Development of the electric engine simulator completed
- Under the leadership of the German-Dutch Wind Tunnels (DNW) and in collaboration with the Royal Netherlands Aerospace Centre (NRL) we developed an electric engine simulator for aerodynamic and aeroacoustic testing of aircraft with integrated propulsion systems in the wind tunnel.
- It realistically simulates an engine using the nacelle, thrust generator and wing attachment components.
- In this engine representation, the fan rotor is driven by a high-power density electric motor.
Development began with the definition of the geometric and performance-related specification of the fan on a scale of 1:1, considering an expected technology level in 2035, which is characterised by high bypass ratios and low fan pressure ratios. During the design of the fan, which was carried out at the DLR Institute of Propulsion Technology, particular attention was paid to the division of the air mass flow into the bypass and core flow channels downstream of the rotor. The aerodynamic design of the fan was then used to develop a valid design strategy for a realistic down-scaling of the aircraft engine to a fan diameter of 23.6 cm: the preservation of the core bypass configuration, the retention of the number of blades and the preservation of key blade parameters are all relevant here. The latter is achieved by retaining the characteristic parameters such as the aspect ratio and the pitch to chord ratio, whereas the blade thickness ratio had to be significantly adjusted due to structural mechanical and manufacturing aspects.
The biggest challenge during the scaling phase was to achieve the specification data for the operating point of maximum climb. Aerodynamically, this is characterised by the highest mass flow density and translates into a very high-power requirement of approx. 350kW, which must be provided by the electric motor. Realising this high power with a small integration space was one of the core challenges of the project. In the iterative design process, the NLR is responsible for the nacelle design and the definition of the nozzle geometries, which is essential for the operability of the overall system. The configuration is currently being manufactured and the propulsion unit with measuring probes will then be prepared for commissioning. The electric engine test rig will then be transferred to the DLR project LU(FT)² 2030 (Quiet Environmentally Friendly Transport Aircraft through Advanced Technology Simulation for 2030) and will be tested in the low-speed wind tunnel (NWB) of the DNW at the DLR site in Braunschweig.In the LU(FT)² 2030 project, under the leadership of the DLR Institute of Aerodynamics and Flow Simulation, technologies for the noise reduction of aircraft are being developed, evaluated numerically and experimentally and finally transferred to commercial aircraft.