An investigaion of boattail geometry and Reynolds number effects on forebody and afterbody drag at transonic Mach numbers /

An experimental investigation was conducted in the AEDC 16-foot Transonic Wind Tunnel (16T) to determine both Reynolds number and nozzle afterbody configuration effects on model forebody and afterbody drag. The model was a sting-mounted body of revolution with interchangeable contoured, cylindrical, and 15-deg boattail configurations. Pressure and force data were obtained at Mach numbers from 0.60 to 1.40 and at unit Reynolds numbers from 1,470,000 per foot to 5,300,000 per foot. The experimental results showed that large variations in afterbody drag levels produced no significant change in forebody drag. The data also revealed that all three configurations exhibited little or no Reynolds number dependence subsonically and that only the 15-deg boattail afterbody was affected by Reynolds number supersonically. It was also demonstrated that data precision and wind tunnel calibration can have a significant effect on model drag and should be given careful consideration. (Author)."February 1977.""Final Report: 28 -- 31 January 1976."Includes bibliographical references (pages 17-18).An experimental investigation was conducted in the AEDC 16-foot Transonic Wind Tunnel (16T) to determine both Reynolds number and nozzle afterbody configuration effects on model forebody and afterbody drag. The model was a sting-mounted body of revolution with interchangeable contoured, cylindrical, and 15-deg boattail configurations. Pressure and force data were obtained at Mach numbers from 0.60 to 1.40 and at unit Reynolds numbers from 1,470,000 per foot to 5,300,000 per foot. The experimental results showed that large variations in afterbody drag levels produced no significant change in forebody drag. The data also revealed that all three configurations exhibited little or no Reynolds number dependence subsonically and that only the 15-deg boattail afterbody was affected by Reynolds number supersonically. It was also demonstrated that data precision and wind tunnel calibration can have a significant effect on model drag and should be given careful consideration. (Author).Report supported by the Air Force Systems Command and prepared by ARO, Inc, under Program Element,Mode of access: Internet