The High-Speed Rotor and Turbine Blades

Following successful preliminary tests, we have now manufactured the final versions of the rotor components that will actually run in the engine.

• Robust Blade Integration: The over 180 HP/LP turbine blades, cast entirely in-house with high-volume consistency, are now securely fitted into the disc, eliminating the need for the original spring clips.
• Precision Balancing: The test impeller, intermediate stub shaft, and disc are ready for final balancing before being built in situ within the engine.
• Spares and X-Ray Inspection: To support a seamless testing programme, we have produced multiple engine sets of turbine blades. These have recently returned from X-ray inspection, allowing us to sort the viable components for testing and mechanical trials.

Precision Machining and Sealing Systems

Achieving the GT50’s exceptional performance, including its projected ~99% combustion efficiency, requires incredibly tight tolerances and advanced sealing technology.

• Blade Liners and Clearances: The latest blade liner has been fully machined to exact profiles, ensuring the tight tip clearances necessary for optimal engine performance.
• Advanced Sealing: We are utilising a variety of metal-to-metal seals, including piston ring types for radial gaps and concertina-profile omega and W seals. These maintain the correct pressurisation across different engine cavities.
• Squeeze Film Dampers: Our in-house manufactured bearings, supported by a spring bar system and squeeze film dampers, smooth out rotor dynamics to ensure vibration-free operation.

The Combustor and Fuel Delivery

With the rotor and bearings prepared, the next crucial step is generating power. The test combustor is nearly ready for installation, featuring a sliding assembly designed to accommodate thermal expansion during operation.

• Fuel Nozzles and Swirlers: The fuel nozzles and swirler assemblies have been test-assembled and leak-checked. The swirlers create the necessary airflow to atomise the fuel perfectly.
• Optimising Combustion: A comprehensive range of fuel nozzles is on hand to fully characterise and optimise the engine's combustion settings during the upcoming test runs.

A Methodical Assembly Process

After nearly six months of painstakingly manufacturing these components, the assembly process is highly methodical.

We begin by building sub-assemblies and conducting trial fits using a non-instrumented combustor casing. This ensures every hole aligns, every seal achieves uniform compression, and every component interacts exactly as intended. Once verified, the engine is stripped down and rebuilt with its full suite of instrumentation, including thermocouples, pressure sensors, and strain gauges, connected via intricate hypodermic tubing.

This step-by-step approach guarantees the engine is assembled exactly to design intent, minimising issues during live testing.

Preparing for the Test Rig

Alongside the physical engine, the test rig and control systems are coming together at pace. The control panels for offline systems, such as lubrication and fuel, are currently in build, alongside the inverters and electrical controls. The accessory gears, which spin at nearly 50,000 RPM to drive the starter generator, are also prepped and ready, complete with spares to ensure uninterrupted testing.