DRDL's Pioneering Test of Active Cooled Scramjet Engine

The Defence Research & Development Laboratory (DRDL), located in Hyderabad and operating under the Defence Research and Development Organisation (DRDO), has made significant progress in advancing next-generation hypersonic technology. This technology centers around the Supersonic Combustion Ramjet (Scramjet), a groundbreaking propulsion system designed for hypersonic missiles. Recently, DRDL achieved a historic feat by successfully conducting a 120-second ground test of an Active Cooled Scramjet Combustor, marking India’s first such accomplishment. This achievement brings the country closer to developing hypersonic missiles with unprecedented speed and maneuverability.

What Are Hypersonic Missiles?
Hypersonic missiles are advanced weapons that travel at speeds above Mach 5 (more than five times the speed of sound), exceeding 5,400 km/h. Their primary advantage is their ability to bypass current air defense systems, allowing for rapid, high-impact strikes. Countries like the USA, Russia, China, and India are heavily invested in the development of hypersonic technology due to its transformative impact on modern warfare.

The Role of Scramjet Engines in Hypersonic Technology
Scramjets are air-breathing engines that sustain combustion at supersonic speeds without requiring moving parts. Unlike conventional engines, scramjets compress and ignite air flowing through the engine at extreme speeds, similar to "keeping a candle lit in a hurricane."

Key Achievements of the Active Cooled Scramjet Ground Test
The recent scramjet combustor ground test revealed several significant advancements:

• Successful Ignition and Stable Combustion: Achieving and maintaining combustion at air speeds exceeding 1.5 km/s shows the engine’s potential for use in hypersonic vehicles.
• Innovative Flame Stabilization Technique: A new method was developed to ensure continuous flame stability inside the combustor, addressing a major challenge in scramjet technology.
• Advanced Computational Tools: Computational Fluid Dynamics (CFD) simulations were essential in evaluating and predicting engine performance throughout development.

These breakthroughs underscore India’s growing expertise in hypersonic propulsion systems.

Indigenous Development of Endothermic Scramjet Fuel
A key part of this success was the development of an indigenous endothermic scramjet fuel, a first for India. This fuel, jointly developed by DRDL and the Indian industry, offers two main benefits:

• Improved Cooling: The fuel enhances thermal management by absorbing and dissipating the heat generated during high-speed combustion.
• Easy Ignition: It meets the stringent requirements of scramjet operation, ensuring reliable performance.

To facilitate this, DRDL developed a specialized manufacturing process to produce the fuel on an industrial scale.

Thermal Barrier Coating: A Technological Breakthrough
Managing the extreme temperatures generated by speeds over Mach 5 is one of the most significant challenges of hypersonic flight. To address this, DRDL, in collaboration with the Department of Science & Technology (DST) Laboratory, developed an advanced Thermal Barrier Coating (TBC). Key features include:

• Advanced Ceramic Composition: The coating can endure temperatures higher than the melting point of steel, providing exceptional thermal resistance.
• Specialized Deposition Techniques: The coating is applied inside the scramjet engine using unique methods to improve performance and durability.
   

Strategic Implications and Future Prospects
The successful demonstration of stable combustion, advanced thermal management, and the development of indigenous fuel marks a pivotal moment in India’s pursuit of operational hypersonic missiles. These breakthroughs position India as a global leader in hypersonic technology.

Acknowledgments and Recognitions
Defence Minister Shri Rajnath Singh praised DRDO and the Indian industry for their contributions to this technological achievement, highlighting its significance for India's defense capabilities. Dr. Samir V. Kamat, Secretary of the Department of Defence R&D and Chairman of DRDO, also commended the DRDL team and their industry partners for their pioneering work in scramjet technology. He emphasized that stable combustion, enhanced performance, and advanced thermal management were critical to this success.