Fluidic System Optimization For Active Core Exhaust Control in High Bypass Ratio Turbofan Engines

Elimination of diverter valve sensitivity to core exhaust backpressure fluctuations will be critical to the success of future fluidic exhaust nozzle control technology enhancement programs. During Phase I extensive analysis of the pilot valve size,injection configuration and feed losses, as well as pulse format (frequency, pulse width, etc.) influences on main diverter valve operation, will be completed. Combined one-dimensional lumped parameter and three-dimensional Large Eddy Simulation (LES)Navier Stokes based fluidic system analysis will be completed in CFDRC''s MDICEr software to accurately capture the backpressure fluctuations associated with actively controlled exhaust plume mixing. The fidelity of this analysis approach will bedemonstrated with active core exhaust (ACE) control JT8D data in combination with recent GTRI F117-PW-100 test results. Phase I demonstration of optimum fluidic injection nozzle technology will focus on improving C-17 plume core mixing during offload andbacking operations.During Phase II CFDRC will work with Honeywell and Boeing to complete ground testing of a an F117-PW-100 fluidic injection nozzle system at GTRI facilities. Implementation of this system into a C-17 aircraft will be completed during Phase III. Elimination of core reverser operation during offload and backing operations, reduction of flap temperatures during powered lift and improved flap capture make this technology immediately commercializable in any high-bypass ratio turbofan engine.Boeing, P&W and Honeywell have committed to supporting rapid commercial and military implementation of this technology into both commercial and military aircraft.