This complex and at the same time extremely flexible facility is used to investigate novel gas turbine-based aviation propulsion concepts such as hybrid-electric propulsion and to systematically conduct concept demonstrations of novel cycle concepts. Partners like MTU Aero Engines and Safran already made use of the possibilities the platform offers for innovative aviation propulsion concepts.
The test bench is based on a twin-shaft helicopter gas turbine (Rolls-Royce M250-C20B) with a shaft power of 313 kW. The modular design of the engine makes the entire system highly adaptable in terms of integration and investigation of new propulsion concepts and cycle components.
Designed for real flight loads, the gas turbine was coupled with a 300 kW motorgenerator-converter unit (MGU) and modified to form a high-power density gen-set. This enables the test bench to directly generate high-voltage DC power, which is supplied to a programmable battery emulator. Additionally, the load shaft of the gas turbine is coupled to a bidirectional 500 kW load machine, to emulate mechanical loads such as a propeller. The load machine can also accommodate combined loads from the gas turbine and MGU.
The combustion chamber of the gas turbine has been retrofitted with a bleed and injection system, allowing to introduce steam and hydrogen to the combustion chamber. This facilitates the investigation of system behaviors that come to bear in cases such as the coupling of gas turbines with fuel cells, for example. In addition, a dedicated fuel control unit was developed and implemented into the gas turbine, which allows a more flexible operation with changing boundary conditions and components.
With the help of a real-time capable Speedgoat computer, combined with the test bench PLC, real-time capable models (e.g. of an SOFC high-temperature fuel cell) can be coupled with the test bench hardware. Such hardware-in-the-loop (HiL) setups allow to replicate the real dynamic behavior of different configurations of a hybrid electric powertrain.
The M250 test bench in detail
The HeBo Gen-Set: A Rolls-Royce M250 gas turbine with coupled motor-generator-converter unit (MGU). The struts are designed for actual flight loads of a Do228 aircraft.
