Scramjet engine

SCRAMJET ENGINE

NAME- SHUBHAM GUPTAROLL NO- 54 (ME) 3RD SEM

CONTENTS

IntroductionWhat is scramjet engine?

Components

principle of working Advantages Disadvantages

Applications Programmes Recent progress

Conclusion

INTRODUCTION

• Rockets combine a liquid fuel with liquid oxygen to create thrust.

• If the need for liquid oxygen is taken away, spacecraft can be smaller or carry more payloads.

• This is the concept behind a different propulsion system called “scramjet” or “super sonic combustion ramjet”.

WHAT IS A 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.

• As in ramjets, a scramjet relies on high vehicle speed to forcefully compress and decelerates the incoming air before combustion (hence ramjet), but whereas a ramjet decelerates the air to subsonic throughout the entire engine.

• The theoretical projections place top speed of scram between Mach 12 and Mach 24, which is near orbital velocity.

• The fastest air-breathing plane is a SCRAMJET design, the NASA X-43a which reached Mach 9.6 or 12,144 km/h, on 16 Nov 2004.

COMPONENTS OF SCRAMJET ENGINE

The Scramjet is composed of three basic components:

1) A CONVERGING INLET, where incoming air is compressed and decelerates.

2) A COMBUSTER, where gaseous fuel is burned with atmospheric oxygen to produce heat.

3) A DIVERGING NOZZLE, where the heated air is accelerated to produce thrust.

SIMPLE DESIGN OF SCRAMJET

PRINCIPLE OF WORKING

Scramjets also works on the principle of ramjets.

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.

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.

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.

COMPARISION

ADVANTAGES

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 eco-friendly in nature.

DISADVANTAGES

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.

APPLICATIONS

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.

TUPOLEV TU-144 (CHARGER)“Tupolev tu-144 (charger)” was the 1st commercial supersonicAircraft.

• Introduction- 26 Dec 1975• Highest speed- 2430 km/hr• Retired- 1 Jun 1978

CONCORDE“CONCORDE” one of the successful supersonic airlinerby British airways & Air france.• Introduction- 21 Jan 1976• Highest speed- 2179 km/hr• Retired- 26 Nov 2003• After a crash on 25th Jul 2000 & Less passenger capability & high Cost it was retired.

SCRAMJET AIRBUSThe future by “Scramjet Airbus”.Concept about aviation In 2050.

An ‘Invisible’ airbus wouldgive passengers of floatingin the sky & a 360” view of surrounding with a supersonic speed.

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.

British bloodhound missile British MBDA Meteor missile

Russian Indian Brahmos Supersonic cruise missile

RECENT PROGRESS

X-43B A scaled-up version of the X-43A, to be powered by the ISTAR engine. ISTAR will use a hydrocarbon-based liquid-rocket mode for initial boost, a ramjet mode for speeds above Mach 2.5, and a scramjet mode forspeeds above Mach 5 to take it to maximum speeds of at least Mach 7.

X- 51A

The Boeing X- 51A (WaveRider) is the longest air-breathing hypersonic flight.

On 1 May 2013, the X-51 Performed its first fully successfully flight test on its fourth test flight.Aircraft flew for 210 sec at Mach 5.1 (5400 km/hr)

GOING SUPERSONIC AGAIN!!

NASA and industry partners have designed concepts for the Next- generation supersonicTransport (SST) planned for deployment by 2030.A passenger jet that would fly 300 passengers at more Than 2,400 km/hr.

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.

REFERENCES 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

“THANK YOU”