THEERENDAR. C
II AGRI
Introduction
Rockets commonly burn propellants to create pressurized gas that propels them upward. The combination of fuel, oxygen, and heat, results in fire. The heat is generated externally, causing the liquid oxygen and fuel to react and produce fire, which boosts the rocket’s movement.
Types of fuel used in rocket
Rockets use various types of fuels depending on their design and purpose. Here are some common types:
- Liquid Hydrogen (LH2): Combined with liquid oxygen (LOX), it provides high specific impulse (efficiency) but requires low temperatures.
- RP-1 (Kerosene): Often used with LOX, it’s denser than LH2 and easier to handle.
- Hydrazine and its derivatives: Used in hypergolic systems where the fuel spontaneously ignites upon contact with an oxidizer like nitrogen tetroxide (N2O4).
- Composite Propellants: Solid mixtures of fuel and oxidizer bound together in a rubbery or plastic matrix. Examples include ammonium perchlorate composite propellant (APCP).
What is RP -1 (kerosene)?
RP-1, or Rocket Propellant-1, is a highly refined kerosene fuel used in rocket engines, turbine engines, and air-breathing engines. Developed in the 1950s, it consists of a complex mixture of paraffin, alkenes, and aromatics. RP-1 has lower sulfur, olefin, and aromatic content compared to other turbine fuels, and its density and volatility range are more narrowly defined. Different batches of RP-1 can vary in chemical composition, including distillation profiles, viscosities, specific gravities, and levels of sulfur, olefin, and aromatics.
RP-1 offers several advantages over other rocket fuels:
- Cost: RP-1 is cheaper, costing approximately $2.3 per kilogram.
- Stability: RP-1 remains stable at room temperature.
- Safety: RP-1 has a lower risk of explosion compared to other fuels.
- Toxicity: RP-1 is less toxic and carcinogenic than room-temperature liquid fuels like hydrazine.
Kerosene is used as a rocket fuel because it’s chemically energy-rich, stable at room temperature, and relatively safe to store and handle:
- Energy-rich
- Kerosene is a hydrocarbon fuel that’s rich in chemical energy. When mixed with oxygen, kerosene creates a powerful fuel that can generate millions of horsepower. For example, the Saturn V rocket used kerosene to take humans to the moon, generating around 217 million horsepower during lift-off.
- Safe
- Kerosene’s stability and flash point make it relatively safe to store and handle.
ISRO’s semi-cryogenic engine
- Many modern rockets use a mixture of kerosene and oxygen, called kerolox, as their fuel. Kerolox doesn’t burn cleanly, which limits the reusability of rockets that use it.
- ISRO’s semi-cryogenic engine is being developed for the Launch Vehicle Mark-3 (LVM3) and future launch vehicles. It uses a combination of liquid oxygen (LOX) and kerosene as propellant. The Liquid Propulsion Systems Centre (LPSC) is leading the development of the engine, and assembly and testing are taking place at the ISRO propulsion complex (IPRC) in Mahendragiri. In May 2024, ISRO successfully ignited a semi-cryo pre-burner at the semi-cryo integrated engine test facility (SIET) at IPRC.
Conclusion
Kerosene, as RP-1, is a popular rocket propellant because it’s energy-rich, stable at room temperature, and safe to handle. Its cost-effectiveness and practicality make it a top choice for many rockets. Used in historic rockets like the Saturn V and modern ones like SpaceX’s Falcon series, RP-1 provides the necessary thrust for successful missions, balancing efficiency, cost, and safety effectively.
References:
https://www.detailedpedia.com/wiki-RP-1
