Subsonic Aerodynamic Characteristics of Semispan Commercial Transport Model With Wing-Mounted Advanced Ducted Propeller Operating in Reverse Thrust

Summary A test asw conducted in the Lanlgey 14- y 22-ootF Subsonic unnelT to determine the e ect of thereerse-thrustv ow eld of a wing-mounted advancedducted propeller on the aerodynamic haracteristicscof a semispan subsonic high-lift transport model(TM). The advanced ducted propeller (ADP) modelwas mounted separately in position alongside thewing so that only the aerodynamic interference ofthe propeller and nacelle a ected the aerodynamicperformance of the transport model. estT Machumbers ranged from 0.14 to 0.2;6 correspondingReynolds umbers ranged from 2.2 to 3 : 9 10 6 . Theprimary e ect of the ADP on the transport modelwas reduced lift and drag and was caused y thereverse-thrust ow eld of the ADP, which shieldeda portion of the wing from the free-stream airow.The reduction in lift and drag was a function of ADProtational speed and free-stream elov.cityA erticalv ground plane (GP) was installed todetermine the ground e ect on the transport modeland ADP con guration. estT data indicated thatthe ground plane caused a bene cial increase in dragand an undesirable slight increase in lift. The ADPand transport model performance in ground e ectwas similar to performance trends observed for outof ground e ect.The test results form a comprehensive data setthat supports the application of the ADP engine andairplane concept on the next generation of advancedsubsonic transports. Before this inestigation,v theengine concept was predicted to haev detrimentalground e ect haracteristics.c Ground e ect testmeasurements indicated no critical problems andwere the rst step in proving the viability of thisengine and airplane con guration.