ISRO to Conduct Test of Air-Breathing Hypersonic Technology on July 22
tech: ISRO to test air-breathing hypersonic tech on July 22
On July 22, 2024, ISRO conducted a significant test of its air-breathing hypersonic technology using the Advanced Technology Vehicle (ATV), a modified version of the Rohini-560 experimental rocket. This test took place at the Satish Dhawan Space Centre in Sriharikota at 7:30 AM IST
The air-breathing propulsion system tested uses atmospheric oxygen to burn hydrogen fuel, making the rocket lighter and more efficient as it does not need to carry an onboard oxidizer. This technology is suitable for operations within the Earth’s atmosphere up to 70 kilometers in altitude The scramjet engine, central to this technology, operates at hypersonic speeds (Mach 5 and above) and was previously flight-tested by ISRO in 2016, achieving Mach 6 for 5 seconds
The test’s success is part of ISRO’s ongoing efforts to develop advanced hypersonic propulsion systems, which have strategic importance for high-speed aerospace applications and potentially reusable launch vehicles This positions India among a select group of nations, including the US, Russia, and China, actively developing and testing hypersonic technologies
The scramjet technology is expected to be pivotal for ISRO’s Reusable Launch Vehicle (RLV) program, which aims to reduce the cost of access to space by developing systems that can be launched, recovered, and reused multiple times. The test on July 22 builds on previous successes, including the initial scramjet test in 2016 and subsequent developments in hypersonic technology
India’s advancements in hypersonic technology are part of a broader strategic initiative to enhance its aerospace and defense capabilities. This puts India in a competitive position alongside other nations like the US, Russia, and China, who are also pursuing advanced hypersonic systems for both civilian and military applications
What Is Air-Breathing Propulsion?
Air-breathing propulsion refers to a type of engine that uses atmospheric air to oxidize its fuel, allowing it to generate thrust. Common examples include jet engines and ramjets, which intake air from the atmosphere, compress it, mix it with fuel, and ignite the mixture to produce high-speed exhaust gases that propel the vehicle forward. This contrasts with rocket engines, which carry both fuel and oxidizer onboard. Air-breathing engines are commonly used in aircraft and some types of missiles.
What are the types of air-breathing propulsion?
Ramjet, Scramjet and Dual Mode Ramjet (DMRJ) are the three concepts of air-breathing engines which are being developed by various space agencies.
Ramjet –
A ramjet is a type of air-breathing engine that operates efficiently at supersonic speeds. Here’s a closer look at its design and operation:
How It Works:
1. Air Intake: The ramjet has a streamlined intake that captures and compresses incoming air using the vehicle’s forward motion. As the air enters the engine, it slows down and increases in pressure due to the shape of the intake.
2. Compression: The air is further compressed by the engine’s design, which can include converging sections of the intake.
3. Combustion: The compressed air is mixed with fuel in the combustion chamber. The fuel is ignited, and the high-pressure, high-temperature gases expand rapidly.
4. Exhaust: The expanding gases are expelled through a nozzle at the rear of the engine, generating thrust as they exit.
Key Characteristics:
– No Moving Parts: Unlike turbojets and turbofans, ramjets have no moving parts. They rely solely on the vehicle’s high-speed motion to compress incoming air.
– Speed Range: Ramjets are effective at supersonic speeds (Mach 2 to Mach 6). They become less efficient at subsonic speeds and cannot operate at hypersonic speeds where a scramjet might be used.
– Design Simplicity: The absence of moving parts makes the ramjet design relatively simple compared to other jet engines.
Scramjet –
A scramjet (Supersonic Combustion Ramjet) is an advanced type of air-breathing engine designed for hypersonic flight, which involves speeds greater than Mach 5. Here’s an overview of its design and functionality:
How It Works:
1. Air Intake: Like a ramjet, a scramjet has an intake that captures and compresses air using the vehicle’s forward motion. However, in a scramjet, the air remains supersonic throughout the engine.
2. Compression: The intake design is optimized to compress the incoming supersonic air to a high pressure while maintaining its supersonic velocity.
3. Combustion: Fuel is injected into the compressed supersonic airflow. Unlike in ramjets where combustion occurs at subsonic speeds, scramjets burn the fuel in supersonic airflow. This requires advanced technology to ensure stable combustion at such high speeds.
