Development of a real-time transport performance optimization methodology

AxfpThe practical application of real-time performanceoptimization is addressed (using a wide-body transport Azfpsimulation) based on real-time measurements andcalculation of incremental drag from forced response C Lmaneuvers. Various controller combinations can beenvisioned although this study used symmetric outboard CDaileron and stabilizer. The approach is based onnavigation instrumentation and other measurements CL@n_n CDfound on state-of-the-art transports. This information isused to calculate winds and angle of attack. Thrust is CD Mestimated from a representative engine model as afunction of measured variables. The lift and dragequations are then used to calculate lift and drag CDocoefficients. An expression for drag coefficient, which is c.g.a function of parasite drag, induced drag, and aileron DFRCdrag, is solved from forced excitation response data.Estimates of the parasite drag, curvature of the ailerondrag variation, and minimum drag aileron position areproduced. Minimum drag is then obtained byrepositioning the symmetric aileron. Simulation resultsare also presented which evaluate the affects ofmeasurement bias and resolution.NomenclatureAPO adaptive performance optimizationACEE aircraft energy efficiencyAFTI advanced fighter technologyintegration*Aerospace Engineer, A1AA,MemberCopyright © 1995 by the American Institute of Aeronautics andAstronautics, Inc. No copyright is asserted in the United States underTitle 17,U.S. Code. The U.S. Government hasaroyalty-freelicensetoexercise all rights under the copyright claimed herein forGovernmental purposes. All other rights are reservedby the copyrightowner.EPRFMSGPSghINSK 1, K 2L/DMMAWPSCacceleration along the flightpath, g(positive forward)acceleration normal to the flightpath,g (positive up)coefficient of liftcoefficient of dragC L at minimum CDcoefficient of drag caused by Machnumberminimum drag coefficientcenter of gravityNASA Dryden Flight ResearchCenter, Edwards, Californiaengine pressure ratioflight management systemGlobal Positioning Systemacceleration caused by gravityaltitude, ftinertial navigation systemdrag equation coefficientslift-to-drag ratioMach numbermission adaptive wingperformance-seeking controldynamic pressure, lb/ft 2