Poor performance at high altitude, inadequate thrust, excessive weight and a mysterious sound — these are some issues that often find mention in the list of problems that have stalled the Kaveri jet engine project.

Kota Harinarayana, former director and the chief designer of light combat aircraft Tejas, the fighter that this jet engine was supposed to power, has added another critical problem to this list — the lack of testing facilities in India.

Speaking at the IIT-Industry Conclave, Harinarayana said that the lack of test facilities in the country meant that the team working on the engine had to rush to Russia and other countries to validate the components — a time consuming process.

Speaking on specifics, he said that India does not have a fully functional wind tunnel facility that is used to study aerodynamic characteristics. There is no facility for stimulation of an engine that will work at 40,000 to 50,000 feet above ground.

The engine had to undergo testing in Russia on many occasions over the years.

The Kaveri engine has been undergoing tests in Russia since the 1990s.

In 2004, a high altitude testing of the Kaveri engine was conducted in Russia, and the test had ended in a failure. By 2008, the Kaveri engine had been sent to Russia twice already to undergo high-altitude tests for which India has no facility. High-altitude testing has been conducted on Russian bomber Tupolev Tu-124.

In 2010 -11, the Kaveri engine was tested using a Russian Ilyushin Il-76 transport aircraft as a Flying Test Bed at a Russian facility — Gromov Flight Research Institute.

This process, experts have said, slowed down development of the engine.

A Series Of Complications

The project remains stalled today as there are a series of complications with the Kaveri engine. Most of these complications, experts say, are in the engine core. The main phenomenon in this part of the engine is high pressure combustion.

“Developing a high thrust low bypass turbofan for military applications is a whole different ballgame from regular gas turbines. It requires deep expertise across combustion, fluid dynamics, materials and control theory applied, tested and iterated continuously over years,” an expert, writing under his pen name, has pointed out.

The core of the engine, called Kabini (consisting of compressor, turbine and combustor) was tested in Russia in the late 1990s.

The lack of testing facilities in India only makes the development difficult.

Reviving The Engine

Over the last few years, there have been some developments in the direction of reviving the Kaveri engine project — most recently after the signing of the Rafale deal.

After India signed the multi-billion dollar deal for 36 Rafales, Safran Group of France (which makes the Snecma M88 engine on Rafale) had offered to work with the Defence Research and Development Organisation (DRDO) to rescue the engine.

Under the arrangement that was offered, the French engine-maker was to help DRDO
“fix all problems with the struggling Kaveri engine and bring up to the mark for fitment on India’s Light Combat Aircraft and future air platforms”.

Russian Bomber Tupolev Tu-124

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