In order to meet the challenges of sustainable aviation, researchers at the Technische Universität Braunschweig are working on new engine technologies and drive concepts in the Mobility research focus area. In the European joint project CICLOP led by the TU Braunschweig distributed propulsion systems are being studied in more detail: Aircraft are equipped with many small propellers mounted along the wings. This type of propulsion makes it possible to reduce weight, noise and energy consumption. For experiments, a model with motors and propellers will be developed by 2022, which will be tested and measured in the wind tunnel.
Many small electrically powered propellers along the wings have a positive effect on the lift of the aircraft. This can reduce the wing area and thus also reduce the weight and energy consumption of the aircraft. Such propulsion concepts are referred to in research as "distributed propulsion". While the basic effect is known, it is necessary to fully understand in detail not only the effect from the propeller to the wing, but also the feedback effect from the wing to the propeller and also between the propellers. This is precisely the goal of CICLOP, a joint project within the framework of the European aeronautics research programme "Clean Sky2".
The TU Braunschweig is responsible for all CICLOP experiments. For this purpose, a large research model is built with three engines and propellers of different geometries. The propellers are then subjected to various tests in the wind tunnel at the TU Braunschweig and measurements are taken. Here, the forces on the wing as well as on the rotating propeller are measured in detail.
At the same time, there are typical pressure measurement points in aerodynamics to analyse the behaviour of the aerofoil. These measurements are combined with special techniques such as pressure sensitve paint tests on the model. In tests, a liquid oil suspension is applied, which runs through the flow around the model in the wind tunnel and leaves behind a paint pattern. This pattern allows conclusions to be made about the flow structure and the important behaviour of the boundary layer, for example.
Project data:
The CICLOP project is funded under the "Clean Sky 2" research framework programme. The TU Braunschweig's share of the funding is 850,000 EUR. On the part of TU Braunschweig, the Institute of Flight Propulsion and Turbomachinery and the Institute of Fluid Mechanics are working together with CIRA, the Italian aeronautical research organisation, as well as with aircraft manufacturers. The project started on 01.12.2020 and ends on 30.11.2022.
"Clean Sky 2 is a public-private partnership between the European Commission and the European aviation industry. The aim is to reduce fuel consumption and the associated CO2 emissions as well as to reduce noise in aviation. To this end, "Clean Sky 2" researches, demonstrates and evaluates individual technologies and vehicle concepts.