Salient Features Of Scramjet Engine And Its Applications For Hypersonic Vehicles

 

Salient Features Of Scramjet Engine And Its Applications For Hypersonic Vehicles

        The scramejet uses a slightly modified Brayton Cycle to produce power, similar to that used for both the classical ramjet and turbine engine. Where Air is compressed and the  fuel injected, mixed and burned to increase the air, the combustion products are Temperature and Pressure then these combustion products are expanded.

For Turbojet engine Air is mechanically compressed by combustor using a turbine. In principle the ramjet and scramjet works the same. Where the forward motion of the vehicle compresses the air then the Fuel injected into the compressed air and burned. Results the high pressure combustion products expand through the Nozzle. Elevating the surface pressure and moving the vehicle forward.

 

SCRAMJET

• The wall of Ramjet will tend to fail at the higher temperature around 2500k,
• Like Turbojets, Conventional ramjets are also limited by material problem at high Mach Number.
• When the temperature of the air entering the combustor is too high, during which the fuel injected, it will be decomposed by the higher temperature instead been burned (Fuel will absorb rather than producing energy).
• The engine will become a Drag producing machine instead for a Thrust producing device.
• When the air flow is decrease by the scramjet the relative velocity and kinetic energy both decrease, during that energy required that any missing kinetic energy will reappear as internal energy.
• When the flight Mach number exceeds about 6 led to decelerate the flow to subsonic speeds.

Advantage

• No moving parts easies to manufacture.

• Has less weight and simple design.

• Does not have to carry oxygen tank.

• High seed could be achieved easier, so cheaper access to outer space in the future.

Disadvantage

• Scramjet cannot produce efficient thrust unless achieves high speed, around Mach 5.

• Testing a Scramjet design requires a expensive equipments (hypersonic test chambers and launching vehicles).

• Lack of strength.

 

 

 

Parts of Scramjet Engine

Scramjet Engine

        Scramjet is a variation of a Ramjet Engine, It is a type of Air breathing Engine where the combustion takes place in subsonic airflow, Scramjet  is supersonic throughout the entire engine , Scramjet operate more effective at extreme high speed of about Mach 5.

Parts of Scramjet Engine

• Inlet

• Isolator

• Combustor

• Nozzle

 

        The different Part of a Scramjet engine is Inlet, Isolator, Combustor and Nozzle. The scramjet engine must be integrated with the Fuselage of the aircraft, specially the air inlet and the Nozzle. Part of the forebody aircraft fuselarge makes the function of air let compressing the freestream air, and the after body acts as a nozzle expanding the gases for the combustion.

Salient Features of Liquid Propellant Rockets

 

Salient Features of Liquid Propellant Rockets:

                A liquid propellant propulsion system is commonly called rocket engines. It has all the hardware components and propellants necessary for its operations for producing thrust.

Liquid propellant propulsion system

Consists of one or more thrust chambers, one or more tanks to store propellants, a feed mechanism to force the propellants from the tanks into the thrust chamber, power source to furnish the energy for the feed mechanism, suitable plumbing or piping or piping to transfer the liquids,

Has a structure to transmit the thrust force, and control devices to initiate and regulate the propellant flow and thus the thrust.

In some application an engine may also include a thrust vector control system, various instrumentation and residual propellant (trapped in pipes, valves, or wetting tanks).

It does not include hardware for non-propulsive purpose, such as aerodynamic surface, guidance, or navigation equipment, or useful payload such as scientific space exploration package or missile warhead.