Credit: DLR (CC BY-NC-ND 3.0).
Assembling of an experimental counter rotating rotor with fan blades made from CFRP
The demand for cost-effective and efficient transport on the one hand and the need for a sustainable handling of resources and the environment on the other hand is a challenging task for today’s aviation. Aero engines can be seen as a key enabler for reaching the ambitious goals regarding the requested emission reduction of air transport. The DLR Institute of Structures and Design (BT) covers an important aspect of aero engine research inside DLR. Aero engine structures as well as the corresponding construction methods represent a traditional field of work of the institute. Already from 1976 to 1979, engine blades made from fibre-reinforced aluminium for the J79 engine were developed in a fibre-suitable design.
One contemporary focus of the institute’s work regarding aero engines is on numerical methods, embracing the whole content from the material to the entire system. A highlight in this context is the multidisciplinary design and optimisation of engine structures. These activities are embedded into an established DLR-wide collaboration with the Institutes of Propulsion Technology (DLR AT), Aeroelasticity (DLR AE) and Materials Research (DLR WF), gaining a high level of awareness within the turbomachinery community.
Another focal point is the development of construction methods and manufacturing technologies for highly loaded engine structures within compressors, combustion chambers and turbines, whether made of metal, of composites (such as fibre-reinforced plastics or ceramics) or designed as hybrids. Also structures outside the gas path like unison rings or thrust reversers are subjects of the institute’s research. Summarised, the aim is to provide a feasible solution in terms of material, design and manufacturing technology for a given structural and mechanical task.
The necessary competences regarding manufacturing technologies are widely present in the institute. As it is neither necessary nor possible to provide every technology in terms of experience or facility, the institute’s technology portfolio is extended by additional resources and competences, like those of the DLR Systemhaus Technik (ShT) or of external manufacturing partners. For analysing and testing of materials, samples or components the Institute of Structures and Design in collaboration with its partner Institute of Materials Research offers an extensive capability of non-destructive and destructive testing methods. The areas of simulation (“digital twin”) and actual component (“reality”) are linked by means of physical testing, which allows for validation and refinement of the applied numerical methods. This follows the approach of the “Virtual Engine” and leads to new topics which are addressed within the institute’s strategy and DLR’s research agendas, from “Virtual Testing” for supporting virtual certification to a “Virtual OEM” under collaboration of all participating DLR institutes.