4. Exhaust: The high-pressure, high-temperature gases from combustion are expelled through a nozzle, generating thrust.
Key Characteristics:
– Supersonic Combustion: The primary innovation of the scramjet is its ability to sustain combustion in supersonic airflow, which is crucial for hypersonic flight.
– No Moving Parts: Like ramjets, scramjets have no moving parts. They rely entirely on aerodynamic principles and the vehicle’s high speed to compress air.
– Efficiency: Scramjets are highly efficient at hypersonic speeds due to their streamlined design and high-speed air intake.
Overall, scramjets represent a significant advancement in air-breathing propulsion technology, with promising applications in high-speed and space travel.
A dual-mode ramjet –
A dual-mode ramjet is a type of engine designed to operate efficiently across a range of speeds, combining the capabilities of both ramjets and scramjets. Here’s a detailed look:
How It Works:
1. Air Intake: Similar to ramjets and scramjets, the dual-mode ramjet features an intake system that captures and compresses incoming air.
2. Mode Switching:
– Subsonic to Supersonic Transition: The engine can operate in two modes:
– Ramjet Mode: At lower supersonic speeds, where the air can be efficiently compressed and combusted at subsonic speeds.
– Scramjet Mode: At higher speeds, where combustion occurs in supersonic airflow.
3. Combustion:
– Ramjet Mode: The engine burns fuel in a subsonic compressed airflow.
– Scramjet Mode: At higher speeds, the engine burns fuel in a supersonic compressed airflow.
4. Exhaust: The combustion products are expelled through a nozzle to produce thrust. The nozzle design can vary to optimize performance in both modes.
Key Characteristics:
– Versatility: The dual-mode ramjet is designed to operate efficiently across a wide range of speeds, from subsonic to hypersonic. This flexibility allows it to be used in various applications that require different speed regimes.
– Mode Transition: The engine must smoothly transition between ramjet and scramjet modes as the vehicle accelerates or decelerates.
– Complex Design: Incorporating both ramjet and scramjet technologies makes the dual-mode ramjet more complex than single-mode engines, requiring advanced engineering to manage the transition between modes.
Overall, the dual-mode ramjet represents a significant advancement in air-breathing propulsion technology, offering the potential for high-performance engines capable of operating across a broad range of speeds.
ISRO’s scramjet engine –
ISRO’s scramjet engine is an advanced propulsion technology developed by the Indian Space Research Organisation (ISRO) to achieve hypersonic flight. Here’s a summary of ISRO’s work on scramjets:
Development and Goals:
1. Objective: ISRO aims to develop scramjet technology to enhance the efficiency and reduce the cost of launching spacecraft. Scramjets are designed to operate efficiently at speeds above Mach 5, making them suitable for future space access and high-speed atmospheric flight.
2. Testing: ISRO has conducted several successful tests of its scramjet engine technology. The first experimental flight of ISRO’s scramjet engine was conducted on August 28, 2016, aboard a suborbital launch vehicle. The engine demonstrated the ability to ignite and sustain combustion at hypersonic speeds.
Design and Functionality:
1. Air Intake: The scramjet engine has an air intake system that captures and compresses incoming air. Unlike ramjets, the air remains supersonic throughout the engine.
2. Combustion: Fuel is injected into the supersonic airflow and ignited. The combustion process occurs at supersonic speeds, which requires advanced technology to manage.
3. Exhaust: The combustion gases are expelled through a nozzle, generating thrust. The nozzle design is optimized for high-speed operation.
Key Features:
– Advanced Technology: ISRO’s scramjet engine uses cutting-edge technology to manage combustion at hypersonic speeds, including advanced materials and cooling systems.
– Hypersonic Testing: The successful testing of ISRO’s scramjet engine demonstrates its capability to function at the extreme conditions associated with hypersonic flight.
– Potential Applications: The technology could be used in future space launch vehicles, potentially reducing the cost of accessing space by providing more efficient propulsion through the atmosphere.
ISRO’s work on scramjet engines represents a significant step forward in hypersonic propulsion technology, with the potential to impact future space exploration and high-speed flight.
