Project Details
Projekt
Data analysis and flow modeling
Applicant
Dr.-Ing. Andre Weiner
Subject Area
Fluid Mechanics
Term
since 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 406435057
Three-dimensional transonic buffet refers to shock oscillations on swept wings that can lead to strong aeroelastic reactions on commercial aircraft. These short-wave shock oscillations are characterized by shock-boundary layer interactions, which propagate from about one-third of the spanwise length toward the wing tip. At the same time, experimental investigations also show long-wave shock oscillations running in the opposite direction, i.e. from the tip toward the root. Since the latter effect could not yet be reproduced by numerical simulations of rigid wings, the phenomenon might by caused by aeroelastic vibrations. The goal of this project is to shed some light on this suspicion by means of investigating experimental and numerical datasets. For this purpose, a set of analysis and modeling tools for data reduction, modal analysis, synchronization analysis, and reduced-order flow modeling will be developed and integrated into the open-source flowTorch library. In order to use extremely large numerical simulations for modal analysis, the data must first be reduced without compromising the main flow dynamics. For this purpose, a customized version of Sparse Spatial Sampling (S³) was developed in advance, which iteratively generates a reduced octree grid. For productive use, the efficiency of the current S³ implementation needs to be improved further, which will be done by replacing critical parts of the source code using C/C++. The essential analysis tool for the reduced numerical and experimental data is Dynamic Mode Decomposition (DMD). In this project, an adapted version of DMD with Control (DMDc) will be used, which accounts for the influence of structural vibrations in the modal analysis. Structural vibrations can be induced not only in the region of the dominant Buffet frequency but also by harmonic and triadic interactions. The synchronization of Buffet frequency or harmonics and structural vibrations is investigated and modeled by an extended Stuart-Landau model. To better identify the critical angle-of-attack and Mach number envelop of the Buffet, its modeling is tested by means of parametric DMD (pDMD) and cluster-based network modeling (CNM). All previously mentioned developments (S³, DMDc, pDMD, CNM) will be published sustainably with extensive documentation, unit tests, and application examples through the flowTorch library.
DFG Programme
Research Units
International Connection
United Kingdom
Cooperation Partner
Dr. Sebastian Timme
