cryogenic engine ppt by santosh

1. CRYOGENIC ROCKET ENGINE A.SANTOSH

2. CONTENTS 1.CRYOGENICS ? 2.INTRODUCTION 3.HISTORY OF CRE 4.CONSTRUCTION 5.WORKING 6.APPLICATIONS 7.REFERENCES

3. CRYOGENICS The word ‘ cryogenics ’ is derived from Greek , meaning “production of freezing cold”. cryogenics  is the study of the production and behaviour of materials at very low   temperatures   ( below −150 °C, −238 °F or 123 K ). Rather than the relative temperature scales of Celsius and Fahrenheit, cryogenicists use the absolute temperature scales. These are  Kelvin  (SI units) or Rankine scale  (Imperial and US units ). Oxygen liquifies at -183c(90k) Hydrogen liquifies at -253c(20k)

4. INTRODUCTION A  cryogenic engine  is a  rocket engine  that uses a  cryogenic fuel  . Cryogenic fuels  are  fuels  that require storage at extremely low temperatures in order to maintain them in a liquid state . Various cryogenic fuel-oxidizer combinations have been tried, but the combination of liquid hydrogen ( LH2 ) fuel and the liquid oxygen ( LOX ) oxidizer is one of the most widely used .

5. principle The basic principle driving a rocket engine are: Newton third law of motion Law of conservation of momentum In principle, cryogenic rocket engine derives thrust like all other rocket engines by accelerating an impulse carrier to high speeds. The chemical energy stored in the fuel is converted into kinetic energy by burning the fuel in the thrust chamber and subsequent expansion in the nozzle to produce thrust

6. history American and Soviet engineers independently, all discovered that rocket engines need high  mass flow rate  of both oxidizer and fuel to generate a sufficient thrust . At that time oxygen and low molecular weight hydrocarbons were used as oxidizer and fuel pair. At room temperature and pressure , both are in gaseous state. Hypothetically, if propellants had been stored as pressurized gases, the size and mass of fuel tanks themselves would severely decrease rocket efficiency . Therefore , to get the required mass flow rate, the only option was to cool the propellants down to  cryogenic  temperatures (below −150 °C, −238 °F), converting them to  liquid  form. Hence, all cryogenic rocket engines are also, by definition, either  liquid-propellant rocket engines  or  hybrid rocket engines

7. The RL10 was the first liquid hydrogen cryogenic rocket engine to be built in the United States, and development of the engine by  Marshall Space Flight Center  and  Pratt & Whitney  began in the 1950s, with the first flight occurring in 1961. T hese engines were one of the main factors of  NASA 's success in reaching the Moon by the  Saturn V rocket

8. Lpsc mahendragiri On 1 February 2014, this unit was renamed as  Indian Space Research Organisation (ISRO) Propulsion Complex  and was also made an autonomous department under ISRO. The main activities carried out at here are : Assembly and integration of liquid engines and stages Testing of liquid engines and stages High altitude test facilities for upper stage engines Propellant storage facilities

9. C e 7.5 The specifications and key characteristics of the engine are: Operating Cycle – Staged combustion Propellant Combination –  LOX  /  LH2 Maximum thrust (Vacuum) – 75  kN Operating Thrust Range (as demonstrated during GSLV Mk2 D5 flight) – 73.55 kN to 82 kN   Chamber Pressure (Nom) – 58 bar Engine Mixture ratio (Oxidizer/Fuel by mass) – 5.05 Engine Specific Impulse - 454 ± 3 seconds (4.452 ± 0.029 km/s ) Engine Burn Duration (Nom) – 720 seconds Propellant Mass – 12800  kg Two independent regulators: thrust control and mixture ratio control Steering during thrust: provided by two gimbaled steering engines

10. C e 20 The specifications of the engine as listed on the  LPSC   handouts : Operating Cycle -  Gas Generator Propellant Combination -  LOX  /  LH2 Thrust Nominal (Vacuum) - 200  kN Operating Thrust Range - 180  kN to 220  kN (To be set at any fix values) Chamber Pressure (Nom) - 6  MPa Engine Mixture ratio (Oxidizer/Fuel by weight) - 5.05 Engine Specific Impulse - 443 ± 3 seconds (4.344 ± 0.029 km/s) Engine Burn Duration (Nom) - 595 seconds Total Flow rate - 462 kg/s Nozzle Area ratio - 100 Mass - 588 kg

11. construction The major components of a cryogenic rocket engine are: 1.The   combustion chamber  (thrust chamber ) 2.  P yrotechnic initiator 3.Fuel injector 4.Fuel   cryopumps , 5.oxidizer cryopumps 6.Gas turbine 7. cryo valves, 8.regulators , 9.The fuel tanks, and  10. rocket engine nozzle .

12. PRESSURE FED SYSTEM PUMP FED SYSTEM

13. advantages High Energy per unit mass: Propellants like oxygen and hydrogen in liquid form give very high amounts of energy per unit mass due to which the amount of fuel to be carried aboard the rockets decreases . Clean Fuels Hydrogen and oxygen are extremely clean fuels. When they combine, they give out only water. This water is thrown out of the nozzle in form of very hot vapour. Thus the rocket is nothing but a high burning steam engine Economical Use of oxygen and hydrogen as fuels is very economical, as liquid oxygen costs less than gasoline.

14. comparison Solid -fuel advantages Solid -fuel disadvantages Liquid-fuel advantages Liquid-fuel disadvantages Very stable, durable Can’t be turned off. Once the burn starts , it goes on until the fuel is used up. Variable thrust- The amount of fuel and rate of burn can be changed in flight Fragile, more complex parts Fuel system is simpler, safer and cheaper Low efficiency Relatively high efficiency Highly complex system and requires high maintenance More thrust for a similar rocket size Fuel decomposes, must be replaced Liquid-fuel boosters are more easily re-useable. Oxidizer(liquid oxygen) must be kept extremely cold

15. disadvantages Cryogenic liquids difficult to store for longer periods High density requires larger tanks Highly reactive gases Leakage problems Boil off rate Hydrogen embrittlement Zero gravity conditions

16. Applications of cryogenics Cryogenic fuels Liquid nitrogen : used in cryo -therapy , as a coolant, cryonic preservation Nuclear magnetic resonance spectroscopy: NMR is one of the most common methods to determine the physical and chemical properties of atoms by detecting the radio frequency absorbed and subsequent relaxation of nuclei in a magnetic field . Frozen food: Cryogenic gases are used in transportation of large masses of frozen food . Blood banking: Certain rare blood groups are stored at low temperatures, such as −165 °C . And many more…..

17. IN DI As ROAD TO CRE

18. An Indian-made cryogenically-powered rocket, launch vehicle GSLV-D5, carrying a GSAT-14 satellite, blasts off from the Satish Dhawan Space Centre at Sriharikota , some 110 kilometers (69 miles) north east of Chennai on January 5, 2014 (AFP Photo / STR)

19. REFERENCES http ://en.wikipedia.org/wiki/solar tree http://articles.economictimes.indiatimes.com/ http://en.wikipedia.org/wiki/solar energy http://books.google.co.in/books?id=wm6uAIiuCc8C& http://en.wikipedia.org/wiki/renewablesenergies http://library.thinkquest.org / http://isro.org/ http://howstuffworks.com/