T. Effing, F. Peter, E. Stumpf, M. Hornung

This paper presents an approach for consciously tailoring the lift distribution of a given wing geometry in early stages of aircraft design. Based on Top Level Aircraft Requirements and minimal user input, conceptual aircraft design suites such as the MICADO environment, an RWTH Aachen University (ILR) in-house development, generally enable the design of consistent aircraft. This includes the design of wing geometries based on handbook methods. For these, the twist distribution of a wing is often neither a required input nor an output. Although available in MICADOs geometric data to allow detailed analysis, the twist distribution for both clean sheet and reference aircraft designs is kept constant during the design loop. As a result, the twist is not intentionally adjusted despite its direct relationship to the lift distribution and the induced drag. For this reason, an approach is developed and incorporated in MICADO that adjusts the twist to match a given target lift distribution. First, the course of the development of the approach is discussed. This includes not only the initial idea and its implementation but also adjustments based on first results. The final approach foresees an iterative adjustment of the twist on given wing sections to match a target lift distribution; this is done using results from DLRs multi-lifting-line code LIFTING_LINE. To judge the plausibility of the resulting twist distributions, a 3D panel method is applied next. However, since no advantages can be achieved by this, LIFTING_LINE will be the default method to keep computational effort as low as possible. To show robustness and versatile usability of the approach, tool-specific studies are presented; these demonstrate, e.g., the applicability for different wing geometries and target lift distributions. Finally, the impact of incorporating the new method into MICADO and thereby matching an elliptical lift distribution is analyzed. Although significant potential in terms of trip fuel reduction is revealed for a short-range reference design, this does not hold for the clean sheet design. For the latter, various effects on both aerodynamics and structures lead to poorer overall aircraft performance. This indicates the need for more exhaustive studies to find the optimal compromise between the different disciplines in aircraft design. However, the presented approach simplifies the future >setup of such studies.

Deutscher Luft- und Raumfahrtkongress 2021

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

Conference Paper

englisch

21,0 x 29,7 cm, 14 Seiten

urn:nbn:de:101:1-2022030412550491092649

10.25967/550197

Conceptual aircraft design, MICADO, Lift distribution, Wing aerodynamics

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Effing, T.; Peter, F.; et al. (2022): Approach for the Aerodynamic Optimization of the Twist Distribution of Arbitrary Wing Geometries on Conceptual Aircraft Design Level. Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V.. (Text). https://doi.org/10.25967/550197. urn:nbn:de:101:1-2022030412550491092649.

04.03.2022