Numerical Analysis of CROR Propulsion System Aerodynamics and Aeroacoustics at DLR

Kurzfassung

Increasing environmental and economic pressures have renewed interest in Contra-Rotating Open Rotor (CROR) propulsion systems as a potential powerplant for future commercial transport aircraft as they promise a step change in specific fuel consumption due to their ultra-high bypass ratio. The primary challenges to be tackled for the realization of such a commercially viable engine relate to the issues of noise emissions and installation eects with the airframe. The rapid improvement of modern numerical tools for the aerodynamic and aeroacoustic analysis, such as the DLR TAU- and APSIM-Codes, as well as the availability of massively parallel high-performance compute clusters have made high-fidelity numerical simulations of the complex aerodynamics and aeroacoustics of CROR propulsion systems feasible. The application of these tools is expected to greatly enhance the understanding of the underlying flow physics, making them invaluable for the development of these engines into service-ready products. DLR has been actively involved in several CROR-related EU reserach projects, industrial contracts as well as internal research efforts with the aim of building expertise both on the fundamental aerodynamic and aeroacoustic characteristics of this type of engine as well as to develop and establish the numerical tools and approaches used for their analysis and simulation. This presentation will highlight some of the key aerodynamic and aeroacoustic aspects of CROR powerplants and give an overview of DLRs activities in this field.