A 1/24-scale wide-body high-wing transport model was tested in the Langley Sixteen-Foot Transonic Tunnel at free-stream Mach numbers 0.7 and 0.8 and angles of attack from -3 to 4 degrees to determine the installation effects of a series of pylons that had differing cross-sectional shapes. In addition, an aft-mounted separate-flow, flow-through nacelle was studied. Pylon toe angle was varied from 5 degrees inboard to 5 degrees outboard. A new concept in pylon cross-sectional shape, i.e. a compression pylon, was developed and tested. This pylon was designed to reduce wing/pylon junction velocities and therefore reduce installed drag. Model aerodynamic forces and moments and wing static pressures were measured for the complete model configuration. Results of the wind tunnel investigation show that the installed drag was lowest for the compression pylon. The flow under the wing in the pylon/wing junction was kept comparable to clean wing velocities with the installation of the compression type pylon. The predicted trends in pylon side force and airplane drag with pylon toe angle compare favorably with the experimental data. Additionally the data show that the D-shaped aft-mounted nacelle exhibited very high interference drag as did previously tested circular-shaped nacelles in the same position.
Integration effects of pylon geometry and rearward mounted nacelles for a high-wing transport
Integrationseffekte der Aussenspannturmgeometrie und nach rueckwaerts versetztem Rumpf auf ein Hochdecker-Transportflugzeug
AIAA-Papers ; Jul ; 1-10
1987
10 Seiten, 15 Bilder, 1 Tabelle, 12 Quellen
Aufsatz (Konferenz)
Englisch