rocket technology
-
Upload
vikram-chouhan -
Category
Documents
-
view
220 -
download
0
Transcript of rocket technology
ROCKET TECHNOLOGY
What is Rocket?A rocket or rocket vehicle is a missile, spacecraft, aircraft or
other vehicle which obtains thrust from a rocket engine. Rocket engines work by action and reaction.Rocket engines push rockets forwards simply by
throwing their exhaust backwards extremely fast.
Rockets are used for fireworks, weaponry, ejection seats, launch vehicles for artificial satellites, human spaceflight and exploration of other planets.
History of rocket A common claim is that the first recorded use of
a rocket in battle was by the Chinese in 1232 against the Mongol hordes at Kai Feng Fu.
Rocket technology first became known to Europeans
following its use by the Mongols Genghis Khan when they conquered parts of Russia, Eastern, and Central Europe.• In 1792, the first iron-cased rockets were successfully developed
used militarily by Hyder Ali and his son Tipu Sultan, rulers of the Kingdom of Mysore in India against the larger British East India Company forces during the Anglo-Mysore Wars.
History of rocket• Modern rockets were born when Robert
Goddard attached a supersonic (de Laval) nozzle to a liquid-fueled rocket engine's combustion chamber.
These nozzles turn the hot gas from the combustion chamber into a cooler, hypersonic, highly directed jet of gas, more than doubling the thrust and raising the engine efficiency from 2% to 64%.
Types of Rocket tiny models such as balloon rockets, water rockets, skyrockets or small solid rockets
that can be purchased at a hobby store Missiles, space rockets such as the enormous Saturn V used for the Apollo program rocket cars , rocket bike rocket powered aircraft (including rocket assisted takeoff of conventional aircraft-
JATO)
rocket sleds , rocket trains, rocket torpedos ,
rocket powered jet packs. rapid escape systems such as ejection seats and launch
escape systems , space probes.
DesignDesignA rocket design can be as simple as a cardboard tube filled with black powder but to make an efficient, accurate rocket or missile involves overcoming a number of difficult problems. The main difficulties include cooling the combustion chamber, pumping the fuel (in the case of a liquid fuel), and controlling and correcting the direction of motion.
Components Rockets consist of a propellant, a place to put propellant and a nozzle.
They may also have one or more rocket engines, directional stabilization device(s) (such as vernier engines or engine gimbals for thrust vectoring, gyroscopes) and a structure to hold these components together.
DesignDesignEngines Rocket engines employ the principle of jet
propulsion. Most current rockets are chemically powered rockets
(usually internal combustion engines) that emit a hot exhaust gas.
The acceleration of these gases through the
engine exerts force ("thrust") on the combustion chamber and nozzle, propelling the vehicle (according to
Newton's Third Law).
DesignDesignPropellant Rocket propellant is mass that is stored, usually in
some form of propellant tank or casing, prior to being used as the propulsive mass that is ejected from a
rocket engine in the form of a fluid jet to produce thrust.
The propellants are a fuel such as liquid hydrogen or kerosene which is burned with an oxidizer such as liquid oxygen or nitric acid to produce large volumes of very hot gas.
Sometimes the propellant is not burned but still undergoes a chemical reaction, and can be a 'monopropellant' such as hydrazine, nitrou oxide or hydrogen peroxide that can be catalytically decomposed to hot gas.
Technology The action of the rocket engine's combustion chambers and
expansion nozzles on a high pressure fluid is able to accelerate the fluid to extremely high speed, and conversely this exerts a large reactive thrust on the rocket (an equal and opposite reaction according to Newton's third law) which propels the rocket forwards.
Forces on a rocket in flightFlying rockets are primarily affected by the following:
Drag if moving in atmosphere Lift; usually relatively small effect except for rocket-powered aircraft Thrust from the engine Gravity from celestial bodies
Technology• Net thrust• It can be shown that the net thrust of a rocket is:
Fn =˙mv
where: ˙m=propellant flow (kg/s or lb/s) v=the effective exhaust velocity (m/s or ft/s)
Technology• Impulse• The total impulse of a rocket burning its
propellant is simply
I=∫Fdt
• When there is fixed thrust, this is simply:I=Ft
TechnologyTypical performances of common
propellantsPropellant mix Vacuum Isp (seconds) Effective exhaust
velocity (m/s)
liquid oxygen/liquid hydrogen
455 4462
liquid oxygen/kerosene (RP-1)
358 3510
nitrogen tetroxide/hydrazine
305 2993
TechnologyMass ratios
TechnologyAcceleration and thrust-to-weight ratio
From Newton's second law, the acceleration, a, of a vehicle is simply:a= (Fn/m)
where m is the instantaneous mass of the vehicle and Fn is the net force acting on the rocket (mostly thrust but air drag and other forces can play a part.)
TechnologyDrag Drag is a force which acts opposite to the
direction of the rocket's motion.Drag causes a decrease in the acceleration of
the vehicle whilst also producing structural loads.
Drag can be minimised by an aerodynamic nose cone and by using a shape with a high ballistic coefficient and by keeping the rocket's angle of attack as low as possible.
TechnologyEnergyRocket launch vehicles take-off with a great deal of
flames, noise and drama, and it might seem obvious that they are grievously inefficient.
The energy density of a typical rocket propellant is often around one-third that of conventional hydrocarbon fuels; the bulk of the mass is oxidizer.
Energy from the fuel is lost in air drag and gravity drag and is used for the rocket to gain altitude and speed. However, much of the lost energy ends up in the exhaust.
Technology
Rocket propulsive efficiency as a function of vehicle speed divided by effective exhaust speed
Noise For all but the very smallest sizes, rocket exhaust compared to
other engines is generally very noisy. As the hypersonic exhaust mixes with the ambient air, shock waves are formed. The sound intensity from these shock waves depends on the size of the rocket as well as the exhaust speed. The sound intensity of large, high performance rockets could potentially kill at close range.
The Space Shuttle generates over 200 dB(A) of noise around its base.
Noise is generally most intense when a rocket is close to the ground, since the noise from the engines radiates up away from the plume, as well as reflecting off the ground.
CONCLUSIONWith the progress of our civilization and technology
, rocket technology is developed to improve other technology for the development of the future. But sometimes rocket is used as weapon,and also it causes many environmental problems. It depends
on the human whether it gives beautiful life or takes lives as weapon of destruction.
PREPARED BYSWARNENDU SAMANTA (09108016083)
VIDYA SAGAR PRASAD(09108016087)
TANMAY PAL(09108016084)
VIKASH MANDAL(09108016088)
TAUSIF AHMED(09108016085)
VIKRAM CHAHAN(09108016089)
UMA SHANKAR(09108016086)
PROSENJITGOSWAMI(10108010089)