A Base Drag Reduction Experiment on the X-33 Linear Aerospike SR-71 Experiment (LASRE) Flight Program. Meeting Paper AIAA-1999-0277, Research Engineering, NASA Dryden Flight Research Center

Whitmore, Stephen A. and Moes, Timothy R. (1999) A Base Drag Reduction Experiment on the X-33 Linear Aerospike SR-71 Experiment (LASRE) Flight Program. Meeting Paper AIAA-1999-0277, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

Drag reduction tests were conducted on the LASRE/X-33 flight experiment. The LASRE experiment is a flight test of a roughly 20-percent scale model of an X-33 forebody with a single aerospike engine at the rear. The experiment apparatus is mounted on top of an SR-71 aircraft. This paper suggests a method for reducing base drag by adding surface roughness along the forebody. Calculations show a potential for base drag reductions of 8 to 14 percent. Flight results corroborate the base drag reduction, with actual reductions of 15 percent in the high-subsonic flight regime. An unexpected result of this experiment is that drag benefits were shown to persist well into the supersonic flight regime. Flight results show no overall net drag reduction. Applied surface roughness causes forebody pressures to rise and offset base drag reductions. Apparently the grit displaced streamlines outward, causing forebody compression. Results of the LASRE drag experiments are inconclusive and more work is needed. Clearly, however, the forebody grit application works as a viable drag reduction tool.

EPrint Type:	Other
Keywords:	Aerospike engine, Base drag, Single-stage-to-orbit, SR-71 aircraft, X-33 vehicle
Subjects:	(01 - 09) Aeronautics: (05) Aircraft Design, Testing And Performance Aircraft/Project: SR-71 Blackbird Aircraft/Project: X-33
ID Code:	1261
Deposited On:	05 Febuary 2007
Additional Information:	17 pages. 37th American Institute of Aeronautics and Astronautics Aerospace Sciences Meeting and Exhibit, Reno, Nevada, January 11-14, 1999.