Lagrangian aspects of turbulent superstructures: numerical analysis of long-term dynamics and transport properties

Project: Research

Project participants

Padberg-Gehle, Kathrin (Project manager, academic)
Schneide, Christiane (Project staff)

Professorship for Applied Mathematics

Description

Turbulent fluid flows often exhibit large-scale, long-lived coherent structures, termed turbulent superstructures. In turbulent shear flows superstructures are characterized by elongated regions of streamwise velocity fluctuations, whereas in turbulent convection they are identified as patterns in the time-averaged velocity or temperature fields. While clearly observable in the Eulerian frame of reference, the origin and dynamics of these superstructures and their impact on turbulent flow properties and transport processes are far from being understood. To this end, there is a need for mathematical descriptions of turbulent superstructures beyond the Eulerian specifications.In the first funding period, trajectory-based methods have been developed for the study of coherent behavior in the Lagrangian frame of reference, using concepts from dynamical systems and ergodic theory as well as data science. In the second phase of the project, we will continue to develop and apply computational approaches to approximate and characterize Lagrangian superstructures in 3D turbulent flows. Our focus will be on (i) the analysis of the long-term dynamics of superstructures including the prediction of bifurcations, (ii) attempting a systematic understanding of the relation between Eulerian and Lagrangian superstructures, and (iii) a characterization of their transport properties. In cooperation with our interdisciplinary project partners within the Priority Programme, we will study the Lagrangian aspects of turbulent superstructures both in Rayleigh-Bénard convection and in turbulent shear flows.

Status	Finished
Period	09.12.19 → 30.06.23
Links	https://gepris.dfg.de/gepris/projekt/316204571

Activities

Network-Based Analysis of Lagrangian Transport and Mixing
Activity: Talk or presentation › Conference Presentations › Research
Lagrangian aspects of turbulent superstructures: numerical analysis of long-term dynamics and transport properties
Activity: Talk or presentation › Conference Presentations › Research
Data-based study of Lagrangian coherence and mixing in turbulent flows
Activity: Talk or presentation › Conference Presentations › Research
Data-based analysis of Lagrangian transport
Activity: Talk or presentation › Conference Presentations › Research
Evolutionary clustering of Lagrangian trajectories in turbulent convection
Activity: Talk or presentation › Guest lectures › Research
Anuual Meeting of the DFG - Priority Programme 1881
Activity: Participating in or organising an academic or articstic event › External workshops, courses, seminars › Research
Data-based analysis of Lagrangian transport
Activity: Talk or presentation › Guest lectures › Research
Transport analysis in turbulent convection by Lagrangian trajectories
Activity: Talk or presentation › Conference Presentations › Research
Probabilistic and discrete computational methods for studying coherent behavior in flows
Activity: Talk or presentation › Guest lectures › Research
Jahrestreffen DFG-SPP 1881 Turbulent Superstructures 2020
Activity: Participating in or organising an academic or articstic event › Conferences › Research
Kick-off Meeting DFG-SPP 1881 Turbulent Superstructures (2. Phase) 2019
Activity: Participating in or organising an academic or articstic event › External workshops, courses, seminars › Research
Applications of transfer operator methods in fluid dynamics
Activity: Talk or presentation › Conference Presentations › Research
Coordination Meeting DFG-SPP 1881 (Phase 2)
Activity: Participating in or organising an academic or articstic event › External workshops, courses, seminars › Research
Ilmenau University of Technology
Activity: Visiting an external institution › Visiting an external academic institution › Research

Research outputs

Computational Study of Three-Dimensional Lagrangian Transport and Mixing in a Stirred Tank Reactor  
Research output: Journal contributions › Journal articles › Research › peer-review
Open-flow mixing and transfer operators
Research output: Journal contributions › Journal articles › Research › peer-review
Evolutionary clustering of Lagrangian trajectories in turbulent Rayleigh-Bénard convection flows
Research output: Journal contributions › Journal articles › Research › peer-review
Lagrangian Coherent Sets as transport barriers in convection
Research output: Journal contributions › Conference abstract in journal › Research
Extraction of finite-time coherent sets in 3D Rayleigh-Benard Convection using the dynamic Laplacian
Research output: Journal contributions › Conference abstract in journal › Research
Lagrangian heat transport in turbulent three-dimensional convection
Research output: Journal contributions › Journal articles › Research › peer-review
Spectral Early-Warning Signals for Sudden Changes in Time-Dependent Flow Patterns
Research output: Journal contributions › Journal articles › Research › peer-review
Set-Oriented and Finite-Element Study of Coherent Behavior in Rayleigh-Bénard Convection
Research output: Contributions to collected editions/works › Chapter › peer-review