Mechanical Engineering Study materials & Science & Technology

• Screw Compressor basically consist of two mutually engaged helically grooved rotors inside a casing.
• One of them are male rotors consist of four lobe and it's a driving rotor.
• And the other is female rotor consist of six gullies and it's a driven rotor.
• These screw Compressor is coupled with an electric motor which gives mechanical rotational movement to the male rotors.

• When the driving rotor starts rotating along with the female rotar.then at the same time the suction end opened and the air is now starts to entrapping inside the casing .as these rotors rotate continuously the air entrapped continuously inside the casing.
• Due to this now the air is inside the casing and both rotors rotating radially and axially with the rotation of rotars  and gets compressed due to this reduction in volume happens continuously until it reaches the discharge end.
• As we know that the male rotors and the female rotor have different type of lobes so due to this they both rotate at different speeds.

• In this lobe Compressor,First an external mechanical energy is given to one of the rotors from an external source like electric motor.and due to this the second rotor makes gear driven from the first lobe. 
• When motor start moving the first lobe also start moving along with the second lobe which is gear driven from the first.
• Due to continuous moving of both lobe the air trapped inside the casing after coming from the inlet part.due to continuous moving the entrapped air is now pressurized and this pressurized air is delivered  when first and second lobe makes perpendicular at this time.the pressurized air is passed at this time to the delivery chamber.

• It is very noisy in nature.
• It is setup in the sound isolated room.

1. Lobe Compressor
2. Rotary screw Compressor
3. Rotary vane compressor.

• Cruise missiles:-It can flight at lower layer of the atmosphere and can hit the target accurately.
• Ballistic missiles:-It can flight above the upper layer of atmosphere and then came towards the target due to high influence of gravity.and can hit the target accurately.

On the basis of launch mode

• Surface to Surface missile:-It can target only surface to surface.eg:-Agni
• Surface to Air:- It can target the missile from surface of the earth to the air.eg:-Akash
• Air to Air:-It can hit the target from air to air.eg:-Astra
• Air to surface:-It can hit the target from Air to Surface.eg:-Brahmos
• Anti tank Missile:-It can prevent the tank by targetting the missile which is coming towards tank body.eg:-Nag

On the basis of Range

• Short range:-It can target less than 1000 km.
• Medium range:-It can target between 1000 to 3000 km.
• Intermediate range:-It can target between 3000 to 5500 km.
• Intercontinental range:-It can target over 5500 km.

On the basis of warhead

• Conventional type:- This is used as oldmethod to contains high energy explosives.
• Strategic Type:-It contains radioactive materials and can wipe off even out cities.this radioactive elements become dangerous when it be released because it makes nuclear chain reaction during nuclear fission.

Integrated Guided missile Development programme 

• Launched in 1980
• Completion of programme in 2008
• Architect of this program by Dr.APJ Abdul Kalam.
• Under this programme 5 missile are Agni,Aakash,prithvi,Trishul,Aakash and Nag.

Agni Missiles

• Agni 1:-Its Range is about 700 to 900 km.and can carry nuclear warhead.
• Agni 2:-Its range is about 2000 to 2500 km.and can carry nuclear warhead.
• Agni 3:-Its range is about 3500 km. And this nuclear warhead carrying capability.
• Agni 4:-Its range is about 5500 km. And it is nuclear warhead carrying capability.
• Agni 5:- It's Range is about 5000 km.and this is nuclear warhead carrying capability due to this it is very destructive in nature.
• Agni 6:- It is under development and it can be assume that range will be 5000 to 8000 km.and a new system is enhanced in it that is multiple independent reventry vehicle technique.

Prithvi Missiles

• Prithvi 1:- It's Range is about 150 km and can carry 1000 kg nuclear Warhead.
• Prithvi 2:-Its range is about 250 km.and carry 250 kg nuclear warhead.and it is Nuclear capable Missile.
• Prithvi 3:-Its warhead weight 500 to 1000 kg. And range is about 350 km to 750 km.

Dhanush Missile

• This is modification or naval version of prithvi missile .It can be used by ships.

Nag Missile

• It is Anti tank Missile and this is fire and forget missile guided system.this can be used to protect tanks.

Nirbhay Missile

• It is long distance subsonic cruise Missile and it is Nuclear carrying capability.its range is about over 1000 km.and it's speed is less than that of speed of Sound.

Shaurya Missile

• It is Surface to Surface missile and it's Range is 700 to 1900 km. it is Supersonic Missile and can travel at a speed of Mach 7.5 which means grater than that of speed of sound.it is Nuclear warhead carrying capability.

Aakash Missile

• It is Surface to air missile and it's Range is about 25 Km. It is used by Indian army as well as Indian Air Force.

BARACK-8 Missile

• It is Surface to air missile.its range is about over 70 km.and it is developed jointly by India and israil by Indian organization DRDO and israil Aerospace Industry.

Brahmos Missile

• It is cruise missile and it can flight at lower layer of atmosphere.Radar can't be detect easily and it is very destructive and hit the target accurately.it is range capable missile and nuclear capable missile.And it can be launched by ships,aircrafts as well as surface.It is developed jointly by India and Russia.

Astra Missile

1. Guidance System:- The function of guided system is to maintain the desired path or position of missiles after launching.
2. Propulsion system:- This system is very important for any missiles because it gives to achieve desired position .it gives speed,range and warhead carrying capability.the missiles is propelled either by jet engines or rockets and fuel is used in solid or in liquid form.
3. Terminal guidance in case of precision guided missiles:- In this system the missiles first detect the image of a target and this image is detected by a infrared (IR)or laser devices after that an electrical signal is generated and this signal is send to trigger the activation and the missiles is activated.
4. Aerodynamic Systems and features:-This system is used to control missiles flight .the find,wings and tails are the three most important aerodynamic control system.
5. Warhead:- It means that a missiles contain explosives for destroying target. It determines how a missile is destructive.