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Scramjets
By Emily Davisand Raechel Tan
August 6, 2005
Cluster 3: Introduction to Engineering Mechanics
Professor HafezPicture from http://www.msnbc.msn.com/id/6448094/
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OverviewOverview
What is a scramjet?What is a scramjet?
RamjetsRamjets History and recent developmentsHistory and recent developments
Ramjets vs. conventional jetsRamjets vs. conventional jets
Scramjets vs. ramjetsScramjets vs. ramjets
Engine layout of a scramjetEngine layout of a scramjet
FuelFuel Launching and landingLaunching and landing
Advantages and disadvantagesAdvantages and disadvantages
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What is a scramjet?What is a scramjet?
Stands for Supersonic CombustionStands for Supersonic Combustion
RamjetRamjet Travels at hypersonic speeds (aboveTravels at hypersonic speeds (above
Mach 5)Mach 5)
Has an airHas an air--breathing engine, meaningbreathing engine, meaning
that it takes oxygen from the airthat it takes oxygen from the air
instead of carrying oxygen in a tank.instead of carrying oxygen in a tank.
http://en.wikipedia.org/wiki/Scramjet
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RamjetsRamjets
A scramjet is a variation of a ramjet.A scramjet is a variation of a ramjet. Ramjets remove most moving parts ofRamjets remove most moving parts of
an engine by traveling at very highan engine by traveling at very high
speeds to eliminate the need for fans tospeeds to eliminate the need for fans tocompress the air.compress the air.
At subsonic speeds ramjets andAt subsonic speeds ramjets and
scramjets tend not to produce muchscramjets tend not to produce muchthrust, nor are they very fuelthrust, nor are they very fuel--efficient.efficient.
http://en.wikipedia.org/wiki/Ramjet
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HistoryHistory
Research into practical supersonic flightResearch into practical supersonic flight
started during WWIIstarted during WWII 1950s: U.S. Air Force, Navy, and NASA1950s: U.S. Air Force, Navy, and NASA
began to develop scramjet enginesbegan to develop scramjet engines
1986: NASA's National Aerospace Plane1986: NASA's National Aerospace Plane(NASP) program established to develop(NASP) program established to developa vehicle with speed greater than Macha vehicle with speed greater than Mach
15, the ability to take off horizontally,15, the ability to take off horizontally,and the ability to landand the ability to land
http://en.wikipedia.org/wiki/Scramjet
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Scramjet ProgramsScramjet Programs
RussiaRussia Nov. 17, 1992: Russian scientists launched aNov. 17, 1992: Russian scientists launched a
scramjet inscramjet in KazakhstanKazakhstan (in a wind tunnel)(in a wind tunnel)
19941994 1998: NASA and Russian Central Institute of1998: NASA and Russian Central Institute ofAviation Motors (CIAM) did 4 tests and reached MachAviation Motors (CIAM) did 4 tests and reached Machnumbers of 5.5, 5.35, 5.8, and 6.5 (in a simulatednumbers of 5.5, 5.35, 5.8, and 6.5 (in a simulatedenvironment).environment).
AustraliaAustralia Jul. 30, 2002: University of QueenslandsJul. 30, 2002: University of Queenslands HyShotHyShot
team successfully tested a scramjetteam successfully tested a scramjet
NASAs HyperNASAs Hyper--X ProgramX Program Replaced NASP program in 1994Replaced NASP program in 1994
Mar. 27, 2004: Successfully launched the XMar. 27, 2004: Successfully launched the X--43A43A
Nov. 16, 2004: 3Nov. 16, 2004: 3rdrd XX--43 flight set new speed record43 flight set new speed record
of 6,600 mph (almost Mach 10)of 6,600 mph (almost Mach 10)
http://en.wikipedia.org/wiki/Scramjet
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Recent DevelopmentsRecent Developments
HyShotHyShot Project in 2002 was the firstProject in 2002 was the firstsuccessful test of a scramjet in thesuccessful test of a scramjet in theatmosphereatmosphere
U.S. Air Force and Pratt & Whitney haveU.S. Air Force and Pratt & Whitney havecollaborated on the Hypersoniccollaborated on the HypersonicTechnology (Technology (HyTECHHyTECH) scramjet engine) scramjet engine
NASA's Marshall Space PropulsionNASA's Marshall Space PropulsionCenter has created an IntegratedCenter has created an Integrated
Systems Test of an AirSystems Test of an Air
--BreathingBreathing
Rocket (ISTAR) program.Rocket (ISTAR) program. Pratt &Pratt &WhitneyWhitney,, AerojetAerojet, and, and RocketdyneRocketdyne arearecollaborating on the development.collaborating on the development.
