J. Oldeweme, T. Lindner, P. Scholz, J. Friedrichs

The complexity of propeller wing interactions in a distributed propulsion (DP) configuration requires high quality wind tunnel data to fully exploit the benefit of such a configuration. Benefits of DP are most pronounced in high lift, high thrust configurations, which sets the focus for the proposed experiment. The designed wind tunnel model features a two element wing with three co-rotating propulsion units on a separate carrier that can be readily traversed and pitched relative to the wing. This enables a thorough investigation of propeller position from 0 < x/D < 1 and -0.25 < z/D < 0.25, excluding nacelle effects. Experiments are conducted up to Re = 2.9 * 10^6 based on wing chord. The 2D wing spans 2.4 m in the closed test section of the Propulsion Test Facility, TU Braunschweig. It features an adjustable fowler flap. To avoid data contamination from side wall effects, the model is split in three sections, each representing a periodic section from an infinite DP wing. While the outboard sections provide the quasi periodic conditions but suffer from side wall effects, the centre section is instrumented. This includes angle resolved thrust and torque measurements of the drive train, internal 6K force measurement on the profile section and pressure sensitive paint on the suction side. Multiple sets of propellers with two different diameters are installed, following different design strategies. A homogeneous induced axial velocity design and a MIL propeller are compared regarding propeller wing interaction. The constant speed propellers are pitched to deliver thrust in the range of 0.07 < cT < 0.3 at two different advance ratios. The propellers are designed to have a constant Matip for all operation points and a scaled D/c, J and cT . With the proposed instrumentation plan a full set of integral parameters for drive train and wing can be measured, while keeping the configuration highly modular. Time resolved pressure measurement and time-averaged PSP allow an in depth analysis of three dimensional pressure distribution and instationary effects on the wing.

Deutscher Luft- und Raumfahrtkongress 2022, Dresden

Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn, 2022

Conference Paper

englisch

21,0 x 29,7 cm, 8 Seiten

urn:nbn:de:101:1-2022102815590752521027

10.25967/570125

Wind tunnel model, Distributed Propulsion, High-lift

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Oldeweme, J.; Lindner, T.; et al. (2022): Experiment Design for a Distributed Propulsion Configuration at High Lift. Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.. (Text). https://doi.org/10.25967/570125. urn:nbn:de:101:1-2022102815590752521027.

28.10.2022