1. Department of Technical Acoustics, Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR), 38108 Braunschweig, Germany
2. Department of Transport Aircraft, Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR), 38108 Braunschweig, Germany
3. Engine Department, Institute of Propulsion Technology, German Aerospace Center (DLR), 51147 Cologne, Germany
4. Department of Engine Acoustics, Institute of Propulsion Technology, German Aerospace Center (DLR), 10623 Berlin, Germany