Effect of Afterbody Geometry on Aerodynamic Characteristics of Isolated Nonaxisymmetric Afterbodies at Transonic Mach Numbers
Effect of Afterbody Geometry on Aerodynamic Characteristics of Isolated Nonaxisymmetric Afterbodies at Transonic Mach Numbers

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-07-24

Total Pages: 272

ISBN-13: 9781723563997

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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. Bangert, Linda S. and Carson, George T., Jr. Langley Research Center NASA-TP-3236, L-17034, NAS 1.60:3236 RTOP 505-62-30-01...

Mass Injection and Jet Flow Simulation Effects on Transonic Afterbody Drag
Mass Injection and Jet Flow Simulation Effects on Transonic Afterbody Drag

Author: Wladimiro Calarese

Publisher:

Published: 1978

Total Pages: 184

ISBN-13:

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An experimental investigation has been performed to determine the effects of boattail injection and jet flow simulation on the afterbody drag of a slender body of revolution in the transonic regime at zero angle of attack, such as engine nacelles and boattailed afterbodies with isolated engines. A correlation between sting and jet diameter has been established. The jet plume and the nozzle pressure ratio simulators have been found appropriate and useful as a testing technique. Boattail mass injection usually produces a drag coefficient reduction and is more effective at high nozzle pressure ratios. Boattail injection is more effective if used in regions of separated flow. (Author).