Cryogenic rocket engines use cryogenic fuels such as liquid hydrogen and liquid oxygen that must be stored at extremely low temperatures to remain liquid. They work by accelerating these cryogenic propellants to high speeds through combustion in the thrust chamber and expansion through a nozzle to produce thrust according to Newton's third law of motion. Some key cryogenic rocket engines include the RL-10, CE 7.5, and CE-20. Cryogenic engines offer high energy density and clean, economical propellants but also present challenges like boil-off, reactivity, and leakage of the cryogenic fuels.

1. Cryogenic rocket
engine

2. CONTENTS
1. Cryogenic
2. Introduction
3. History of cryogenic
4. Construction
5. Working principle
6. Application
7. Advantage & Disadvantage
8. Conclusions

3. CRYOGENIC
Cryogenic is derived from greek , Kryos means cold , genes means
production.
Cryogenic is the study of production and behavior of materials at very
low temperature (Below 150*C ,123*K,-238*F)
 Oxygen liquefies at -183*C
 Hydrogen liquefies at -253*C

4. INTRODUCTION
1. A cryogenic rocket engine is a engine which use cryogenic fuel.
2. Cryogenic fuel are fuel that requires storage at extremely low
temperature in order to maintain the in a liquid state.
3. Various cryogenic fuel-oxidizer combination have been fired but
the combination of liquid hydrogen (LH2), and the liquid oxygen
(LOX) oxidizer is most used.

5. RL-10
 The RL-10 was the first liquid Hydrogen
Cryogenic engine to nr 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
 These engines were one of the main
factors of NASA's success in reaching
the Moon by the Saturn V rocket

6. CE 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 -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

7. CE-20
The specifications of the engine as listed on the
 Operating Cycle-Gas Generator
 Propellant Combination - LCX/LHE
 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

8. CONSTRUCTION
 pyrotechnic igniter
 fuel injector
 fuel turbo-pumps
 gas turbine-
 cryo valves
 Regulators
 The fuel tanks
 rocket engine- nozzle

9. 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

11. 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.

12. ADVANTAGE AND DISADVANTAGE
ADVANTAGE
 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.
DISADVANTAGE
 Boil off Rate
 Cryogenic fluid are difficult to store for longer
period
 Highly reactive gases
 Zero gravity condition
 Leakage
 High density requires larger tank
 Hydrogen Embrittlement