air-breathing propulsion: the future of access to space
TRANSCRIPT
F. GNANI, H. ZARE-BEHTASH & K. KONTIS
AIR-BREATHING PROPULSION: THE FUTURE OF ACCESS TO SPACE
Space Glasgow Research Conference28th October 2014
OVERVIEW
Francesca Gnani [email protected]
•Hystoricaloverview
•Presenttechnology
•High-speedintakes
•Pseudo-shockwaves
•Conclusions
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ORIGINS
Francesca Gnani [email protected]
•1913-RenéLorin:jetpropulsioncreated
bydirectingexhaustfromcombustioninto
nozzles.
•1944-Messerschmitt Me 163 Komet:
rocket-poweredfighteraircraftflight.
•1949-Leduc 0.10:world’sfirstaircraft
poweredexclusivelybyaramjetatM=0.9.
•1958-Nord 1500 Griffon:reachedM=2.19.3
AIR-BREATHING PROPULSION
Francesca Gnani [email protected]
(CourtesyofNASA)
•Machnumbergreaterthan3
andlessthan18.
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AIR-BREATHING PROPULSION
Francesca Gnani [email protected]
(CourtesyofNASA)
•Machnumbergreaterthan3
andlessthan18.
•Aircompressionbygeometry
changes,i.e.shockwaves.
•Absenceofrotatingcomponents.
•Ambitiontoreusablelaunch
systems.
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SCRAMJET VS ROCKET
Francesca Gnani [email protected]
•Absenceofoxidants.
•Improvementinpayloadcapabilityandmanoeuvring.
•Increaseinthepropulsiveefficiency.
•Reductionofvolumeandstructuralweight.
•Simplicityforabsenceofrotatingcomponents.
•Drawbacknothrustatzerospeed.
•Needtoflyintheatmosphere:aerodynamicforcesandheating.
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PRESENT TECHNOLOGY
Francesca Gnani [email protected]
•Maintaininganacceptablethrustlevelandfuelconsumption
overtheentireflightrange.
•Multi-modevehicles&combined-cycleengines.
•Combined-cyclesystemsareproblematicinthetransitionfrom
gas-turbinetoramjet/scramjetpowerandvice-versa.
•Scramjettechnologyforspaceaccessisonegenerationbehind
thatformissilesduetotherequirementfortestingatsuchhigh
Machnumber.8
HIGH-SPEED INTAKES
Francesca Gnani [email protected]
(Chenetal.2014)
Largecompressionratio.
Providestableflowtocombustionchamber.
Mixedcompression:shockstructureexternallyandinternally
theengine.
Composedof:
•Forebody
•Cowl
•Isolator10
ISOLATOR
Francesca Gnani [email protected]
(Ikui&Matsuo1969)
Nearlyparallelductplacedbetweentheinletandthecombustor.
Maintaindifferentconditionsupstreamanddownstreamtheduct.
Allowsthegenerationoftheprecombustionshockwave.
Flowstabilisation.
Higherenginethrust.
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NORMAL SHOCK TRAIN
Francesca Gnani [email protected]
(Heiser&Pratt1994) (Weissetal.2010)
(Sun2004)
Seriesofnormalshockswithdecreasingstrengthanddistance.
Majorportionofcompressionatthefirstshock.
Normalshockinthecentreoftheduct.
Obliqueshockwavesnearthewall.
Sequentialflowde-andacceleration.
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OBLIQUE SHOCK TRAIN
Francesca Gnani [email protected]
(Heiser&Pratt1994) (Sugiyamaetal.2006)
(Sun2004)
Initialobliqueshockseparatestheboundarylayer.
Alternatingcompressionandexpansionasaconsequenceof
shockpropagationalongtheduct.
GreaterflowMachnumber.
Largerboundary-layerseparation.
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CONCLUSIONS
Francesca Gnani [email protected]
•Currentunderstandingonthemechanismsofthepseudo-shock
phenomenaisnotsufficient.
•Aimtodesignacompletelyreusable,single-stagespaceplane,
abletotakeoffandlandwithouttheaidofanothervehicle.
•Thestudyshockwavestructureinsideisolatorisahighly
importanttodesignadvancedvehicles.
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THANK YOU
