A parametric study was conducted in the Langley 16-Foot Transonic Tunnel on an isolated nonaxisymmetic fuselage model that simulates a twin-engine fighter. The effects of aft-end closure distribution (top/bottom) nozzle-flap boattail angle versus nozzle-sidewall boattail angle) and afterbody and nozzle corner treatment (sharp or radius) were investigated. Four different closure distributions with three different corner radii were tested. Tests were conducted over a range of Mach numbers from 0.40 to 1.25 and over a range of angles of attack from -3 to 9 degrees. Solid plume simulators were used to simulate the jet exhaust. For a given closure distribution in the range of Mach numbers tested, the sharp-corner nozzles generally had the highest drag, and the 2-in. corner-radius nozzles generally had the lowest drag. The effect of closure distribution on afterbody drag was highly dependent on configuration and flight condition.
Effect of Afterbody Geometry on Aerodynamic Characteristics of Isolated Nonaxisymmetric Afterbodies at Transonic Mach Numbers
1992
265 pages
Report
No indication
English
Aerodynamics , Aircraft , Aerodynamic characteristics , Afterbodies , Aircraft configurations , Aircraft models , Fighter aircraft , Interactional aerodynamics , Wind tunnel models , Wind tunnel tests , Boattails , Aerodynamic drag , Angle of attack , Flight conditions , Fuselages , Jet exhaust , Mach number , Transonic wind tunnels