehicle aerodynamic flowfield on downstream plume evolution. Plans for Phase III evaluation of the suppression concepts at full-scale with production F414-400 and F135 engines will also be provided to the US Navy.