http://en.wikipedia.org/wiki/Scramjet
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CIAMsCIAMs IGLA hypersonic flying laboratoryIGLA hypersonic flying laboratory
http://www.ciam.ru/eversion/research/VRD/HYPER/
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Second launch of HyShot, on Jul. 30, 2002
http://www.mech.uq.edu.au/hyper/level2/hyper_photographs.html
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CGI image of XCGI image of X--43 separating from booster43 separating from booster
http://www.aerospace-technology.com/projects/x43/x439.html
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Ramjets vs. Conventional JetsRamjets vs. Conventional Jets Conventional jets needConventional jets need
compressors to compresscompressors to compressthe air they take in.the air they take in.
Ramjets use extremelyRamjets use extremelyhigh velocities tohigh velocities tocompress the air.compress the air.
Ramjets slow down theRamjets slow down the
air before combustion,air before combustion,which results in a rise inwhich results in a rise inpressure. (PV=pressure. (PV=nRTnRT))
http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
Picture fromhttp://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
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Picture fromhttp://www.globalsecurity.org/space/systems/x-43.htm
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Scramjets vs. RamjetsScramjets vs. Ramjets
Both ramjets and scramjets travelBoth ramjets and scramjets travelhypersonically.hypersonically.
Ramjets slow down the intake air toRamjets slow down the intake air tosubsonic speeds to boost the pressure,subsonic speeds to boost the pressure,and then combusts it.and then combusts it.
Scramjets slow down the air, but not toScramjets slow down the air, but not tosubsonic speeds. Combustion takessubsonic speeds. Combustion takesplace while the air is still movingplace while the air is still movinghypersonically.hypersonically.
http://www.aviation-history.com/engines/ramjet.htm
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Ramjet
Scramjet
Pictures from http://www.aviation-history.com/engines/ramjet.htm
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Shock WavesShock Waves
The incoming air slows down when itThe incoming air slows down when itpiles up against the other air. Thispiles up against the other air. This
results in an increase in pressure.results in an increase in pressure.
The sudden increase in pressure causesThe sudden increase in pressure causesa shock wave.a shock wave.
http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
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Engine LayoutEngine Layout
The engine is located on the bottom ofThe engine is located on the bottom of
the scramjet body.the scramjet body.
5 main engine components:5 main engine components: internal inletinternal inlet
isolatorisolator combustorcombustor
internal nozzleinternal nozzle
fuel supply subsystemfuel supply subsystem
2 main vehicle components2 main vehicle components
forebodyforebody aftbodyaftbody http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
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Picture from http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
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FuelFuel
Most scramjets run on hydrogen fuel.Most scramjets run on hydrogen fuel.When the hydrogen burns in oxygen,When the hydrogen burns in oxygen,
the only byproduct is water.the only byproduct is water. 2 H2 H22 + O+ O22 2 H2 H22OO
The hydrogen fuel is used as a coolant prior to beingThe hydrogen fuel is used as a coolant prior to being
combusted, since it can absorb so much heat. Thecombusted, since it can absorb so much heat. The
absorption of heat also acts to preheat the fuelabsorption of heat also acts to preheat the fuel
before combustion.before combustion.
