NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsOptimal trajectories for an aerospace plane. Part 1: Formulation, results, and analysisThe optimization of the trajectories of an aerospace plane is discussed. This is a hypervelocity vehicle capable of achieving orbital speed, while taking off horizontally. The vehicle is propelled by four types of engines: turbojet engines for flight at subsonic speeds/low supersonic speeds; ramjet engines for flight at moderate supersonic speeds/low hypersonic speeds; scramjet engines for flight at hypersonic speeds; and rocket engines for flight at near-orbital speeds. A single-stage-to-orbit (SSTO) configuration is considered, and the transition from low supersonic speeds to orbital speeds is studied under the following assumptions: the turbojet portion of the trajectory has been completed; the aerospace plane is controlled via the angle of attack and the power setting; the aerodynamic model is the generic hypersonic aerodynamics model example (GHAME). Concerning the engine model, three options are considered: (EM1), a ramjet/scramjet combination in which the scramjet specific impulse tends to a nearly-constant value at large Mach numbers; (EM2), a ramjet/scramjet combination in which the scramjet specific impulse decreases monotonically at large Mach numbers; and (EM3), a ramjet/scramjet/rocket combination in which, owing to stagnation temperature limitations, the scramjet operates only at M approx. less than 15; at higher Mach numbers, the scramjet is shut off and the aerospace plane is driven only by the rocket engines. Under the above assumptions, four optimization problems are solved using the sequential gradient-restoration algorithm for optimal control problems: (P1) minimization of the weight of fuel consumed; (P2) minimization of the peak dynamic pressure; (P3) minimization of the peak heating rate; and (P4) minimization of the peak tangential acceleration.Document ID19910006700Acquisition SourceLegacy CDMSDocument TypeContractor Report (CR)AuthorsMiele, Angelo*(Rice Univ. Houston, TX, United States)*Lee, W. Y.*(Rice Univ. Houston, TX, United States)*Wu, G. D.*(Rice Univ. Houston, TX, United States)*Date AcquiredSeptember 6, 2013Publication DateJanuary 1, 1990Subject CategoryAircraft Design, Testing And PerformanceReport/Patent NumberNASA-CR-187868AAR-247NAS 1.26:187868Meeting InformationMeeting: American Control ConferenceLocation: San Diego, CACountry: United StatesStart Date: May 23, 1990End Date: May 25, 1990Accession Number91N16013Funding Number(s)CONTRACT_GRANT: NAG1-1029CONTRACT_GRANT: TATP-003604020Distribution LimitsPublicCopyrightWork of the US Gov. Public Use Permitted.Available DownloadsNameType19910006700.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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