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Tiny Engines, Mighty Skies: The CSIR-NAL Gas Turbine Breakthrough

Imagine a tiny engine, small enough to hold in your hands, spinning 250 times faster than the blades of a ceiling fan, and so powerful that they can lift small drones and even guide precision missiles. This is the world of small gas turbines, a high-tech marvel that until recently, India relied on other countries to provide. But now, scientists at CSIR‑National Aerospace Laboratories (CSIR-NAL) have changed the game, developing these miniature powerhouses right here in India.

A small gas turbine is a mini version of a jet engine that works just like the ones on airplanes, it compresses air, mixes it with fuel, burns it, and pushes the hot gases out to create thrust. These engines are much smaller and lighter, producing anywhere from a few dozen to up to a thousand newtons (N) of thrust. They run on aviation-grade kerosene like Jet-A1 fuel, known for its high energy and reliability. Even though they can fit in your hands, they spin at around 1,00,000 rotations per minute (RPM), making them complex to design and a real test of precision engineering.

Development of the Micro/Small Gas Turbine Engine

One of the early milestones in India was the development of the engine called NJ‑5. This micro gas turbine engine was developed by CSIR-NAL as a technology demonstrator. This achievement, though small in thrust, is significant in demonstrating core competencies: high-speed turbomachinery, micro-scale compressor and turbine design, combustor miniaturisation, bearings/lubrication in extreme RPM regimes, and system integration within compact volumes.

Building on the NJ-5 foundation, CSIR-NAL has developed the next-generation engine, the NJ‑100, which pushes thrust to approximately 1000 N, which is enough force to lift an object weighing around 100 kilograms, like a motorbike, straight off the ground. Its design focuses on having a high thrust-to-weight ratio, compact design, and fuel efficiency, making it suitable for both agile and long-endurance missions.

The NJ‑100 is CSIR-NAL’s next-generation small gas turbine engine in the mid‑range class between micro unmanned aerial vehicle (UAV) engines and larger turbojets. It is aimed at tactical UAVs, loitering munitions, and compact cruise missiles, offering an indigenous alternative to imported engines. Its development demonstrates India’s growing capability in high-RPM turbomachinery, miniaturized combustion systems, and integrated propulsion solutions, paving the way for domestic production, system integration, and potential export opportunities in the aerospace and defence sectors.

Economic/Industrial Impact

Developing small gas turbine engines helps boost India’s aerospace supply chain by advancing precision manufacturing, control systems, testing, and engineering capabilities. It also is set to reduce import dependency. It opens opportunities for exporting defence and aerospace hardware, contributing to defence diplomacy and technology leadership in the region. Beyond defence, these engines can be used in small power generators, remote energy units, and educational training systems.

Propelling into the Future

The NJ-100 marks more than just a leap in propulsion, it signals India’s steady rise as a designer and manufacturer of advanced aerospace systems. By mastering technologies once considered out of reach, CSIR-NAL has given India the power to build engines that can drive its own defence ambitions. Compact, efficient, and home-grown, the NJ-100 has built a strong foundation for building more advanced propulsion systems in the future. It is a quiet revolution, one that turns self-reliance from a slogan into a spinning, roaring reality.

Vaijayanthi Sambath Kumar   
Research Intern, CSIR