Scramjet Engine: Why in News Headlines Now? | General Awareness & Knowledge - Bank Exams PDF Download

Understanding Scramjet Engines

• A scramjet engine is a type of jet engine that operates by combusting air at supersonic speeds.
• It is a variant of the ramjet engine but differs in that combustion occurs in supersonic airflow.
• To comprehend scramjets, it's essential to distinguish between jet engines and rocket engines.

Key Difference: Jet vs. Rocket Engine

• Jet engines use atmospheric oxygen for combustion, while rocket engines carry their own supply of oxygen (oxidizer tank).
• Jet engines are more energy-efficient than rocket engines due to this difference.

Jet Engine Overview

• Jet engines convert liquid fuel into thrust, propelling an aircraft.
• Developed by Hans von Ohain of Germany, with credit often attributed to Britain's Frank Whittle.

The main processes in a Jet Engine

A jet engine undergoes three fundamental processes:

• Compression: In this phase, the engine elevates the air's pressure confined within the chamber.
• Combustion: During this stage, the engine raises the temperature of the air-fuel blend by liberating heat energy from the fuel.
• Exhaust: This step amplifies the speed of the exhaust gases, thus propelling the vehicle forward in accordance with Newton's third law of motion.

Types of Jet Engines

• Turbojet: Common in airplanes, it's an air-breathing jet engine.
• Turbofan Engines: Include a fan that aids in air compression and combustion.
• Ramjet: Utilizes high-speed forward motion to compress air and ignite fuel.
• Scramjet: Operates efficiently at hypersonic speeds (greater than Mach 6).
• Dual-Mode Ramjet (DMRJ): Type of jet engine where a ramjet transforms into scramjet over Mach 4-8 range, therefore, it can operate both in subsonic and supersonic combustion modes.

Scramjet Engine Operation

• Scramjets use high-speed motion to compress air (no compressor) and operate efficiently at hypersonic speeds, allowing supersonic combustion.
• Fuel is typically hydrogen, with atmospheric oxygen serving as the oxidizer.
• Scramjet engines are known for their potential to reduce launch costs significantly.

India and Scramjet Technology

• India achieved a major milestone by successfully testing the Scramjet engine.
• The experiment involved a two-stage Advanced Technology Vehicle (ATV) developed by ISRO.
• India became the fourth country to claim a successful scramjet flight test, following Russia, the US, and the European Space Agency.

Challenges of Scramjet Technology

• Scramjets are most effective at high speeds, making it a challenge to initiate their operation.
• ISRO overcame this by using scramjets in the second stage of a multi-stage launch vehicle.
• Other challenges included developing materials to withstand high temperatures, creating effective computational tools, and ensuring engine performance across various flight speeds.

Importance of Scramjet Technology

• Scramjets have the potential to significantly reduce launch vehicle weight and increase speed, enhancing launch efficiency.
• This technology can contribute to more cost-effective satellite launches, bolstering India's position in the satellite launching business.
• Scramjets can also be used to augment India's reusable launch vehicle (RLV) program, such as the Avatar platform.
• It plays a vital role in ISRO's future space transportation systems, contributing to advanced space missions.

Conclusion

• Scramjet engines mark a crucial milestone in India's pursuit of advanced space technologies.
• They offer the promise of reducing launch costs, improving efficiency, and expanding India's capabilities in the space industry.
• The development of scramjet and related technologies aligns with the "Make In India" initiative, contributing to India's self-reliance in space exploration.