The NASA STI Program Office provides(5)

Since its founding, NASA has been dedicated to the advancement of aeronautics and space

Abstract

AcomparisonismadebetweentheresultsoftrimmingaHighSpeedCivilTransport(H-SCT)conceptalongareferencemissionpro leusingtwotrimmodes.Onemodeusesthestabilator.Theothermodeusesforeandaftplacementofthecenterofgravity.Acomparisonismadeofthethrottlesettings(cruisesegments)orthetotalacceleration(ascentanddescentsegments)andofthedragcoef cient.Thecomparativestabilityoftrimmingusingthetwomodesisalsoassessedbycomparingthestabilitymarginsandtheplacementofthelateralandlongitudinaleigenvalues.

Introduction

ThestudyreportedinthisdocumentisafollowonstudytotheworkreportedbyChowdhry

andButtrillintheirmemorandum[1].Inthatreport,theydocumented“astudyperformedtoassessthebareairframestabilitycharacteristicsofaHSCTcon gurationandtoinvestigatethebene ts,ifany,ofusinganactivefuelmanagementsystemtoreducetrimdrag.”Thestudyconsistsoftrimmingtheaircraftateachpointalongareferencemissionpro le(1)holdingthex-cgatitsnominalpositionandusingthestabilatorand(2)holdingthestabilatoratzerode ectionandmovingthex-cgtotrim.Stabilityandperformancemeasuresoftheaircraftarecomparedatthetwotrimconditionsateachpointofthereferencemissionpro le.

Ref.[1]studiedtheReferenceH,cycle1HSCTconcept.Thepresentstudyusesthe

ReferenceHCycle3airplane(Ref.H-3)[2].

ReferenceMissionPro le

Thereferencemissionpro lewastakenfromaTCACon gurationDescriptionDocument

[3,pp.A32–A43].Itisdescribedbyasampleof79 ightconditionsdividedinto vesegments:Seg.1Climb,30 ightconditions(numbers1–30).

Seg.2Supersoniccruise,13 ightconditions(numbers31–43).Seg.3Supersonicdescent,16 ightconditions(numbers44–59).Seg.4Subsoniccruise,13 ightconditions(numbers60–72).Seg.5Subsonicdescent,7 ightconditions(numbers73–79).

Thismissionpro lewasdesignedfortheTechnologyConceptAirplane(TCA)whichis

heavierthanRef.H-3.Tocorrectforthisweightdifferential,theaircraftweightsfromtheTCAmissionpro lehavebeenmultipliedbythefactor649914/740600whichistheratioofthemaxi-mumtaxiweightofRef.H-3tothatofTCA.Each ightconditionofthereferencemissionpro leisthende nedbyitsMachnumber,itsaltitude,its(scaled)weight,anditsrateofclimb.TheseareshowninFigs.1–4.

ModelingandAnalysisSoftware

ThemodelofRef.H-3andmuchoftheanalysissoftwarewascontainedinanintegrated

MATLAB/SIMULINKHSCTsimulation[4].Thesoftwaremodulerefhsim3

FLAGandtheAUTOWT

百度搜索“77cn”或“免费范文网”即可找到本站免费阅读全部范文。收藏本站方便下次阅读，免费范文网，提供经典小说教育文库The NASA STI Program Office provides(5)在线全文阅读。