By : Shreedhar Singh
GTRE is implementing several critical upgrades to enhance the performance, reliability, and efficiency of the Kaveri engine. These improvements aim to make it viable for integration with modern fighter platforms and unmanned systems.
1. Thermal Capability Upgrade with CMSX-4 Turbine Blades
GTRE is replacing the current directionally solid turbine blades—which handle up to 1050°C—with second-generation single crystal blades (CMSX-4). These blades can operate at 1080°C, and when combined with thermal barrier coatings and advanced cooling hole designs, the engine’s Turbine Entry Temperature (TET) will rise from 1450°C to 1500°C. This change significantly improves the thermal efficiency and durability of the engine.
2. Enhanced Thrust-to-Weight Ratio
GTRE is working to increase the engine’s thrust-to-weight ratio from 6.5 to 8. To reduce overall weight:
- GTRE is introducing blisks (bladed disks) in the 3 Low-Pressure Compressor (LPC) stages and 6 High-Pressure Compressor (HPC) stages. This design reduces component weight by 25% to 30% compared to conventional blade-disc assemblies.
- On the turbine side, GTRE is adopting a boltless blade arrangement, further contributing to weight reduction and increased structural integrity.
3. Polymer Matrix Composite (PMC) By-Pass Duct
GTRE has developed a Polymer Matrix Composite-based by-pass duct for the Kaveri engine. It offers a significant weight advantage—6 kg lighter than its metallic counterpart—without compromising structural performance. This lightweight component enhances the overall thrust-to-weight ratio and contributes to better fuel efficiency.
4. New Fan Design for Better Distortion Tolerance
To address the high inlet pressure distortion caused by serpentine intakes used in stealth aircraft, GTRE has designed a new fan with high tolerance to pressure fluctuations:
- The fan provides a 25% surge margin, improving operability under distorted flow conditions.
- GTRE has incorporated Variable Inlet Guide Vanes (VIGVs) with wide-chord blades to suppress flutter and enhance stability.
- A 3D stacking technique is used to reduce aerodynamic losses and manage secondary flow interactions.
Fan Specifications:
- Bypass Ratio: 3.4:1
- Mass Flow Rate: 78 kg/s
- Efficiency: 86%
5. Powder Metallurgy Discs for Hot Section Durability
GTRE, in collaboration with DMRL, is developing Powder Metallurgy (PM) turbine discs to withstand high thermal and mechanical stresses in the engine’s hot section. PM discs offer improved creep resistance and mechanical strength, essential for long-term performance. For this, India is setting up a 50,000-tonne forging press—a key enabler for indigenous high-performance aerospace components.
6. Resolving the Afterburner Deficiency
The afterburner has long been a limiting factor in the Kaveri engine. While the dry version produces 49 kN of thrust, the afterburner fails to deliver even 30 kN. GTRE has partnered with BrahMos Aerospace to develop a new afterburner based on GTRE’s design. This collaboration is expected to finally address the afterburner shortfall and unlock the engine’s full potential for combat aircraft applications.
love the information
Too slow in development. 40 years but still not able to develop the engine.
How many of these Technologies have reached a mature state and estimated how much time will it take for these to be integrated into the final variant?
very good information. It will be now 1500 centigrade class turbine. Japan has already developed 1800 degree class turning. one main part for speed variation is fuel injection valve & nozzle
please also give information about the same.
Kudos for detailed account of improvements. I’m neither scientist nor engineer, but could see that the improvements range across design, material selection and fabrication, all leading to superior thrust, reliability, efficiency and longevity. Thank you Alpha Defence 🙏🏽
This is a good summation however if intent is to increase knowledge base of general public regarding modern combustion engine can you please further elaborate this article’s salient points with know why information with historical temprature ranges and associated materials of generation of combustion engines Thanks a lot
Why GTRE is releasing full technical details. Why are you posting full details? What benefit for public? Enemies might benefit.
yeah but you didn’t mention the total weight after all improvements
[…] Kaveri is a two-spool bypass turbofan engine that features advanced technologies such as a full annular combustor, transonic […]
Though the information is encouraging , has GTRE implemented these developments and any engine is ready for testing with these improvements?
yeah but you didn’t mention the total weight after all improvements
Agreed it has taken 40 years to develop, but we have built Kaveri in a really indegenous manner. Not copying or stealing the west knowledge. The project has faced lots of obstacles like the western sanctions, lack of funds, poorest mindset of previous governments and the major was lack of proper infrastructure to support. It was great that Russia stood for India in the development cycle not only for high end critical testing but also with R&D inputs. Now the vision is crystal clear not only for GTRE but also for the government and the day is not long when we will have our own jet engine for sure. Respect the work of our scientists and engineers that they did not got disheartened even after lack of support and funds. In current jet engines developed Kaveri is the least funded engine than any engine globally, but standing equal to these global engines. With further funding the Kaveri will be a reality to roar in Indian skies.
Jai Hind