Scramjet engines operate by compressing incoming air through ramjet-style inlets at supersonic speeds for combustion, without rotating parts. They can reach speeds between Mach 12-24 and use oxygen from the air rather than carrying it. Scramjets have converging inlets, combustors where fuel burns with air, and diverging nozzles. They start at Mach 6 and provide efficient, eco-friendly thrust for applications like hypersonic transportation and missiles. However, scramjets require additional boosting and have testing difficulties.

1. SCRAMJET ENGINE
BY
MITHUN T
S8 ME
ROLL NO 38
B4ENME4237

2. CONTENTS
 INTRODUCTION
 TURBOJET ENGINE
 RAMJET ENGINE
 SCRAMJET ENGINE
 PRINCIPLE OF WORKING
 COMPARISON
 Advantages
 Disadvantages
 Applications
 Recent progress
 Conclusion
 References

3. INTRODUCTION
 Scramjet is stand as supersonic combustion ramjet
 Has no turbo machinery
 Top speed of a scramjet engine vary between Mach 12 and
Mach 24
 main difference from a rocket ,it collects O2 from the air to
burn its fuel
 Air breathing jet engine
 A Scramjet is a variant of a ramjet air breathing combustion jet
engine

4. TURBOJET ENGINE
 Turbojets are the oldest kind of general-purpose jet engines
 Turbojets are rotary engines that extracts energy from a flow of
combustion gas
 They produce thrust by increasing the velocity of the air flowing
through the engine and operate on Newton’s third law of motion

5. TURBOJET ENGINE

6. RAMJET ENGINE
 A Ramjet is a areo thermodynamic duct
 Is a form of air breathing jet engine that uses the engine's forward
motion to compress incoming air without an axial compressor
 Ramjets cannot produce thrust at zero air speed, they
cannot move an aircraft from a standstill
 It uses subsonic flow of air for combustion
 During the compression process in Ram jet engine ,kinetic energy
of incoming atmospheric air is converted in to the potential energy
by the diffuser

7. RAMJET ENGINE
Beyond M = 6,the combustion is inefficient and incomplete because of very
high temperature of entry air, and this gives improper expansion in the nozzle

8. SCRAMJET ENGINE
 A Scramjet (supersonic combustion ramjet) is a variant of a ramjet air
breathing combustion jet engine in which the combustion process takes
place in supersonic airflow
 Scramjet starts to operate when the speed of the craft reaches
Mach6

9. COMPONENTS OF SCRAMJET ENGINE
The Scramjet is composed of three basic components:
A converging inlet, where incoming air is compressed and
decelerates.
A combustor, where gaseous fuel is burned with atmospheric
oxygen to produce heat.
A diverging nozzle, where the heated air is accelerated to produce
thrust.

11. PRINCIPLE OF WORKING
 Scramjets also works on the principle of ramjets.
 All the operations done by the varying cross section of passages.
 Basically in order to achieve the initial speed, a second engine is
integrated in the scramjet model, it may be rocket or turbojet
engine.
 Air from the atmosphere enters at very high speed in the inlet
passage.
 In case of a scramjet the diffuser is merged with inlet.

12.  Hence, the air from the atmosphere enters in the inlet section having
very high velocity is reduced in diffuser section, thereby its static
pressure increases.
 Temperature of air increases when passing through the narrow cross
section towards combustion chamber.
 Hot air flows in the combustion chamber and at this moment the
propellant i.e. hydrogen (having a very low ignition temperature)
are injected by the injector in the combustor.

13.  Where it gets self ignited within a millisecond and the combustion
process is carried out at the supersonic speed.
The fresh air supply to the diffuser builds up a pressure at the
diffuser so that these burned gases cannot expand towards the diffuser.
Instead, the gases are made expand in combustor towards tail engine
hence providing the required thrust.

15. DOES NOT HAVE TO CARRY OXYGEN TANK.
NO ROTATING PARTS MAKES IT EASIER TO MANUFACTURE.
LESS WEIGHT AND SIMPLE DESIGN.
AS THE HYDROGEN IS USED AS A PROPELLANT AND COMBUSTION IS CARRIED
OUT AT SUPERSONIC VELOCITY WITH THE HELP OF OXYGEN
FROM THE ATMOSPHERE.
AS A RESULT OF THAT, STEAM (H2O) IS BEING EXHAUST GAS WHICH IS
ECOFRIENDLY IN NATURE
ADVANTAGES

16. A SCRAMJET CANNOT PRODUCE EFFICIENT THRUST UNLESS
BOOSTED TO HIGH SPEED, AROUND MACH 5.
AS A RESULT AN ADDITIONAL PROPULSION SYSTEMS ARE
REQUIRED.
LACK OF STEALTH.
TESTING DIFFICULTIES.
DISADVANTAGES

17. CIVIL APPLICATIONS
SCRAMJET SPEED COULD REACH 15 TIMES THE SPEED OF SOUND .
AN AIRCRAFT USING THIS TYPE OF JET ENGINE COULD
DRAMATICALLY REDUCE THE TIME IT TAKES TO TRAVEL FROM
ONE PLACE TO ANOTHER, POTENTIALLY PUTTING ANY PLACE
ON EARTH WITHIN A 90 MINUTES FLIGHT, I.E. AN 18 HOUR
TRIP TO TOKYO FROM NEW YORK CITY BECOMES A 2 HOUR
FLIGHT.
APPLICATIONS

18. MILITARY APPLICATION:-
Scramjet can be used to propel missiles. Currently used scramjet
propelled missiles are:-
1) British bloodhound surface to air missile.
2) British MBDA Meteor air to air missile.
3) Russian Indian Brahmos Supersonic cruise missile

20. RECENT PROGRESS

21. CONCLUSION
Scramjet programme is a fast developing field in the
present world.
There are many application with scramjet. It provides a cheaper
and efficient access to space.
Scramjet has the potential for supersonic or
hypersonic transportation.
Scramjet technologies are also used for advanced
military applications

22. WWW.WIKIPEDIA.ORG/WIKI/SCRAMJET
WWW.SCRAMJET.COM
WWW.NASA.COM
WWW.AEROSPACEWEB.ORG
AIRCRAFT AND MISSILE PROPULSION- M J ZUCROW, JOHN
WILLY
HYPERSONIC AIR BREATHING PROPULSION- WH HEISER,
DT PRATT
REFERENCES