Some scramjets burn hydrocarbons.Some scramjets burn hydrocarbons.
(e.g.(e.g. HyTECHHyTECH)) Hydrocarbon fuel does not have as much energy asHydrocarbon fuel does not have as much energy as
hydrogen fuel.hydrogen fuel.
But hydrocarbons are easier to handle thanBut hydrocarbons are easier to handle than
hydrogen.hydrogen.http://en.wikipedia.org/wiki/Scramjethttp://www.afrlhorizons.com/Briefs/Dec01/PR0102.html
hi / diL hi /L di
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Launching/LandingLaunching/Landing
Scramjets cannot function at speedsScramjets cannot function at speedsbelow Mach 5. This means that theybelow Mach 5. This means that they
cannot take off on their own.cannot take off on their own.
Currently, scramjets are launched fromCurrently, scramjets are launched froma large airplane (such as a Ba large airplane (such as a B--52), with52), with
a rocket connected to it. The rocketa rocket connected to it. The rocket
accelerates the scramjet until it is fastaccelerates the scramjet until it is fast
enough to fly on its own.enough to fly on its own.
As of yet, scramjets do not have anyAs of yet, scramjets do not have anyreal landing capabilities. Tests ofreal landing capabilities. Tests of
scramjets have them splash down inscramjets have them splash down in
the ocean.the ocean. http://en.wikipedia.org/wiki/Scramjethttp://www.popsci.com/popsci/lgimg/0,21039,765284,00.html
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Picture by Garry Marshall, fromhttp://www.popsci.com/popsci/lgimg/0,21039,765284,00.html
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AdvantagesAdvantages
Does not have to carry oxygenDoes not have to carry oxygen
No rotating parts = easy toNo rotating parts = easy to
manufacturemanufacture Has a higher specific impulse (change inHas a higher specific impulse (change in
momentum per unit of propellant) thanmomentum per unit of propellant) than
a conventional engine; could providea conventional engine; could providebetween 1000 and 4000 seconds, whilebetween 1000 and 4000 seconds, whilea rocket only provides 600 seconds ora rocket only provides 600 seconds or
lessless Higher speed could mean cheaperHigher speed could mean cheaper
access to outer space in the futureaccess to outer space in the future
http://en.wikipedia.org/wiki/Scramjet
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DisadvantagesDisadvantages
Gets very hotGets very hot
Heat due to shock wavesHeat due to shock waves
High aerodynamic loadsHigh aerodynamic loads High, fluctuating pressureHigh, fluctuating pressure
Erosion from airflow over the vehicleErosion from airflow over the vehicle
and through the engineand through the engine
Cannot launch on its ownCannot launch on its own
Cannot land on landCannot land on land Vehicle may not be reusableVehicle may not be reusable
If made to carry passengers, sonicIf made to carry passengers, sonicbooms and high gbooms and high g--levels would be alevels would be ahttp://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html
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SummarySummary
A scramjet is a hypersonic jet that hasA scramjet is a hypersonic jet that has
an airan air--breathing engine.breathing engine.
There are very few moving parts in theThere are very few moving parts in the
engine.engine.
Most scramjets run on hydrogen fuel.Most scramjets run on hydrogen fuel. They must get to hypersonic speedsThey must get to hypersonic speeds
with a rocket, and can only splashwith a rocket, and can only splash
down in the ocean.down in the ocean.
Scramjets are still in testing modeScramjets are still in testing mode----
not yet suitable for commercial use.not yet suitable for commercial use.
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AcknowledgementsAcknowledgements
Thank you to MikeThank you to Mike PaskowitzPaskowitz, our, ourteacher fellow, for helping us withteacher fellow, for helping us with
this presentation!this presentation!
Also thank you to Professor Hafez,Also thank you to Professor Hafez,
our T.A. Bethour T.A. Beth KuspaKuspa, and our R.A., and our R.A.Tim McGuire.Tim McGuire.