my scramjet

8/13/2019 My Scramjet

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ByHimanshu Gupta

111638

I have one speed,I have one Gear;

Go!


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A scramjet (supersoniccombustion ramjet) is avariant of a ramjet air

breathing combustionjet engine in whichcontinuous combustionprocess takes place insupersonic airflow.

Requires forwardmotion to producethrust


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Scramjets operate at

hypersonic (>Mach 5)velocities, through flow

and combustion takesplace at supersonic

velocities.

No operational systems,but a number of testflights and many ground

tests

Ramjets fly at high

subsonic to supersonicspeeds but the airflow

through them and theircombustion is subsonic

velocities.

Widely used for missiles,and on a few aircraft.


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A CONVERGING INLET,

where incoming air iscompressed and

decelerated. 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.


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Scramjet works on the same principle of Ramjet.

All the operations are done by the varying cross section ofpassages.

There are inlet passage, diffuser passage, combustion passage andexhaust passage.

Basically in order to achieve the initial speed, a second engine is

integrated in the Scramjet model, it may be rocket or turbojetengine.


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As these are air breathing engines, air from the

atmosphere enters at very high speed in the inletpassage.

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 also increases when passingthrough the narrow cross section towards

combustion chamber.


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Hot air flows in the combustion chamber and at thismoment the propellant i.e. hydrogen (having a very

low ignition temperature) as a fuel are injected by the

injector in the combustor.

Where it gets self ignited within a millisecond andthe 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


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Artist's conception of the NASA X-43with scramjetattached to the underside
http://en.wikipedia.org/wiki/NASA_X-43http://en.wikipedia.org/wiki/NASA_X-43http://en.wikipedia.org/wiki/NASA_X-43http://en.wikipedia.org/wiki/NASA_X-43


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Ramjets and Scramjets have been used in

missiles, helicopters, and the SR71 Blackbird withvarying degrees of success.
http://upload.wikimedia.org/wikipedia/en/c/c8/Hiller_YH-32_Hornet.jpg


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Does not have to carryoxygen

No rotating parts makes

it easier to manufacture

Higher speed could meancheaper access to outerspace in the future

Higher efficiencies

Testing difficulties:-expensive launch

vehicles, both of which

lead to high

instrumentation costs. A scramjet cannot

produce efficient thrust

unless boosted to high

speed, around Mach 5,although depending on

the design it could act as a

ramjet at low speeds.


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my scramjet

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