Cryogenic engines use cryogenic fuels that must be stored at extremely low temperatures in liquid form, such as liquid hydrogen at -253°C and liquid oxygen at -183°C. The basic principle is that the chemical energy from burning the cryogenic fuel in the thrust chamber is converted to kinetic energy through expansion in the rocket nozzle to produce thrust. Some key components of a cryogenic engine include the combustion chamber, fuel and oxidizer pumps, valves and regulators, fuel tanks, and rocket nozzle. Cryogenic engines provide high energy density but the low temperatures make storage and leakage challenges. They find applications in rocketry due to their performance and in other areas such as cooling and medical uses.

1. CRYOGENIC
ENGINE
BY- GUIDED BY-
NITESH KUMAR Prof. VENKATE GOWDA T
1SG13ME079 Dept. of MECHANICAL ENGG.
S C E BENGALURU

2. INTRODUCTION
 A cryogenic rocket 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.
 Oxygen liquifies at -183c(90k)
 Hydrogen liquifies at -253c(20k)

3. WHAT IS CRYOGENIC?
 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).

4. PRINCIPLE
 The basic principle driving a rocket engine are:
 Newton third law of motion
 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

5. THE FIRST OPERATIONAL CRYOGENIC ENGINE

6. COMPONENT OF CRYOGENIC ENGINE-
 Combustion chamber (thrust chamber)
 Pyrotechnic ignite
 Fuel injector
 Fuel cryopumps
 Oxidizer cryopumps
 Gas turbine
 Cryo valves
 Regulators
 Fuel tanks, and
 Rocket engine nozzle
Among them, the combustion chamber & the rocket
engine nozzle are the main components of the cryogenic
engine.

8. WORKING DIAGRAM

9. COMBUSTION PHASES IN THRUST
CHAMBER

10. THRUST EQUATION

12. ADVANTAGES
 High Energy per unit mass
 Clean Fuels
 Economical

13. DISADVATAGES
 Cryogenic liquids difficult to store for longer periods
 High density requires larger tanks
 Highly reactive gases
 Leakage problems
 Boil off rate

14. APPLICATIONS OF CRYOGENICS
 Cryogenic Fuels
 Liquid nitrogen:used in cryo-therapy, as a coolant,
cryonic preservation
 Nuclear magnetic resonance spectroscopy
 Frozen food
 Blood banking
 And many more…..

16. THANK YOU