Picture of the month: Novel propeller under test SE²A researchers working on aircraft of the future

The image was created as part of a project in the SE²A Cluster of Excellence. The aim is to understand the interaction between propellers and wings in new and future aircraft configurations. To do this, it is first necessary to know the aerodynamic properties and characteristics of the wing and propeller.

Schematic representation of a novel propeller with a typical helical wake. Photo credit: Bastian Kirsch/TU Braunschweig

The propeller is a design specifically created for a future aircraft with multiple propellers per wing – up to five per side. To validate the design, researchers at the Institute of Aircraft Propulsion and Turbomachinery (IFAS) use advanced methods such as CFD simulations (flow simulations based on numerical methods as an alternative to tests in the flow channel), as in this case. These provide a very detailed insight into the flow field around the propeller.

The image itself shows the four-blade propeller on the left. The coloured area shows the speed field in the centre. The wake of the nacelle (streamlined container for the engine) in the centre and the strong colour changes from blue (low speeds) to yellow (high speeds) in the outer area are very noticeable. This strong change is caused by the edge vortex of the propeller blades, which is shown in three dimensions as grey shading.

This edge vortex is caused by the pressure balance between the front and back of the individual propeller blades, and floats helically backwards away from the propeller blades due to the superposition of airspeed and propeller rotation.

The information from this simulation was used to validate the preliminary design of the propeller. This may reduce the need for further simulations in the future.