Starter Generator (MGU) Upgrade

Remember the Motor Generator Unit (MGU)? It's critical for starting the GT50 and generating power. Our initial testing was successful but revealed areas for improvement, particularly with the rotor position sensor and balancing the high-speed components.

- Challenge: Achieving smooth operation at incredibly high speeds (up to 40,000 RPM!) required such precise balancing with the original "bearingless" design that volume manufacturing became impractical.

- Solution: We've re-engineered the MGU with a more robust, traditional dual-bearing design. While slightly more complex, it ensures reliability and manufacturability. We also designed, integrated, and validated a new rotor position sensor.

- Result: Testing with the new sensor and design is complete. Zhenyu has validated the power management unit and calibrated the control systems. The system is now being tested under electrical load. New, production-grade shafts and rotors are arriving soon for final validation across the full speed and load range.

Speed Reduction Gearbox (SRG) Test Rig

A rigorous bench testing allows us to identify and resolve any potential issues before it reaches the engine, ensuring the SRG is ready for the demands of flight.

- Purpose: The rig simulates the entire engine drivetrain load – power turbine input (at 35,500 RPM!), tail rotor drive, and main rotor drive.

- Method: We run two gearboxes back-to-back under maximum torque, pushing them to their limits for a simulated 5,000 hours. This validates everything from the lubrication system and gear tooth contact patches to rotor dynamic stability.

- Progress: The sophisticated test rig, featuring a high-speed drive motor and industrial systems mimicking engine functions (oil pumps, valves), is nearing final assembly.

- Next Steps: Initial tests will calibrate the oil jets, ensuring precise lubrication. Then, we move to contact patch testing, performance and heat rejection analysis, and finally, the full 5,000-hour endurance run.

Fuel Nozzles & Combustion Testing

We're refining our unique duplex fuel nozzles and preparing for critical combustion tests.

- Fuel Nozzle : Alex is designing a dedicated hydraulic test rig to independently verify nozzle performance – measuring flow rates, spray patterns, and atomisation quality using advanced sensors and laser scanning.

- Combustion Validation: Once the optimal nozzle configuration is selected, testing moves to our "Rufus" rig. Here, we'll analyse the interaction between the spray nozzle and the air swirler, ensuring stable and robust combustion across the engine's operating range.

Firewall and Inlet Advancements

- Firewall: Basic material testing is complete. We've also successfully tested ablative coatings. If the main firewall were ever breached, this coating expands with heat, creating a temporary insulating layer to protect the aircraft's structure long enough for a safe landing.

- Engine Inlet: As accessories were added to the engine front and integrated with the Gen 2 fuselage, we redesigned the inlet tract. The optimised radial inlet provides a large area for smooth airflow into the sensitive compressor, minimising pressure drops and integrating seamlessly with the airframe.

Compressor, Blades, and Shafts

- Compressor: We've subtly modified blade shapes, boosting mass flow and efficiency (now 2% higher!). We've also implemented a braidable coating on the shroud, allowing tighter tip clearances for maximum performance while protecting against potential titanium fires.

- Turbine Blades: We've made huge progress, moving from initial struggles to reliably casting blades with excellent fill and surface finish, right here in-house. Next steps involve switching to the final super-alloy and perfecting the crystal structure for optimal strength.

- Drive Shafts: These require being incredibly thin-walled yet strong. The manufacturing process (deep-drilling, heat treatment, hard machining) is complex, and heat treatment can cause warping. Mick and the team have developed sophisticated machining techniques ensuring the final parts meet exacting tolerances. The main engine drive shaft – a key component for the SRG test – is currently undergoing this process.