NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsExperimental Aerodynamic Characteristics of the Pegasus Air-Launched Booster and Comparisons with Predicted and Flight ResultsExperimental longitudinal and lateral-directional aerodynamic characteristics were obtained for the Pegasus and Pegasus XL configurations over a Mach number range from 1.6 to 6 and angles of attack from -4 to +24 degrees. Angle of sideslip was varied from -6 to +6 degrees, and control surfaces were deflected to obtain elevon, aileron, and rudder effectiveness. Experimental data for the Pegasus configuration are compared with engineering code predictions performed by Nielsen Engineering & Research, Inc. (NEAR) in the aerodynamic design of the Pegasus vehicle, and with results from the Aerodynamic Preliminary Analysis System (APAS) code. Comparisons of experimental results are also made with longitudinal flight data from Flight #2 of the Pegasus vehicle. Results show that the longitudinal aerodynamic characteristics of the Pegasus and Pegasus XL configurations are similar, having the same lift-curve slope and drag levels across the Mach number range. Both configurations are longitudinally stable, with stability decreasing towards neutral levels as Mach number increases. Directional stability is negative at moderate to high angles of attack due to separated flow over the vertical tail. Dihedral effect is positive for both configurations, but is reduced 30-50 percent for the Pegasus XL configuration because of the horizontal tail anhedral. Predicted longitudinal characteristics and both longitudinal and lateral-directional control effectiveness are generally in good agreement with experiment. Due to the complex leeside flowfield, lateral-directional characteristics are not as well predicted by the engineering codes. Experiment and flight data are in good agreement across the Mach number range.Document ID19970013282Acquisition SourceLangley Research CenterDocument TypeTechnical Memorandum (TM)AuthorsRhode, M. N.*(NASA Langley Research Center Hampton, VA United States)*Engelund, Walter C.*(NASA Langley Research Center Hampton, VA United States)*Mendenhall, Michael R.*(Nielsen Engineering and Research, Inc. Mountain View, CA United States)*Date AcquiredSeptember 6, 2013Publication DateJune 22, 1995Publication InformationPublisher: American Inst. of Aeronautics and AstronauticsSubject CategoryAerodynamicsReport/Patent NumberNAS 1.15:112004AIAA Paper 95-1830NASA-TM-112004Meeting InformationMeeting: Applied AerodynamicsLocation: San Diego, CACountry: United StatesStart Date: June 19, 1995End Date: June 22, 1995Sponsors:American Inst. of Aeronautics and AstronauticsAccession Number97N17204Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19970013282.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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