6097214-Scramjets.pdf

7/29/2019 6097214-Scramjets.pdf

1/24

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/

7/29/2019 6097214-Scramjets.pdf

2/24

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

7/29/2019 6097214-Scramjets.pdf

3/24

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

7/29/2019 6097214-Scramjets.pdf

4/24

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

7/29/2019 6097214-Scramjets.pdf

5/24

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


7/29/2019 6097214-Scramjets.pdf

6/24

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)


7/29/2019 6097214-Scramjets.pdf

7/24

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.


7/29/2019 6097214-Scramjets.pdf

8/24

CIAMsCIAMs IGLA hypersonic flying laboratoryIGLA hypersonic flying laboratory

http://www.ciam.ru/eversion/research/VRD/HYPER/

7/29/2019 6097214-Scramjets.pdf

9/24

Second launch of HyShot, on Jul. 30, 2002

http://www.mech.uq.edu.au/hyper/level2/hyper_photographs.html

7/29/2019 6097214-Scramjets.pdf

10/24

CGI image of XCGI image of X--43 separating from booster43 separating from booster

http://www.aerospace-technology.com/projects/x43/x439.html

7/29/2019 6097214-Scramjets.pdf

11/24

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

7/29/2019 6097214-Scramjets.pdf

12/24

Picture fromhttp://www.globalsecurity.org/space/systems/x-43.htm

7/29/2019 6097214-Scramjets.pdf

13/24

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

7/29/2019 6097214-Scramjets.pdf

14/24

Ramjet

Scramjet

Pictures from http://www.aviation-history.com/engines/ramjet.htm

7/29/2019 6097214-Scramjets.pdf

15/24

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

7/29/2019 6097214-Scramjets.pdf

16/24

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

7/29/2019 6097214-Scramjets.pdf

17/24

Picture from http://www.aip.org/tip/INPHFA/vol-10/iss-4/p24.html

7/29/2019 6097214-Scramjets.pdf

18/24

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

7/29/2019 6097214-Scramjets.pdf

19/24

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

7/29/2019 6097214-Scramjets.pdf

20/24

Picture by Garry Marshall, fromhttp://www.popsci.com/popsci/lgimg/0,21039,765284,00.html

7/29/2019 6097214-Scramjets.pdf

21/24

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


7/29/2019 6097214-Scramjets.pdf

22/24

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

7/29/2019 6097214-Scramjets.pdf

23/24

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.

7/29/2019 6097214-Scramjets.pdf

24/24

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.

Documents

6097214-Scramjets.pdf