Core Refinements

To build a truly next-generation engine, we focused on three critical areas of the combustor's core design.

• Integrated Turbine Nozzle Guide Vane: One of the most significant upgrades is the integration of the High-Pressure (HP) turbine nozzle guide vane directly into the combustor as a welded component. This creates an aerodynamically seamless transition for hot gas flow and results in a connection that is incredibly strong and robust.
• Enhanced Sealing: We've re-engineered the way fuel injection nozzles are fitted and sealed as they pass through the combustor casing. This ensures a tighter, more reliable seal, which is critical for engine efficiency and safety.
• Advanced Thermomechanical: A combustor gets incredibly hot, and managing thermal expansion is key. Our new design is engineered to "breathe" more effectively, expanding and contracting both axially and radially within the engine, ensuring structural integrity under all operating conditions.

Perfectly Formed Rings

The combustor is built from several rings, each formed from strips of high-performance nickel alloy. To create the new profiles, we had to manufacture entirely new sets of roll-forming tools for every inner and outer ring. These have been hardened to meet full production standards for longevity and reliability, ensuring every ring is formed perfectly.

On our original demonstrator, we saw areas where the material was overworked or the surface finish wasn't quite right. Our new processes eliminate these issues, producing incredibly well-formed rings with crisp, accurate profile details.

Precision Laser Welding

Joining the rolled strips into continuous rings requires flawless welds. For the prototype engine, "good enough" isn't an option. Our laser welding processes are now carefully controlled and consistently executed to deliver parent metal properties in every weld. This provides exceptional fatigue and static strength, ensuring the combustor can withstand the immense stresses of operation.

Achieving Perfect Shape and Size

Once the rings are formed and welded, they must be sized with absolute precision.

This is achieved using a powerful expander. We are building a new suite of "pie slice" tools for this machine. Each set of tools is machined from a large bar of steel, with the ring's final profile cut into its edge. The entire tool is then sliced using a wire EDM machine into perfect segments. When a tapered pin is pulled through the center, these "pie slices" expand outwards, stretching the combustor ring to be perfectly round and to the exact specified diameter.

Simultaneously, the flat rear face of the combustor is created using a male and female press tool. We sandwich a sheet of superalloy between the tools and press it into the precise shape needed to accept the fuel injection nozzles.

Sealing the Fuel Nozzles

One of the most complex challenges is sealing the 12 fuel nozzles where they enter the back of the combustor. For this, a floating seal washer sits around the fuel manifold, and it's held firmly against the combustor casing by custom spring plates.

The team has been hard at work pressing these three-dimensional spring plates from the same superalloy material. These components are then welded onto the back of the combustor, providing the necessary spring loading to guarantee a perfect seal on every single swirler and fuel nozzle.

With all these manufacturing processes developed and validated for the new GT50 annular combustor, we are now officially in production mode. The team is building the very first set of parts that will be assembled into the prototype engine for its first run later this year.