|Kaveri engine at Aero India 2011. Photo © Copyright: Vijainder K Thakur|
DRDO Director General (Aero) K. Tamilmani and Director, Gas Turbine Research Establishment (GTRE) C.P. Ramanarayanan told The Hindu in October 2013 that GTRE will resolve the five issues that came up during airborne testing of the Kaveri engine in 2011 using an IL-76 testbed at Gromov Flight Research Institute (GFRI), Russia
Next year, the tweaked engine would be fitted first on an IL-76 testbed and then a MiG-29 fighter for trials and eventual certification.
“When we do that, we will have the first indigenous engine with proven and certified performance for exploitation,” Dr. Ramanarayanan said.
GTRE had earlier planned to obtain certification using an LCA testbed. (The LCA PV-1 was built to support the Kaveri engine.)
GTRE has sought sanction from MoD for developing the "dry thrust only" versions of the Kaveri engines. The money will be utilized to build two prototypes and send them to Russia for flight testing.
Dr. Ramnarayanan had earlier told the press, “We will take 48 months from the date we get clearance from the government, for completing 50 hours of testing the Kaveri on the Tejas LCA. During the last 12 months, we will actually fly the Tejas with the Kaveri.”
The testing will now presumably be done on a MiG-29.
According to Dr. Ramanarayanan, in future India would endeavor to build aircraft around a proven engine, a model followed worldwide.
During testing at the Gramov Flight Test Center, the Kaveri had demonstrated a dry thrust of 49.2 KN against a designed 51KN. With reheat the thrust deficit was substantial; 70.4 KN against the designed 81 KN.
Due to the thrust deficit with reheat, Kaveri was dropped as a prospective LCA powerplant.
Since Kaveri's dry thrust performance comes close the design values, DRDO has taken a decision to develop Kaveri as a UCAV powerplant.
UCAVs use un-reheated engines to minimize their heat and noise signatures. Also, the thrust requirement for the USAV is more modest.
DRDO has embarked on the development of a UCAV matching the capabilities of the X-47B and nEuron. The Indian analog is called Unmanned Strike Air Vehicle (USAV).
The USAV cannot use an imported engine on account of the MTCR regime which prohibits sale to another country of technology that maybe used in a missile or unmanned vehicle exceeding 300 km in range.
Removing the reheat from the Kaveri would lighten the engine considerably.
"Since the USAV will weigh less than 10 tonnes, the Kaveri’s 50 KN will suffice. And, with the afterburner removed, we would significantly reduce the weight of the Kaveri," a top DRDO scientist told the Business Standard earlier this year.
Along the way, GTRE will need to tweak the Kaveri dry for use on low RCS aircraft. Typically, stealth aircraft powerplants use shaped intakes to prevent enemy radar from reflecting off their compressor blades. Also, the engines are designed to operate with shaped exhausts to reduce stern radar and heat signature
In addition to the Kaveri, GTRE is co-developing a powerplant for the AMCA with a foreign vendor to be selected through open tendering.
Meanwhile, HAL is independently developing aircraft engines for use on drones, helicopters and trainer aircraft by 2018.
Details about the Kaveri project are at Kaveri Jet Engine - IDP Sentinel.
You can read more about the India USAV a Unmanned Strike Air Vehicle (USAV) / AURA UCAV